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  * mei_fw_status2str - convert fw status registers to printable string
  59  *
  60  * @fw_status:  firmware status
  61  * @buf: string buffer at minimal size MEI_FW_STATUS_STR_SZ
  62  * @len: buffer len must be >= MEI_FW_STATUS_STR_SZ
  63  *
  64  * Return: number of bytes written or -EINVAL if buffer is to small
  65  */
  66 ssize_t mei_fw_status2str(struct mei_fw_status *fw_status,
  67                           char *buf, size_t len)
  68 {
  69         ssize_t cnt = 0;
  70         int i;
  71
  72         buf[0] = '\0';
  73
  74         if (len < MEI_FW_STATUS_STR_SZ)
  75                 return -EINVAL;
  76
  77         for (i = 0; i < fw_status->count; i++)
  78                 cnt += scnprintf(buf + cnt, len - cnt, "%08X ",
  79                                 fw_status->status[i]);
  80
  81         /* drop last space */
  82         buf[cnt] = '\0';
  83         return cnt;
  84 }
  85 EXPORT_SYMBOL_GPL(mei_fw_status2str);
  86
  87 /**
  88  * mei_cancel_work - Cancel mei background jobs
  89  *
  90  * @dev: the device structure
  91  */
  92 void mei_cancel_work(struct mei_device *dev)
  93 {
  94         cancel_work_sync(&dev->reset_work);
  95         cancel_work_sync(&dev->bus_rescan_work);
  96
  97         cancel_delayed_work_sync(&dev->timer_work);
  98 }
  99 EXPORT_SYMBOL_GPL(mei_cancel_work);
 100
 101 /**
 102  * mei_reset - resets host and fw.
 103  *
 104  * @dev: the device structure
 105  *
 106  * Return: 0 on success or < 0 if the reset hasn't succeeded
 107  */
 108 int mei_reset(struct mei_device *dev)
 109 {
 110         enum mei_dev_state state = dev->dev_state;
 111         bool interrupts_enabled;
 112         int ret;
 113
 114         if (state != MEI_DEV_INITIALIZING &&
 115             state != MEI_DEV_DISABLED &&
 116             state != MEI_DEV_POWER_DOWN &&
 117             state != MEI_DEV_POWER_UP) {
 118                 char fw_sts_str[MEI_FW_STATUS_STR_SZ];
 119
 120                 mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ);
 121                 dev_warn(dev->dev, "unexpected reset: dev_state = %s fw status = %s\n",
 122                          mei_dev_state_str(state), fw_sts_str);
 123         }
 124
 125         mei_clear_interrupts(dev);
 126
 127         mei_synchronize_irq(dev);
 128
 129         /* we're already in reset, cancel the init timer
 130          * if the reset was called due the hbm protocol error
 131          * we need to call it before hw start
 132          * so the hbm watchdog won't kick in
 133          */
 134         mei_hbm_idle(dev);
 135
 136         /* enter reset flow */
 137         interrupts_enabled = state != MEI_DEV_POWER_DOWN;
 138         dev->dev_state = MEI_DEV_RESETTING;
 139
 140         dev->reset_count++;
 141         if (dev->reset_count > MEI_MAX_CONSEC_RESET) {
 142                 dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n");
 143                 dev->dev_state = MEI_DEV_DISABLED;
 144                 return -ENODEV;
 145         }
 146
 147         ret = mei_hw_reset(dev, interrupts_enabled);
 148         /* fall through and remove the sw state even if hw reset has failed */
 149
 150         /* no need to clean up software state in case of power up */
 151         if (state != MEI_DEV_INITIALIZING &&
 152             state != MEI_DEV_POWER_UP) {
 153
 154                 /* remove all waiting requests */
 155                 mei_cl_all_disconnect(dev);
 156
 157                 /* remove entry if already in list */
 158                 dev_dbg(dev->dev, "remove iamthif from the file list.\n");
 159                 mei_cl_unlink(&dev->iamthif_cl);
 160                 mei_amthif_reset_params(dev);
 161         }
 162
 163         mei_hbm_reset(dev);
 164
 165         dev->rd_msg_hdr = 0;
 166
 167         if (ret) {
 168                 dev_err(dev->dev, "hw_reset failed ret = %d\n", ret);
 169                 return ret;
 170         }
 171
 172         if (state == MEI_DEV_POWER_DOWN) {
 173                 dev_dbg(dev->dev, "powering down: end of reset\n");
 174                 dev->dev_state = MEI_DEV_DISABLED;
 175                 return 0;
 176         }
 177
 178         ret = mei_hw_start(dev);
 179         if (ret) {
 180                 dev_err(dev->dev, "hw_start failed ret = %d\n", ret);
 181                 return ret;
 182         }
 183
 184         dev_dbg(dev->dev, "link is established start sending messages.\n");
 185
 186         dev->dev_state = MEI_DEV_INIT_CLIENTS;
 187         ret = mei_hbm_start_req(dev);
 188         if (ret) {
 189                 dev_err(dev->dev, "hbm_start failed ret = %d\n", ret);
 190                 dev->dev_state = MEI_DEV_RESETTING;
 191                 return ret;
 192         }
 193
 194         return 0;
 195 }
 196 EXPORT_SYMBOL_GPL(mei_reset);
 197
 198 /**
 199  * mei_start - initializes host and fw to start work.
 200  *
 201  * @dev: the device structure
 202  *
 203  * Return: 0 on success, <0 on failure.
 204  */
 205 int mei_start(struct mei_device *dev)
 206 {
 207         int ret;
 208
 209         mutex_lock(&dev->device_lock);
 210
 211         /* acknowledge interrupt and stop interrupts */
 212         mei_clear_interrupts(dev);
 213
 214         mei_hw_config(dev);
 215
 216         dev_dbg(dev->dev, "reset in start the mei device.\n");
 217
 218         dev->reset_count = 0;
 219         do {
 220                 dev->dev_state = MEI_DEV_INITIALIZING;
 221                 ret = mei_reset(dev);
 222
 223                 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
 224                         dev_err(dev->dev, "reset failed ret = %d", ret);
 225                         goto err;
 226                 }
 227         } while (ret);
 228
 229         /* we cannot start the device w/o hbm start message completed */
 230         if (dev->dev_state == MEI_DEV_DISABLED) {
 231                 dev_err(dev->dev, "reset failed");
 232                 goto err;
 233         }
 234
 235         if (mei_hbm_start_wait(dev)) {
 236                 dev_err(dev->dev, "HBM haven't started");
 237                 goto err;
 238         }
 239
 240         if (!mei_host_is_ready(dev)) {
 241                 dev_err(dev->dev, "host is not ready.\n");
 242                 goto err;
 243         }
 244
 245         if (!mei_hw_is_ready(dev)) {
 246                 dev_err(dev->dev, "ME is not ready.\n");
 247                 goto err;
 248         }
 249
 250         if (!mei_hbm_version_is_supported(dev)) {
 251                 dev_dbg(dev->dev, "MEI start failed.\n");
 252                 goto err;
 253         }
 254
 255         dev_dbg(dev->dev, "link layer has been established.\n");
 256
 257         mutex_unlock(&dev->device_lock);
 258         return 0;
 259 err:
 260         dev_err(dev->dev, "link layer initialization failed.\n");
 261         dev->dev_state = MEI_DEV_DISABLED;
 262         mutex_unlock(&dev->device_lock);
 263         return -ENODEV;
 264 }
 265 EXPORT_SYMBOL_GPL(mei_start);
 266
 267 /**
 268  * mei_restart - restart device after suspend
 269  *
 270  * @dev: the device structure
 271  *
 272  * Return: 0 on success or -ENODEV if the restart hasn't succeeded
 273  */
 274 int mei_restart(struct mei_device *dev)
 275 {
 276         int err;
 277
 278         mutex_lock(&dev->device_lock);
 279
 280         dev->dev_state = MEI_DEV_POWER_UP;
 281         dev->reset_count = 0;
 282
 283         err = mei_reset(dev);
 284
 285         mutex_unlock(&dev->device_lock);
 286
 287         if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
 288                 dev_err(dev->dev, "device disabled = %d\n", err);
 289                 return -ENODEV;
 290         }
 291
 292         /* try to start again */
 293         if (err)
 294                 schedule_work(&dev->reset_work);
 295
 296
 297         return 0;
 298 }
 299 EXPORT_SYMBOL_GPL(mei_restart);
 300
 301 static void mei_reset_work(struct work_struct *work)
 302 {
 303         struct mei_device *dev =
 304                 container_of(work, struct mei_device,  reset_work);
 305         int ret;
 306
 307         mutex_lock(&dev->device_lock);
 308
 309         ret = mei_reset(dev);
 310
 311         mutex_unlock(&dev->device_lock);
 312
 313         if (dev->dev_state == MEI_DEV_DISABLED) {
 314                 dev_err(dev->dev, "device disabled = %d\n", ret);
 315                 return;
 316         }
 317
 318         /* retry reset in case of failure */
 319         if (ret)
 320                 schedule_work(&dev->reset_work);
 321 }
 322
 323 void mei_stop(struct mei_device *dev)
 324 {
 325         dev_dbg(dev->dev, "stopping the device.\n");
 326
 327         mei_cl_bus_remove_devices(dev);
 328
 329         mei_cancel_work(dev);
 330
 331         mutex_lock(&dev->device_lock);
 332
 333         dev->dev_state = MEI_DEV_POWER_DOWN;
 334         mei_reset(dev);
 335         /* move device to disabled state unconditionally */
 336         dev->dev_state = MEI_DEV_DISABLED;
 337
 338         mutex_unlock(&dev->device_lock);
 339 }
 340 EXPORT_SYMBOL_GPL(mei_stop);
 341
 342 /**
 343  * mei_write_is_idle - check if the write queues are idle
 344  *
 345  * @dev: the device structure
 346  *
 347  * Return: true of there is no pending write
 348  */
 349 bool mei_write_is_idle(struct mei_device *dev)
 350 {
 351         bool idle = (dev->dev_state == MEI_DEV_ENABLED &&
 352                 list_empty(&dev->ctrl_wr_list.list) &&
 353                 list_empty(&dev->write_list.list)   &&
 354                 list_empty(&dev->write_waiting_list.list));
 355
 356         dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n",
 357                 idle,
 358                 mei_dev_state_str(dev->dev_state),
 359                 list_empty(&dev->ctrl_wr_list.list),
 360                 list_empty(&dev->write_list.list),
 361                 list_empty(&dev->write_waiting_list.list));
 362
 363         return idle;
 364 }
 365 EXPORT_SYMBOL_GPL(mei_write_is_idle);
 366
 367 /**
 368  * mei_device_init  -- initialize mei_device structure
 369  *
 370  * @dev: the mei device
 371  * @device: the device structure
 372  * @hw_ops: hw operations
 373  */
 374 void mei_device_init(struct mei_device *dev,
 375                      struct device *device,
 376                      const struct mei_hw_ops *hw_ops)
 377 {
 378         /* setup our list array */
 379         INIT_LIST_HEAD(&dev->file_list);
 380         INIT_LIST_HEAD(&dev->device_list);
 381         INIT_LIST_HEAD(&dev->me_clients);
 382         mutex_init(&dev->device_lock);
 383         init_rwsem(&dev->me_clients_rwsem);
 384         mutex_init(&dev->cl_bus_lock);
 385         init_waitqueue_head(&dev->wait_hw_ready);
 386         init_waitqueue_head(&dev->wait_pg);
 387         init_waitqueue_head(&dev->wait_hbm_start);
 388         dev->dev_state = MEI_DEV_INITIALIZING;
 389         dev->reset_count = 0;
 390
 391         mei_io_list_init(&dev->write_list);
 392         mei_io_list_init(&dev->write_waiting_list);
 393         mei_io_list_init(&dev->ctrl_wr_list);
 394         mei_io_list_init(&dev->ctrl_rd_list);
 395
 396         INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
 397         INIT_WORK(&dev->reset_work, mei_reset_work);
 398         INIT_WORK(&dev->bus_rescan_work, mei_cl_bus_rescan_work);
 399
 400         INIT_LIST_HEAD(&dev->iamthif_cl.link);
 401         mei_io_list_init(&dev->amthif_cmd_list);
 402
 403         bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
 404         dev->open_handle_count = 0;
 405
 406         /*
 407          * Reserving the first client ID
 408          * 0: Reserved for MEI Bus Message communications
 409          */
 410         bitmap_set(dev->host_clients_map, 0, 1);
 411
 412         dev->pg_event = MEI_PG_EVENT_IDLE;
 413         dev->ops      = hw_ops;
 414         dev->dev      = device;
 415 }
 416 EXPORT_SYMBOL_GPL(mei_device_init);
 417