Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus

[deliverable/linux.git] / net / bluetooth / hci_core.c

/*
   BlueZ - Bluetooth protocol stack for Linux
   Copyright (C) 2000-2001 Qualcomm Incorporated
   Copyright (C) 2011 ProFUSION Embedded Systems

   Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com>

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License version 2 as
   published by the Free Software Foundation;

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
   IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
   CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

   ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
   COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
   SOFTWARE IS DISCLAIMED.
*/

/* Bluetooth HCI core. */

#include <linux/export.h>
#include <linux/idr.h>
#include <linux/rfkill.h>
#include <linux/debugfs.h>
#include <linux/crypto.h>
#include <asm/unaligned.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include <net/bluetooth/l2cap.h>
#include <net/bluetooth/mgmt.h>

#include "smp.h"

static void hci_rx_work(struct work_struct *work);
static void hci_cmd_work(struct work_struct *work);
static void hci_tx_work(struct work_struct *work);

/* HCI device list */
LIST_HEAD(hci_dev_list);
DEFINE_RWLOCK(hci_dev_list_lock);

/* HCI callback list */
LIST_HEAD(hci_cb_list);
DEFINE_RWLOCK(hci_cb_list_lock);

/* HCI ID Numbering */
static DEFINE_IDA(hci_index_ida);

/* ----- HCI requests ----- */

#define HCI_REQ_DONE      0
#define HCI_REQ_PEND      1
#define HCI_REQ_CANCELED  2

#define hci_req_lock(d)         mutex_lock(&d->req_lock)
#define hci_req_unlock(d)       mutex_unlock(&d->req_lock)

/* ---- HCI notifications ---- */

static void hci_notify(struct hci_dev *hdev, int event)
{
        hci_sock_dev_event(hdev, event);
}

/* ---- HCI debugfs entries ---- */

static ssize_t dut_mode_read(struct file *file, char __user *user_buf,
                             size_t count, loff_t *ppos)
{
        struct hci_dev *hdev = file->private_data;
        char buf[3];

        buf[0] = test_bit(HCI_DUT_MODE, &hdev->dbg_flags) ? 'Y': 'N';
        buf[1] = '\n';
        buf[2] = '\0';
        return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
}

static ssize_t dut_mode_write(struct file *file, const char __user *user_buf,
                              size_t count, loff_t *ppos)
{
        struct hci_dev *hdev = file->private_data;
        struct sk_buff *skb;
        char buf[32];
        size_t buf_size = min(count, (sizeof(buf)-1));
        bool enable;
        int err;

        if (!test_bit(HCI_UP, &hdev->flags))
                return -ENETDOWN;

        if (copy_from_user(buf, user_buf, buf_size))
                return -EFAULT;

        buf[buf_size] = '\0';
        if (strtobool(buf, &enable))
                return -EINVAL;

        if (enable == test_bit(HCI_DUT_MODE, &hdev->dbg_flags))
                return -EALREADY;

        hci_req_lock(hdev);
        if (enable)
                skb = __hci_cmd_sync(hdev, HCI_OP_ENABLE_DUT_MODE, 0, NULL,
                                     HCI_CMD_TIMEOUT);
        else
                skb = __hci_cmd_sync(hdev, HCI_OP_RESET, 0, NULL,
                                     HCI_CMD_TIMEOUT);
        hci_req_unlock(hdev);

        if (IS_ERR(skb))
                return PTR_ERR(skb);

        err = -bt_to_errno(skb->data[0]);
        kfree_skb(skb);

        if (err < 0)
                return err;

        change_bit(HCI_DUT_MODE, &hdev->dbg_flags);

        return count;
}

static const struct file_operations dut_mode_fops = {
        .open           = simple_open,
        .read           = dut_mode_read,
        .write          = dut_mode_write,
        .llseek         = default_llseek,
};

static int features_show(struct seq_file *f, void *ptr)
{
        struct hci_dev *hdev = f->private;
        u8 p;

        hci_dev_lock(hdev);
        for (p = 0; p < HCI_MAX_PAGES && p <= hdev->max_page; p++) {
                seq_printf(f, "%2u: 0x%2.2x 0x%2.2x 0x%2.2x 0x%2.2x "
                           "0x%2.2x 0x%2.2x 0x%2.2x 0x%2.2x\n", p,
                           hdev->features[p][0], hdev->features[p][1],
                           hdev->features[p][2], hdev->features[p][3],
                           hdev->features[p][4], hdev->features[p][5],
                           hdev->features[p][6], hdev->features[p][7]);
        }
        if (lmp_le_capable(hdev))
                seq_printf(f, "LE: 0x%2.2x 0x%2.2x 0x%2.2x 0x%2.2x "
                           "0x%2.2x 0x%2.2x 0x%2.2x 0x%2.2x\n",
                           hdev->le_features[0], hdev->le_features[1],
                           hdev->le_features[2], hdev->le_features[3],
                           hdev->le_features[4], hdev->le_features[5],
                           hdev->le_features[6], hdev->le_features[7]);
        hci_dev_unlock(hdev);

        return 0;
}

static int features_open(struct inode *inode, struct file *file)
{
        return single_open(file, features_show, inode->i_private);
}

static const struct file_operations features_fops = {
        .open           = features_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int blacklist_show(struct seq_file *f, void *p)
{
        struct hci_dev *hdev = f->private;
        struct bdaddr_list *b;

        hci_dev_lock(hdev);
        list_for_each_entry(b, &hdev->blacklist, list)
                seq_printf(f, "%pMR (type %u)\n", &b->bdaddr, b->bdaddr_type);
        hci_dev_unlock(hdev);

        return 0;
}

static int blacklist_open(struct inode *inode, struct file *file)
{
        return single_open(file, blacklist_show, inode->i_private);
}

static const struct file_operations blacklist_fops = {
        .open           = blacklist_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int whitelist_show(struct seq_file *f, void *p)
{
        struct hci_dev *hdev = f->private;
        struct bdaddr_list *b;

        hci_dev_lock(hdev);
        list_for_each_entry(b, &hdev->whitelist, list)
                seq_printf(f, "%pMR (type %u)\n", &b->bdaddr, b->bdaddr_type);
        hci_dev_unlock(hdev);

        return 0;
}

static int whitelist_open(struct inode *inode, struct file *file)
{
        return single_open(file, whitelist_show, inode->i_private);
}

static const struct file_operations whitelist_fops = {
        .open           = whitelist_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int uuids_show(struct seq_file *f, void *p)
{
        struct hci_dev *hdev = f->private;
        struct bt_uuid *uuid;

        hci_dev_lock(hdev);
        list_for_each_entry(uuid, &hdev->uuids, list) {
                u8 i, val[16];

                /* The Bluetooth UUID values are stored in big endian,
                 * but with reversed byte order. So convert them into
                 * the right order for the %pUb modifier.
                 */
                for (i = 0; i < 16; i++)
                        val[i] = uuid->uuid[15 - i];

                seq_printf(f, "%pUb\n", val);
        }
        hci_dev_unlock(hdev);

        return 0;
}

static int uuids_open(struct inode *inode, struct file *file)
{
        return single_open(file, uuids_show, inode->i_private);
}

static const struct file_operations uuids_fops = {
        .open           = uuids_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int inquiry_cache_show(struct seq_file *f, void *p)
{
        struct hci_dev *hdev = f->private;
        struct discovery_state *cache = &hdev->discovery;
        struct inquiry_entry *e;

        hci_dev_lock(hdev);

        list_for_each_entry(e, &cache->all, all) {
                struct inquiry_data *data = &e->data;
                seq_printf(f, "%pMR %d %d %d 0x%.2x%.2x%.2x 0x%.4x %d %d %u\n",
                           &data->bdaddr,
                           data->pscan_rep_mode, data->pscan_period_mode,
                           data->pscan_mode, data->dev_class[2],
                           data->dev_class[1], data->dev_class[0],
                           __le16_to_cpu(data->clock_offset),
                           data->rssi, data->ssp_mode, e->timestamp);
        }

        hci_dev_unlock(hdev);

        return 0;
}

static int inquiry_cache_open(struct inode *inode, struct file *file)
{
        return single_open(file, inquiry_cache_show, inode->i_private);
}

static const struct file_operations inquiry_cache_fops = {
        .open           = inquiry_cache_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int link_keys_show(struct seq_file *f, void *ptr)
{
        struct hci_dev *hdev = f->private;
        struct list_head *p, *n;

        hci_dev_lock(hdev);
        list_for_each_safe(p, n, &hdev->link_keys) {
                struct link_key *key = list_entry(p, struct link_key, list);
                seq_printf(f, "%pMR %u %*phN %u\n", &key->bdaddr, key->type,
                           HCI_LINK_KEY_SIZE, key->val, key->pin_len);
        }
        hci_dev_unlock(hdev);

        return 0;
}

static int link_keys_open(struct inode *inode, struct file *file)
{
        return single_open(file, link_keys_show, inode->i_private);
}

static const struct file_operations link_keys_fops = {
        .open           = link_keys_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int dev_class_show(struct seq_file *f, void *ptr)
{
        struct hci_dev *hdev = f->private;

        hci_dev_lock(hdev);
        seq_printf(f, "0x%.2x%.2x%.2x\n", hdev->dev_class[2],
                   hdev->dev_class[1], hdev->dev_class[0]);
        hci_dev_unlock(hdev);

        return 0;
}

static int dev_class_open(struct inode *inode, struct file *file)
{
        return single_open(file, dev_class_show, inode->i_private);
}

static const struct file_operations dev_class_fops = {
        .open           = dev_class_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int voice_setting_get(void *data, u64 *val)
{
        struct hci_dev *hdev = data;

        hci_dev_lock(hdev);
        *val = hdev->voice_setting;
        hci_dev_unlock(hdev);

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(voice_setting_fops, voice_setting_get,
                        NULL, "0x%4.4llx\n");

static int auto_accept_delay_set(void *data, u64 val)
{
        struct hci_dev *hdev = data;

        hci_dev_lock(hdev);
        hdev->auto_accept_delay = val;
        hci_dev_unlock(hdev);

        return 0;
}

static int auto_accept_delay_get(void *data, u64 *val)
{
        struct hci_dev *hdev = data;

        hci_dev_lock(hdev);
        *val = hdev->auto_accept_delay;
        hci_dev_unlock(hdev);

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(auto_accept_delay_fops, auto_accept_delay_get,
                        auto_accept_delay_set, "%llu\n");

static ssize_t force_sc_support_read(struct file *file, char __user *user_buf,
                                     size_t count, loff_t *ppos)
{
        struct hci_dev *hdev = file->private_data;
        char buf[3];

        buf[0] = test_bit(HCI_FORCE_SC, &hdev->dbg_flags) ? 'Y': 'N';
        buf[1] = '\n';
        buf[2] = '\0';
        return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
}

static ssize_t force_sc_support_write(struct file *file,
                                      const char __user *user_buf,
                                      size_t count, loff_t *ppos)
{
        struct hci_dev *hdev = file->private_data;
        char buf[32];
        size_t buf_size = min(count, (sizeof(buf)-1));
        bool enable;

        if (test_bit(HCI_UP, &hdev->flags))
                return -EBUSY;

        if (copy_from_user(buf, user_buf, buf_size))
                return -EFAULT;

        buf[buf_size] = '\0';
        if (strtobool(buf, &enable))
                return -EINVAL;

        if (enable == test_bit(HCI_FORCE_SC, &hdev->dbg_flags))
                return -EALREADY;

        change_bit(HCI_FORCE_SC, &hdev->dbg_flags);

        return count;
}

static const struct file_operations force_sc_support_fops = {
        .open           = simple_open,
        .read           = force_sc_support_read,
        .write          = force_sc_support_write,
        .llseek         = default_llseek,
};

static ssize_t sc_only_mode_read(struct file *file, char __user *user_buf,
                                 size_t count, loff_t *ppos)
{
        struct hci_dev *hdev = file->private_data;
        char buf[3];

        buf[0] = test_bit(HCI_SC_ONLY, &hdev->dev_flags) ? 'Y': 'N';
        buf[1] = '\n';
        buf[2] = '\0';
        return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
}

static const struct file_operations sc_only_mode_fops = {
        .open           = simple_open,
        .read           = sc_only_mode_read,
        .llseek         = default_llseek,
};

static int idle_timeout_set(void *data, u64 val)
{
        struct hci_dev *hdev = data;

        if (val != 0 && (val < 500 || val > 3600000))
                return -EINVAL;

        hci_dev_lock(hdev);
        hdev->idle_timeout = val;
        hci_dev_unlock(hdev);

        return 0;
}

static int idle_timeout_get(void *data, u64 *val)
{
        struct hci_dev *hdev = data;

        hci_dev_lock(hdev);
        *val = hdev->idle_timeout;
        hci_dev_unlock(hdev);

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(idle_timeout_fops, idle_timeout_get,
                        idle_timeout_set, "%llu\n");

static int rpa_timeout_set(void *data, u64 val)
{
        struct hci_dev *hdev = data;

        /* Require the RPA timeout to be at least 30 seconds and at most
         * 24 hours.
         */
        if (val < 30 || val > (60 * 60 * 24))
                return -EINVAL;

        hci_dev_lock(hdev);
        hdev->rpa_timeout = val;
        hci_dev_unlock(hdev);

        return 0;
}

static int rpa_timeout_get(void *data, u64 *val)
{
        struct hci_dev *hdev = data;

        hci_dev_lock(hdev);
        *val = hdev->rpa_timeout;
        hci_dev_unlock(hdev);

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(rpa_timeout_fops, rpa_timeout_get,
                        rpa_timeout_set, "%llu\n");

static int sniff_min_interval_set(void *data, u64 val)
{
        struct hci_dev *hdev = data;

        if (val == 0 || val % 2 || val > hdev->sniff_max_interval)
                return -EINVAL;

        hci_dev_lock(hdev);
        hdev->sniff_min_interval = val;
        hci_dev_unlock(hdev);

        return 0;
}

static int sniff_min_interval_get(void *data, u64 *val)
{
        struct hci_dev *hdev = data;

        hci_dev_lock(hdev);
        *val = hdev->sniff_min_interval;
        hci_dev_unlock(hdev);

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(sniff_min_interval_fops, sniff_min_interval_get,
                        sniff_min_interval_set, "%llu\n");

static int sniff_max_interval_set(void *data, u64 val)
{
        struct hci_dev *hdev = data;

        if (val == 0 || val % 2 || val < hdev->sniff_min_interval)
                return -EINVAL;

        hci_dev_lock(hdev);
        hdev->sniff_max_interval = val;
        hci_dev_unlock(hdev);

        return 0;
}

static int sniff_max_interval_get(void *data, u64 *val)
{
        struct hci_dev *hdev = data;

        hci_dev_lock(hdev);
        *val = hdev->sniff_max_interval;
        hci_dev_unlock(hdev);

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(sniff_max_interval_fops, sniff_max_interval_get,
                        sniff_max_interval_set, "%llu\n");

static int conn_info_min_age_set(void *data, u64 val)
{
        struct hci_dev *hdev = data;

        if (val == 0 || val > hdev->conn_info_max_age)
                return -EINVAL;

        hci_dev_lock(hdev);
        hdev->conn_info_min_age = val;
        hci_dev_unlock(hdev);

        return 0;
}

static int conn_info_min_age_get(void *data, u64 *val)
{
        struct hci_dev *hdev = data;

        hci_dev_lock(hdev);
        *val = hdev->conn_info_min_age;
        hci_dev_unlock(hdev);

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(conn_info_min_age_fops, conn_info_min_age_get,
                        conn_info_min_age_set, "%llu\n");

static int conn_info_max_age_set(void *data, u64 val)
{
        struct hci_dev *hdev = data;

        if (val == 0 || val < hdev->conn_info_min_age)
                return -EINVAL;

        hci_dev_lock(hdev);
        hdev->conn_info_max_age = val;
        hci_dev_unlock(hdev);

        return 0;
}

static int conn_info_max_age_get(void *data, u64 *val)
{
        struct hci_dev *hdev = data;

        hci_dev_lock(hdev);
        *val = hdev->conn_info_max_age;
        hci_dev_unlock(hdev);

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(conn_info_max_age_fops, conn_info_max_age_get,
                        conn_info_max_age_set, "%llu\n");

static int identity_show(struct seq_file *f, void *p)
{
        struct hci_dev *hdev = f->private;
        bdaddr_t addr;
        u8 addr_type;

        hci_dev_lock(hdev);

        hci_copy_identity_address(hdev, &addr, &addr_type);

        seq_printf(f, "%pMR (type %u) %*phN %pMR\n", &addr, addr_type,
                   16, hdev->irk, &hdev->rpa);

        hci_dev_unlock(hdev);

        return 0;
}

static int identity_open(struct inode *inode, struct file *file)
{
        return single_open(file, identity_show, inode->i_private);
}

static const struct file_operations identity_fops = {
        .open           = identity_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int random_address_show(struct seq_file *f, void *p)
{
        struct hci_dev *hdev = f->private;

        hci_dev_lock(hdev);
        seq_printf(f, "%pMR\n", &hdev->random_addr);
        hci_dev_unlock(hdev);

        return 0;
}

static int random_address_open(struct inode *inode, struct file *file)
{
        return single_open(file, random_address_show, inode->i_private);
}

static const struct file_operations random_address_fops = {
        .open           = random_address_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int static_address_show(struct seq_file *f, void *p)
{
        struct hci_dev *hdev = f->private;

        hci_dev_lock(hdev);
        seq_printf(f, "%pMR\n", &hdev->static_addr);
        hci_dev_unlock(hdev);

        return 0;
}

static int static_address_open(struct inode *inode, struct file *file)
{
        return single_open(file, static_address_show, inode->i_private);
}

static const struct file_operations static_address_fops = {
        .open           = static_address_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static ssize_t force_static_address_read(struct file *file,
                                         char __user *user_buf,
                                         size_t count, loff_t *ppos)
{
        struct hci_dev *hdev = file->private_data;
        char buf[3];

        buf[0] = test_bit(HCI_FORCE_STATIC_ADDR, &hdev->dbg_flags) ? 'Y': 'N';
        buf[1] = '\n';
        buf[2] = '\0';
        return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
}

static ssize_t force_static_address_write(struct file *file,
                                          const char __user *user_buf,
                                          size_t count, loff_t *ppos)
{
        struct hci_dev *hdev = file->private_data;
        char buf[32];
        size_t buf_size = min(count, (sizeof(buf)-1));
        bool enable;

        if (test_bit(HCI_UP, &hdev->flags))
                return -EBUSY;

        if (copy_from_user(buf, user_buf, buf_size))
                return -EFAULT;

        buf[buf_size] = '\0';
        if (strtobool(buf, &enable))
                return -EINVAL;

        if (enable == test_bit(HCI_FORCE_STATIC_ADDR, &hdev->dbg_flags))
                return -EALREADY;

        change_bit(HCI_FORCE_STATIC_ADDR, &hdev->dbg_flags);

        return count;
}

static const struct file_operations force_static_address_fops = {
        .open           = simple_open,
        .read           = force_static_address_read,
        .write          = force_static_address_write,
        .llseek         = default_llseek,
};

static int white_list_show(struct seq_file *f, void *ptr)
{
        struct hci_dev *hdev = f->private;
        struct bdaddr_list *b;

        hci_dev_lock(hdev);
        list_for_each_entry(b, &hdev->le_white_list, list)
                seq_printf(f, "%pMR (type %u)\n", &b->bdaddr, b->bdaddr_type);
        hci_dev_unlock(hdev);

        return 0;
}

static int white_list_open(struct inode *inode, struct file *file)
{
        return single_open(file, white_list_show, inode->i_private);
}

static const struct file_operations white_list_fops = {
        .open           = white_list_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int identity_resolving_keys_show(struct seq_file *f, void *ptr)
{
        struct hci_dev *hdev = f->private;
        struct list_head *p, *n;

        hci_dev_lock(hdev);
        list_for_each_safe(p, n, &hdev->identity_resolving_keys) {
                struct smp_irk *irk = list_entry(p, struct smp_irk, list);
                seq_printf(f, "%pMR (type %u) %*phN %pMR\n",
                           &irk->bdaddr, irk->addr_type,
                           16, irk->val, &irk->rpa);
        }
        hci_dev_unlock(hdev);

        return 0;
}

static int identity_resolving_keys_open(struct inode *inode, struct file *file)
{
        return single_open(file, identity_resolving_keys_show,
                           inode->i_private);
}

static const struct file_operations identity_resolving_keys_fops = {
        .open           = identity_resolving_keys_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int long_term_keys_show(struct seq_file *f, void *ptr)
{
        struct hci_dev *hdev = f->private;
        struct list_head *p, *n;

        hci_dev_lock(hdev);
        list_for_each_safe(p, n, &hdev->long_term_keys) {
                struct smp_ltk *ltk = list_entry(p, struct smp_ltk, list);
                seq_printf(f, "%pMR (type %u) %u 0x%02x %u %.4x %.16llx %*phN\n",
                           &ltk->bdaddr, ltk->bdaddr_type, ltk->authenticated,
                           ltk->type, ltk->enc_size, __le16_to_cpu(ltk->ediv),
                           __le64_to_cpu(ltk->rand), 16, ltk->val);
        }
        hci_dev_unlock(hdev);

        return 0;
}

static int long_term_keys_open(struct inode *inode, struct file *file)
{
        return single_open(file, long_term_keys_show, inode->i_private);
}

static const struct file_operations long_term_keys_fops = {
        .open           = long_term_keys_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int conn_min_interval_set(void *data, u64 val)
{
        struct hci_dev *hdev = data;

        if (val < 0x0006 || val > 0x0c80 || val > hdev->le_conn_max_interval)
                return -EINVAL;

        hci_dev_lock(hdev);
        hdev->le_conn_min_interval = val;
        hci_dev_unlock(hdev);

        return 0;
}

static int conn_min_interval_get(void *data, u64 *val)
{
        struct hci_dev *hdev = data;

        hci_dev_lock(hdev);
        *val = hdev->le_conn_min_interval;
        hci_dev_unlock(hdev);

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(conn_min_interval_fops, conn_min_interval_get,
                        conn_min_interval_set, "%llu\n");

static int conn_max_interval_set(void *data, u64 val)
{
        struct hci_dev *hdev = data;

        if (val < 0x0006 || val > 0x0c80 || val < hdev->le_conn_min_interval)
                return -EINVAL;

        hci_dev_lock(hdev);
        hdev->le_conn_max_interval = val;
        hci_dev_unlock(hdev);

        return 0;
}

static int conn_max_interval_get(void *data, u64 *val)
{
        struct hci_dev *hdev = data;

        hci_dev_lock(hdev);
        *val = hdev->le_conn_max_interval;
        hci_dev_unlock(hdev);

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(conn_max_interval_fops, conn_max_interval_get,
                        conn_max_interval_set, "%llu\n");

static int conn_latency_set(void *data, u64 val)
{
        struct hci_dev *hdev = data;

        if (val > 0x01f3)
                return -EINVAL;

        hci_dev_lock(hdev);
        hdev->le_conn_latency = val;
        hci_dev_unlock(hdev);

        return 0;
}

static int conn_latency_get(void *data, u64 *val)
{
        struct hci_dev *hdev = data;

        hci_dev_lock(hdev);
        *val = hdev->le_conn_latency;
        hci_dev_unlock(hdev);

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(conn_latency_fops, conn_latency_get,
                        conn_latency_set, "%llu\n");

static int supervision_timeout_set(void *data, u64 val)
{
        struct hci_dev *hdev = data;

        if (val < 0x000a || val > 0x0c80)
                return -EINVAL;

        hci_dev_lock(hdev);
        hdev->le_supv_timeout = val;
        hci_dev_unlock(hdev);

        return 0;
}

static int supervision_timeout_get(void *data, u64 *val)
{
        struct hci_dev *hdev = data;

        hci_dev_lock(hdev);
        *val = hdev->le_supv_timeout;
        hci_dev_unlock(hdev);

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(supervision_timeout_fops, supervision_timeout_get,
                        supervision_timeout_set, "%llu\n");

static int adv_channel_map_set(void *data, u64 val)
{
        struct hci_dev *hdev = data;

        if (val < 0x01 || val > 0x07)
                return -EINVAL;

        hci_dev_lock(hdev);
        hdev->le_adv_channel_map = val;
        hci_dev_unlock(hdev);

        return 0;
}

static int adv_channel_map_get(void *data, u64 *val)
{
        struct hci_dev *hdev = data;

        hci_dev_lock(hdev);
        *val = hdev->le_adv_channel_map;
        hci_dev_unlock(hdev);

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(adv_channel_map_fops, adv_channel_map_get,
                        adv_channel_map_set, "%llu\n");

static int adv_min_interval_set(void *data, u64 val)
{
        struct hci_dev *hdev = data;

        if (val < 0x0020 || val > 0x4000 || val > hdev->le_adv_max_interval)
                return -EINVAL;

        hci_dev_lock(hdev);
        hdev->le_adv_min_interval = val;
        hci_dev_unlock(hdev);

        return 0;
}

static int adv_min_interval_get(void *data, u64 *val)
{
        struct hci_dev *hdev = data;

        hci_dev_lock(hdev);
        *val = hdev->le_adv_min_interval;
        hci_dev_unlock(hdev);

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(adv_min_interval_fops, adv_min_interval_get,
                        adv_min_interval_set, "%llu\n");

static int adv_max_interval_set(void *data, u64 val)
{
        struct hci_dev *hdev = data;

        if (val < 0x0020 || val > 0x4000 || val < hdev->le_adv_min_interval)
                return -EINVAL;

        hci_dev_lock(hdev);
        hdev->le_adv_max_interval = val;
        hci_dev_unlock(hdev);

        return 0;
}

static int adv_max_interval_get(void *data, u64 *val)
{
        struct hci_dev *hdev = data;

        hci_dev_lock(hdev);
        *val = hdev->le_adv_max_interval;
        hci_dev_unlock(hdev);

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(adv_max_interval_fops, adv_max_interval_get,
                        adv_max_interval_set, "%llu\n");

static int device_list_show(struct seq_file *f, void *ptr)
{
        struct hci_dev *hdev = f->private;
        struct hci_conn_params *p;

        hci_dev_lock(hdev);
        list_for_each_entry(p, &hdev->le_conn_params, list) {
                seq_printf(f, "%pMR %u %u\n", &p->addr, p->addr_type,
                           p->auto_connect);
        }
        hci_dev_unlock(hdev);

        return 0;
}

static int device_list_open(struct inode *inode, struct file *file)
{
        return single_open(file, device_list_show, inode->i_private);
}

static const struct file_operations device_list_fops = {
        .open           = device_list_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

/* ---- HCI requests ---- */

static void hci_req_sync_complete(struct hci_dev *hdev, u8 result)
{
        BT_DBG("%s result 0x%2.2x", hdev->name, result);

        if (hdev->req_status == HCI_REQ_PEND) {
                hdev->req_result = result;
                hdev->req_status = HCI_REQ_DONE;
                wake_up_interruptible(&hdev->req_wait_q);
        }
}

static void hci_req_cancel(struct hci_dev *hdev, int err)
{
        BT_DBG("%s err 0x%2.2x", hdev->name, err);

        if (hdev->req_status == HCI_REQ_PEND) {
                hdev->req_result = err;
                hdev->req_status = HCI_REQ_CANCELED;
                wake_up_interruptible(&hdev->req_wait_q);
        }
}

static struct sk_buff *hci_get_cmd_complete(struct hci_dev *hdev, u16 opcode,
                                            u8 event)
{
        struct hci_ev_cmd_complete *ev;
        struct hci_event_hdr *hdr;
        struct sk_buff *skb;

        hci_dev_lock(hdev);

        skb = hdev->recv_evt;
        hdev->recv_evt = NULL;

        hci_dev_unlock(hdev);

        if (!skb)
                return ERR_PTR(-ENODATA);

        if (skb->len < sizeof(*hdr)) {
                BT_ERR("Too short HCI event");
                goto failed;
        }

        hdr = (void *) skb->data;
        skb_pull(skb, HCI_EVENT_HDR_SIZE);

        if (event) {
                if (hdr->evt != event)
                        goto failed;
                return skb;
        }

        if (hdr->evt != HCI_EV_CMD_COMPLETE) {
                BT_DBG("Last event is not cmd complete (0x%2.2x)", hdr->evt);
                goto failed;
        }

        if (skb->len < sizeof(*ev)) {
                BT_ERR("Too short cmd_complete event");
                goto failed;
        }

        ev = (void *) skb->data;
        skb_pull(skb, sizeof(*ev));

        if (opcode == __le16_to_cpu(ev->opcode))
                return skb;

        BT_DBG("opcode doesn't match (0x%2.2x != 0x%2.2x)", opcode,
               __le16_to_cpu(ev->opcode));

failed:
        kfree_skb(skb);
        return ERR_PTR(-ENODATA);
}

struct sk_buff *__hci_cmd_sync_ev(struct hci_dev *hdev, u16 opcode, u32 plen,
                                  const void *param, u8 event, u32 timeout)
{
        DECLARE_WAITQUEUE(wait, current);
        struct hci_request req;
        int err = 0;

        BT_DBG("%s", hdev->name);

        hci_req_init(&req, hdev);

        hci_req_add_ev(&req, opcode, plen, param, event);

        hdev->req_status = HCI_REQ_PEND;

        err = hci_req_run(&req, hci_req_sync_complete);
        if (err < 0)
                return ERR_PTR(err);

        add_wait_queue(&hdev->req_wait_q, &wait);
        set_current_state(TASK_INTERRUPTIBLE);

        schedule_timeout(timeout);

        remove_wait_queue(&hdev->req_wait_q, &wait);

        if (signal_pending(current))
                return ERR_PTR(-EINTR);

        switch (hdev->req_status) {
        case HCI_REQ_DONE:
                err = -bt_to_errno(hdev->req_result);
                break;

        case HCI_REQ_CANCELED:
                err = -hdev->req_result;
                break;

        default:
                err = -ETIMEDOUT;
                break;
        }

        hdev->req_status = hdev->req_result = 0;

        BT_DBG("%s end: err %d", hdev->name, err);

        if (err < 0)
                return ERR_PTR(err);

        return hci_get_cmd_complete(hdev, opcode, event);
}
EXPORT_SYMBOL(__hci_cmd_sync_ev);

struct sk_buff *__hci_cmd_sync(struct hci_dev *hdev, u16 opcode, u32 plen,
                               const void *param, u32 timeout)
{
        return __hci_cmd_sync_ev(hdev, opcode, plen, param, 0, timeout);
}
EXPORT_SYMBOL(__hci_cmd_sync);

/* Execute request and wait for completion. */
static int __hci_req_sync(struct hci_dev *hdev,
                          void (*func)(struct hci_request *req,
                                      unsigned long opt),
                          unsigned long opt, __u32 timeout)
{
        struct hci_request req;
        DECLARE_WAITQUEUE(wait, current);
        int err = 0;

        BT_DBG("%s start", hdev->name);

        hci_req_init(&req, hdev);

        hdev->req_status = HCI_REQ_PEND;

        func(&req, opt);

        err = hci_req_run(&req, hci_req_sync_complete);
        if (err < 0) {
                hdev->req_status = 0;

                /* ENODATA means the HCI request command queue is empty.
                 * This can happen when a request with conditionals doesn't
                 * trigger any commands to be sent. This is normal behavior
                 * and should not trigger an error return.
                 */
                if (err == -ENODATA)
                        return 0;

                return err;
        }

        add_wait_queue(&hdev->req_wait_q, &wait);
        set_current_state(TASK_INTERRUPTIBLE);

        schedule_timeout(timeout);

        remove_wait_queue(&hdev->req_wait_q, &wait);

        if (signal_pending(current))
                return -EINTR;

        switch (hdev->req_status) {
        case HCI_REQ_DONE:
                err = -bt_to_errno(hdev->req_result);
                break;

        case HCI_REQ_CANCELED:
                err = -hdev->req_result;
                break;

        default:
                err = -ETIMEDOUT;
                break;
        }

        hdev->req_status = hdev->req_result = 0;

        BT_DBG("%s end: err %d", hdev->name, err);

        return err;
}

static int hci_req_sync(struct hci_dev *hdev,
                        void (*req)(struct hci_request *req,
                                    unsigned long opt),
                        unsigned long opt, __u32 timeout)
{
        int ret;

        if (!test_bit(HCI_UP, &hdev->flags))
                return -ENETDOWN;

        /* Serialize all requests */
        hci_req_lock(hdev);
        ret = __hci_req_sync(hdev, req, opt, timeout);
        hci_req_unlock(hdev);

        return ret;
}

static void hci_reset_req(struct hci_request *req, unsigned long opt)
{
        BT_DBG("%s %ld", req->hdev->name, opt);

        /* Reset device */
        set_bit(HCI_RESET, &req->hdev->flags);
        hci_req_add(req, HCI_OP_RESET, 0, NULL);
}

static void bredr_init(struct hci_request *req)
{
        req->hdev->flow_ctl_mode = HCI_FLOW_CTL_MODE_PACKET_BASED;

        /* Read Local Supported Features */
        hci_req_add(req, HCI_OP_READ_LOCAL_FEATURES, 0, NULL);

        /* Read Local Version */
        hci_req_add(req, HCI_OP_READ_LOCAL_VERSION, 0, NULL);

        /* Read BD Address */
        hci_req_add(req, HCI_OP_READ_BD_ADDR, 0, NULL);
}

static void amp_init(struct hci_request *req)
{
        req->hdev->flow_ctl_mode = HCI_FLOW_CTL_MODE_BLOCK_BASED;

        /* Read Local Version */
        hci_req_add(req, HCI_OP_READ_LOCAL_VERSION, 0, NULL);

        /* Read Local Supported Commands */
        hci_req_add(req, HCI_OP_READ_LOCAL_COMMANDS, 0, NULL);

        /* Read Local Supported Features */
        hci_req_add(req, HCI_OP_READ_LOCAL_FEATURES, 0, NULL);

        /* Read Local AMP Info */
        hci_req_add(req, HCI_OP_READ_LOCAL_AMP_INFO, 0, NULL);

        /* Read Data Blk size */
        hci_req_add(req, HCI_OP_READ_DATA_BLOCK_SIZE, 0, NULL);

        /* Read Flow Control Mode */
        hci_req_add(req, HCI_OP_READ_FLOW_CONTROL_MODE, 0, NULL);

        /* Read Location Data */
        hci_req_add(req, HCI_OP_READ_LOCATION_DATA, 0, NULL);
}

static void hci_init1_req(struct hci_request *req, unsigned long opt)
{
        struct hci_dev *hdev = req->hdev;

        BT_DBG("%s %ld", hdev->name, opt);

        /* Reset */
        if (!test_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks))
                hci_reset_req(req, 0);

        switch (hdev->dev_type) {
        case HCI_BREDR:
                bredr_init(req);
                break;

        case HCI_AMP:
                amp_init(req);
                break;

        default:
                BT_ERR("Unknown device type %d", hdev->dev_type);
                break;
        }
}

static void bredr_setup(struct hci_request *req)
{
        struct hci_dev *hdev = req->hdev;

        __le16 param;
        __u8 flt_type;

        /* Read Buffer Size (ACL mtu, max pkt, etc.) */
        hci_req_add(req, HCI_OP_READ_BUFFER_SIZE, 0, NULL);

        /* Read Class of Device */
        hci_req_add(req, HCI_OP_READ_CLASS_OF_DEV, 0, NULL);

        /* Read Local Name */
        hci_req_add(req, HCI_OP_READ_LOCAL_NAME, 0, NULL);

        /* Read Voice Setting */
        hci_req_add(req, HCI_OP_READ_VOICE_SETTING, 0, NULL);

        /* Read Number of Supported IAC */
        hci_req_add(req, HCI_OP_READ_NUM_SUPPORTED_IAC, 0, NULL);

        /* Read Current IAC LAP */
        hci_req_add(req, HCI_OP_READ_CURRENT_IAC_LAP, 0, NULL);

        /* Clear Event Filters */
        flt_type = HCI_FLT_CLEAR_ALL;
        hci_req_add(req, HCI_OP_SET_EVENT_FLT, 1, &flt_type);

        /* Connection accept timeout ~20 secs */
        param = cpu_to_le16(0x7d00);
        hci_req_add(req, HCI_OP_WRITE_CA_TIMEOUT, 2, &param);

        /* AVM Berlin (31), aka "BlueFRITZ!", reports version 1.2,
         * but it does not support page scan related HCI commands.
         */
        if (hdev->manufacturer != 31 && hdev->hci_ver > BLUETOOTH_VER_1_1) {
                hci_req_add(req, HCI_OP_READ_PAGE_SCAN_ACTIVITY, 0, NULL);
                hci_req_add(req, HCI_OP_READ_PAGE_SCAN_TYPE, 0, NULL);
        }
}

static void le_setup(struct hci_request *req)
{
        struct hci_dev *hdev = req->hdev;

        /* Read LE Buffer Size */
        hci_req_add(req, HCI_OP_LE_READ_BUFFER_SIZE, 0, NULL);

        /* Read LE Local Supported Features */
        hci_req_add(req, HCI_OP_LE_READ_LOCAL_FEATURES, 0, NULL);

        /* Read LE Supported States */
        hci_req_add(req, HCI_OP_LE_READ_SUPPORTED_STATES, 0, NULL);

        /* Read LE White List Size */
        hci_req_add(req, HCI_OP_LE_READ_WHITE_LIST_SIZE, 0, NULL);

        /* Clear LE White List */
        hci_req_add(req, HCI_OP_LE_CLEAR_WHITE_LIST, 0, NULL);

        /* LE-only controllers have LE implicitly enabled */
        if (!lmp_bredr_capable(hdev))
                set_bit(HCI_LE_ENABLED, &hdev->dev_flags);
}

static u8 hci_get_inquiry_mode(struct hci_dev *hdev)
{
        if (lmp_ext_inq_capable(hdev))
                return 0x02;

        if (lmp_inq_rssi_capable(hdev))
                return 0x01;

        if (hdev->manufacturer == 11 && hdev->hci_rev == 0x00 &&
            hdev->lmp_subver == 0x0757)
                return 0x01;

        if (hdev->manufacturer == 15) {
                if (hdev->hci_rev == 0x03 && hdev->lmp_subver == 0x6963)
                        return 0x01;
                if (hdev->hci_rev == 0x09 && hdev->lmp_subver == 0x6963)
                        return 0x01;
                if (hdev->hci_rev == 0x00 && hdev->lmp_subver == 0x6965)
                        return 0x01;
        }

        if (hdev->manufacturer == 31 && hdev->hci_rev == 0x2005 &&
            hdev->lmp_subver == 0x1805)
                return 0x01;

        return 0x00;
}

static void hci_setup_inquiry_mode(struct hci_request *req)
{
        u8 mode;

        mode = hci_get_inquiry_mode(req->hdev);

        hci_req_add(req, HCI_OP_WRITE_INQUIRY_MODE, 1, &mode);
}

static void hci_setup_event_mask(struct hci_request *req)
{
        struct hci_dev *hdev = req->hdev;

        /* The second byte is 0xff instead of 0x9f (two reserved bits
         * disabled) since a Broadcom 1.2 dongle doesn't respond to the
         * command otherwise.
         */
        u8 events[8] = { 0xff, 0xff, 0xfb, 0xff, 0x00, 0x00, 0x00, 0x00 };

        /* CSR 1.1 dongles does not accept any bitfield so don't try to set
         * any event mask for pre 1.2 devices.
         */
        if (hdev->hci_ver < BLUETOOTH_VER_1_2)
                return;

        if (lmp_bredr_capable(hdev)) {
                events[4] |= 0x01; /* Flow Specification Complete */
                events[4] |= 0x02; /* Inquiry Result with RSSI */
                events[4] |= 0x04; /* Read Remote Extended Features Complete */
                events[5] |= 0x08; /* Synchronous Connection Complete */
                events[5] |= 0x10; /* Synchronous Connection Changed */
        } else {
                /* Use a different default for LE-only devices */
                memset(events, 0, sizeof(events));
                events[0] |= 0x10; /* Disconnection Complete */
                events[1] |= 0x08; /* Read Remote Version Information Complete */
                events[1] |= 0x20; /* Command Complete */
                events[1] |= 0x40; /* Command Status */
                events[1] |= 0x80; /* Hardware Error */
                events[2] |= 0x04; /* Number of Completed Packets */
                events[3] |= 0x02; /* Data Buffer Overflow */

                if (hdev->le_features[0] & HCI_LE_ENCRYPTION) {
                        events[0] |= 0x80; /* Encryption Change */
                        events[5] |= 0x80; /* Encryption Key Refresh Complete */
                }
        }

        if (lmp_inq_rssi_capable(hdev))
                events[4] |= 0x02; /* Inquiry Result with RSSI */

        if (lmp_sniffsubr_capable(hdev))
                events[5] |= 0x20; /* Sniff Subrating */

        if (lmp_pause_enc_capable(hdev))
                events[5] |= 0x80; /* Encryption Key Refresh Complete */

        if (lmp_ext_inq_capable(hdev))
                events[5] |= 0x40; /* Extended Inquiry Result */

        if (lmp_no_flush_capable(hdev))
                events[7] |= 0x01; /* Enhanced Flush Complete */

        if (lmp_lsto_capable(hdev))
                events[6] |= 0x80; /* Link Supervision Timeout Changed */

        if (lmp_ssp_capable(hdev)) {
                events[6] |= 0x01;      /* IO Capability Request */
                events[6] |= 0x02;      /* IO Capability Response */
                events[6] |= 0x04;      /* User Confirmation Request */
                events[6] |= 0x08;      /* User Passkey Request */
                events[6] |= 0x10;      /* Remote OOB Data Request */
                events[6] |= 0x20;      /* Simple Pairing Complete */
                events[7] |= 0x04;      /* User Passkey Notification */
                events[7] |= 0x08;      /* Keypress Notification */
                events[7] |= 0x10;      /* Remote Host Supported
                                         * Features Notification
                                         */
        }

        if (lmp_le_capable(hdev))
                events[7] |= 0x20;      /* LE Meta-Event */

        hci_req_add(req, HCI_OP_SET_EVENT_MASK, sizeof(events), events);
}

static void hci_init2_req(struct hci_request *req, unsigned long opt)
{
        struct hci_dev *hdev = req->hdev;

        if (lmp_bredr_capable(hdev))
                bredr_setup(req);
        else
                clear_bit(HCI_BREDR_ENABLED, &hdev->dev_flags);

        if (lmp_le_capable(hdev))
                le_setup(req);

        /* AVM Berlin (31), aka "BlueFRITZ!", doesn't support the read
         * local supported commands HCI command.
         */
        if (hdev->manufacturer != 31 && hdev->hci_ver > BLUETOOTH_VER_1_1)
                hci_req_add(req, HCI_OP_READ_LOCAL_COMMANDS, 0, NULL);

        if (lmp_ssp_capable(hdev)) {
                /* When SSP is available, then the host features page
                 * should also be available as well. However some
                 * controllers list the max_page as 0 as long as SSP
                 * has not been enabled. To achieve proper debugging
                 * output, force the minimum max_page to 1 at least.
                 */
                hdev->max_page = 0x01;

                if (test_bit(HCI_SSP_ENABLED, &hdev->dev_flags)) {
                        u8 mode = 0x01;
                        hci_req_add(req, HCI_OP_WRITE_SSP_MODE,
                                    sizeof(mode), &mode);
                } else {
                        struct hci_cp_write_eir cp;

                        memset(hdev->eir, 0, sizeof(hdev->eir));
                        memset(&cp, 0, sizeof(cp));

                        hci_req_add(req, HCI_OP_WRITE_EIR, sizeof(cp), &cp);
                }
        }

        if (lmp_inq_rssi_capable(hdev))
                hci_setup_inquiry_mode(req);

        if (lmp_inq_tx_pwr_capable(hdev))
                hci_req_add(req, HCI_OP_READ_INQ_RSP_TX_POWER, 0, NULL);

        if (lmp_ext_feat_capable(hdev)) {
                struct hci_cp_read_local_ext_features cp;

                cp.page = 0x01;
                hci_req_add(req, HCI_OP_READ_LOCAL_EXT_FEATURES,
                            sizeof(cp), &cp);
        }

        if (test_bit(HCI_LINK_SECURITY, &hdev->dev_flags)) {
                u8 enable = 1;
                hci_req_add(req, HCI_OP_WRITE_AUTH_ENABLE, sizeof(enable),
                            &enable);
        }
}

static void hci_setup_link_policy(struct hci_request *req)
{
        struct hci_dev *hdev = req->hdev;
        struct hci_cp_write_def_link_policy cp;
        u16 link_policy = 0;

        if (lmp_rswitch_capable(hdev))
                link_policy |= HCI_LP_RSWITCH;
        if (lmp_hold_capable(hdev))
                link_policy |= HCI_LP_HOLD;
        if (lmp_sniff_capable(hdev))
                link_policy |= HCI_LP_SNIFF;
        if (lmp_park_capable(hdev))
                link_policy |= HCI_LP_PARK;

        cp.policy = cpu_to_le16(link_policy);
        hci_req_add(req, HCI_OP_WRITE_DEF_LINK_POLICY, sizeof(cp), &cp);
}

static void hci_set_le_support(struct hci_request *req)
{
        struct hci_dev *hdev = req->hdev;
        struct hci_cp_write_le_host_supported cp;

        /* LE-only devices do not support explicit enablement */
        if (!lmp_bredr_capable(hdev))
                return;

        memset(&cp, 0, sizeof(cp));

        if (test_bit(HCI_LE_ENABLED, &hdev->dev_flags)) {
                cp.le = 0x01;
                cp.simul = 0x00;
        }

        if (cp.le != lmp_host_le_capable(hdev))
                hci_req_add(req, HCI_OP_WRITE_LE_HOST_SUPPORTED, sizeof(cp),
                            &cp);
}

static void hci_set_event_mask_page_2(struct hci_request *req)
{
        struct hci_dev *hdev = req->hdev;
        u8 events[8] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

        /* If Connectionless Slave Broadcast master role is supported
         * enable all necessary events for it.
         */
        if (lmp_csb_master_capable(hdev)) {
                events[1] |= 0x40;      /* Triggered Clock Capture */
                events[1] |= 0x80;      /* Synchronization Train Complete */
                events[2] |= 0x10;      /* Slave Page Response Timeout */
                events[2] |= 0x20;      /* CSB Channel Map Change */
        }

        /* If Connectionless Slave Broadcast slave role is supported
         * enable all necessary events for it.
         */
        if (lmp_csb_slave_capable(hdev)) {
                events[2] |= 0x01;      /* Synchronization Train Received */
                events[2] |= 0x02;      /* CSB Receive */
                events[2] |= 0x04;      /* CSB Timeout */
                events[2] |= 0x08;      /* Truncated Page Complete */
        }

        /* Enable Authenticated Payload Timeout Expired event if supported */
        if (lmp_ping_capable(hdev) || hdev->le_features[0] & HCI_LE_PING)
                events[2] |= 0x80;

        hci_req_add(req, HCI_OP_SET_EVENT_MASK_PAGE_2, sizeof(events), events);
}

static void hci_init3_req(struct hci_request *req, unsigned long opt)
{
        struct hci_dev *hdev = req->hdev;
        u8 p;

        hci_setup_event_mask(req);

        /* Some Broadcom based Bluetooth controllers do not support the
         * Delete Stored Link Key command. They are clearly indicating its
         * absence in the bit mask of supported commands.
         *
         * Check the supported commands and only if the the command is marked
         * as supported send it. If not supported assume that the controller
         * does not have actual support for stored link keys which makes this
         * command redundant anyway.
         *
         * Some controllers indicate that they support handling deleting
         * stored link keys, but they don't. The quirk lets a driver
         * just disable this command.
         */
        if (hdev->commands[6] & 0x80 &&
            !test_bit(HCI_QUIRK_BROKEN_STORED_LINK_KEY, &hdev->quirks)) {
                struct hci_cp_delete_stored_link_key cp;

                bacpy(&cp.bdaddr, BDADDR_ANY);
                cp.delete_all = 0x01;
                hci_req_add(req, HCI_OP_DELETE_STORED_LINK_KEY,
                            sizeof(cp), &cp);
        }

        if (hdev->commands[5] & 0x10)
                hci_setup_link_policy(req);

        if (lmp_le_capable(hdev)) {
                u8 events[8];

                memset(events, 0, sizeof(events));
                events[0] = 0x0f;

                if (hdev->le_features[0] & HCI_LE_ENCRYPTION)
                        events[0] |= 0x10;      /* LE Long Term Key Request */

                /* If controller supports the Connection Parameters Request
                 * Link Layer Procedure, enable the corresponding event.
                 */
                if (hdev->le_features[0] & HCI_LE_CONN_PARAM_REQ_PROC)
                        events[0] |= 0x20;      /* LE Remote Connection
                                                 * Parameter Request
                                                 */

                hci_req_add(req, HCI_OP_LE_SET_EVENT_MASK, sizeof(events),
                            events);

                if (hdev->commands[25] & 0x40) {
                        /* Read LE Advertising Channel TX Power */
                        hci_req_add(req, HCI_OP_LE_READ_ADV_TX_POWER, 0, NULL);
                }

                hci_set_le_support(req);
        }

        /* Read features beyond page 1 if available */
        for (p = 2; p < HCI_MAX_PAGES && p <= hdev->max_page; p++) {
                struct hci_cp_read_local_ext_features cp;

                cp.page = p;
                hci_req_add(req, HCI_OP_READ_LOCAL_EXT_FEATURES,
                            sizeof(cp), &cp);
        }
}

static void hci_init4_req(struct hci_request *req, unsigned long opt)
{
        struct hci_dev *hdev = req->hdev;

        /* Set event mask page 2 if the HCI command for it is supported */
        if (hdev->commands[22] & 0x04)
                hci_set_event_mask_page_2(req);

        /* Read local codec list if the HCI command is supported */
        if (hdev->commands[29] & 0x20)
                hci_req_add(req, HCI_OP_READ_LOCAL_CODECS, 0, NULL);

        /* Get MWS transport configuration if the HCI command is supported */
        if (hdev->commands[30] & 0x08)
                hci_req_add(req, HCI_OP_GET_MWS_TRANSPORT_CONFIG, 0, NULL);

        /* Check for Synchronization Train support */
        if (lmp_sync_train_capable(hdev))
                hci_req_add(req, HCI_OP_READ_SYNC_TRAIN_PARAMS, 0, NULL);

        /* Enable Secure Connections if supported and configured */
        if ((lmp_sc_capable(hdev) ||
             test_bit(HCI_FORCE_SC, &hdev->dbg_flags)) &&
            test_bit(HCI_SC_ENABLED, &hdev->dev_flags)) {
                u8 support = 0x01;
                hci_req_add(req, HCI_OP_WRITE_SC_SUPPORT,
                            sizeof(support), &support);
        }
}

static int __hci_init(struct hci_dev *hdev)
{
        int err;

        err = __hci_req_sync(hdev, hci_init1_req, 0, HCI_INIT_TIMEOUT);
        if (err < 0)
                return err;

        /* The Device Under Test (DUT) mode is special and available for
         * all controller types. So just create it early on.
         */
        if (test_bit(HCI_SETUP, &hdev->dev_flags)) {
                debugfs_create_file("dut_mode", 0644, hdev->debugfs, hdev,
                                    &dut_mode_fops);
        }

        /* HCI_BREDR covers both single-mode LE, BR/EDR and dual-mode
         * BR/EDR/LE type controllers. AMP controllers only need the
         * first stage init.
         */
        if (hdev->dev_type != HCI_BREDR)
                return 0;

        err = __hci_req_sync(hdev, hci_init2_req, 0, HCI_INIT_TIMEOUT);
        if (err < 0)
                return err;

        err = __hci_req_sync(hdev, hci_init3_req, 0, HCI_INIT_TIMEOUT);
        if (err < 0)
                return err;

        err = __hci_req_sync(hdev, hci_init4_req, 0, HCI_INIT_TIMEOUT);
        if (err < 0)
                return err;

        /* Only create debugfs entries during the initial setup
         * phase and not every time the controller gets powered on.
         */
        if (!test_bit(HCI_SETUP, &hdev->dev_flags))
                return 0;

        debugfs_create_file("features", 0444, hdev->debugfs, hdev,
                            &features_fops);
        debugfs_create_u16("manufacturer", 0444, hdev->debugfs,
                           &hdev->manufacturer);
        debugfs_create_u8("hci_version", 0444, hdev->debugfs, &hdev->hci_ver);
        debugfs_create_u16("hci_revision", 0444, hdev->debugfs, &hdev->hci_rev);
        debugfs_create_file("blacklist", 0444, hdev->debugfs, hdev,
                            &blacklist_fops);
        debugfs_create_file("whitelist", 0444, hdev->debugfs, hdev,
                            &whitelist_fops);
        debugfs_create_file("uuids", 0444, hdev->debugfs, hdev, &uuids_fops);

        debugfs_create_file("conn_info_min_age", 0644, hdev->debugfs, hdev,
                            &conn_info_min_age_fops);
        debugfs_create_file("conn_info_max_age", 0644, hdev->debugfs, hdev,
                            &conn_info_max_age_fops);

        if (lmp_bredr_capable(hdev)) {
                debugfs_create_file("inquiry_cache", 0444, hdev->debugfs,
                                    hdev, &inquiry_cache_fops);
                debugfs_create_file("link_keys", 0400, hdev->debugfs,
                                    hdev, &link_keys_fops);
                debugfs_create_file("dev_class", 0444, hdev->debugfs,
                                    hdev, &dev_class_fops);
                debugfs_create_file("voice_setting", 0444, hdev->debugfs,
                                    hdev, &voice_setting_fops);
        }

        if (lmp_ssp_capable(hdev)) {
                debugfs_create_file("auto_accept_delay", 0644, hdev->debugfs,
                                    hdev, &auto_accept_delay_fops);
                debugfs_create_file("force_sc_support", 0644, hdev->debugfs,
                                    hdev, &force_sc_support_fops);
                debugfs_create_file("sc_only_mode", 0444, hdev->debugfs,
                                    hdev, &sc_only_mode_fops);
        }

        if (lmp_sniff_capable(hdev)) {
                debugfs_create_file("idle_timeout", 0644, hdev->debugfs,
                                    hdev, &idle_timeout_fops);
                debugfs_create_file("sniff_min_interval", 0644, hdev->debugfs,
                                    hdev, &sniff_min_interval_fops);
                debugfs_create_file("sniff_max_interval", 0644, hdev->debugfs,
                                    hdev, &sniff_max_interval_fops);
        }

        if (lmp_le_capable(hdev)) {
                debugfs_create_file("identity", 0400, hdev->debugfs,
                                    hdev, &identity_fops);
                debugfs_create_file("rpa_timeout", 0644, hdev->debugfs,
                                    hdev, &rpa_timeout_fops);
                debugfs_create_file("random_address", 0444, hdev->debugfs,
                                    hdev, &random_address_fops);
                debugfs_create_file("static_address", 0444, hdev->debugfs,
                                    hdev, &static_address_fops);

                /* For controllers with a public address, provide a debug
                 * option to force the usage of the configured static
                 * address. By default the public address is used.
                 */
                if (bacmp(&hdev->bdaddr, BDADDR_ANY))
                        debugfs_create_file("force_static_address", 0644,
                                            hdev->debugfs, hdev,
                                            &force_static_address_fops);

                debugfs_create_u8("white_list_size", 0444, hdev->debugfs,
                                  &hdev->le_white_list_size);
                debugfs_create_file("white_list", 0444, hdev->debugfs, hdev,
                                    &white_list_fops);
                debugfs_create_file("identity_resolving_keys", 0400,
                                    hdev->debugfs, hdev,
                                    &identity_resolving_keys_fops);
                debugfs_create_file("long_term_keys", 0400, hdev->debugfs,
                                    hdev, &long_term_keys_fops);
                debugfs_create_file("conn_min_interval", 0644, hdev->debugfs,
                                    hdev, &conn_min_interval_fops);
                debugfs_create_file("conn_max_interval", 0644, hdev->debugfs,
                                    hdev, &conn_max_interval_fops);
                debugfs_create_file("conn_latency", 0644, hdev->debugfs,
                                    hdev, &conn_latency_fops);
                debugfs_create_file("supervision_timeout", 0644, hdev->debugfs,
                                    hdev, &supervision_timeout_fops);
                debugfs_create_file("adv_channel_map", 0644, hdev->debugfs,
                                    hdev, &adv_channel_map_fops);
                debugfs_create_file("adv_min_interval", 0644, hdev->debugfs,
                                    hdev, &adv_min_interval_fops);
                debugfs_create_file("adv_max_interval", 0644, hdev->debugfs,
                                    hdev, &adv_max_interval_fops);
                debugfs_create_file("device_list", 0444, hdev->debugfs, hdev,
                                    &device_list_fops);
                debugfs_create_u16("discov_interleaved_timeout", 0644,
                                   hdev->debugfs,
                                   &hdev->discov_interleaved_timeout);
        }

        return 0;
}

static void hci_init0_req(struct hci_request *req, unsigned long opt)
{
        struct hci_dev *hdev = req->hdev;

        BT_DBG("%s %ld", hdev->name, opt);

        /* Reset */
        if (!test_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks))
                hci_reset_req(req, 0);

        /* Read Local Version */
        hci_req_add(req, HCI_OP_READ_LOCAL_VERSION, 0, NULL);

        /* Read BD Address */
        if (hdev->set_bdaddr)
                hci_req_add(req, HCI_OP_READ_BD_ADDR, 0, NULL);
}

static int __hci_unconf_init(struct hci_dev *hdev)
{
        int err;

        if (test_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks))
                return 0;

        err = __hci_req_sync(hdev, hci_init0_req, 0, HCI_INIT_TIMEOUT);
        if (err < 0)
                return err;

        return 0;
}

static void hci_scan_req(struct hci_request *req, unsigned long opt)
{
        __u8 scan = opt;

        BT_DBG("%s %x", req->hdev->name, scan);

        /* Inquiry and Page scans */
        hci_req_add(req, HCI_OP_WRITE_SCAN_ENABLE, 1, &scan);
}

static void hci_auth_req(struct hci_request *req, unsigned long opt)
{
        __u8 auth = opt;

        BT_DBG("%s %x", req->hdev->name, auth);

        /* Authentication */
        hci_req_add(req, HCI_OP_WRITE_AUTH_ENABLE, 1, &auth);
}

static void hci_encrypt_req(struct hci_request *req, unsigned long opt)
{
        __u8 encrypt = opt;

        BT_DBG("%s %x", req->hdev->name, encrypt);

        /* Encryption */
        hci_req_add(req, HCI_OP_WRITE_ENCRYPT_MODE, 1, &encrypt);
}

static void hci_linkpol_req(struct hci_request *req, unsigned long opt)
{
        __le16 policy = cpu_to_le16(opt);

        BT_DBG("%s %x", req->hdev->name, policy);

        /* Default link policy */
        hci_req_add(req, HCI_OP_WRITE_DEF_LINK_POLICY, 2, &policy);
}

/* Get HCI device by index.
 * Device is held on return. */
struct hci_dev *hci_dev_get(int index)
{
        struct hci_dev *hdev = NULL, *d;

        BT_DBG("%d", index);

        if (index < 0)
                return NULL;

        read_lock(&hci_dev_list_lock);
        list_for_each_entry(d, &hci_dev_list, list) {
                if (d->id == index) {
                        hdev = hci_dev_hold(d);
                        break;
                }
        }
        read_unlock(&hci_dev_list_lock);
        return hdev;
}

/* ---- Inquiry support ---- */

bool hci_discovery_active(struct hci_dev *hdev)
{
        struct discovery_state *discov = &hdev->discovery;

        switch (discov->state) {
        case DISCOVERY_FINDING:
        case DISCOVERY_RESOLVING:
                return true;

        default:
                return false;
        }
}

void hci_discovery_set_state(struct hci_dev *hdev, int state)
{
        int old_state = hdev->discovery.state;

        BT_DBG("%s state %u -> %u", hdev->name, hdev->discovery.state, state);

        if (old_state == state)
                return;

        hdev->discovery.state = state;

        switch (state) {
        case DISCOVERY_STOPPED:
                hci_update_background_scan(hdev);

                if (old_state != DISCOVERY_STARTING)
                        mgmt_discovering(hdev, 0);
                break;
        case DISCOVERY_STARTING:
                break;
        case DISCOVERY_FINDING:
                mgmt_discovering(hdev, 1);
                break;
        case DISCOVERY_RESOLVING:
                break;
        case DISCOVERY_STOPPING:
                break;
        }
}

void hci_inquiry_cache_flush(struct hci_dev *hdev)
{
        struct discovery_state *cache = &hdev->discovery;
        struct inquiry_entry *p, *n;

        list_for_each_entry_safe(p, n, &cache->all, all) {
                list_del(&p->all);
                kfree(p);
        }

        INIT_LIST_HEAD(&cache->unknown);
        INIT_LIST_HEAD(&cache->resolve);
}

struct inquiry_entry *hci_inquiry_cache_lookup(struct hci_dev *hdev,
                                               bdaddr_t *bdaddr)
{
        struct discovery_state *cache = &hdev->discovery;
        struct inquiry_entry *e;

        BT_DBG("cache %p, %pMR", cache, bdaddr);

        list_for_each_entry(e, &cache->all, all) {
                if (!bacmp(&e->data.bdaddr, bdaddr))
                        return e;
        }

        return NULL;
}

struct inquiry_entry *hci_inquiry_cache_lookup_unknown(struct hci_dev *hdev,
                                                       bdaddr_t *bdaddr)
{
        struct discovery_state *cache = &hdev->discovery;
        struct inquiry_entry *e;

        BT_DBG("cache %p, %pMR", cache, bdaddr);

        list_for_each_entry(e, &cache->unknown, list) {
                if (!bacmp(&e->data.bdaddr, bdaddr))
                        return e;
        }

        return NULL;
}

struct inquiry_entry *hci_inquiry_cache_lookup_resolve(struct hci_dev *hdev,
                                                       bdaddr_t *bdaddr,
                                                       int state)
{
        struct discovery_state *cache = &hdev->discovery;
        struct inquiry_entry *e;

        BT_DBG("cache %p bdaddr %pMR state %d", cache, bdaddr, state);

        list_for_each_entry(e, &cache->resolve, list) {
                if (!bacmp(bdaddr, BDADDR_ANY) && e->name_state == state)
                        return e;
                if (!bacmp(&e->data.bdaddr, bdaddr))
                        return e;
        }

        return NULL;
}

void hci_inquiry_cache_update_resolve(struct hci_dev *hdev,
                                      struct inquiry_entry *ie)
{
        struct discovery_state *cache = &hdev->discovery;
        struct list_head *pos = &cache->resolve;
        struct inquiry_entry *p;

        list_del(&ie->list);

        list_for_each_entry(p, &cache->resolve, list) {
                if (p->name_state != NAME_PENDING &&
                    abs(p->data.rssi) >= abs(ie->data.rssi))
                        break;
                pos = &p->list;
        }

        list_add(&ie->list, pos);
}

u32 hci_inquiry_cache_update(struct hci_dev *hdev, struct inquiry_data *data,
                             bool name_known)
{
        struct discovery_state *cache = &hdev->discovery;
        struct inquiry_entry *ie;
        u32 flags = 0;

        BT_DBG("cache %p, %pMR", cache, &data->bdaddr);

        hci_remove_remote_oob_data(hdev, &data->bdaddr);

        if (!data->ssp_mode)
                flags |= MGMT_DEV_FOUND_LEGACY_PAIRING;

        ie = hci_inquiry_cache_lookup(hdev, &data->bdaddr);
        if (ie) {
                if (!ie->data.ssp_mode)
                        flags |= MGMT_DEV_FOUND_LEGACY_PAIRING;

                if (ie->name_state == NAME_NEEDED &&
                    data->rssi != ie->data.rssi) {
                        ie->data.rssi = data->rssi;
                        hci_inquiry_cache_update_resolve(hdev, ie);
                }

                goto update;
        }

        /* Entry not in the cache. Add new one. */
        ie = kzalloc(sizeof(*ie), GFP_KERNEL);
        if (!ie) {
                flags |= MGMT_DEV_FOUND_CONFIRM_NAME;
                goto done;
        }

        list_add(&ie->all, &cache->all);

        if (name_known) {
                ie->name_state = NAME_KNOWN;
        } else {
                ie->name_state = NAME_NOT_KNOWN;
                list_add(&ie->list, &cache->unknown);
        }

update:
        if (name_known && ie->name_state != NAME_KNOWN &&
            ie->name_state != NAME_PENDING) {
                ie->name_state = NAME_KNOWN;
                list_del(&ie->list);
        }

        memcpy(&ie->data, data, sizeof(*data));
        ie->timestamp = jiffies;
        cache->timestamp = jiffies;

        if (ie->name_state == NAME_NOT_KNOWN)
                flags |= MGMT_DEV_FOUND_CONFIRM_NAME;

done:
        return flags;
}

static int inquiry_cache_dump(struct hci_dev *hdev, int num, __u8 *buf)
{
        struct discovery_state *cache = &hdev->discovery;
        struct inquiry_info *info = (struct inquiry_info *) buf;
        struct inquiry_entry *e;
        int copied = 0;

        list_for_each_entry(e, &cache->all, all) {
                struct inquiry_data *data = &e->data;

                if (copied >= num)
                        break;

                bacpy(&info->bdaddr, &data->bdaddr);
                info->pscan_rep_mode    = data->pscan_rep_mode;
                info->pscan_period_mode = data->pscan_period_mode;
                info->pscan_mode        = data->pscan_mode;
                memcpy(info->dev_class, data->dev_class, 3);
                info->clock_offset      = data->clock_offset;

                info++;
                copied++;
        }

        BT_DBG("cache %p, copied %d", cache, copied);
        return copied;
}

static void hci_inq_req(struct hci_request *req, unsigned long opt)
{
        struct hci_inquiry_req *ir = (struct hci_inquiry_req *) opt;
        struct hci_dev *hdev = req->hdev;
        struct hci_cp_inquiry cp;

        BT_DBG("%s", hdev->name);

        if (test_bit(HCI_INQUIRY, &hdev->flags))
                return;

        /* Start Inquiry */
        memcpy(&cp.lap, &ir->lap, 3);
        cp.length  = ir->length;
        cp.num_rsp = ir->num_rsp;
        hci_req_add(req, HCI_OP_INQUIRY, sizeof(cp), &cp);
}

int hci_inquiry(void __user *arg)
{
        __u8 __user *ptr = arg;
        struct hci_inquiry_req ir;
        struct hci_dev *hdev;
        int err = 0, do_inquiry = 0, max_rsp;
        long timeo;
        __u8 *buf;

        if (copy_from_user(&ir, ptr, sizeof(ir)))
                return -EFAULT;

        hdev = hci_dev_get(ir.dev_id);
        if (!hdev)
                return -ENODEV;

        if (test_bit(HCI_USER_CHANNEL, &hdev->dev_flags)) {
                err = -EBUSY;
                goto done;
        }

        if (test_bit(HCI_UNCONFIGURED, &hdev->dev_flags)) {
                err = -EOPNOTSUPP;
                goto done;
        }

        if (hdev->dev_type != HCI_BREDR) {
                err = -EOPNOTSUPP;
                goto done;
        }

        if (!test_bit(HCI_BREDR_ENABLED, &hdev->dev_flags)) {
                err = -EOPNOTSUPP;
                goto done;
        }

        hci_dev_lock(hdev);
        if (inquiry_cache_age(hdev) > INQUIRY_CACHE_AGE_MAX ||
            inquiry_cache_empty(hdev) || ir.flags & IREQ_CACHE_FLUSH) {
                hci_inquiry_cache_flush(hdev);
                do_inquiry = 1;
        }
        hci_dev_unlock(hdev);

        timeo = ir.length * msecs_to_jiffies(2000);

        if (do_inquiry) {
                err = hci_req_sync(hdev, hci_inq_req, (unsigned long) &ir,
                                   timeo);
                if (err < 0)
                        goto done;

                /* Wait until Inquiry procedure finishes (HCI_INQUIRY flag is
                 * cleared). If it is interrupted by a signal, return -EINTR.
                 */
                if (wait_on_bit(&hdev->flags, HCI_INQUIRY,
                                TASK_INTERRUPTIBLE))
                        return -EINTR;
        }

        /* for unlimited number of responses we will use buffer with
         * 255 entries
         */
        max_rsp = (ir.num_rsp == 0) ? 255 : ir.num_rsp;

        /* cache_dump can't sleep. Therefore we allocate temp buffer and then
         * copy it to the user space.
         */
        buf = kmalloc(sizeof(struct inquiry_info) * max_rsp, GFP_KERNEL);
        if (!buf) {
                err = -ENOMEM;
                goto done;
        }

        hci_dev_lock(hdev);
        ir.num_rsp = inquiry_cache_dump(hdev, max_rsp, buf);
        hci_dev_unlock(hdev);

        BT_DBG("num_rsp %d", ir.num_rsp);

        if (!copy_to_user(ptr, &ir, sizeof(ir))) {
                ptr += sizeof(ir);
                if (copy_to_user(ptr, buf, sizeof(struct inquiry_info) *
                                 ir.num_rsp))
                        err = -EFAULT;
        } else
                err = -EFAULT;

        kfree(buf);

done:
        hci_dev_put(hdev);
        return err;
}

static int hci_dev_do_open(struct hci_dev *hdev)
{
        int ret = 0;

        BT_DBG("%s %p", hdev->name, hdev);

        hci_req_lock(hdev);

        if (test_bit(HCI_UNREGISTER, &hdev->dev_flags)) {
                ret = -ENODEV;
                goto done;
        }

        if (!test_bit(HCI_SETUP, &hdev->dev_flags) &&
            !test_bit(HCI_CONFIG, &hdev->dev_flags)) {
                /* Check for rfkill but allow the HCI setup stage to
                 * proceed (which in itself doesn't cause any RF activity).
                 */
                if (test_bit(HCI_RFKILLED, &hdev->dev_flags)) {
                        ret = -ERFKILL;
                        goto done;
                }

                /* Check for valid public address or a configured static
                 * random adddress, but let the HCI setup proceed to
                 * be able to determine if there is a public address
                 * or not.
                 *
                 * In case of user channel usage, it is not important
                 * if a public address or static random address is
                 * available.
                 *
                 * This check is only valid for BR/EDR controllers
                 * since AMP controllers do not have an address.
                 */
                if (!test_bit(HCI_USER_CHANNEL, &hdev->dev_flags) &&
                    hdev->dev_type == HCI_BREDR &&
                    !bacmp(&hdev->bdaddr, BDADDR_ANY) &&
                    !bacmp(&hdev->static_addr, BDADDR_ANY)) {
                        ret = -EADDRNOTAVAIL;
                        goto done;
                }
        }

        if (test_bit(HCI_UP, &hdev->flags)) {
                ret = -EALREADY;
                goto done;
        }

        if (hdev->open(hdev)) {
                ret = -EIO;
                goto done;
        }

        atomic_set(&hdev->cmd_cnt, 1);
        set_bit(HCI_INIT, &hdev->flags);

        if (test_bit(HCI_SETUP, &hdev->dev_flags)) {
                if (hdev->setup)
                        ret = hdev->setup(hdev);

                /* The transport driver can set these quirks before
                 * creating the HCI device or in its setup callback.
                 *
                 * In case any of them is set, the controller has to
                 * start up as unconfigured.
                 */
                if (test_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks) ||
                    test_bit(HCI_QUIRK_INVALID_BDADDR, &hdev->quirks))
                        set_bit(HCI_UNCONFIGURED, &hdev->dev_flags);

                /* For an unconfigured controller it is required to
                 * read at least the version information provided by
                 * the Read Local Version Information command.
                 *
                 * If the set_bdaddr driver callback is provided, then
                 * also the original Bluetooth public device address
                 * will be read using the Read BD Address command.
                 */
                if (test_bit(HCI_UNCONFIGURED, &hdev->dev_flags))
                        ret = __hci_unconf_init(hdev);
        }

        if (test_bit(HCI_CONFIG, &hdev->dev_flags)) {
                /* If public address change is configured, ensure that
                 * the address gets programmed. If the driver does not
                 * support changing the public address, fail the power
                 * on procedure.
                 */
                if (bacmp(&hdev->public_addr, BDADDR_ANY) &&
                    hdev->set_bdaddr)
                        ret = hdev->set_bdaddr(hdev, &hdev->public_addr);
                else
                        ret = -EADDRNOTAVAIL;
        }

        if (!ret) {
                if (!test_bit(HCI_UNCONFIGURED, &hdev->dev_flags) &&
                    !test_bit(HCI_USER_CHANNEL, &hdev->dev_flags))
                        ret = __hci_init(hdev);
        }

        clear_bit(HCI_INIT, &hdev->flags);

        if (!ret) {
                hci_dev_hold(hdev);
                set_bit(HCI_RPA_EXPIRED, &hdev->dev_flags);
                set_bit(HCI_UP, &hdev->flags);
                hci_notify(hdev, HCI_DEV_UP);
                if (!test_bit(HCI_SETUP, &hdev->dev_flags) &&
                    !test_bit(HCI_CONFIG, &hdev->dev_flags) &&
                    !test_bit(HCI_UNCONFIGURED, &hdev->dev_flags) &&
                    !test_bit(HCI_USER_CHANNEL, &hdev->dev_flags) &&
                    hdev->dev_type == HCI_BREDR) {
                        hci_dev_lock(hdev);
                        mgmt_powered(hdev, 1);
                        hci_dev_unlock(hdev);
                }
        } else {
                /* Init failed, cleanup */
                flush_work(&hdev->tx_work);
                flush_work(&hdev->cmd_work);
                flush_work(&hdev->rx_work);

                skb_queue_purge(&hdev->cmd_q);
                skb_queue_purge(&hdev->rx_q);

                if (hdev->flush)
                        hdev->flush(hdev);

                if (hdev->sent_cmd) {
                        kfree_skb(hdev->sent_cmd);
                        hdev->sent_cmd = NULL;
                }

                hdev->close(hdev);
                hdev->flags &= BIT(HCI_RAW);
        }

done:
        hci_req_unlock(hdev);
        return ret;
}

/* ---- HCI ioctl helpers ---- */

int hci_dev_open(__u16 dev)
{
        struct hci_dev *hdev;
        int err;

        hdev = hci_dev_get(dev);
        if (!hdev)
                return -ENODEV;

        /* Devices that are marked as unconfigured can only be powered
         * up as user channel. Trying to bring them up as normal devices
         * will result into a failure. Only user channel operation is
         * possible.
         *
         * When this function is called for a user channel, the flag
         * HCI_USER_CHANNEL will be set first before attempting to
         * open the device.
         */
        if (test_bit(HCI_UNCONFIGURED, &hdev->dev_flags) &&
            !test_bit(HCI_USER_CHANNEL, &hdev->dev_flags)) {
                err = -EOPNOTSUPP;
                goto done;
        }

        /* We need to ensure that no other power on/off work is pending
         * before proceeding to call hci_dev_do_open. This is
         * particularly important if the setup procedure has not yet
         * completed.
         */
        if (test_and_clear_bit(HCI_AUTO_OFF, &hdev->dev_flags))
                cancel_delayed_work(&hdev->power_off);

        /* After this call it is guaranteed that the setup procedure
         * has finished. This means that error conditions like RFKILL
         * or no valid public or static random address apply.
         */
        flush_workqueue(hdev->req_workqueue);

        /* For controllers not using the management interface and that
         * are brought up using legacy ioctl, set the HCI_BONDABLE bit
         * so that pairing works for them. Once the management interface
         * is in use this bit will be cleared again and userspace has
         * to explicitly enable it.
         */
        if (!test_bit(HCI_USER_CHANNEL, &hdev->dev_flags) &&
            !test_bit(HCI_MGMT, &hdev->dev_flags))
                set_bit(HCI_BONDABLE, &hdev->dev_flags);

        err = hci_dev_do_open(hdev);

done:
        hci_dev_put(hdev);
        return err;
}

/* This function requires the caller holds hdev->lock */
static void hci_pend_le_actions_clear(struct hci_dev *hdev)
{
        struct hci_conn_params *p;

        list_for_each_entry(p, &hdev->le_conn_params, list)
                list_del_init(&p->action);

        BT_DBG("All LE pending actions cleared");
}

static int hci_dev_do_close(struct hci_dev *hdev)
{
        BT_DBG("%s %p", hdev->name, hdev);

        cancel_delayed_work(&hdev->power_off);

        hci_req_cancel(hdev, ENODEV);
        hci_req_lock(hdev);

        if (!test_and_clear_bit(HCI_UP, &hdev->flags)) {
                cancel_delayed_work_sync(&hdev->cmd_timer);
                hci_req_unlock(hdev);
                return 0;
        }

        /* Flush RX and TX works */
        flush_work(&hdev->tx_work);
        flush_work(&hdev->rx_work);

        if (hdev->discov_timeout > 0) {
                cancel_delayed_work(&hdev->discov_off);
                hdev->discov_timeout = 0;
                clear_bit(HCI_DISCOVERABLE, &hdev->dev_flags);
                clear_bit(HCI_LIMITED_DISCOVERABLE, &hdev->dev_flags);
        }

        if (test_and_clear_bit(HCI_SERVICE_CACHE, &hdev->dev_flags))
                cancel_delayed_work(&hdev->service_cache);

        cancel_delayed_work_sync(&hdev->le_scan_disable);

        if (test_bit(HCI_MGMT, &hdev->dev_flags))
                cancel_delayed_work_sync(&hdev->rpa_expired);

        hci_dev_lock(hdev);
        hci_inquiry_cache_flush(hdev);
        hci_conn_hash_flush(hdev);
        hci_pend_le_actions_clear(hdev);
        hci_dev_unlock(hdev);

        hci_notify(hdev, HCI_DEV_DOWN);

        if (hdev->flush)
                hdev->flush(hdev);

        /* Reset device */
        skb_queue_purge(&hdev->cmd_q);
        atomic_set(&hdev->cmd_cnt, 1);
        if (!test_bit(HCI_AUTO_OFF, &hdev->dev_flags) &&
            !test_bit(HCI_UNCONFIGURED, &hdev->dev_flags) &&
            test_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks)) {
                set_bit(HCI_INIT, &hdev->flags);
                __hci_req_sync(hdev, hci_reset_req, 0, HCI_CMD_TIMEOUT);
                clear_bit(HCI_INIT, &hdev->flags);
        }

        /* flush cmd  work */
        flush_work(&hdev->cmd_work);

        /* Drop queues */
        skb_queue_purge(&hdev->rx_q);
        skb_queue_purge(&hdev->cmd_q);
        skb_queue_purge(&hdev->raw_q);

        /* Drop last sent command */
        if (hdev->sent_cmd) {
                cancel_delayed_work_sync(&hdev->cmd_timer);
                kfree_skb(hdev->sent_cmd);
                hdev->sent_cmd = NULL;
        }

        kfree_skb(hdev->recv_evt);
        hdev->recv_evt = NULL;

        /* After this point our queues are empty
         * and no tasks are scheduled. */
        hdev->close(hdev);

        /* Clear flags */
        hdev->flags &= BIT(HCI_RAW);
        hdev->dev_flags &= ~HCI_PERSISTENT_MASK;

        if (!test_and_clear_bit(HCI_AUTO_OFF, &hdev->dev_flags)) {
                if (hdev->dev_type == HCI_BREDR) {
                        hci_dev_lock(hdev);
                        mgmt_powered(hdev, 0);
                        hci_dev_unlock(hdev);
                }
        }

        /* Controller radio is available but is currently powered down */
        hdev->amp_status = AMP_STATUS_POWERED_DOWN;

        memset(hdev->eir, 0, sizeof(hdev->eir));
        memset(hdev->dev_class, 0, sizeof(hdev->dev_class));
        bacpy(&hdev->random_addr, BDADDR_ANY);

        hci_req_unlock(hdev);

        hci_dev_put(hdev);
        return 0;
}

int hci_dev_close(__u16 dev)
{
        struct hci_dev *hdev;
        int err;

        hdev = hci_dev_get(dev);
        if (!hdev)
                return -ENODEV;

        if (test_bit(HCI_USER_CHANNEL, &hdev->dev_flags)) {
                err = -EBUSY;
                goto done;
        }

        if (test_and_clear_bit(HCI_AUTO_OFF, &hdev->dev_flags))
                cancel_delayed_work(&hdev->power_off);

        err = hci_dev_do_close(hdev);

done:
        hci_dev_put(hdev);
        return err;
}

int hci_dev_reset(__u16 dev)
{
        struct hci_dev *hdev;
        int ret = 0;

        hdev = hci_dev_get(dev);
        if (!hdev)
                return -ENODEV;

        hci_req_lock(hdev);

        if (!test_bit(HCI_UP, &hdev->flags)) {
                ret = -ENETDOWN;
                goto done;
        }

        if (test_bit(HCI_USER_CHANNEL, &hdev->dev_flags)) {
                ret = -EBUSY;
                goto done;
        }

        if (test_bit(HCI_UNCONFIGURED, &hdev->dev_flags)) {
                ret = -EOPNOTSUPP;
                goto done;
        }

        /* Drop queues */
        skb_queue_purge(&hdev->rx_q);
        skb_queue_purge(&hdev->cmd_q);

        hci_dev_lock(hdev);
        hci_inquiry_cache_flush(hdev);
        hci_conn_hash_flush(hdev);
        hci_dev_unlock(hdev);

        if (hdev->flush)
                hdev->flush(hdev);

        atomic_set(&hdev->cmd_cnt, 1);
        hdev->acl_cnt = 0; hdev->sco_cnt = 0; hdev->le_cnt = 0;

        ret = __hci_req_sync(hdev, hci_reset_req, 0, HCI_INIT_TIMEOUT);

done:
        hci_req_unlock(hdev);
        hci_dev_put(hdev);
        return ret;
}

int hci_dev_reset_stat(__u16 dev)
{
        struct hci_dev *hdev;
        int ret = 0;

        hdev = hci_dev_get(dev);
        if (!hdev)
                return -ENODEV;

        if (test_bit(HCI_USER_CHANNEL, &hdev->dev_flags)) {
                ret = -EBUSY;
                goto done;
        }

        if (test_bit(HCI_UNCONFIGURED, &hdev->dev_flags)) {
                ret = -EOPNOTSUPP;
                goto done;
        }

        memset(&hdev->stat, 0, sizeof(struct hci_dev_stats));

done:
        hci_dev_put(hdev);
        return ret;
}

static void hci_update_scan_state(struct hci_dev *hdev, u8 scan)
{
        bool conn_changed, discov_changed;

        BT_DBG("%s scan 0x%02x", hdev->name, scan);

        if ((scan & SCAN_PAGE))
                conn_changed = !test_and_set_bit(HCI_CONNECTABLE,
                                                 &hdev->dev_flags);
        else
                conn_changed = test_and_clear_bit(HCI_CONNECTABLE,
                                                  &hdev->dev_flags);

        if ((scan & SCAN_INQUIRY)) {
                discov_changed = !test_and_set_bit(HCI_DISCOVERABLE,
                                                   &hdev->dev_flags);
        } else {
                clear_bit(HCI_LIMITED_DISCOVERABLE, &hdev->dev_flags);
                discov_changed = test_and_clear_bit(HCI_DISCOVERABLE,
                                                    &hdev->dev_flags);
        }

        if (!test_bit(HCI_MGMT, &hdev->dev_flags))
                return;

        if (conn_changed || discov_changed) {
                /* In case this was disabled through mgmt */
                set_bit(HCI_BREDR_ENABLED, &hdev->dev_flags);

                if (test_bit(HCI_LE_ENABLED, &hdev->dev_flags))
                        mgmt_update_adv_data(hdev);

                mgmt_new_settings(hdev);
        }
}

int hci_dev_cmd(unsigned int cmd, void __user *arg)
{
        struct hci_dev *hdev;
        struct hci_dev_req dr;
        int err = 0;

        if (copy_from_user(&dr, arg, sizeof(dr)))
                return -EFAULT;

        hdev = hci_dev_get(dr.dev_id);
        if (!hdev)
                return -ENODEV;

        if (test_bit(HCI_USER_CHANNEL, &hdev->dev_flags)) {
                err = -EBUSY;
                goto done;
        }

        if (test_bit(HCI_UNCONFIGURED, &hdev->dev_flags)) {
                err = -EOPNOTSUPP;
                goto done;
        }

        if (hdev->dev_type != HCI_BREDR) {
                err = -EOPNOTSUPP;
                goto done;
        }

        if (!test_bit(HCI_BREDR_ENABLED, &hdev->dev_flags)) {
                err = -EOPNOTSUPP;
                goto done;
        }

        switch (cmd) {
        case HCISETAUTH:
                err = hci_req_sync(hdev, hci_auth_req, dr.dev_opt,
                                   HCI_INIT_TIMEOUT);
                break;

        case HCISETENCRYPT:
                if (!lmp_encrypt_capable(hdev)) {
                        err = -EOPNOTSUPP;
                        break;
                }

                if (!test_bit(HCI_AUTH, &hdev->flags)) {
                        /* Auth must be enabled first */
                        err = hci_req_sync(hdev, hci_auth_req, dr.dev_opt,
                                           HCI_INIT_TIMEOUT);
                        if (err)
                                break;
                }

                err = hci_req_sync(hdev, hci_encrypt_req, dr.dev_opt,
                                   HCI_INIT_TIMEOUT);
                break;

        case HCISETSCAN:
                err = hci_req_sync(hdev, hci_scan_req, dr.dev_opt,
                                   HCI_INIT_TIMEOUT);

                /* Ensure that the connectable and discoverable states
                 * get correctly modified as this was a non-mgmt change.
                 */
                if (!err)
                        hci_update_scan_state(hdev, dr.dev_opt);
                break;

        case HCISETLINKPOL:
                err = hci_req_sync(hdev, hci_linkpol_req, dr.dev_opt,
                                   HCI_INIT_TIMEOUT);
                break;

        case HCISETLINKMODE:
                hdev->link_mode = ((__u16) dr.dev_opt) &
                                        (HCI_LM_MASTER | HCI_LM_ACCEPT);
                break;

        case HCISETPTYPE:
                hdev->pkt_type = (__u16) dr.dev_opt;
                break;

        case HCISETACLMTU:
                hdev->acl_mtu  = *((__u16 *) &dr.dev_opt + 1);
                hdev->acl_pkts = *((__u16 *) &dr.dev_opt + 0);
                break;

        case HCISETSCOMTU:
                hdev->sco_mtu  = *((__u16 *) &dr.dev_opt + 1);
                hdev->sco_pkts = *((__u16 *) &dr.dev_opt + 0);
                break;

        default:
                err = -EINVAL;
                break;
        }

done:
        hci_dev_put(hdev);
        return err;
}

int hci_get_dev_list(void __user *arg)
{
        struct hci_dev *hdev;
        struct hci_dev_list_req *dl;
        struct hci_dev_req *dr;
        int n = 0, size, err;
        __u16 dev_num;

        if (get_user(dev_num, (__u16 __user *) arg))
                return -EFAULT;

        if (!dev_num || dev_num > (PAGE_SIZE * 2) / sizeof(*dr))
                return -EINVAL;

        size = sizeof(*dl) + dev_num * sizeof(*dr);

        dl = kzalloc(size, GFP_KERNEL);
        if (!dl)
                return -ENOMEM;

        dr = dl->dev_req;

        read_lock(&hci_dev_list_lock);
        list_for_each_entry(hdev, &hci_dev_list, list) {
                unsigned long flags = hdev->flags;

                /* When the auto-off is configured it means the transport
                 * is running, but in that case still indicate that the
                 * device is actually down.
                 */
                if (test_bit(HCI_AUTO_OFF, &hdev->dev_flags))
                        flags &= ~BIT(HCI_UP);

                (dr + n)->dev_id  = hdev->id;
                (dr + n)->dev_opt = flags;

                if (++n >= dev_num)
                        break;
        }
        read_unlock(&hci_dev_list_lock);

        dl->dev_num = n;
        size = sizeof(*dl) + n * sizeof(*dr);

        err = copy_to_user(arg, dl, size);
        kfree(dl);

        return err ? -EFAULT : 0;
}

int hci_get_dev_info(void __user *arg)
{
        struct hci_dev *hdev;
        struct hci_dev_info di;
        unsigned long flags;
        int err = 0;

        if (copy_from_user(&di, arg, sizeof(di)))
                return -EFAULT;

        hdev = hci_dev_get(di.dev_id);
        if (!hdev)
                return -ENODEV;

        /* When the auto-off is configured it means the transport
         * is running, but in that case still indicate that the
         * device is actually down.
         */
        if (test_bit(HCI_AUTO_OFF, &hdev->dev_flags))
                flags = hdev->flags & ~BIT(HCI_UP);
        else
                flags = hdev->flags;

        strcpy(di.name, hdev->name);
        di.bdaddr   = hdev->bdaddr;
        di.type     = (hdev->bus & 0x0f) | ((hdev->dev_type & 0x03) << 4);
        di.flags    = flags;
        di.pkt_type = hdev->pkt_type;
        if (lmp_bredr_capable(hdev)) {
                di.acl_mtu  = hdev->acl_mtu;
                di.acl_pkts = hdev->acl_pkts;
                di.sco_mtu  = hdev->sco_mtu;
                di.sco_pkts = hdev->sco_pkts;
        } else {
                di.acl_mtu  = hdev->le_mtu;
                di.acl_pkts = hdev->le_pkts;
                di.sco_mtu  = 0;
                di.sco_pkts = 0;
        }
        di.link_policy = hdev->link_policy;
        di.link_mode   = hdev->link_mode;

        memcpy(&di.stat, &hdev->stat, sizeof(di.stat));
        memcpy(&di.features, &hdev->features, sizeof(di.features));

        if (copy_to_user(arg, &di, sizeof(di)))
                err = -EFAULT;

        hci_dev_put(hdev);

        return err;
}

/* ---- Interface to HCI drivers ---- */

static int hci_rfkill_set_block(void *data, bool blocked)
{
        struct hci_dev *hdev = data;

        BT_DBG("%p name %s blocked %d", hdev, hdev->name, blocked);

        if (test_bit(HCI_USER_CHANNEL, &hdev->dev_flags))
                return -EBUSY;

        if (blocked) {
                set_bit(HCI_RFKILLED, &hdev->dev_flags);
                if (!test_bit(HCI_SETUP, &hdev->dev_flags) &&
                    !test_bit(HCI_CONFIG, &hdev->dev_flags))
                        hci_dev_do_close(hdev);
        } else {
                clear_bit(HCI_RFKILLED, &hdev->dev_flags);
        }

        return 0;
}

static const struct rfkill_ops hci_rfkill_ops = {
        .set_block = hci_rfkill_set_block,
};

static void hci_power_on(struct work_struct *work)
{
        struct hci_dev *hdev = container_of(work, struct hci_dev, power_on);
        int err;

        BT_DBG("%s", hdev->name);

        err = hci_dev_do_open(hdev);
        if (err < 0) {
                mgmt_set_powered_failed(hdev, err);
                return;
        }

        /* During the HCI setup phase, a few error conditions are
         * ignored and they need to be checked now. If they are still
         * valid, it is important to turn the device back off.
         */
        if (test_bit(HCI_RFKILLED, &hdev->dev_flags) ||
            test_bit(HCI_UNCONFIGURED, &hdev->dev_flags) ||
            (hdev->dev_type == HCI_BREDR &&
             !bacmp(&hdev->bdaddr, BDADDR_ANY) &&
             !bacmp(&hdev->static_addr, BDADDR_ANY))) {
                clear_bit(HCI_AUTO_OFF, &hdev->dev_flags);
                hci_dev_do_close(hdev);
        } else if (test_bit(HCI_AUTO_OFF, &hdev->dev_flags)) {
                queue_delayed_work(hdev->req_workqueue, &hdev->power_off,
                                   HCI_AUTO_OFF_TIMEOUT);
        }

        if (test_and_clear_bit(HCI_SETUP, &hdev->dev_flags)) {
                /* For unconfigured devices, set the HCI_RAW flag
                 * so that userspace can easily identify them.
                 */
                if (test_bit(HCI_UNCONFIGURED, &hdev->dev_flags))
                        set_bit(HCI_RAW, &hdev->flags);

                /* For fully configured devices, this will send
                 * the Index Added event. For unconfigured devices,
                 * it will send Unconfigued Index Added event.
                 *
                 * Devices with HCI_QUIRK_RAW_DEVICE are ignored
                 * and no event will be send.
                 */
                mgmt_index_added(hdev);
        } else if (test_and_clear_bit(HCI_CONFIG, &hdev->dev_flags)) {
                /* When the controller is now configured, then it
                 * is important to clear the HCI_RAW flag.
                 */
                if (!test_bit(HCI_UNCONFIGURED, &hdev->dev_flags))
                        clear_bit(HCI_RAW, &hdev->flags);

                /* Powering on the controller with HCI_CONFIG set only
                 * happens with the transition from unconfigured to
                 * configured. This will send the Index Added event.
                 */
                mgmt_index_added(hdev);
        }
}

static void hci_power_off(struct work_struct *work)
{
        struct hci_dev *hdev = container_of(work, struct hci_dev,
                                            power_off.work);

        BT_DBG("%s", hdev->name);

        hci_dev_do_close(hdev);
}

static void hci_discov_off(struct work_struct *work)
{
        struct hci_dev *hdev;

        hdev = container_of(work, struct hci_dev, discov_off.work);

        BT_DBG("%s", hdev->name);

        mgmt_discoverable_timeout(hdev);
}

void hci_uuids_clear(struct hci_dev *hdev)
{
        struct bt_uuid *uuid, *tmp;

        list_for_each_entry_safe(uuid, tmp, &hdev->uuids, list) {
                list_del(&uuid->list);
                kfree(uuid);
        }
}

void hci_link_keys_clear(struct hci_dev *hdev)
{
        struct list_head *p, *n;

        list_for_each_safe(p, n, &hdev->link_keys) {
                struct link_key *key;

                key = list_entry(p, struct link_key, list);

                list_del(p);
                kfree(key);
        }
}

void hci_smp_ltks_clear(struct hci_dev *hdev)
{
        struct smp_ltk *k, *tmp;

        list_for_each_entry_safe(k, tmp, &hdev->long_term_keys, list) {
                list_del(&k->list);
                kfree(k);
        }
}

void hci_smp_irks_clear(struct hci_dev *hdev)
{
        struct smp_irk *k, *tmp;

        list_for_each_entry_safe(k, tmp, &hdev->identity_resolving_keys, list) {
                list_del(&k->list);
                kfree(k);
        }
}

struct link_key *hci_find_link_key(struct hci_dev *hdev, bdaddr_t *bdaddr)
{
        struct link_key *k;

        list_for_each_entry(k, &hdev->link_keys, list)
                if (bacmp(bdaddr, &k->bdaddr) == 0)
                        return k;

        return NULL;
}

static bool hci_persistent_key(struct hci_dev *hdev, struct hci_conn *conn,
                               u8 key_type, u8 old_key_type)
{
        /* Legacy key */
        if (key_type < 0x03)
                return true;

        /* Debug keys are insecure so don't store them persistently */
        if (key_type == HCI_LK_DEBUG_COMBINATION)
                return false;

        /* Changed combination key and there's no previous one */
        if (key_type == HCI_LK_CHANGED_COMBINATION && old_key_type == 0xff)
                return false;

        /* Security mode 3 case */
        if (!conn)
                return true;

        /* Neither local nor remote side had no-bonding as requirement */
        if (conn->auth_type > 0x01 && conn->remote_auth > 0x01)
                return true;

        /* Local side had dedicated bonding as requirement */
        if (conn->auth_type == 0x02 || conn->auth_type == 0x03)
                return true;

        /* Remote side had dedicated bonding as requirement */
        if (conn->remote_auth == 0x02 || conn->remote_auth == 0x03)
                return true;

        /* If none of the above criteria match, then don't store the key
         * persistently */
        return false;
}

static u8 ltk_role(u8 type)
{
        if (type == SMP_LTK)
                return HCI_ROLE_MASTER;

        return HCI_ROLE_SLAVE;
}

struct smp_ltk *hci_find_ltk(struct hci_dev *hdev, __le16 ediv, __le64 rand,
                             u8 role)
{
        struct smp_ltk *k;

        list_for_each_entry(k, &hdev->long_term_keys, list) {
                if (k->ediv != ediv || k->rand != rand)
                        continue;

                if (ltk_role(k->type) != role)
                        continue;

                return k;
        }

        return NULL;
}

struct smp_ltk *hci_find_ltk_by_addr(struct hci_dev *hdev, bdaddr_t *bdaddr,
                                     u8 addr_type, u8 role)
{
        struct smp_ltk *k;

        list_for_each_entry(k, &hdev->long_term_keys, list)
                if (addr_type == k->bdaddr_type &&
                    bacmp(bdaddr, &k->bdaddr) == 0 &&
                    ltk_role(k->type) == role)
                        return k;

        return NULL;
}

struct smp_irk *hci_find_irk_by_rpa(struct hci_dev *hdev, bdaddr_t *rpa)
{
        struct smp_irk *irk;

        list_for_each_entry(irk, &hdev->identity_resolving_keys, list) {
                if (!bacmp(&irk->rpa, rpa))
                        return irk;
        }

        list_for_each_entry(irk, &hdev->identity_resolving_keys, list) {
                if (smp_irk_matches(hdev->tfm_aes, irk->val, rpa)) {
                        bacpy(&irk->rpa, rpa);
                        return irk;
                }
        }

        return NULL;
}

struct smp_irk *hci_find_irk_by_addr(struct hci_dev *hdev, bdaddr_t *bdaddr,
                                     u8 addr_type)
{
        struct smp_irk *irk;

        /* Identity Address must be public or static random */
        if (addr_type == ADDR_LE_DEV_RANDOM && (bdaddr->b[5] & 0xc0) != 0xc0)
                return NULL;

        list_for_each_entry(irk, &hdev->identity_resolving_keys, list) {
                if (addr_type == irk->addr_type &&
                    bacmp(bdaddr, &irk->bdaddr) == 0)
                        return irk;
        }

        return NULL;
}

struct link_key *hci_add_link_key(struct hci_dev *hdev, struct hci_conn *conn,
                                  bdaddr_t *bdaddr, u8 *val, u8 type,
                                  u8 pin_len, bool *persistent)
{
        struct link_key *key, *old_key;
        u8 old_key_type;

        old_key = hci_find_link_key(hdev, bdaddr);
        if (old_key) {
                old_key_type = old_key->type;
                key = old_key;
        } else {
                old_key_type = conn ? conn->key_type : 0xff;
                key = kzalloc(sizeof(*key), GFP_KERNEL);
                if (!key)
                        return NULL;
                list_add(&key->list, &hdev->link_keys);
        }

        BT_DBG("%s key for %pMR type %u", hdev->name, bdaddr, type);

        /* Some buggy controller combinations generate a changed
         * combination key for legacy pairing even when there's no
         * previous key */
        if (type == HCI_LK_CHANGED_COMBINATION &&
            (!conn || conn->remote_auth == 0xff) && old_key_type == 0xff) {
                type = HCI_LK_COMBINATION;
                if (conn)
                        conn->key_type = type;
        }

        bacpy(&key->bdaddr, bdaddr);
        memcpy(key->val, val, HCI_LINK_KEY_SIZE);
        key->pin_len = pin_len;

        if (type == HCI_LK_CHANGED_COMBINATION)
                key->type = old_key_type;
        else
                key->type = type;

        if (persistent)
                *persistent = hci_persistent_key(hdev, conn, type,
                                                 old_key_type);

        return key;
}

struct smp_ltk *hci_add_ltk(struct hci_dev *hdev, bdaddr_t *bdaddr,
                            u8 addr_type, u8 type, u8 authenticated,
                            u8 tk[16], u8 enc_size, __le16 ediv, __le64 rand)
{
        struct smp_ltk *key, *old_key;
        u8 role = ltk_role(type);

        old_key = hci_find_ltk_by_addr(hdev, bdaddr, addr_type, role);
        if (old_key)
                key = old_key;
        else {
                key = kzalloc(sizeof(*key), GFP_KERNEL);
                if (!key)
                        return NULL;
                list_add(&key->list, &hdev->long_term_keys);
        }

        bacpy(&key->bdaddr, bdaddr);
        key->bdaddr_type = addr_type;
        memcpy(key->val, tk, sizeof(key->val));
        key->authenticated = authenticated;
        key->ediv = ediv;
        key->rand = rand;
        key->enc_size = enc_size;
        key->type = type;

        return key;
}

struct smp_irk *hci_add_irk(struct hci_dev *hdev, bdaddr_t *bdaddr,
                            u8 addr_type, u8 val[16], bdaddr_t *rpa)
{
        struct smp_irk *irk;

        irk = hci_find_irk_by_addr(hdev, bdaddr, addr_type);
        if (!irk) {
                irk = kzalloc(sizeof(*irk), GFP_KERNEL);
                if (!irk)
                        return NULL;

                bacpy(&irk->bdaddr, bdaddr);
                irk->addr_type = addr_type;

                list_add(&irk->list, &hdev->identity_resolving_keys);
        }

        memcpy(irk->val, val, 16);
        bacpy(&irk->rpa, rpa);

        return irk;
}

int hci_remove_link_key(struct hci_dev *hdev, bdaddr_t *bdaddr)
{
        struct link_key *key;

        key = hci_find_link_key(hdev, bdaddr);
        if (!key)
                return -ENOENT;

        BT_DBG("%s removing %pMR", hdev->name, bdaddr);

        list_del(&key->list);
        kfree(key);

        return 0;
}

int hci_remove_ltk(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 bdaddr_type)
{
        struct smp_ltk *k, *tmp;
        int removed = 0;

        list_for_each_entry_safe(k, tmp, &hdev->long_term_keys, list) {
                if (bacmp(bdaddr, &k->bdaddr) || k->bdaddr_type != bdaddr_type)
                        continue;

                BT_DBG("%s removing %pMR", hdev->name, bdaddr);

                list_del(&k->list);
                kfree(k);
                removed++;
        }

        return removed ? 0 : -ENOENT;
}

void hci_remove_irk(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 addr_type)
{
        struct smp_irk *k, *tmp;

        list_for_each_entry_safe(k, tmp, &hdev->identity_resolving_keys, list) {
                if (bacmp(bdaddr, &k->bdaddr) || k->addr_type != addr_type)
                        continue;

                BT_DBG("%s removing %pMR", hdev->name, bdaddr);

                list_del(&k->list);
                kfree(k);
        }
}

/* HCI command timer function */
static void hci_cmd_timeout(struct work_struct *work)
{
        struct hci_dev *hdev = container_of(work, struct hci_dev,
                                            cmd_timer.work);

        if (hdev->sent_cmd) {
                struct hci_command_hdr *sent = (void *) hdev->sent_cmd->data;
                u16 opcode = __le16_to_cpu(sent->opcode);

                BT_ERR("%s command 0x%4.4x tx timeout", hdev->name, opcode);
        } else {
                BT_ERR("%s command tx timeout", hdev->name);
        }

        atomic_set(&hdev->cmd_cnt, 1);
        queue_work(hdev->workqueue, &hdev->cmd_work);
}

struct oob_data *hci_find_remote_oob_data(struct hci_dev *hdev,
                                          bdaddr_t *bdaddr)
{
        struct oob_data *data;

        list_for_each_entry(data, &hdev->remote_oob_data, list)
                if (bacmp(bdaddr, &data->bdaddr) == 0)
                        return data;

        return NULL;
}

int hci_remove_remote_oob_data(struct hci_dev *hdev, bdaddr_t *bdaddr)
{
        struct oob_data *data;

        data = hci_find_remote_oob_data(hdev, bdaddr);
        if (!data)
                return -ENOENT;

        BT_DBG("%s removing %pMR", hdev->name, bdaddr);

        list_del(&data->list);
        kfree(data);

        return 0;
}

void hci_remote_oob_data_clear(struct hci_dev *hdev)
{
        struct oob_data *data, *n;

        list_for_each_entry_safe(data, n, &hdev->remote_oob_data, list) {
                list_del(&data->list);
                kfree(data);
        }
}

int hci_add_remote_oob_data(struct hci_dev *hdev, bdaddr_t *bdaddr,
                            u8 *hash, u8 *randomizer)
{
        struct oob_data *data;

        data = hci_find_remote_oob_data(hdev, bdaddr);
        if (!data) {
                data = kmalloc(sizeof(*data), GFP_KERNEL);
                if (!data)
                        return -ENOMEM;

                bacpy(&data->bdaddr, bdaddr);
                list_add(&data->list, &hdev->remote_oob_data);
        }

        memcpy(data->hash192, hash, sizeof(data->hash192));
        memcpy(data->randomizer192, randomizer, sizeof(data->randomizer192));

        memset(data->hash256, 0, sizeof(data->hash256));
        memset(data->randomizer256, 0, sizeof(data->randomizer256));

        BT_DBG("%s for %pMR", hdev->name, bdaddr);

        return 0;
}

int hci_add_remote_oob_ext_data(struct hci_dev *hdev, bdaddr_t *bdaddr,
                                u8 *hash192, u8 *randomizer192,
                                u8 *hash256, u8 *randomizer256)
{
        struct oob_data *data;

        data = hci_find_remote_oob_data(hdev, bdaddr);
        if (!data) {
                data = kmalloc(sizeof(*data), GFP_KERNEL);
                if (!data)
                        return -ENOMEM;

                bacpy(&data->bdaddr, bdaddr);
                list_add(&data->list, &hdev->remote_oob_data);
        }

        memcpy(data->hash192, hash192, sizeof(data->hash192));
        memcpy(data->randomizer192, randomizer192, sizeof(data->randomizer192));

        memcpy(data->hash256, hash256, sizeof(data->hash256));
        memcpy(data->randomizer256, randomizer256, sizeof(data->randomizer256));

        BT_DBG("%s for %pMR", hdev->name, bdaddr);

        return 0;
}

struct bdaddr_list *hci_bdaddr_list_lookup(struct list_head *bdaddr_list,
                                         bdaddr_t *bdaddr, u8 type)
{
        struct bdaddr_list *b;

        list_for_each_entry(b, bdaddr_list, list) {
                if (!bacmp(&b->bdaddr, bdaddr) && b->bdaddr_type == type)
                        return b;
        }

        return NULL;
}

void hci_bdaddr_list_clear(struct list_head *bdaddr_list)
{
        struct list_head *p, *n;

        list_for_each_safe(p, n, bdaddr_list) {
                struct bdaddr_list *b = list_entry(p, struct bdaddr_list, list);

                list_del(p);
                kfree(b);
        }
}

int hci_bdaddr_list_add(struct list_head *list, bdaddr_t *bdaddr, u8 type)
{
        struct bdaddr_list *entry;

        if (!bacmp(bdaddr, BDADDR_ANY))
                return -EBADF;

        if (hci_bdaddr_list_lookup(list, bdaddr, type))
                return -EEXIST;

        entry = kzalloc(sizeof(*entry), GFP_KERNEL);
        if (!entry)
                return -ENOMEM;

        bacpy(&entry->bdaddr, bdaddr);
        entry->bdaddr_type = type;

        list_add(&entry->list, list);

        return 0;
}

int hci_bdaddr_list_del(struct list_head *list, bdaddr_t *bdaddr, u8 type)
{
        struct bdaddr_list *entry;

        if (!bacmp(bdaddr, BDADDR_ANY)) {
                hci_bdaddr_list_clear(list);
                return 0;
        }

        entry = hci_bdaddr_list_lookup(list, bdaddr, type);
        if (!entry)
                return -ENOENT;

        list_del(&entry->list);
        kfree(entry);

        return 0;
}

/* This function requires the caller holds hdev->lock */
struct hci_conn_params *hci_conn_params_lookup(struct hci_dev *hdev,
                                               bdaddr_t *addr, u8 addr_type)
{
        struct hci_conn_params *params;

        /* The conn params list only contains identity addresses */
        if (!hci_is_identity_address(addr, addr_type))
                return NULL;

        list_for_each_entry(params, &hdev->le_conn_params, list) {
                if (bacmp(&params->addr, addr) == 0 &&
                    params->addr_type == addr_type) {
                        return params;
                }
        }

        return NULL;
}

static bool is_connected(struct hci_dev *hdev, bdaddr_t *addr, u8 type)
{
        struct hci_conn *conn;

        conn = hci_conn_hash_lookup_ba(hdev, LE_LINK, addr);
        if (!conn)
                return false;

        if (conn->dst_type != type)
                return false;

        if (conn->state != BT_CONNECTED)
                return false;

        return true;
}

/* This function requires the caller holds hdev->lock */
struct hci_conn_params *hci_pend_le_action_lookup(struct list_head *list,
                                                  bdaddr_t *addr, u8 addr_type)
{
        struct hci_conn_params *param;

        /* The list only contains identity addresses */
        if (!hci_is_identity_address(addr, addr_type))
                return NULL;

        list_for_each_entry(param, list, action) {
                if (bacmp(&param->addr, addr) == 0 &&
                    param->addr_type == addr_type)
                        return param;
        }

        return NULL;
}

/* This function requires the caller holds hdev->lock */
struct hci_conn_params *hci_conn_params_add(struct hci_dev *hdev,
                                            bdaddr_t *addr, u8 addr_type)
{
        struct hci_conn_params *params;

        if (!hci_is_identity_address(addr, addr_type))
                return NULL;

        params = hci_conn_params_lookup(hdev, addr, addr_type);
        if (params)
                return params;

        params = kzalloc(sizeof(*params), GFP_KERNEL);
        if (!params) {
                BT_ERR("Out of memory");
                return NULL;
        }

        bacpy(&params->addr, addr);
        params->addr_type = addr_type;

        list_add(&params->list, &hdev->le_conn_params);
        INIT_LIST_HEAD(&params->action);

        params->conn_min_interval = hdev->le_conn_min_interval;
        params->conn_max_interval = hdev->le_conn_max_interval;
        params->conn_latency = hdev->le_conn_latency;
        params->supervision_timeout = hdev->le_supv_timeout;
        params->auto_connect = HCI_AUTO_CONN_DISABLED;

        BT_DBG("addr %pMR (type %u)", addr, addr_type);

        return params;
}

/* This function requires the caller holds hdev->lock */
int hci_conn_params_set(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
                        u8 auto_connect)
{
        struct hci_conn_params *params;

        params = hci_conn_params_add(hdev, addr, addr_type);
        if (!params)
                return -EIO;

        if (params->auto_connect == auto_connect)
                return 0;

        list_del_init(&params->action);

        switch (auto_connect) {
        case HCI_AUTO_CONN_DISABLED:
        case HCI_AUTO_CONN_LINK_LOSS:
                hci_update_background_scan(hdev);
                break;
        case HCI_AUTO_CONN_REPORT:
                list_add(&params->action, &hdev->pend_le_reports);
                hci_update_background_scan(hdev);
                break;
        case HCI_AUTO_CONN_DIRECT:
        case HCI_AUTO_CONN_ALWAYS:
                if (!is_connected(hdev, addr, addr_type)) {
                        list_add(&params->action, &hdev->pend_le_conns);
                        hci_update_background_scan(hdev);
                }
                break;
        }

        params->auto_connect = auto_connect;

        BT_DBG("addr %pMR (type %u) auto_connect %u", addr, addr_type,
               auto_connect);

        return 0;
}

/* This function requires the caller holds hdev->lock */
void hci_conn_params_del(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type)
{
        struct hci_conn_params *params;

        params = hci_conn_params_lookup(hdev, addr, addr_type);
        if (!params)
                return;

        list_del(&params->action);
        list_del(&params->list);
        kfree(params);

        hci_update_background_scan(hdev);

        BT_DBG("addr %pMR (type %u)", addr, addr_type);
}

/* This function requires the caller holds hdev->lock */
void hci_conn_params_clear_disabled(struct hci_dev *hdev)
{
        struct hci_conn_params *params, *tmp;

        list_for_each_entry_safe(params, tmp, &hdev->le_conn_params, list) {
                if (params->auto_connect != HCI_AUTO_CONN_DISABLED)
                        continue;
                list_del(&params->list);
                kfree(params);
        }

        BT_DBG("All LE disabled connection parameters were removed");
}

/* This function requires the caller holds hdev->lock */
void hci_conn_params_clear_all(struct hci_dev *hdev)
{
        struct hci_conn_params *params, *tmp;

        list_for_each_entry_safe(params, tmp, &hdev->le_conn_params, list) {
                list_del(&params->action);
                list_del(&params->list);
                kfree(params);
        }

        hci_update_background_scan(hdev);

        BT_DBG("All LE connection parameters were removed");
}

static void inquiry_complete(struct hci_dev *hdev, u8 status)
{
        if (status) {
                BT_ERR("Failed to start inquiry: status %d", status);

                hci_dev_lock(hdev);
                hci_discovery_set_state(hdev, DISCOVERY_STOPPED);
                hci_dev_unlock(hdev);
                return;
        }
}

static void le_scan_disable_work_complete(struct hci_dev *hdev, u8 status)
{
        /* General inquiry access code (GIAC) */
        u8 lap[3] = { 0x33, 0x8b, 0x9e };
        struct hci_request req;
        struct hci_cp_inquiry cp;
        int err;

        if (status) {
                BT_ERR("Failed to disable LE scanning: status %d", status);
                return;
        }

        switch (hdev->discovery.type) {
        case DISCOV_TYPE_LE:
                hci_dev_lock(hdev);
                hci_discovery_set_state(hdev, DISCOVERY_STOPPED);
                hci_dev_unlock(hdev);
                break;

        case DISCOV_TYPE_INTERLEAVED:
                hci_req_init(&req, hdev);

                memset(&cp, 0, sizeof(cp));
                memcpy(&cp.lap, lap, sizeof(cp.lap));
                cp.length = DISCOV_INTERLEAVED_INQUIRY_LEN;
                hci_req_add(&req, HCI_OP_INQUIRY, sizeof(cp), &cp);

                hci_dev_lock(hdev);

                hci_inquiry_cache_flush(hdev);

                err = hci_req_run(&req, inquiry_complete);
                if (err) {
                        BT_ERR("Inquiry request failed: err %d", err);
                        hci_discovery_set_state(hdev, DISCOVERY_STOPPED);
                }

                hci_dev_unlock(hdev);
                break;
        }
}

static void le_scan_disable_work(struct work_struct *work)
{
        struct hci_dev *hdev = container_of(work, struct hci_dev,
                                            le_scan_disable.work);
        struct hci_request req;
        int err;

        BT_DBG("%s", hdev->name);

        hci_req_init(&req, hdev);

        hci_req_add_le_scan_disable(&req);

        err = hci_req_run(&req, le_scan_disable_work_complete);
        if (err)
                BT_ERR("Disable LE scanning request failed: err %d", err);
}

static void set_random_addr(struct hci_request *req, bdaddr_t *rpa)
{
        struct hci_dev *hdev = req->hdev;

        /* If we're advertising or initiating an LE connection we can't
         * go ahead and change the random address at this time. This is
         * because the eventual initiator address used for the
         * subsequently created connection will be undefined (some
         * controllers use the new address and others the one we had
         * when the operation started).
         *
         * In this kind of scenario skip the update and let the random
         * address be updated at the next cycle.
         */
        if (test_bit(HCI_LE_ADV, &hdev->dev_flags) ||
            hci_conn_hash_lookup_state(hdev, LE_LINK, BT_CONNECT)) {
                BT_DBG("Deferring random address update");
                return;
        }

        hci_req_add(req, HCI_OP_LE_SET_RANDOM_ADDR, 6, rpa);
}

int hci_update_random_address(struct hci_request *req, bool require_privacy,
                              u8 *own_addr_type)
{
        struct hci_dev *hdev = req->hdev;
        int err;

        /* If privacy is enabled use a resolvable private address. If
         * current RPA has expired or there is something else than
         * the current RPA in use, then generate a new one.
         */
        if (test_bit(HCI_PRIVACY, &hdev->dev_flags)) {
                int to;

                *own_addr_type = ADDR_LE_DEV_RANDOM;

                if (!test_and_clear_bit(HCI_RPA_EXPIRED, &hdev->dev_flags) &&
                    !bacmp(&hdev->random_addr, &hdev->rpa))
                        return 0;

                err = smp_generate_rpa(hdev->tfm_aes, hdev->irk, &hdev->rpa);
                if (err < 0) {
                        BT_ERR("%s failed to generate new RPA", hdev->name);
                        return err;
                }

                set_random_addr(req, &hdev->rpa);

                to = msecs_to_jiffies(hdev->rpa_timeout * 1000);
                queue_delayed_work(hdev->workqueue, &hdev->rpa_expired, to);

                return 0;
        }

        /* In case of required privacy without resolvable private address,
         * use an unresolvable private address. This is useful for active
         * scanning and non-connectable advertising.
         */
        if (require_privacy) {
                bdaddr_t urpa;

                get_random_bytes(&urpa, 6);
                urpa.b[5] &= 0x3f;      /* Clear two most significant bits */

                *own_addr_type = ADDR_LE_DEV_RANDOM;
                set_random_addr(req, &urpa);
                return 0;
        }

        /* If forcing static address is in use or there is no public
         * address use the static address as random address (but skip
         * the HCI command if the current random address is already the
         * static one.
         */
        if (test_bit(HCI_FORCE_STATIC_ADDR, &hdev->dbg_flags) ||
            !bacmp(&hdev->bdaddr, BDADDR_ANY)) {
                *own_addr_type = ADDR_LE_DEV_RANDOM;
                if (bacmp(&hdev->static_addr, &hdev->random_addr))
                        hci_req_add(req, HCI_OP_LE_SET_RANDOM_ADDR, 6,
                                    &hdev->static_addr);
                return 0;
        }

        /* Neither privacy nor static address is being used so use a
         * public address.
         */
        *own_addr_type = ADDR_LE_DEV_PUBLIC;

        return 0;
}

/* Copy the Identity Address of the controller.
 *
 * If the controller has a public BD_ADDR, then by default use that one.
 * If this is a LE only controller without a public address, default to
 * the static random address.
 *
 * For debugging purposes it is possible to force controllers with a
 * public address to use the static random address instead.
 */
void hci_copy_identity_address(struct hci_dev *hdev, bdaddr_t *bdaddr,
                               u8 *bdaddr_type)
{
        if (test_bit(HCI_FORCE_STATIC_ADDR, &hdev->dbg_flags) ||
            !bacmp(&hdev->bdaddr, BDADDR_ANY)) {
                bacpy(bdaddr, &hdev->static_addr);
                *bdaddr_type = ADDR_LE_DEV_RANDOM;
        } else {
                bacpy(bdaddr, &hdev->bdaddr);
                *bdaddr_type = ADDR_LE_DEV_PUBLIC;
        }
}

/* Alloc HCI device */
struct hci_dev *hci_alloc_dev(void)
{
        struct hci_dev *hdev;

        hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
        if (!hdev)
                return NULL;

        hdev->pkt_type  = (HCI_DM1 | HCI_DH1 | HCI_HV1);
        hdev->esco_type = (ESCO_HV1);
        hdev->link_mode = (HCI_LM_ACCEPT);
        hdev->num_iac = 0x01;           /* One IAC support is mandatory */
        hdev->io_capability = 0x03;     /* No Input No Output */
        hdev->manufacturer = 0xffff;    /* Default to internal use */
        hdev->inq_tx_power = HCI_TX_POWER_INVALID;
        hdev->adv_tx_power = HCI_TX_POWER_INVALID;

        hdev->sniff_max_interval = 800;
        hdev->sniff_min_interval = 80;

        hdev->le_adv_channel_map = 0x07;
        hdev->le_adv_min_interval = 0x0800;
        hdev->le_adv_max_interval = 0x0800;
        hdev->le_scan_interval = 0x0060;
        hdev->le_scan_window = 0x0030;
        hdev->le_conn_min_interval = 0x0028;
        hdev->le_conn_max_interval = 0x0038;
        hdev->le_conn_latency = 0x0000;
        hdev->le_supv_timeout = 0x002a;

        hdev->rpa_timeout = HCI_DEFAULT_RPA_TIMEOUT;
        hdev->discov_interleaved_timeout = DISCOV_INTERLEAVED_TIMEOUT;
        hdev->conn_info_min_age = DEFAULT_CONN_INFO_MIN_AGE;
        hdev->conn_info_max_age = DEFAULT_CONN_INFO_MAX_AGE;

        mutex_init(&hdev->lock);
        mutex_init(&hdev->req_lock);

        INIT_LIST_HEAD(&hdev->mgmt_pending);
        INIT_LIST_HEAD(&hdev->blacklist);
        INIT_LIST_HEAD(&hdev->whitelist);
        INIT_LIST_HEAD(&hdev->uuids);
        INIT_LIST_HEAD(&hdev->link_keys);
        INIT_LIST_HEAD(&hdev->long_term_keys);
        INIT_LIST_HEAD(&hdev->identity_resolving_keys);
        INIT_LIST_HEAD(&hdev->remote_oob_data);
        INIT_LIST_HEAD(&hdev->le_white_list);
        INIT_LIST_HEAD(&hdev->le_conn_params);
        INIT_LIST_HEAD(&hdev->pend_le_conns);
        INIT_LIST_HEAD(&hdev->pend_le_reports);
        INIT_LIST_HEAD(&hdev->conn_hash.list);

        INIT_WORK(&hdev->rx_work, hci_rx_work);
        INIT_WORK(&hdev->cmd_work, hci_cmd_work);
        INIT_WORK(&hdev->tx_work, hci_tx_work);
        INIT_WORK(&hdev->power_on, hci_power_on);

        INIT_DELAYED_WORK(&hdev->power_off, hci_power_off);
        INIT_DELAYED_WORK(&hdev->discov_off, hci_discov_off);
        INIT_DELAYED_WORK(&hdev->le_scan_disable, le_scan_disable_work);

        skb_queue_head_init(&hdev->rx_q);
        skb_queue_head_init(&hdev->cmd_q);
        skb_queue_head_init(&hdev->raw_q);

        init_waitqueue_head(&hdev->req_wait_q);

        INIT_DELAYED_WORK(&hdev->cmd_timer, hci_cmd_timeout);

        hci_init_sysfs(hdev);
        discovery_init(hdev);

        return hdev;
}
EXPORT_SYMBOL(hci_alloc_dev);

/* Free HCI device */
void hci_free_dev(struct hci_dev *hdev)
{
        /* will free via device release */
        put_device(&hdev->dev);
}
EXPORT_SYMBOL(hci_free_dev);

/* Register HCI device */
int hci_register_dev(struct hci_dev *hdev)
{
        int id, error;

        if (!hdev->open || !hdev->close || !hdev->send)
                return -EINVAL;

        /* Do not allow HCI_AMP devices to register at index 0,
         * so the index can be used as the AMP controller ID.
         */
        switch (hdev->dev_type) {
        case HCI_BREDR:
                id = ida_simple_get(&hci_index_ida, 0, 0, GFP_KERNEL);
                break;
        case HCI_AMP:
                id = ida_simple_get(&hci_index_ida, 1, 0, GFP_KERNEL);
                break;
        default:
                return -EINVAL;
        }

        if (id < 0)
                return id;

        sprintf(hdev->name, "hci%d", id);
        hdev->id = id;

        BT_DBG("%p name %s bus %d", hdev, hdev->name, hdev->bus);

        hdev->workqueue = alloc_workqueue("%s", WQ_HIGHPRI | WQ_UNBOUND |
                                          WQ_MEM_RECLAIM, 1, hdev->name);
        if (!hdev->workqueue) {
                error = -ENOMEM;
                goto err;
        }

        hdev->req_workqueue = alloc_workqueue("%s", WQ_HIGHPRI | WQ_UNBOUND |
                                              WQ_MEM_RECLAIM, 1, hdev->name);
        if (!hdev->req_workqueue) {
                destroy_workqueue(hdev->workqueue);
                error = -ENOMEM;
                goto err;
        }

        if (!IS_ERR_OR_NULL(bt_debugfs))
                hdev->debugfs = debugfs_create_dir(hdev->name, bt_debugfs);

        dev_set_name(&hdev->dev, "%s", hdev->name);

        hdev->tfm_aes = crypto_alloc_blkcipher("ecb(aes)", 0,
                                               CRYPTO_ALG_ASYNC);
        if (IS_ERR(hdev->tfm_aes)) {
                BT_ERR("Unable to create crypto context");
                error = PTR_ERR(hdev->tfm_aes);
                hdev->tfm_aes = NULL;
                goto err_wqueue;
        }

        error = device_add(&hdev->dev);
        if (error < 0)
                goto err_tfm;

        hdev->rfkill = rfkill_alloc(hdev->name, &hdev->dev,
                                    RFKILL_TYPE_BLUETOOTH, &hci_rfkill_ops,
                                    hdev);
        if (hdev->rfkill) {
                if (rfkill_register(hdev->rfkill) < 0) {
                        rfkill_destroy(hdev->rfkill);
                        hdev->rfkill = NULL;
                }
        }

        if (hdev->rfkill && rfkill_blocked(hdev->rfkill))
                set_bit(HCI_RFKILLED, &hdev->dev_flags);

        set_bit(HCI_SETUP, &hdev->dev_flags);
        set_bit(HCI_AUTO_OFF, &hdev->dev_flags);

        if (hdev->dev_type == HCI_BREDR) {
                /* Assume BR/EDR support until proven otherwise (such as
                 * through reading supported features during init.
                 */
                set_bit(HCI_BREDR_ENABLED, &hdev->dev_flags);
        }

        write_lock(&hci_dev_list_lock);
        list_add(&hdev->list, &hci_dev_list);
        write_unlock(&hci_dev_list_lock);

        /* Devices that are marked for raw-only usage are unconfigured
         * and should not be included in normal operation.
         */
        if (test_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks))
                set_bit(HCI_UNCONFIGURED, &hdev->dev_flags);

        hci_notify(hdev, HCI_DEV_REG);
        hci_dev_hold(hdev);

        queue_work(hdev->req_workqueue, &hdev->power_on);

        return id;

err_tfm:
        crypto_free_blkcipher(hdev->tfm_aes);
err_wqueue:
        destroy_workqueue(hdev->workqueue);
        destroy_workqueue(hdev->req_workqueue);
err:
        ida_simple_remove(&hci_index_ida, hdev->id);

        return error;
}
EXPORT_SYMBOL(hci_register_dev);

/* Unregister HCI device */
void hci_unregister_dev(struct hci_dev *hdev)
{
        int i, id;

        BT_DBG("%p name %s bus %d", hdev, hdev->name, hdev->bus);

        set_bit(HCI_UNREGISTER, &hdev->dev_flags);

        id = hdev->id;

        write_lock(&hci_dev_list_lock);
        list_del(&hdev->list);
        write_unlock(&hci_dev_list_lock);

        hci_dev_do_close(hdev);

        for (i = 0; i < NUM_REASSEMBLY; i++)
                kfree_skb(hdev->reassembly[i]);

        cancel_work_sync(&hdev->power_on);

        if (!test_bit(HCI_INIT, &hdev->flags) &&
            !test_bit(HCI_SETUP, &hdev->dev_flags) &&
            !test_bit(HCI_CONFIG, &hdev->dev_flags)) {
                hci_dev_lock(hdev);
                mgmt_index_removed(hdev);
                hci_dev_unlock(hdev);
        }

        /* mgmt_index_removed should take care of emptying the
         * pending list */
        BUG_ON(!list_empty(&hdev->mgmt_pending));

        hci_notify(hdev, HCI_DEV_UNREG);

        if (hdev->rfkill) {
                rfkill_unregister(hdev->rfkill);
                rfkill_destroy(hdev->rfkill);
        }

        if (hdev->tfm_aes)
                crypto_free_blkcipher(hdev->tfm_aes);

        device_del(&hdev->dev);

        debugfs_remove_recursive(hdev->debugfs);

        destroy_workqueue(hdev->workqueue);
        destroy_workqueue(hdev->req_workqueue);

        hci_dev_lock(hdev);
        hci_bdaddr_list_clear(&hdev->blacklist);
        hci_bdaddr_list_clear(&hdev->whitelist);
        hci_uuids_clear(hdev);
        hci_link_keys_clear(hdev);
        hci_smp_ltks_clear(hdev);
        hci_smp_irks_clear(hdev);
        hci_remote_oob_data_clear(hdev);
        hci_bdaddr_list_clear(&hdev->le_white_list);
        hci_conn_params_clear_all(hdev);
        hci_dev_unlock(hdev);

        hci_dev_put(hdev);

        ida_simple_remove(&hci_index_ida, id);
}
EXPORT_SYMBOL(hci_unregister_dev);

/* Suspend HCI device */
int hci_suspend_dev(struct hci_dev *hdev)
{
        hci_notify(hdev, HCI_DEV_SUSPEND);
        return 0;
}
EXPORT_SYMBOL(hci_suspend_dev);

/* Resume HCI device */
int hci_resume_dev(struct hci_dev *hdev)
{
        hci_notify(hdev, HCI_DEV_RESUME);
        return 0;
}
EXPORT_SYMBOL(hci_resume_dev);

/* Receive frame from HCI drivers */
int hci_recv_frame(struct hci_dev *hdev, struct sk_buff *skb)
{
        if (!hdev || (!test_bit(HCI_UP, &hdev->flags)
                      && !test_bit(HCI_INIT, &hdev->flags))) {
                kfree_skb(skb);
                return -ENXIO;
        }

        /* Incoming skb */
        bt_cb(skb)->incoming = 1;

        /* Time stamp */
        __net_timestamp(skb);

        skb_queue_tail(&hdev->rx_q, skb);
        queue_work(hdev->workqueue, &hdev->rx_work);

        return 0;
}
EXPORT_SYMBOL(hci_recv_frame);

static int hci_reassembly(struct hci_dev *hdev, int type, void *data,
                          int count, __u8 index)
{
        int len = 0;
        int hlen = 0;
        int remain = count;
        struct sk_buff *skb;
        struct bt_skb_cb *scb;

        if ((type < HCI_ACLDATA_PKT || type > HCI_EVENT_PKT) ||
            index >= NUM_REASSEMBLY)
                return -EILSEQ;

        skb = hdev->reassembly[index];

        if (!skb) {
                switch (type) {
                case HCI_ACLDATA_PKT:
                        len = HCI_MAX_FRAME_SIZE;
                        hlen = HCI_ACL_HDR_SIZE;
                        break;
                case HCI_EVENT_PKT:
                        len = HCI_MAX_EVENT_SIZE;
                        hlen = HCI_EVENT_HDR_SIZE;
                        break;
                case HCI_SCODATA_PKT:
                        len = HCI_MAX_SCO_SIZE;
                        hlen = HCI_SCO_HDR_SIZE;
                        break;
                }

                skb = bt_skb_alloc(len, GFP_ATOMIC);
                if (!skb)
                        return -ENOMEM;

                scb = (void *) skb->cb;
                scb->expect = hlen;
                scb->pkt_type = type;

                hdev->reassembly[index] = skb;
        }

        while (count) {
                scb = (void *) skb->cb;
                len = min_t(uint, scb->expect, count);

                memcpy(skb_put(skb, len), data, len);

                count -= len;
                data += len;
                scb->expect -= len;
                remain = count;

                switch (type) {
                case HCI_EVENT_PKT:
                        if (skb->len == HCI_EVENT_HDR_SIZE) {
                                struct hci_event_hdr *h = hci_event_hdr(skb);
                                scb->expect = h->plen;

                                if (skb_tailroom(skb) < scb->expect) {
                                        kfree_skb(skb);
                                        hdev->reassembly[index] = NULL;
                                        return -ENOMEM;
                                }
                        }
                        break;

                case HCI_ACLDATA_PKT:
                        if (skb->len  == HCI_ACL_HDR_SIZE) {
                                struct hci_acl_hdr *h = hci_acl_hdr(skb);
                                scb->expect = __le16_to_cpu(h->dlen);

                                if (skb_tailroom(skb) < scb->expect) {
                                        kfree_skb(skb);
                                        hdev->reassembly[index] = NULL;
                                        return -ENOMEM;
                                }
                        }
                        break;

                case HCI_SCODATA_PKT:
                        if (skb->len == HCI_SCO_HDR_SIZE) {
                                struct hci_sco_hdr *h = hci_sco_hdr(skb);
                                scb->expect = h->dlen;

                                if (skb_tailroom(skb) < scb->expect) {
                                        kfree_skb(skb);
                                        hdev->reassembly[index] = NULL;
                                        return -ENOMEM;
                                }
                        }
                        break;
                }

                if (scb->expect == 0) {
                        /* Complete frame */

                        bt_cb(skb)->pkt_type = type;
                        hci_recv_frame(hdev, skb);

                        hdev->reassembly[index] = NULL;
                        return remain;
                }
        }

        return remain;
}

int hci_recv_fragment(struct hci_dev *hdev, int type, void *data, int count)
{
        int rem = 0;

        if (type < HCI_ACLDATA_PKT || type > HCI_EVENT_PKT)
                return -EILSEQ;

        while (count) {
                rem = hci_reassembly(hdev, type, data, count, type - 1);
                if (rem < 0)
                        return rem;

                data += (count - rem);
                count = rem;
        }

        return rem;
}
EXPORT_SYMBOL(hci_recv_fragment);

#define STREAM_REASSEMBLY 0

int hci_recv_stream_fragment(struct hci_dev *hdev, void *data, int count)
{
        int type;
        int rem = 0;

        while (count) {
                struct sk_buff *skb = hdev->reassembly[STREAM_REASSEMBLY];

                if (!skb) {
                        struct { char type; } *pkt;

                        /* Start of the frame */
                        pkt = data;
                        type = pkt->type;

                        data++;
                        count--;
                } else
                        type = bt_cb(skb)->pkt_type;

                rem = hci_reassembly(hdev, type, data, count,
                                     STREAM_REASSEMBLY);
                if (rem < 0)
                        return rem;

                data += (count - rem);
                count = rem;
        }

        return rem;
}
EXPORT_SYMBOL(hci_recv_stream_fragment);

/* ---- Interface to upper protocols ---- */

int hci_register_cb(struct hci_cb *cb)
{
        BT_DBG("%p name %s", cb, cb->name);

        write_lock(&hci_cb_list_lock);
        list_add(&cb->list, &hci_cb_list);
        write_unlock(&hci_cb_list_lock);

        return 0;
}
EXPORT_SYMBOL(hci_register_cb);

int hci_unregister_cb(struct hci_cb *cb)
{
        BT_DBG("%p name %s", cb, cb->name);

        write_lock(&hci_cb_list_lock);
        list_del(&cb->list);
        write_unlock(&hci_cb_list_lock);

        return 0;
}
EXPORT_SYMBOL(hci_unregister_cb);

static void hci_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
{
        int err;

        BT_DBG("%s type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);

        /* Time stamp */
        __net_timestamp(skb);

        /* Send copy to monitor */
        hci_send_to_monitor(hdev, skb);

        if (atomic_read(&hdev->promisc)) {
                /* Send copy to the sockets */
                hci_send_to_sock(hdev, skb);
        }

        /* Get rid of skb owner, prior to sending to the driver. */
        skb_orphan(skb);

        err = hdev->send(hdev, skb);
        if (err < 0) {
                BT_ERR("%s sending frame failed (%d)", hdev->name, err);
                kfree_skb(skb);
        }
}

void hci_req_init(struct hci_request *req, struct hci_dev *hdev)
{
        skb_queue_head_init(&req->cmd_q);
        req->hdev = hdev;
        req->err = 0;
}

int hci_req_run(struct hci_request *req, hci_req_complete_t complete)
{
        struct hci_dev *hdev = req->hdev;
        struct sk_buff *skb;
        unsigned long flags;

        BT_DBG("length %u", skb_queue_len(&req->cmd_q));

        /* If an error occured during request building, remove all HCI
         * commands queued on the HCI request queue.
         */
        if (req->err) {
                skb_queue_purge(&req->cmd_q);
                return req->err;
        }

        /* Do not allow empty requests */
        if (skb_queue_empty(&req->cmd_q))
                return -ENODATA;

        skb = skb_peek_tail(&req->cmd_q);
        bt_cb(skb)->req.complete = complete;

        spin_lock_irqsave(&hdev->cmd_q.lock, flags);
        skb_queue_splice_tail(&req->cmd_q, &hdev->cmd_q);
        spin_unlock_irqrestore(&hdev->cmd_q.lock, flags);

        queue_work(hdev->workqueue, &hdev->cmd_work);

        return 0;
}

bool hci_req_pending(struct hci_dev *hdev)
{
        return (hdev->req_status == HCI_REQ_PEND);
}

static struct sk_buff *hci_prepare_cmd(struct hci_dev *hdev, u16 opcode,
                                       u32 plen, const void *param)
{
        int len = HCI_COMMAND_HDR_SIZE + plen;
        struct hci_command_hdr *hdr;
        struct sk_buff *skb;

        skb = bt_skb_alloc(len, GFP_ATOMIC);
        if (!skb)
                return NULL;

        hdr = (struct hci_command_hdr *) skb_put(skb, HCI_COMMAND_HDR_SIZE);
        hdr->opcode = cpu_to_le16(opcode);
        hdr->plen   = plen;

        if (plen)
                memcpy(skb_put(skb, plen), param, plen);

        BT_DBG("skb len %d", skb->len);

        bt_cb(skb)->pkt_type = HCI_COMMAND_PKT;

        return skb;
}

/* Send HCI command */
int hci_send_cmd(struct hci_dev *hdev, __u16 opcode, __u32 plen,
                 const void *param)
{
        struct sk_buff *skb;

        BT_DBG("%s opcode 0x%4.4x plen %d", hdev->name, opcode, plen);

        skb = hci_prepare_cmd(hdev, opcode, plen, param);
        if (!skb) {
                BT_ERR("%s no memory for command", hdev->name);
                return -ENOMEM;
        }

        /* Stand-alone HCI commands must be flaged as
         * single-command requests.
         */
        bt_cb(skb)->req.start = true;

        skb_queue_tail(&hdev->cmd_q, skb);
        queue_work(hdev->workqueue, &hdev->cmd_work);

        return 0;
}

/* Queue a command to an asynchronous HCI request */
void hci_req_add_ev(struct hci_request *req, u16 opcode, u32 plen,
                    const void *param, u8 event)
{
        struct hci_dev *hdev = req->hdev;
        struct sk_buff *skb;

        BT_DBG("%s opcode 0x%4.4x plen %d", hdev->name, opcode, plen);

        /* If an error occured during request building, there is no point in
         * queueing the HCI command. We can simply return.
         */
        if (req->err)
                return;

        skb = hci_prepare_cmd(hdev, opcode, plen, param);
        if (!skb) {
                BT_ERR("%s no memory for command (opcode 0x%4.4x)",
                       hdev->name, opcode);
                req->err = -ENOMEM;
                return;
        }

        if (skb_queue_empty(&req->cmd_q))
                bt_cb(skb)->req.start = true;

        bt_cb(skb)->req.event = event;

        skb_queue_tail(&req->cmd_q, skb);
}

void hci_req_add(struct hci_request *req, u16 opcode, u32 plen,
                 const void *param)
{
        hci_req_add_ev(req, opcode, plen, param, 0);
}

/* Get data from the previously sent command */
void *hci_sent_cmd_data(struct hci_dev *hdev, __u16 opcode)
{
        struct hci_command_hdr *hdr;

        if (!hdev->sent_cmd)
                return NULL;

        hdr = (void *) hdev->sent_cmd->data;

        if (hdr->opcode != cpu_to_le16(opcode))
                return NULL;

        BT_DBG("%s opcode 0x%4.4x", hdev->name, opcode);

        return hdev->sent_cmd->data + HCI_COMMAND_HDR_SIZE;
}

/* Send ACL data */
static void hci_add_acl_hdr(struct sk_buff *skb, __u16 handle, __u16 flags)
{
        struct hci_acl_hdr *hdr;
        int len = skb->len;

        skb_push(skb, HCI_ACL_HDR_SIZE);
        skb_reset_transport_header(skb);
        hdr = (struct hci_acl_hdr *)skb_transport_header(skb);
        hdr->handle = cpu_to_le16(hci_handle_pack(handle, flags));
        hdr->dlen   = cpu_to_le16(len);
}

static void hci_queue_acl(struct hci_chan *chan, struct sk_buff_head *queue,
                          struct sk_buff *skb, __u16 flags)
{
        struct hci_conn *conn = chan->conn;
        struct hci_dev *hdev = conn->hdev;
        struct sk_buff *list;

        skb->len = skb_headlen(skb);
        skb->data_len = 0;

        bt_cb(skb)->pkt_type = HCI_ACLDATA_PKT;

        switch (hdev->dev_type) {
        case HCI_BREDR:
                hci_add_acl_hdr(skb, conn->handle, flags);
                break;
        case HCI_AMP:
                hci_add_acl_hdr(skb, chan->handle, flags);
                break;
        default:
                BT_ERR("%s unknown dev_type %d", hdev->name, hdev->dev_type);
                return;
        }

        list = skb_shinfo(skb)->frag_list;
        if (!list) {
                /* Non fragmented */
                BT_DBG("%s nonfrag skb %p len %d", hdev->name, skb, skb->len);

                skb_queue_tail(queue, skb);
        } else {
                /* Fragmented */
                BT_DBG("%s frag %p len %d", hdev->name, skb, skb->len);

                skb_shinfo(skb)->frag_list = NULL;

                /* Queue all fragments atomically */
                spin_lock(&queue->lock);

                __skb_queue_tail(queue, skb);

                flags &= ~ACL_START;
                flags |= ACL_CONT;
                do {
                        skb = list; list = list->next;

                        bt_cb(skb)->pkt_type = HCI_ACLDATA_PKT;
                        hci_add_acl_hdr(skb, conn->handle, flags);

                        BT_DBG("%s frag %p len %d", hdev->name, skb, skb->len);

                        __skb_queue_tail(queue, skb);
                } while (list);

                spin_unlock(&queue->lock);
        }
}

void hci_send_acl(struct hci_chan *chan, struct sk_buff *skb, __u16 flags)
{
        struct hci_dev *hdev = chan->conn->hdev;

        BT_DBG("%s chan %p flags 0x%4.4x", hdev->name, chan, flags);

        hci_queue_acl(chan, &chan->data_q, skb, flags);

        queue_work(hdev->workqueue, &hdev->tx_work);
}

/* Send SCO data */
void hci_send_sco(struct hci_conn *conn, struct sk_buff *skb)
{
        struct hci_dev *hdev = conn->hdev;
        struct hci_sco_hdr hdr;

        BT_DBG("%s len %d", hdev->name, skb->len);

        hdr.handle = cpu_to_le16(conn->handle);
        hdr.dlen   = skb->len;

        skb_push(skb, HCI_SCO_HDR_SIZE);
        skb_reset_transport_header(skb);
        memcpy(skb_transport_header(skb), &hdr, HCI_SCO_HDR_SIZE);

        bt_cb(skb)->pkt_type = HCI_SCODATA_PKT;

        skb_queue_tail(&conn->data_q, skb);
        queue_work(hdev->workqueue, &hdev->tx_work);
}

/* ---- HCI TX task (outgoing data) ---- */

/* HCI Connection scheduler */
static struct hci_conn *hci_low_sent(struct hci_dev *hdev, __u8 type,
                                     int *quote)
{
        struct hci_conn_hash *h = &hdev->conn_hash;
        struct hci_conn *conn = NULL, *c;
        unsigned int num = 0, min = ~0;

        /* We don't have to lock device here. Connections are always
         * added and removed with TX task disabled. */

        rcu_read_lock();

        list_for_each_entry_rcu(c, &h->list, list) {
                if (c->type != type || skb_queue_empty(&c->data_q))
                        continue;

                if (c->state != BT_CONNECTED && c->state != BT_CONFIG)
                        continue;

                num++;

                if (c->sent < min) {
                        min  = c->sent;
                        conn = c;
                }

                if (hci_conn_num(hdev, type) == num)
                        break;
        }

        rcu_read_unlock();

        if (conn) {
                int cnt, q;

                switch (conn->type) {
                case ACL_LINK:
                        cnt = hdev->acl_cnt;
                        break;
                case SCO_LINK:
                case ESCO_LINK:
                        cnt = hdev->sco_cnt;
                        break;
                case LE_LINK:
                        cnt = hdev->le_mtu ? hdev->le_cnt : hdev->acl_cnt;
                        break;
                default:
                        cnt = 0;
                        BT_ERR("Unknown link type");
                }

                q = cnt / num;
                *quote = q ? q : 1;
        } else
                *quote = 0;

        BT_DBG("conn %p quote %d", conn, *quote);
        return conn;
}

static void hci_link_tx_to(struct hci_dev *hdev, __u8 type)
{
        struct hci_conn_hash *h = &hdev->conn_hash;
        struct hci_conn *c;

        BT_ERR("%s link tx timeout", hdev->name);

        rcu_read_lock();

        /* Kill stalled connections */
        list_for_each_entry_rcu(c, &h->list, list) {
                if (c->type == type && c->sent) {
                        BT_ERR("%s killing stalled connection %pMR",
                               hdev->name, &c->dst);
                        hci_disconnect(c, HCI_ERROR_REMOTE_USER_TERM);
                }
        }

        rcu_read_unlock();
}

static struct hci_chan *hci_chan_sent(struct hci_dev *hdev, __u8 type,
                                      int *quote)
{
        struct hci_conn_hash *h = &hdev->conn_hash;
        struct hci_chan *chan = NULL;
        unsigned int num = 0, min = ~0, cur_prio = 0;
        struct hci_conn *conn;
        int cnt, q, conn_num = 0;

        BT_DBG("%s", hdev->name);

        rcu_read_lock();

        list_for_each_entry_rcu(conn, &h->list, list) {
                struct hci_chan *tmp;

                if (conn->type != type)
                        continue;

                if (conn->state != BT_CONNECTED && conn->state != BT_CONFIG)
                        continue;

                conn_num++;

                list_for_each_entry_rcu(tmp, &conn->chan_list, list) {
                        struct sk_buff *skb;

                        if (skb_queue_empty(&tmp->data_q))
                                continue;

                        skb = skb_peek(&tmp->data_q);
                        if (skb->priority < cur_prio)
                                continue;

                        if (skb->priority > cur_prio) {
                                num = 0;
                                min = ~0;
                                cur_prio = skb->priority;
                        }

                        num++;

                        if (conn->sent < min) {
                                min  = conn->sent;
                                chan = tmp;
                        }
                }

                if (hci_conn_num(hdev, type) == conn_num)
                        break;
        }

        rcu_read_unlock();

        if (!chan)
                return NULL;

        switch (chan->conn->type) {
        case ACL_LINK:
                cnt = hdev->acl_cnt;
                break;
        case AMP_LINK:
                cnt = hdev->block_cnt;
                break;
        case SCO_LINK:
        case ESCO_LINK:
                cnt = hdev->sco_cnt;
                break;
        case LE_LINK:
                cnt = hdev->le_mtu ? hdev->le_cnt : hdev->acl_cnt;
                break;
        default:
                cnt = 0;
                BT_ERR("Unknown link type");
        }

        q = cnt / num;
        *quote = q ? q : 1;
        BT_DBG("chan %p quote %d", chan, *quote);
        return chan;
}

static void hci_prio_recalculate(struct hci_dev *hdev, __u8 type)
{
        struct hci_conn_hash *h = &hdev->conn_hash;
        struct hci_conn *conn;
        int num = 0;

        BT_DBG("%s", hdev->name);

        rcu_read_lock();

        list_for_each_entry_rcu(conn, &h->list, list) {
                struct hci_chan *chan;

                if (conn->type != type)
                        continue;

                if (conn->state != BT_CONNECTED && conn->state != BT_CONFIG)
                        continue;

                num++;

                list_for_each_entry_rcu(chan, &conn->chan_list, list) {
                        struct sk_buff *skb;

                        if (chan->sent) {
                                chan->sent = 0;
                                continue;
                        }

                        if (skb_queue_empty(&chan->data_q))
                                continue;

                        skb = skb_peek(&chan->data_q);
                        if (skb->priority >= HCI_PRIO_MAX - 1)
                                continue;

                        skb->priority = HCI_PRIO_MAX - 1;

                        BT_DBG("chan %p skb %p promoted to %d", chan, skb,
                               skb->priority);
                }

                if (hci_conn_num(hdev, type) == num)
                        break;
        }

        rcu_read_unlock();

}

static inline int __get_blocks(struct hci_dev *hdev, struct sk_buff *skb)
{
        /* Calculate count of blocks used by this packet */
        return DIV_ROUND_UP(skb->len - HCI_ACL_HDR_SIZE, hdev->block_len);
}

static void __check_timeout(struct hci_dev *hdev, unsigned int cnt)
{
        if (!test_bit(HCI_UNCONFIGURED, &hdev->dev_flags)) {
                /* ACL tx timeout must be longer than maximum
                 * link supervision timeout (40.9 seconds) */
                if (!cnt && time_after(jiffies, hdev->acl_last_tx +
                                       HCI_ACL_TX_TIMEOUT))
                        hci_link_tx_to(hdev, ACL_LINK);
        }
}

static void hci_sched_acl_pkt(struct hci_dev *hdev)
{
        unsigned int cnt = hdev->acl_cnt;
        struct hci_chan *chan;
        struct sk_buff *skb;
        int quote;

        __check_timeout(hdev, cnt);

        while (hdev->acl_cnt &&
               (chan = hci_chan_sent(hdev, ACL_LINK, &quote))) {
                u32 priority = (skb_peek(&chan->data_q))->priority;
                while (quote-- && (skb = skb_peek(&chan->data_q))) {
                        BT_DBG("chan %p skb %p len %d priority %u", chan, skb,
                               skb->len, skb->priority);

                        /* Stop if priority has changed */
                        if (skb->priority < priority)
                                break;

                        skb = skb_dequeue(&chan->data_q);

                        hci_conn_enter_active_mode(chan->conn,
                                                   bt_cb(skb)->force_active);

                        hci_send_frame(hdev, skb);
                        hdev->acl_last_tx = jiffies;

                        hdev->acl_cnt--;
                        chan->sent++;
                        chan->conn->sent++;
                }
        }

        if (cnt != hdev->acl_cnt)
                hci_prio_recalculate(hdev, ACL_LINK);
}

static void hci_sched_acl_blk(struct hci_dev *hdev)
{
        unsigned int cnt = hdev->block_cnt;
        struct hci_chan *chan;
        struct sk_buff *skb;
        int quote;
        u8 type;

        __check_timeout(hdev, cnt);

        BT_DBG("%s", hdev->name);

        if (hdev->dev_type == HCI_AMP)
                type = AMP_LINK;
        else
                type = ACL_LINK;

        while (hdev->block_cnt > 0 &&
               (chan = hci_chan_sent(hdev, type, &quote))) {
                u32 priority = (skb_peek(&chan->data_q))->priority;
                while (quote > 0 && (skb = skb_peek(&chan->data_q))) {
                        int blocks;

                        BT_DBG("chan %p skb %p len %d priority %u", chan, skb,
                               skb->len, skb->priority);

                        /* Stop if priority has changed */
                        if (skb->priority < priority)
                                break;

                        skb = skb_dequeue(&chan->data_q);

                        blocks = __get_blocks(hdev, skb);
                        if (blocks > hdev->block_cnt)
                                return;

                        hci_conn_enter_active_mode(chan->conn,
                                                   bt_cb(skb)->force_active);

                        hci_send_frame(hdev, skb);
                        hdev->acl_last_tx = jiffies;

                        hdev->block_cnt -= blocks;
                        quote -= blocks;

                        chan->sent += blocks;
                        chan->conn->sent += blocks;
                }
        }

        if (cnt != hdev->block_cnt)
                hci_prio_recalculate(hdev, type);
}

static void hci_sched_acl(struct hci_dev *hdev)
{
        BT_DBG("%s", hdev->name);

        /* No ACL link over BR/EDR controller */
        if (!hci_conn_num(hdev, ACL_LINK) && hdev->dev_type == HCI_BREDR)
                return;

        /* No AMP link over AMP controller */
        if (!hci_conn_num(hdev, AMP_LINK) && hdev->dev_type == HCI_AMP)
                return;

        switch (hdev->flow_ctl_mode) {
        case HCI_FLOW_CTL_MODE_PACKET_BASED:
                hci_sched_acl_pkt(hdev);
                break;

        case HCI_FLOW_CTL_MODE_BLOCK_BASED:
                hci_sched_acl_blk(hdev);
                break;
        }
}

/* Schedule SCO */
static void hci_sched_sco(struct hci_dev *hdev)
{
        struct hci_conn *conn;
        struct sk_buff *skb;
        int quote;

        BT_DBG("%s", hdev->name);

        if (!hci_conn_num(hdev, SCO_LINK))
                return;

        while (hdev->sco_cnt && (conn = hci_low_sent(hdev, SCO_LINK, &quote))) {
                while (quote-- && (skb = skb_dequeue(&conn->data_q))) {
                        BT_DBG("skb %p len %d", skb, skb->len);
                        hci_send_frame(hdev, skb);

                        conn->sent++;
                        if (conn->sent == ~0)
                                conn->sent = 0;
                }
        }
}

static void hci_sched_esco(struct hci_dev *hdev)
{
        struct hci_conn *conn;
        struct sk_buff *skb;
        int quote;

        BT_DBG("%s", hdev->name);

        if (!hci_conn_num(hdev, ESCO_LINK))
                return;

        while (hdev->sco_cnt && (conn = hci_low_sent(hdev, ESCO_LINK,
                                                     &quote))) {
                while (quote-- && (skb = skb_dequeue(&conn->data_q))) {
                        BT_DBG("skb %p len %d", skb, skb->len);
                        hci_send_frame(hdev, skb);

                        conn->sent++;
                        if (conn->sent == ~0)
                                conn->sent = 0;
                }
        }
}

static void hci_sched_le(struct hci_dev *hdev)
{
        struct hci_chan *chan;
        struct sk_buff *skb;
        int quote, cnt, tmp;

        BT_DBG("%s", hdev->name);

        if (!hci_conn_num(hdev, LE_LINK))
                return;

        if (!test_bit(HCI_UNCONFIGURED, &hdev->dev_flags)) {
                /* LE tx timeout must be longer than maximum
                 * link supervision timeout (40.9 seconds) */
                if (!hdev->le_cnt && hdev->le_pkts &&
                    time_after(jiffies, hdev->le_last_tx + HZ * 45))
                        hci_link_tx_to(hdev, LE_LINK);
        }

        cnt = hdev->le_pkts ? hdev->le_cnt : hdev->acl_cnt;
        tmp = cnt;
        while (cnt && (chan = hci_chan_sent(hdev, LE_LINK, &quote))) {
                u32 priority = (skb_peek(&chan->data_q))->priority;
                while (quote-- && (skb = skb_peek(&chan->data_q))) {
                        BT_DBG("chan %p skb %p len %d priority %u", chan, skb,
                               skb->len, skb->priority);

                        /* Stop if priority has changed */
                        if (skb->priority < priority)
                                break;

                        skb = skb_dequeue(&chan->data_q);

                        hci_send_frame(hdev, skb);
                        hdev->le_last_tx = jiffies;

                        cnt--;
                        chan->sent++;
                        chan->conn->sent++;
                }
        }

        if (hdev->le_pkts)
                hdev->le_cnt = cnt;
        else
                hdev->acl_cnt = cnt;

        if (cnt != tmp)
                hci_prio_recalculate(hdev, LE_LINK);
}

static void hci_tx_work(struct work_struct *work)
{
        struct hci_dev *hdev = container_of(work, struct hci_dev, tx_work);
        struct sk_buff *skb;

        BT_DBG("%s acl %d sco %d le %d", hdev->name, hdev->acl_cnt,
               hdev->sco_cnt, hdev->le_cnt);

        if (!test_bit(HCI_USER_CHANNEL, &hdev->dev_flags)) {
                /* Schedule queues and send stuff to HCI driver */
                hci_sched_acl(hdev);
                hci_sched_sco(hdev);
                hci_sched_esco(hdev);
                hci_sched_le(hdev);
        }

        /* Send next queued raw (unknown type) packet */
        while ((skb = skb_dequeue(&hdev->raw_q)))
                hci_send_frame(hdev, skb);
}

/* ----- HCI RX task (incoming data processing) ----- */

/* ACL data packet */
static void hci_acldata_packet(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct hci_acl_hdr *hdr = (void *) skb->data;
        struct hci_conn *conn;
        __u16 handle, flags;

        skb_pull(skb, HCI_ACL_HDR_SIZE);

        handle = __le16_to_cpu(hdr->handle);
        flags  = hci_flags(handle);
        handle = hci_handle(handle);

        BT_DBG("%s len %d handle 0x%4.4x flags 0x%4.4x", hdev->name, skb->len,
               handle, flags);

        hdev->stat.acl_rx++;

        hci_dev_lock(hdev);
        conn = hci_conn_hash_lookup_handle(hdev, handle);
        hci_dev_unlock(hdev);

        if (conn) {
                hci_conn_enter_active_mode(conn, BT_POWER_FORCE_ACTIVE_OFF);

                /* Send to upper protocol */
                l2cap_recv_acldata(conn, skb, flags);
                return;
        } else {
                BT_ERR("%s ACL packet for unknown connection handle %d",
                       hdev->name, handle);
        }

        kfree_skb(skb);
}

/* SCO data packet */
static void hci_scodata_packet(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct hci_sco_hdr *hdr = (void *) skb->data;
        struct hci_conn *conn;
        __u16 handle;

        skb_pull(skb, HCI_SCO_HDR_SIZE);

        handle = __le16_to_cpu(hdr->handle);

        BT_DBG("%s len %d handle 0x%4.4x", hdev->name, skb->len, handle);

        hdev->stat.sco_rx++;

        hci_dev_lock(hdev);
        conn = hci_conn_hash_lookup_handle(hdev, handle);
        hci_dev_unlock(hdev);

        if (conn) {
                /* Send to upper protocol */
                sco_recv_scodata(conn, skb);
                return;
        } else {
                BT_ERR("%s SCO packet for unknown connection handle %d",
                       hdev->name, handle);
        }

        kfree_skb(skb);
}

static bool hci_req_is_complete(struct hci_dev *hdev)
{
        struct sk_buff *skb;

        skb = skb_peek(&hdev->cmd_q);
        if (!skb)
                return true;

        return bt_cb(skb)->req.start;
}

static void hci_resend_last(struct hci_dev *hdev)
{
        struct hci_command_hdr *sent;
        struct sk_buff *skb;
        u16 opcode;

        if (!hdev->sent_cmd)
                return;

        sent = (void *) hdev->sent_cmd->data;
        opcode = __le16_to_cpu(sent->opcode);
        if (opcode == HCI_OP_RESET)
                return;

        skb = skb_clone(hdev->sent_cmd, GFP_KERNEL);
        if (!skb)
                return;

        skb_queue_head(&hdev->cmd_q, skb);
        queue_work(hdev->workqueue, &hdev->cmd_work);
}

void hci_req_cmd_complete(struct hci_dev *hdev, u16 opcode, u8 status)
{
        hci_req_complete_t req_complete = NULL;
        struct sk_buff *skb;
        unsigned long flags;

        BT_DBG("opcode 0x%04x status 0x%02x", opcode, status);

        /* If the completed command doesn't match the last one that was
         * sent we need to do special handling of it.
         */
        if (!hci_sent_cmd_data(hdev, opcode)) {
                /* Some CSR based controllers generate a spontaneous
                 * reset complete event during init and any pending
                 * command will never be completed. In such a case we
                 * need to resend whatever was the last sent
                 * command.
                 */
                if (test_bit(HCI_INIT, &hdev->flags) && opcode == HCI_OP_RESET)
                        hci_resend_last(hdev);

                return;
        }

        /* If the command succeeded and there's still more commands in
         * this request the request is not yet complete.
         */
        if (!status && !hci_req_is_complete(hdev))
                return;

        /* If this was the last command in a request the complete
         * callback would be found in hdev->sent_cmd instead of the
         * command queue (hdev->cmd_q).
         */
        if (hdev->sent_cmd) {
                req_complete = bt_cb(hdev->sent_cmd)->req.complete;

                if (req_complete) {
                        /* We must set the complete callback to NULL to
                         * avoid calling the callback more than once if
                         * this function gets called again.
                         */
                        bt_cb(hdev->sent_cmd)->req.complete = NULL;

                        goto call_complete;
                }
        }

        /* Remove all pending commands belonging to this request */
        spin_lock_irqsave(&hdev->cmd_q.lock, flags);
        while ((skb = __skb_dequeue(&hdev->cmd_q))) {
                if (bt_cb(skb)->req.start) {
                        __skb_queue_head(&hdev->cmd_q, skb);
                        break;
                }

                req_complete = bt_cb(skb)->req.complete;
                kfree_skb(skb);
        }
        spin_unlock_irqrestore(&hdev->cmd_q.lock, flags);

call_complete:
        if (req_complete)
                req_complete(hdev, status);
}

static void hci_rx_work(struct work_struct *work)
{
        struct hci_dev *hdev = container_of(work, struct hci_dev, rx_work);
        struct sk_buff *skb;

        BT_DBG("%s", hdev->name);

        while ((skb = skb_dequeue(&hdev->rx_q))) {
                /* Send copy to monitor */
                hci_send_to_monitor(hdev, skb);

                if (atomic_read(&hdev->promisc)) {
                        /* Send copy to the sockets */
                        hci_send_to_sock(hdev, skb);
                }

                if (test_bit(HCI_USER_CHANNEL, &hdev->dev_flags)) {
                        kfree_skb(skb);
                        continue;
                }

                if (test_bit(HCI_INIT, &hdev->flags)) {
                        /* Don't process data packets in this states. */
                        switch (bt_cb(skb)->pkt_type) {
                        case HCI_ACLDATA_PKT:
                        case HCI_SCODATA_PKT:
                                kfree_skb(skb);
                                continue;
                        }
                }

                /* Process frame */
                switch (bt_cb(skb)->pkt_type) {
                case HCI_EVENT_PKT:
                        BT_DBG("%s Event packet", hdev->name);
                        hci_event_packet(hdev, skb);
                        break;

                case HCI_ACLDATA_PKT:
                        BT_DBG("%s ACL data packet", hdev->name);
                        hci_acldata_packet(hdev, skb);
                        break;

                case HCI_SCODATA_PKT:
                        BT_DBG("%s SCO data packet", hdev->name);
                        hci_scodata_packet(hdev, skb);
                        break;

                default:
                        kfree_skb(skb);
                        break;
                }
        }
}

static void hci_cmd_work(struct work_struct *work)
{
        struct hci_dev *hdev = container_of(work, struct hci_dev, cmd_work);
        struct sk_buff *skb;

        BT_DBG("%s cmd_cnt %d cmd queued %d", hdev->name,
               atomic_read(&hdev->cmd_cnt), skb_queue_len(&hdev->cmd_q));

        /* Send queued commands */
        if (atomic_read(&hdev->cmd_cnt)) {
                skb = skb_dequeue(&hdev->cmd_q);
                if (!skb)
                        return;

                kfree_skb(hdev->sent_cmd);

                hdev->sent_cmd = skb_clone(skb, GFP_KERNEL);
                if (hdev->sent_cmd) {
                        atomic_dec(&hdev->cmd_cnt);
                        hci_send_frame(hdev, skb);
                        if (test_bit(HCI_RESET, &hdev->flags))
                                cancel_delayed_work(&hdev->cmd_timer);
                        else
                                schedule_delayed_work(&hdev->cmd_timer,
                                                      HCI_CMD_TIMEOUT);
                } else {
                        skb_queue_head(&hdev->cmd_q, skb);
                        queue_work(hdev->workqueue, &hdev->cmd_work);
                }
        }
}

void hci_req_add_le_scan_disable(struct hci_request *req)
{
        struct hci_cp_le_set_scan_enable cp;

        memset(&cp, 0, sizeof(cp));
        cp.enable = LE_SCAN_DISABLE;
        hci_req_add(req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp);
}

static void add_to_white_list(struct hci_request *req,
                              struct hci_conn_params *params)
{
        struct hci_cp_le_add_to_white_list cp;

        cp.bdaddr_type = params->addr_type;
        bacpy(&cp.bdaddr, &params->addr);

        hci_req_add(req, HCI_OP_LE_ADD_TO_WHITE_LIST, sizeof(cp), &cp);
}

static u8 update_white_list(struct hci_request *req)
{
        struct hci_dev *hdev = req->hdev;
        struct hci_conn_params *params;
        struct bdaddr_list *b;
        uint8_t white_list_entries = 0;

        /* Go through the current white list programmed into the
         * controller one by one and check if that address is still
         * in the list of pending connections or list of devices to
         * report. If not present in either list, then queue the
         * command to remove it from the controller.
         */
        list_for_each_entry(b, &hdev->le_white_list, list) {
                struct hci_cp_le_del_from_white_list cp;

                if (hci_pend_le_action_lookup(&hdev->pend_le_conns,
                                              &b->bdaddr, b->bdaddr_type) ||
                    hci_pend_le_action_lookup(&hdev->pend_le_reports,
                                              &b->bdaddr, b->bdaddr_type)) {
                        white_list_entries++;
                        continue;
                }

                cp.bdaddr_type = b->bdaddr_type;
                bacpy(&cp.bdaddr, &b->bdaddr);

                hci_req_add(req, HCI_OP_LE_DEL_FROM_WHITE_LIST,
                            sizeof(cp), &cp);
        }

        /* Since all no longer valid white list entries have been
         * removed, walk through the list of pending connections
         * and ensure that any new device gets programmed into
         * the controller.
         *
         * If the list of the devices is larger than the list of
         * available white list entries in the controller, then
         * just abort and return filer policy value to not use the
         * white list.
         */
        list_for_each_entry(params, &hdev->pend_le_conns, action) {
                if (hci_bdaddr_list_lookup(&hdev->le_white_list,
                                           &params->addr, params->addr_type))
                        continue;

                if (white_list_entries >= hdev->le_white_list_size) {
                        /* Select filter policy to accept all advertising */
                        return 0x00;
                }

                if (hci_find_irk_by_addr(hdev, &params->addr,
                                         params->addr_type)) {
                        /* White list can not be used with RPAs */
                        return 0x00;
                }

                white_list_entries++;
                add_to_white_list(req, params);
        }

        /* After adding all new pending connections, walk through
         * the list of pending reports and also add these to the
         * white list if there is still space.
         */
        list_for_each_entry(params, &hdev->pend_le_reports, action) {
                if (hci_bdaddr_list_lookup(&hdev->le_white_list,
                                           &params->addr, params->addr_type))
                        continue;

                if (white_list_entries >= hdev->le_white_list_size) {
                        /* Select filter policy to accept all advertising */
                        return 0x00;
                }

                if (hci_find_irk_by_addr(hdev, &params->addr,
                                         params->addr_type)) {
                        /* White list can not be used with RPAs */
                        return 0x00;
                }

                white_list_entries++;
                add_to_white_list(req, params);
        }

        /* Select filter policy to use white list */
        return 0x01;
}

void hci_req_add_le_passive_scan(struct hci_request *req)
{
        struct hci_cp_le_set_scan_param param_cp;
        struct hci_cp_le_set_scan_enable enable_cp;
        struct hci_dev *hdev = req->hdev;
        u8 own_addr_type;
        u8 filter_policy;

        /* Set require_privacy to false since no SCAN_REQ are send
         * during passive scanning. Not using an unresolvable address
         * here is important so that peer devices using direct
         * advertising with our address will be correctly reported
         * by the controller.
         */
        if (hci_update_random_address(req, false, &own_addr_type))
                return;

        /* Adding or removing entries from the white list must
         * happen before enabling scanning. The controller does
         * not allow white list modification while scanning.
         */
        filter_policy = update_white_list(req);

        memset(&param_cp, 0, sizeof(param_cp));
        param_cp.type = LE_SCAN_PASSIVE;
        param_cp.interval = cpu_to_le16(hdev->le_scan_interval);
        param_cp.window = cpu_to_le16(hdev->le_scan_window);
        param_cp.own_address_type = own_addr_type;
        param_cp.filter_policy = filter_policy;
        hci_req_add(req, HCI_OP_LE_SET_SCAN_PARAM, sizeof(param_cp),
                    &param_cp);

        memset(&enable_cp, 0, sizeof(enable_cp));
        enable_cp.enable = LE_SCAN_ENABLE;
        enable_cp.filter_dup = LE_SCAN_FILTER_DUP_ENABLE;
        hci_req_add(req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(enable_cp),
                    &enable_cp);
}

static void update_background_scan_complete(struct hci_dev *hdev, u8 status)
{
        if (status)
                BT_DBG("HCI request failed to update background scanning: "
                       "status 0x%2.2x", status);
}

/* This function controls the background scanning based on hdev->pend_le_conns
 * list. If there are pending LE connection we start the background scanning,
 * otherwise we stop it.
 *
 * This function requires the caller holds hdev->lock.
 */
void hci_update_background_scan(struct hci_dev *hdev)
{
        struct hci_request req;
        struct hci_conn *conn;
        int err;

        if (!test_bit(HCI_UP, &hdev->flags) ||
            test_bit(HCI_INIT, &hdev->flags) ||
            test_bit(HCI_SETUP, &hdev->dev_flags) ||
            test_bit(HCI_CONFIG, &hdev->dev_flags) ||
            test_bit(HCI_AUTO_OFF, &hdev->dev_flags) ||
            test_bit(HCI_UNREGISTER, &hdev->dev_flags))
                return;

        /* No point in doing scanning if LE support hasn't been enabled */
        if (!test_bit(HCI_LE_ENABLED, &hdev->dev_flags))
                return;

        /* If discovery is active don't interfere with it */
        if (hdev->discovery.state != DISCOVERY_STOPPED)
                return;

        hci_req_init(&req, hdev);

        if (list_empty(&hdev->pend_le_conns) &&
            list_empty(&hdev->pend_le_reports)) {
                /* If there is no pending LE connections or devices
                 * to be scanned for, we should stop the background
                 * scanning.
                 */

                /* If controller is not scanning we are done. */
                if (!test_bit(HCI_LE_SCAN, &hdev->dev_flags))
                        return;

                hci_req_add_le_scan_disable(&req);

                BT_DBG("%s stopping background scanning", hdev->name);
        } else {
                /* If there is at least one pending LE connection, we should
                 * keep the background scan running.
                 */

                /* If controller is connecting, we should not start scanning
                 * since some controllers are not able to scan and connect at
                 * the same time.
                 */
                conn = hci_conn_hash_lookup_state(hdev, LE_LINK, BT_CONNECT);
                if (conn)
                        return;

                /* If controller is currently scanning, we stop it to ensure we
                 * don't miss any advertising (due to duplicates filter).
                 */
                if (test_bit(HCI_LE_SCAN, &hdev->dev_flags))
                        hci_req_add_le_scan_disable(&req);

                hci_req_add_le_passive_scan(&req);

                BT_DBG("%s starting background scanning", hdev->name);
        }

        err = hci_req_run(&req, update_background_scan_complete);
        if (err)
                BT_ERR("Failed to run HCI request: err %d", err);
}