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 "unknown";
  42         }
  43 #undef MEI_DEV_STATE
  44 }
  45
  46 /**
  47  * mei_start - initializes host and fw to start work.
  48  *
  49  * @dev: the device structure
  50  *
  51  * returns 0 on success, <0 on failure.
  52  */
  53 int mei_start(struct mei_device *dev)
  54 {
  55         mutex_lock(&dev->device_lock);
  56
  57         /* acknowledge interrupt and stop interupts */
  58         mei_clear_interrupts(dev);
  59
  60         mei_hw_config(dev);
  61
  62         dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");
  63
  64         mei_reset(dev, 1);
  65
  66         if (mei_hbm_start_wait(dev)) {
  67                 dev_err(&dev->pdev->dev, "HBM haven't started");
  68                 goto err;
  69         }
  70
  71         if (!mei_host_is_ready(dev)) {
  72                 dev_err(&dev->pdev->dev, "host is not ready.\n");
  73                 goto err;
  74         }
  75
  76         if (!mei_hw_is_ready(dev)) {
  77                 dev_err(&dev->pdev->dev, "ME is not ready.\n");
  78                 goto err;
  79         }
  80
  81         if (!mei_hbm_version_is_supported(dev)) {
  82                 dev_dbg(&dev->pdev->dev, "MEI start failed.\n");
  83                 goto err;
  84         }
  85
  86         dev_dbg(&dev->pdev->dev, "link layer has been established.\n");
  87
  88         mutex_unlock(&dev->device_lock);
  89         return 0;
  90 err:
  91         dev_err(&dev->pdev->dev, "link layer initialization failed.\n");
  92         dev->dev_state = MEI_DEV_DISABLED;
  93         mutex_unlock(&dev->device_lock);
  94         return -ENODEV;
  95 }
  96 EXPORT_SYMBOL_GPL(mei_start);
  97
  98 /**
  99  * mei_cancel_work. Cancel mei background jobs
 100  *
 101  * @dev: the device structure
 102  */
 103 void mei_cancel_work(struct mei_device *dev)
 104 {
 105         cancel_work_sync(&dev->init_work);
 106         cancel_work_sync(&dev->reset_work);
 107
 108         cancel_delayed_work(&dev->timer_work);
 109 }
 110 EXPORT_SYMBOL_GPL(mei_cancel_work);
 111
 112 /**
 113  * mei_reset - resets host and fw.
 114  *
 115  * @dev: the device structure
 116  * @interrupts_enabled: if interrupt should be enabled after reset.
 117  */
 118 void mei_reset(struct mei_device *dev, int interrupts_enabled)
 119 {
 120         bool unexpected;
 121         int ret;
 122
 123         unexpected = (dev->dev_state != MEI_DEV_INITIALIZING &&
 124                         dev->dev_state != MEI_DEV_DISABLED &&
 125                         dev->dev_state != MEI_DEV_POWER_DOWN &&
 126                         dev->dev_state != MEI_DEV_POWER_UP);
 127
 128         if (unexpected)
 129                 dev_warn(&dev->pdev->dev, "unexpected reset: dev_state = %s\n",
 130                          mei_dev_state_str(dev->dev_state));
 131
 132         ret = mei_hw_reset(dev, interrupts_enabled);
 133         if (ret) {
 134                 dev_err(&dev->pdev->dev, "hw reset failed disabling the device\n");
 135                 interrupts_enabled = false;
 136                 dev->dev_state = MEI_DEV_DISABLED;
 137         }
 138
 139         dev->hbm_state = MEI_HBM_IDLE;
 140
 141         if (dev->dev_state != MEI_DEV_INITIALIZING &&
 142             dev->dev_state != MEI_DEV_POWER_UP) {
 143                 if (dev->dev_state != MEI_DEV_DISABLED &&
 144                     dev->dev_state != MEI_DEV_POWER_DOWN)
 145                         dev->dev_state = MEI_DEV_RESETTING;
 146
 147                 /* remove all waiting requests */
 148                 mei_cl_all_write_clear(dev);
 149
 150                 mei_cl_all_disconnect(dev);
 151
 152                 /* wake up all readings so they can be interrupted */
 153                 mei_cl_all_wakeup(dev);
 154
 155                 /* remove entry if already in list */
 156                 dev_dbg(&dev->pdev->dev, "remove iamthif and wd from the file list.\n");
 157                 mei_cl_unlink(&dev->wd_cl);
 158                 mei_cl_unlink(&dev->iamthif_cl);
 159                 mei_amthif_reset_params(dev);
 160                 memset(&dev->wr_ext_msg, 0, sizeof(dev->wr_ext_msg));
 161         }
 162
 163         /* we're already in reset, cancel the init timer */
 164         dev->init_clients_timer = 0;
 165
 166         dev->me_clients_num = 0;
 167         dev->rd_msg_hdr = 0;
 168         dev->wd_pending = false;
 169
 170         if (!interrupts_enabled) {
 171                 dev_dbg(&dev->pdev->dev, "intr not enabled end of reset\n");
 172                 return;
 173         }
 174
 175         ret = mei_hw_start(dev);
 176         if (ret) {
 177                 dev_err(&dev->pdev->dev, "hw_start failed disabling the device\n");
 178                 dev->dev_state = MEI_DEV_DISABLED;
 179                 return;
 180         }
 181
 182         dev_dbg(&dev->pdev->dev, "link is established start sending messages.\n");
 183         /* link is established * start sending messages.  */
 184
 185         dev->dev_state = MEI_DEV_INIT_CLIENTS;
 186
 187         ret = mei_hbm_start_req(dev);
 188         if (ret) {
 189                 dev_err(&dev->pdev->dev, "hbm_start failed disabling the device\n");
 190                 dev->dev_state = MEI_DEV_DISABLED;
 191                 return;
 192         }
 193 }
 194 EXPORT_SYMBOL_GPL(mei_reset);
 195
 196 static void mei_reset_work(struct work_struct *work)
 197 {
 198         struct mei_device *dev =
 199                 container_of(work, struct mei_device,  reset_work);
 200
 201         mutex_lock(&dev->device_lock);
 202
 203         mei_reset(dev, true);
 204
 205         mutex_unlock(&dev->device_lock);
 206 }
 207
 208 void mei_stop(struct mei_device *dev)
 209 {
 210         dev_dbg(&dev->pdev->dev, "stopping the device.\n");
 211
 212         mei_cancel_work(dev);
 213
 214         mei_nfc_host_exit(dev);
 215
 216         mutex_lock(&dev->device_lock);
 217
 218         mei_wd_stop(dev);
 219
 220         dev->dev_state = MEI_DEV_POWER_DOWN;
 221         mei_reset(dev, 0);
 222
 223         mutex_unlock(&dev->device_lock);
 224
 225         mei_watchdog_unregister(dev);
 226 }
 227 EXPORT_SYMBOL_GPL(mei_stop);
 228
 229
 230
 231 void mei_device_init(struct mei_device *dev)
 232 {
 233         /* setup our list array */
 234         INIT_LIST_HEAD(&dev->file_list);
 235         INIT_LIST_HEAD(&dev->device_list);
 236         mutex_init(&dev->device_lock);
 237         init_waitqueue_head(&dev->wait_hw_ready);
 238         init_waitqueue_head(&dev->wait_recvd_msg);
 239         init_waitqueue_head(&dev->wait_stop_wd);
 240         dev->dev_state = MEI_DEV_INITIALIZING;
 241
 242         mei_io_list_init(&dev->read_list);
 243         mei_io_list_init(&dev->write_list);
 244         mei_io_list_init(&dev->write_waiting_list);
 245         mei_io_list_init(&dev->ctrl_wr_list);
 246         mei_io_list_init(&dev->ctrl_rd_list);
 247
 248         INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
 249         INIT_WORK(&dev->init_work, mei_host_client_init);
 250         INIT_WORK(&dev->reset_work, mei_reset_work);
 251
 252         INIT_LIST_HEAD(&dev->wd_cl.link);
 253         INIT_LIST_HEAD(&dev->iamthif_cl.link);
 254         mei_io_list_init(&dev->amthif_cmd_list);
 255         mei_io_list_init(&dev->amthif_rd_complete_list);
 256
 257         bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
 258         dev->open_handle_count = 0;
 259
 260         /*
 261          * Reserving the first client ID
 262          * 0: Reserved for MEI Bus Message communications
 263          */
 264         bitmap_set(dev->host_clients_map, 0, 1);
 265 }
 266 EXPORT_SYMBOL_GPL(mei_device_init);
 267