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