drivers/misc/mei/init.c

   1 /*
   2  *
   3  * Intel Management Engine Interface (Intel MEI) Linux driver
   4  * Copyright (c) 2003-2012, Intel Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  */
  16
  17 #include <linux/export.h>
  18 #include <linux/pci.h>
  19 #include <linux/sched.h>
  20 #include <linux/wait.h>
  21 #include <linux/delay.h>
  22
  23 #include <linux/mei.h>
  24
  25 #include "mei_dev.h"
  26 #include "hbm.h"
  27 #include "client.h"
  28
  29 const char *mei_dev_state_str(int state)
  30 {
  31 #define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
  32         switch (state) {
  33         MEI_DEV_STATE(INITIALIZING);
  34         MEI_DEV_STATE(INIT_CLIENTS);
  35         MEI_DEV_STATE(ENABLED);
  36         MEI_DEV_STATE(RESETTING);
  37         MEI_DEV_STATE(DISABLED);
  38         MEI_DEV_STATE(POWER_DOWN);
  39         MEI_DEV_STATE(POWER_UP);
  40         default:
  41                 return "unkown";
  42         }
  43 #undef MEI_DEV_STATE
  44 }
  45
  46 void mei_device_init(struct mei_device *dev)
  47 {
  48         /* setup our list array */
  49         INIT_LIST_HEAD(&dev->file_list);
  50         INIT_LIST_HEAD(&dev->device_list);
  51         mutex_init(&dev->device_lock);
  52         init_waitqueue_head(&dev->wait_hw_ready);
  53         init_waitqueue_head(&dev->wait_recvd_msg);
  54         init_waitqueue_head(&dev->wait_stop_wd);
  55         dev->dev_state = MEI_DEV_INITIALIZING;
  56
  57         mei_io_list_init(&dev->read_list);
  58         mei_io_list_init(&dev->write_list);
  59         mei_io_list_init(&dev->write_waiting_list);
  60         mei_io_list_init(&dev->ctrl_wr_list);
  61         mei_io_list_init(&dev->ctrl_rd_list);
  62
  63         INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
  64         INIT_WORK(&dev->init_work, mei_host_client_init);
  65
  66         INIT_LIST_HEAD(&dev->wd_cl.link);
  67         INIT_LIST_HEAD(&dev->iamthif_cl.link);
  68         mei_io_list_init(&dev->amthif_cmd_list);
  69         mei_io_list_init(&dev->amthif_rd_complete_list);
  70
  71 }
  72 EXPORT_SYMBOL_GPL(mei_device_init);
  73
  74 /**
  75  * mei_start - initializes host and fw to start work.
  76  *
  77  * @dev: the device structure
  78  *
  79  * returns 0 on success, <0 on failure.
  80  */
  81 int mei_start(struct mei_device *dev)
  82 {
  83         mutex_lock(&dev->device_lock);
  84
  85         /* acknowledge interrupt and stop interupts */
  86         mei_clear_interrupts(dev);
  87
  88         mei_hw_config(dev);
  89
  90         dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");
  91
  92         mei_reset(dev, 1);
  93
  94         if (mei_hbm_start_wait(dev)) {
  95                 dev_err(&dev->pdev->dev, "HBM haven't started");
  96                 goto err;
  97         }
  98
  99         if (!mei_host_is_ready(dev)) {
 100                 dev_err(&dev->pdev->dev, "host is not ready.\n");
 101                 goto err;
 102         }
 103
 104         if (!mei_hw_is_ready(dev)) {
 105                 dev_err(&dev->pdev->dev, "ME is not ready.\n");
 106                 goto err;
 107         }
 108
 109         if (dev->version.major_version != HBM_MAJOR_VERSION ||
 110             dev->version.minor_version != HBM_MINOR_VERSION) {
 111                 dev_dbg(&dev->pdev->dev, "MEI start failed.\n");
 112                 goto err;
 113         }
 114
 115         dev_dbg(&dev->pdev->dev, "link layer has been established.\n");
 116
 117         mutex_unlock(&dev->device_lock);
 118         return 0;
 119 err:
 120         dev_err(&dev->pdev->dev, "link layer initialization failed.\n");
 121         dev->dev_state = MEI_DEV_DISABLED;
 122         mutex_unlock(&dev->device_lock);
 123         return -ENODEV;
 124 }
 125 EXPORT_SYMBOL_GPL(mei_start);
 126
 127 /**
 128  * mei_reset - resets host and fw.
 129  *
 130  * @dev: the device structure
 131  * @interrupts_enabled: if interrupt should be enabled after reset.
 132  */
 133 void mei_reset(struct mei_device *dev, int interrupts_enabled)
 134 {
 135         bool unexpected;
 136
 137         unexpected = (dev->dev_state != MEI_DEV_INITIALIZING &&
 138                         dev->dev_state != MEI_DEV_DISABLED &&
 139                         dev->dev_state != MEI_DEV_POWER_DOWN &&
 140                         dev->dev_state != MEI_DEV_POWER_UP);
 141
 142         mei_hw_reset(dev, interrupts_enabled);
 143
 144         dev->hbm_state = MEI_HBM_IDLE;
 145
 146         if (dev->dev_state != MEI_DEV_INITIALIZING) {
 147                 if (dev->dev_state != MEI_DEV_DISABLED &&
 148                     dev->dev_state != MEI_DEV_POWER_DOWN)
 149                         dev->dev_state = MEI_DEV_RESETTING;
 150
 151                 mei_cl_all_disconnect(dev);
 152
 153                 /* remove entry if already in list */
 154                 dev_dbg(&dev->pdev->dev, "remove iamthif and wd from the file list.\n");
 155                 mei_cl_unlink(&dev->wd_cl);
 156                 if (dev->open_handle_count > 0)
 157                         dev->open_handle_count--;
 158                 mei_cl_unlink(&dev->iamthif_cl);
 159                 if (dev->open_handle_count > 0)
 160                         dev->open_handle_count--;
 161
 162                 mei_amthif_reset_params(dev);
 163                 memset(&dev->wr_ext_msg, 0, sizeof(dev->wr_ext_msg));
 164         }
 165
 166         dev->me_clients_num = 0;
 167         dev->rd_msg_hdr = 0;
 168         dev->wd_pending = false;
 169
 170         if (unexpected)
 171                 dev_warn(&dev->pdev->dev, "unexpected reset: dev_state = %s\n",
 172                          mei_dev_state_str(dev->dev_state));
 173
 174         if (!interrupts_enabled) {
 175                 dev_dbg(&dev->pdev->dev, "intr not enabled end of reset\n");
 176                 return;
 177         }
 178
 179         mei_hw_start(dev);
 180
 181         dev_dbg(&dev->pdev->dev, "link is established start sending messages.\n");
 182         /* link is established * start sending messages.  */
 183
 184         dev->dev_state = MEI_DEV_INIT_CLIENTS;
 185
 186         mei_hbm_start_req(dev);
 187
 188         /* wake up all readings so they can be interrupted */
 189         mei_cl_all_read_wakeup(dev);
 190
 191         /* remove all waiting requests */
 192         mei_cl_all_write_clear(dev);
 193 }
 194 EXPORT_SYMBOL_GPL(mei_reset);
 195
 196 void mei_stop(struct mei_device *dev)
 197 {
 198         dev_dbg(&dev->pdev->dev, "stopping the device.\n");
 199
 200         mutex_lock(&dev->device_lock);
 201
 202         cancel_delayed_work(&dev->timer_work);
 203
 204         mei_wd_stop(dev);
 205
 206         mei_nfc_host_exit();
 207
 208         dev->dev_state = MEI_DEV_POWER_DOWN;
 209         mei_reset(dev, 0);
 210
 211         mutex_unlock(&dev->device_lock);
 212
 213         flush_scheduled_work();
 214
 215         mei_watchdog_unregister(dev);
 216 }
 217 EXPORT_SYMBOL_GPL(mei_stop);
 218
 219
 220