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/sched.h>
  19 #include <linux/wait.h>
  20 #include <linux/delay.h>
  21
  22 #include <linux/mei.h>
  23
  24 #include "mei_dev.h"
  25 #include "hbm.h"
  26 #include "client.h"
  27
  28 const char *mei_dev_state_str(int state)
  29 {
  30 #define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
  31         switch (state) {
  32         MEI_DEV_STATE(INITIALIZING);
  33         MEI_DEV_STATE(INIT_CLIENTS);
  34         MEI_DEV_STATE(ENABLED);
  35         MEI_DEV_STATE(RESETTING);
  36         MEI_DEV_STATE(DISABLED);
  37         MEI_DEV_STATE(POWER_DOWN);
  38         MEI_DEV_STATE(POWER_UP);
  39         default:
  40                 return "unknown";
  41         }
  42 #undef MEI_DEV_STATE
  43 }
  44
  45 const char *mei_pg_state_str(enum mei_pg_state state)
  46 {
  47 #define MEI_PG_STATE(state) case MEI_PG_##state: return #state
  48         switch (state) {
  49         MEI_PG_STATE(OFF);
  50         MEI_PG_STATE(ON);
  51         default:
  52                 return "unknown";
  53         }
  54 #undef MEI_PG_STATE
  55 }
  56
  57
  58 /**
  59  * mei_cancel_work - Cancel mei background jobs
  60  *
  61  * @dev: the device structure
  62  */
  63 void mei_cancel_work(struct mei_device *dev)
  64 {
  65         cancel_work_sync(&dev->init_work);
  66         cancel_work_sync(&dev->reset_work);
  67
  68         cancel_delayed_work(&dev->timer_work);
  69 }
  70 EXPORT_SYMBOL_GPL(mei_cancel_work);
  71
  72 /**
  73  * mei_reset - resets host and fw.
  74  *
  75  * @dev: the device structure
  76  *
  77  * Return: 0 on success or < 0 if the reset hasn't succeeded
  78  */
  79 int mei_reset(struct mei_device *dev)
  80 {
  81         enum mei_dev_state state = dev->dev_state;
  82         bool interrupts_enabled;
  83         int ret;
  84
  85         if (state != MEI_DEV_INITIALIZING &&
  86             state != MEI_DEV_DISABLED &&
  87             state != MEI_DEV_POWER_DOWN &&
  88             state != MEI_DEV_POWER_UP) {
  89                 struct mei_fw_status fw_status;
  90
  91                 mei_fw_status(dev, &fw_status);
  92                 dev_warn(dev->dev,
  93                         "unexpected reset: dev_state = %s " FW_STS_FMT "\n",
  94                         mei_dev_state_str(state), FW_STS_PRM(fw_status));
  95         }
  96
  97         /* we're already in reset, cancel the init timer
  98          * if the reset was called due the hbm protocol error
  99          * we need to call it before hw start
 100          * so the hbm watchdog won't kick in
 101          */
 102         mei_hbm_idle(dev);
 103
 104         /* enter reset flow */
 105         interrupts_enabled = state != MEI_DEV_POWER_DOWN;
 106         dev->dev_state = MEI_DEV_RESETTING;
 107
 108         dev->reset_count++;
 109         if (dev->reset_count > MEI_MAX_CONSEC_RESET) {
 110                 dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n");
 111                 dev->dev_state = MEI_DEV_DISABLED;
 112                 return -ENODEV;
 113         }
 114
 115         ret = mei_hw_reset(dev, interrupts_enabled);
 116         /* fall through and remove the sw state even if hw reset has failed */
 117
 118         /* no need to clean up software state in case of power up */
 119         if (state != MEI_DEV_INITIALIZING &&
 120             state != MEI_DEV_POWER_UP) {
 121
 122                 /* remove all waiting requests */
 123                 mei_cl_all_write_clear(dev);
 124
 125                 mei_cl_all_disconnect(dev);
 126
 127                 /* wake up all readers and writers so they can be interrupted */
 128                 mei_cl_all_wakeup(dev);
 129
 130                 /* remove entry if already in list */
 131                 dev_dbg(dev->dev, "remove iamthif and wd from the file list.\n");
 132                 mei_cl_unlink(&dev->wd_cl);
 133                 mei_cl_unlink(&dev->iamthif_cl);
 134                 mei_amthif_reset_params(dev);
 135         }
 136
 137         mei_hbm_reset(dev);
 138
 139         dev->rd_msg_hdr = 0;
 140         dev->wd_pending = false;
 141
 142         if (ret) {
 143                 dev_err(dev->dev, "hw_reset failed ret = %d\n", ret);
 144                 return ret;
 145         }
 146
 147         if (state == MEI_DEV_POWER_DOWN) {
 148                 dev_dbg(dev->dev, "powering down: end of reset\n");
 149                 dev->dev_state = MEI_DEV_DISABLED;
 150                 return 0;
 151         }
 152
 153         ret = mei_hw_start(dev);
 154         if (ret) {
 155                 dev_err(dev->dev, "hw_start failed ret = %d\n", ret);
 156                 return ret;
 157         }
 158
 159         dev_dbg(dev->dev, "link is established start sending messages.\n");
 160
 161         dev->dev_state = MEI_DEV_INIT_CLIENTS;
 162         ret = mei_hbm_start_req(dev);
 163         if (ret) {
 164                 dev_err(dev->dev, "hbm_start failed ret = %d\n", ret);
 165                 dev->dev_state = MEI_DEV_RESETTING;
 166                 return ret;
 167         }
 168
 169         return 0;
 170 }
 171 EXPORT_SYMBOL_GPL(mei_reset);
 172
 173 /**
 174  * mei_start - initializes host and fw to start work.
 175  *
 176  * @dev: the device structure
 177  *
 178  * Return: 0 on success, <0 on failure.
 179  */
 180 int mei_start(struct mei_device *dev)
 181 {
 182         int ret;
 183
 184         mutex_lock(&dev->device_lock);
 185
 186         /* acknowledge interrupt and stop interrupts */
 187         mei_clear_interrupts(dev);
 188
 189         mei_hw_config(dev);
 190
 191         dev_dbg(dev->dev, "reset in start the mei device.\n");
 192
 193         dev->reset_count = 0;
 194         do {
 195                 dev->dev_state = MEI_DEV_INITIALIZING;
 196                 ret = mei_reset(dev);
 197
 198                 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
 199                         dev_err(dev->dev, "reset failed ret = %d", ret);
 200                         goto err;
 201                 }
 202         } while (ret);
 203
 204         /* we cannot start the device w/o hbm start message completed */
 205         if (dev->dev_state == MEI_DEV_DISABLED) {
 206                 dev_err(dev->dev, "reset failed");
 207                 goto err;
 208         }
 209
 210         if (mei_hbm_start_wait(dev)) {
 211                 dev_err(dev->dev, "HBM haven't started");
 212                 goto err;
 213         }
 214
 215         if (!mei_host_is_ready(dev)) {
 216                 dev_err(dev->dev, "host is not ready.\n");
 217                 goto err;
 218         }
 219
 220         if (!mei_hw_is_ready(dev)) {
 221                 dev_err(dev->dev, "ME is not ready.\n");
 222                 goto err;
 223         }
 224
 225         if (!mei_hbm_version_is_supported(dev)) {
 226                 dev_dbg(dev->dev, "MEI start failed.\n");
 227                 goto err;
 228         }
 229
 230         dev_dbg(dev->dev, "link layer has been established.\n");
 231
 232         mutex_unlock(&dev->device_lock);
 233         return 0;
 234 err:
 235         dev_err(dev->dev, "link layer initialization failed.\n");
 236         dev->dev_state = MEI_DEV_DISABLED;
 237         mutex_unlock(&dev->device_lock);
 238         return -ENODEV;
 239 }
 240 EXPORT_SYMBOL_GPL(mei_start);
 241
 242 /**
 243  * mei_restart - restart device after suspend
 244  *
 245  * @dev: the device structure
 246  *
 247  * Return: 0 on success or -ENODEV if the restart hasn't succeeded
 248  */
 249 int mei_restart(struct mei_device *dev)
 250 {
 251         int err;
 252
 253         mutex_lock(&dev->device_lock);
 254
 255         mei_clear_interrupts(dev);
 256
 257         dev->dev_state = MEI_DEV_POWER_UP;
 258         dev->reset_count = 0;
 259
 260         err = mei_reset(dev);
 261
 262         mutex_unlock(&dev->device_lock);
 263
 264         if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
 265                 dev_err(dev->dev, "device disabled = %d\n", err);
 266                 return -ENODEV;
 267         }
 268
 269         /* try to start again */
 270         if (err)
 271                 schedule_work(&dev->reset_work);
 272
 273
 274         return 0;
 275 }
 276 EXPORT_SYMBOL_GPL(mei_restart);
 277
 278 static void mei_reset_work(struct work_struct *work)
 279 {
 280         struct mei_device *dev =
 281                 container_of(work, struct mei_device,  reset_work);
 282         int ret;
 283
 284         mutex_lock(&dev->device_lock);
 285
 286         ret = mei_reset(dev);
 287
 288         mutex_unlock(&dev->device_lock);
 289
 290         if (dev->dev_state == MEI_DEV_DISABLED) {
 291                 dev_err(dev->dev, "device disabled = %d\n", ret);
 292                 return;
 293         }
 294
 295         /* retry reset in case of failure */
 296         if (ret)
 297                 schedule_work(&dev->reset_work);
 298 }
 299
 300 void mei_stop(struct mei_device *dev)
 301 {
 302         dev_dbg(dev->dev, "stopping the device.\n");
 303
 304         mei_cancel_work(dev);
 305
 306         mei_nfc_host_exit(dev);
 307
 308         mei_cl_bus_remove_devices(dev);
 309
 310         mutex_lock(&dev->device_lock);
 311
 312         mei_wd_stop(dev);
 313
 314         dev->dev_state = MEI_DEV_POWER_DOWN;
 315         mei_reset(dev);
 316
 317         mutex_unlock(&dev->device_lock);
 318
 319         mei_watchdog_unregister(dev);
 320 }
 321 EXPORT_SYMBOL_GPL(mei_stop);
 322
 323 /**
 324  * mei_write_is_idle - check if the write queues are idle
 325  *
 326  * @dev: the device structure
 327  *
 328  * Return: true of there is no pending write
 329  */
 330 bool mei_write_is_idle(struct mei_device *dev)
 331 {
 332         bool idle = (dev->dev_state == MEI_DEV_ENABLED &&
 333                 list_empty(&dev->ctrl_wr_list.list) &&
 334                 list_empty(&dev->write_list.list));
 335
 336         dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%d write=%d\n",
 337                 idle,
 338                 mei_dev_state_str(dev->dev_state),
 339                 list_empty(&dev->ctrl_wr_list.list),
 340                 list_empty(&dev->write_list.list));
 341
 342         return idle;
 343 }
 344 EXPORT_SYMBOL_GPL(mei_write_is_idle);
 345
 346 /**
 347  * mei_device_init  -- initialize mei_device structure
 348  *
 349  * @dev: the mei device
 350  * @device: the device structure
 351  * @hw_ops: hw operations
 352  */
 353 void mei_device_init(struct mei_device *dev,
 354                      struct device *device,
 355                      const struct mei_hw_ops *hw_ops)
 356 {
 357         /* setup our list array */
 358         INIT_LIST_HEAD(&dev->file_list);
 359         INIT_LIST_HEAD(&dev->device_list);
 360         INIT_LIST_HEAD(&dev->me_clients);
 361         mutex_init(&dev->device_lock);
 362         init_waitqueue_head(&dev->wait_hw_ready);
 363         init_waitqueue_head(&dev->wait_pg);
 364         init_waitqueue_head(&dev->wait_hbm_start);
 365         init_waitqueue_head(&dev->wait_stop_wd);
 366         dev->dev_state = MEI_DEV_INITIALIZING;
 367         dev->reset_count = 0;
 368
 369         mei_io_list_init(&dev->read_list);
 370         mei_io_list_init(&dev->write_list);
 371         mei_io_list_init(&dev->write_waiting_list);
 372         mei_io_list_init(&dev->ctrl_wr_list);
 373         mei_io_list_init(&dev->ctrl_rd_list);
 374
 375         INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
 376         INIT_WORK(&dev->init_work, mei_host_client_init);
 377         INIT_WORK(&dev->reset_work, mei_reset_work);
 378
 379         INIT_LIST_HEAD(&dev->wd_cl.link);
 380         INIT_LIST_HEAD(&dev->iamthif_cl.link);
 381         mei_io_list_init(&dev->amthif_cmd_list);
 382         mei_io_list_init(&dev->amthif_rd_complete_list);
 383
 384         bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
 385         dev->open_handle_count = 0;
 386
 387         /*
 388          * Reserving the first client ID
 389          * 0: Reserved for MEI Bus Message communications
 390          */
 391         bitmap_set(dev->host_clients_map, 0, 1);
 392
 393         dev->pg_event = MEI_PG_EVENT_IDLE;
 394         dev->ops      = hw_ops;
 395         dev->dev      = device;
 396 }
 397 EXPORT_SYMBOL_GPL(mei_device_init);
 398