iwlegacy: rename priv to il

[deliverable/linux.git] / drivers / net / wireless / iwlegacy / iwl-scan.c

/******************************************************************************
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
 * USA
 *
 * The full GNU General Public License is included in this distribution
 * in the file called LICENSE.GPL.
 *
 * Contact Information:
 *  Intel Linux Wireless <ilw@linux.intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *****************************************************************************/
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/etherdevice.h>
#include <net/mac80211.h>

#include "iwl-eeprom.h"
#include "iwl-dev.h"
#include "iwl-core.h"
#include "iwl-sta.h"
#include "iwl-io.h"
#include "iwl-helpers.h"

/* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
 * sending probe req.  This should be set long enough to hear probe responses
 * from more than one AP.  */
#define IL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
#define IL_ACTIVE_DWELL_TIME_52    (20)

#define IL_ACTIVE_DWELL_FACTOR_24GHZ (3)
#define IL_ACTIVE_DWELL_FACTOR_52GHZ (2)

/* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
 * Must be set longer than active dwell time.
 * For the most reliable scan, set > AP beacon interval (typically 100msec). */
#define IL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
#define IL_PASSIVE_DWELL_TIME_52   (10)
#define IL_PASSIVE_DWELL_BASE      (100)
#define IL_CHANNEL_TUNE_TIME       5

static int il_send_scan_abort(struct il_priv *il)
{
        int ret;
        struct il_rx_packet *pkt;
        struct il_host_cmd cmd = {
                .id = REPLY_SCAN_ABORT_CMD,
                .flags = CMD_WANT_SKB,
        };

        /* Exit instantly with error when device is not ready
         * to receive scan abort command or it does not perform
         * hardware scan currently */
        if (!test_bit(STATUS_READY, &il->status) ||
            !test_bit(STATUS_GEO_CONFIGURED, &il->status) ||
            !test_bit(STATUS_SCAN_HW, &il->status) ||
            test_bit(STATUS_FW_ERROR, &il->status) ||
            test_bit(STATUS_EXIT_PENDING, &il->status))
                return -EIO;

        ret = il_send_cmd_sync(il, &cmd);
        if (ret)
                return ret;

        pkt = (struct il_rx_packet *)cmd.reply_page;
        if (pkt->u.status != CAN_ABORT_STATUS) {
                /* The scan abort will return 1 for success or
                 * 2 for "failure".  A failure condition can be
                 * due to simply not being in an active scan which
                 * can occur if we send the scan abort before we
                 * the microcode has notified us that a scan is
                 * completed. */
                IL_DEBUG_SCAN(il, "SCAN_ABORT ret %d.\n", pkt->u.status);
                ret = -EIO;
        }

        il_free_pages(il, cmd.reply_page);
        return ret;
}

static void il_complete_scan(struct il_priv *il, bool aborted)
{
        /* check if scan was requested from mac80211 */
        if (il->scan_request) {
                IL_DEBUG_SCAN(il, "Complete scan in mac80211\n");
                ieee80211_scan_completed(il->hw, aborted);
        }

        il->scan_vif = NULL;
        il->scan_request = NULL;
}

void il_force_scan_end(struct il_priv *il)
{
        lockdep_assert_held(&il->mutex);

        if (!test_bit(STATUS_SCANNING, &il->status)) {
                IL_DEBUG_SCAN(il, "Forcing scan end while not scanning\n");
                return;
        }

        IL_DEBUG_SCAN(il, "Forcing scan end\n");
        clear_bit(STATUS_SCANNING, &il->status);
        clear_bit(STATUS_SCAN_HW, &il->status);
        clear_bit(STATUS_SCAN_ABORTING, &il->status);
        il_complete_scan(il, true);
}

static void il_do_scan_abort(struct il_priv *il)
{
        int ret;

        lockdep_assert_held(&il->mutex);

        if (!test_bit(STATUS_SCANNING, &il->status)) {
                IL_DEBUG_SCAN(il, "Not performing scan to abort\n");
                return;
        }

        if (test_and_set_bit(STATUS_SCAN_ABORTING, &il->status)) {
                IL_DEBUG_SCAN(il, "Scan abort in progress\n");
                return;
        }

        ret = il_send_scan_abort(il);
        if (ret) {
                IL_DEBUG_SCAN(il, "Send scan abort failed %d\n", ret);
                il_force_scan_end(il);
        } else
                IL_DEBUG_SCAN(il, "Successfully send scan abort\n");
}

/**
 * il_scan_cancel - Cancel any currently executing HW scan
 */
int il_scan_cancel(struct il_priv *il)
{
        IL_DEBUG_SCAN(il, "Queuing abort scan\n");
        queue_work(il->workqueue, &il->abort_scan);
        return 0;
}
EXPORT_SYMBOL(il_scan_cancel);

/**
 * il_scan_cancel_timeout - Cancel any currently executing HW scan
 * @ms: amount of time to wait (in milliseconds) for scan to abort
 *
 */
int il_scan_cancel_timeout(struct il_priv *il, unsigned long ms)
{
        unsigned long timeout = jiffies + msecs_to_jiffies(ms);

        lockdep_assert_held(&il->mutex);

        IL_DEBUG_SCAN(il, "Scan cancel timeout\n");

        il_do_scan_abort(il);

        while (time_before_eq(jiffies, timeout)) {
                if (!test_bit(STATUS_SCAN_HW, &il->status))
                        break;
                msleep(20);
        }

        return test_bit(STATUS_SCAN_HW, &il->status);
}
EXPORT_SYMBOL(il_scan_cancel_timeout);

/* Service response to REPLY_SCAN_CMD (0x80) */
static void il_rx_reply_scan(struct il_priv *il,
                              struct il_rx_mem_buffer *rxb)
{
#ifdef CONFIG_IWLWIFI_LEGACY_DEBUG
        struct il_rx_packet *pkt = rxb_addr(rxb);
        struct il_scanreq_notification *notif =
            (struct il_scanreq_notification *)pkt->u.raw;

        IL_DEBUG_SCAN(il, "Scan request status = 0x%x\n", notif->status);
#endif
}

/* Service SCAN_START_NOTIFICATION (0x82) */
static void il_rx_scan_start_notif(struct il_priv *il,
                                    struct il_rx_mem_buffer *rxb)
{
        struct il_rx_packet *pkt = rxb_addr(rxb);
        struct il_scanstart_notification *notif =
            (struct il_scanstart_notification *)pkt->u.raw;
        il->scan_start_tsf = le32_to_cpu(notif->tsf_low);
        IL_DEBUG_SCAN(il, "Scan start: "
                       "%d [802.11%s] "
                       "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
                       notif->channel,
                       notif->band ? "bg" : "a",
                       le32_to_cpu(notif->tsf_high),
                       le32_to_cpu(notif->tsf_low),
                       notif->status, notif->beacon_timer);
}

/* Service SCAN_RESULTS_NOTIFICATION (0x83) */
static void il_rx_scan_results_notif(struct il_priv *il,
                                      struct il_rx_mem_buffer *rxb)
{
#ifdef CONFIG_IWLWIFI_LEGACY_DEBUG
        struct il_rx_packet *pkt = rxb_addr(rxb);
        struct il_scanresults_notification *notif =
            (struct il_scanresults_notification *)pkt->u.raw;

        IL_DEBUG_SCAN(il, "Scan ch.res: "
                       "%d [802.11%s] "
                       "(TSF: 0x%08X:%08X) - %d "
                       "elapsed=%lu usec\n",
                       notif->channel,
                       notif->band ? "bg" : "a",
                       le32_to_cpu(notif->tsf_high),
                       le32_to_cpu(notif->tsf_low),
                       le32_to_cpu(notif->statistics[0]),
                       le32_to_cpu(notif->tsf_low) - il->scan_start_tsf);
#endif
}

/* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
static void il_rx_scan_complete_notif(struct il_priv *il,
                                       struct il_rx_mem_buffer *rxb)
{

#ifdef CONFIG_IWLWIFI_LEGACY_DEBUG
        struct il_rx_packet *pkt = rxb_addr(rxb);
        struct il_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
#endif

        IL_DEBUG_SCAN(il,
                        "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
                       scan_notif->scanned_channels,
                       scan_notif->tsf_low,
                       scan_notif->tsf_high, scan_notif->status);

        /* The HW is no longer scanning */
        clear_bit(STATUS_SCAN_HW, &il->status);

        IL_DEBUG_SCAN(il, "Scan on %sGHz took %dms\n",
                       (il->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
                       jiffies_to_msecs(jiffies - il->scan_start));

        queue_work(il->workqueue, &il->scan_completed);
}

void il_setup_rx_scan_handlers(struct il_priv *il)
{
        /* scan handlers */
        il->rx_handlers[REPLY_SCAN_CMD] = il_rx_reply_scan;
        il->rx_handlers[SCAN_START_NOTIFICATION] =
                                        il_rx_scan_start_notif;
        il->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
                                        il_rx_scan_results_notif;
        il->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
                                        il_rx_scan_complete_notif;
}
EXPORT_SYMBOL(il_setup_rx_scan_handlers);

inline u16 il_get_active_dwell_time(struct il_priv *il,
                                     enum ieee80211_band band,
                                     u8 n_probes)
{
        if (band == IEEE80211_BAND_5GHZ)
                return IL_ACTIVE_DWELL_TIME_52 +
                        IL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
        else
                return IL_ACTIVE_DWELL_TIME_24 +
                        IL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
}
EXPORT_SYMBOL(il_get_active_dwell_time);

u16 il_get_passive_dwell_time(struct il_priv *il,
                               enum ieee80211_band band,
                               struct ieee80211_vif *vif)
{
        struct il_rxon_context *ctx;
        u16 passive = (band == IEEE80211_BAND_2GHZ) ?
            IL_PASSIVE_DWELL_BASE + IL_PASSIVE_DWELL_TIME_24 :
            IL_PASSIVE_DWELL_BASE + IL_PASSIVE_DWELL_TIME_52;

        if (il_is_any_associated(il)) {
                /*
                 * If we're associated, we clamp the maximum passive
                 * dwell time to be 98% of the smallest beacon interval
                 * (minus 2 * channel tune time)
                 */
                for_each_context(il, ctx) {
                        u16 value;

                        if (!il_is_associated_ctx(ctx))
                                continue;
                        value = ctx->vif ? ctx->vif->bss_conf.beacon_int : 0;
                        if ((value > IL_PASSIVE_DWELL_BASE) || !value)
                                value = IL_PASSIVE_DWELL_BASE;
                        value = (value * 98) / 100 - IL_CHANNEL_TUNE_TIME * 2;
                        passive = min(value, passive);
                }
        }

        return passive;
}
EXPORT_SYMBOL(il_get_passive_dwell_time);

void il_init_scan_params(struct il_priv *il)
{
        u8 ant_idx = fls(il->hw_params.valid_tx_ant) - 1;
        if (!il->scan_tx_ant[IEEE80211_BAND_5GHZ])
                il->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
        if (!il->scan_tx_ant[IEEE80211_BAND_2GHZ])
                il->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
}
EXPORT_SYMBOL(il_init_scan_params);

static int il_scan_initiate(struct il_priv *il,
                                    struct ieee80211_vif *vif)
{
        int ret;

        lockdep_assert_held(&il->mutex);

        if (WARN_ON(!il->cfg->ops->utils->request_scan))
                return -EOPNOTSUPP;

        cancel_delayed_work(&il->scan_check);

        if (!il_is_ready_rf(il)) {
                IL_WARN(il, "Request scan called when driver not ready.\n");
                return -EIO;
        }

        if (test_bit(STATUS_SCAN_HW, &il->status)) {
                IL_DEBUG_SCAN(il,
                        "Multiple concurrent scan requests in parallel.\n");
                return -EBUSY;
        }

        if (test_bit(STATUS_SCAN_ABORTING, &il->status)) {
                IL_DEBUG_SCAN(il, "Scan request while abort pending.\n");
                return -EBUSY;
        }

        IL_DEBUG_SCAN(il, "Starting scan...\n");

        set_bit(STATUS_SCANNING, &il->status);
        il->scan_start = jiffies;

        ret = il->cfg->ops->utils->request_scan(il, vif);
        if (ret) {
                clear_bit(STATUS_SCANNING, &il->status);
                return ret;
        }

        queue_delayed_work(il->workqueue, &il->scan_check,
                           IL_SCAN_CHECK_WATCHDOG);

        return 0;
}

int il_mac_hw_scan(struct ieee80211_hw *hw,
                    struct ieee80211_vif *vif,
                    struct cfg80211_scan_request *req)
{
        struct il_priv *il = hw->priv;
        int ret;

        IL_DEBUG_MAC80211(il, "enter\n");

        if (req->n_channels == 0)
                return -EINVAL;

        mutex_lock(&il->mutex);

        if (test_bit(STATUS_SCANNING, &il->status)) {
                IL_DEBUG_SCAN(il, "Scan already in progress.\n");
                ret = -EAGAIN;
                goto out_unlock;
        }

        /* mac80211 will only ask for one band at a time */
        il->scan_request = req;
        il->scan_vif = vif;
        il->scan_band = req->channels[0]->band;

        ret = il_scan_initiate(il, vif);

        IL_DEBUG_MAC80211(il, "leave\n");

out_unlock:
        mutex_unlock(&il->mutex);

        return ret;
}
EXPORT_SYMBOL(il_mac_hw_scan);

static void il_bg_scan_check(struct work_struct *data)
{
        struct il_priv *il =
            container_of(data, struct il_priv, scan_check.work);

        IL_DEBUG_SCAN(il, "Scan check work\n");

        /* Since we are here firmware does not finish scan and
         * most likely is in bad shape, so we don't bother to
         * send abort command, just force scan complete to mac80211 */
        mutex_lock(&il->mutex);
        il_force_scan_end(il);
        mutex_unlock(&il->mutex);
}

/**
 * il_fill_probe_req - fill in all required fields and IE for probe request
 */

u16
il_fill_probe_req(struct il_priv *il, struct ieee80211_mgmt *frame,
                       const u8 *ta, const u8 *ies, int ie_len, int left)
{
        int len = 0;
        u8 *pos = NULL;

        /* Make sure there is enough space for the probe request,
         * two mandatory IEs and the data */
        left -= 24;
        if (left < 0)
                return 0;

        frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
        memcpy(frame->da, iwlegacy_bcast_addr, ETH_ALEN);
        memcpy(frame->sa, ta, ETH_ALEN);
        memcpy(frame->bssid, iwlegacy_bcast_addr, ETH_ALEN);
        frame->seq_ctrl = 0;

        len += 24;

        /* ...next IE... */
        pos = &frame->u.probe_req.variable[0];

        /* fill in our indirect SSID IE */
        left -= 2;
        if (left < 0)
                return 0;
        *pos++ = WLAN_EID_SSID;
        *pos++ = 0;

        len += 2;

        if (WARN_ON(left < ie_len))
                return len;

        if (ies && ie_len) {
                memcpy(pos, ies, ie_len);
                len += ie_len;
        }

        return (u16)len;
}
EXPORT_SYMBOL(il_fill_probe_req);

static void il_bg_abort_scan(struct work_struct *work)
{
        struct il_priv *il = container_of(work, struct il_priv, abort_scan);

        IL_DEBUG_SCAN(il, "Abort scan work\n");

        /* We keep scan_check work queued in case when firmware will not
         * report back scan completed notification */
        mutex_lock(&il->mutex);
        il_scan_cancel_timeout(il, 200);
        mutex_unlock(&il->mutex);
}

static void il_bg_scan_completed(struct work_struct *work)
{
        struct il_priv *il =
            container_of(work, struct il_priv, scan_completed);
        bool aborted;

        IL_DEBUG_SCAN(il, "Completed scan.\n");

        cancel_delayed_work(&il->scan_check);

        mutex_lock(&il->mutex);

        aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &il->status);
        if (aborted)
                IL_DEBUG_SCAN(il, "Aborted scan completed.\n");

        if (!test_and_clear_bit(STATUS_SCANNING, &il->status)) {
                IL_DEBUG_SCAN(il, "Scan already completed.\n");
                goto out_settings;
        }

        il_complete_scan(il, aborted);

out_settings:
        /* Can we still talk to firmware ? */
        if (!il_is_ready_rf(il))
                goto out;

        /*
         * We do not commit power settings while scan is pending,
         * do it now if the settings changed.
         */
        il_power_set_mode(il, &il->power_data.sleep_cmd_next, false);
        il_set_tx_power(il, il->tx_power_next, false);

        il->cfg->ops->utils->post_scan(il);

out:
        mutex_unlock(&il->mutex);
}

void il_setup_scan_deferred_work(struct il_priv *il)
{
        INIT_WORK(&il->scan_completed, il_bg_scan_completed);
        INIT_WORK(&il->abort_scan, il_bg_abort_scan);
        INIT_DELAYED_WORK(&il->scan_check, il_bg_scan_check);
}
EXPORT_SYMBOL(il_setup_scan_deferred_work);

void il_cancel_scan_deferred_work(struct il_priv *il)
{
        cancel_work_sync(&il->abort_scan);
        cancel_work_sync(&il->scan_completed);

        if (cancel_delayed_work_sync(&il->scan_check)) {
                mutex_lock(&il->mutex);
                il_force_scan_end(il);
                mutex_unlock(&il->mutex);
        }
}
EXPORT_SYMBOL(il_cancel_scan_deferred_work);