drivers/misc/mei/wd.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 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/moduleparam.h>
  19 #include <linux/device.h>
  20 #include <linux/pci.h>
  21 #include <linux/sched.h>
  22 #include <linux/watchdog.h>
  23
  24 #include <linux/mei.h>
  25
  26 #include "mei_dev.h"
  27 #include "hbm.h"
  28 #include "client.h"
  29
  30 static const u8 mei_start_wd_params[] = { 0x02, 0x12, 0x13, 0x10 };
  31 static const u8 mei_stop_wd_params[] = { 0x02, 0x02, 0x14, 0x10 };
  32
  33 /*
  34  * AMT Watchdog Device
  35  */
  36 #define INTEL_AMT_WATCHDOG_ID "INTCAMT"
  37
  38 /* UUIDs for AMT F/W clients */
  39 const uuid_le mei_wd_guid = UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, 0x89,
  40                                                 0x9D, 0xA9, 0x15, 0x14, 0xCB,
  41                                                 0x32, 0xAB);
  42
  43 static void mei_wd_set_start_timeout(struct mei_device *dev, u16 timeout)
  44 {
  45         dev_dbg(&dev->pdev->dev, "wd: set timeout=%d.\n", timeout);
  46         memcpy(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE);
  47         memcpy(dev->wd_data + MEI_WD_HDR_SIZE, &timeout, sizeof(u16));
  48 }
  49
  50 /**
  51  * mei_wd_host_init - connect to the watchdog client
  52  *
  53  * @dev: the device structure
  54  *
  55  * returns -ENOTTY if wd client cannot be found
  56  *         -EIO if write has failed
  57  *         0 on success
  58  */
  59 int mei_wd_host_init(struct mei_device *dev)
  60 {
  61         struct mei_cl *cl = &dev->wd_cl;
  62         int id;
  63         int ret;
  64
  65         mei_cl_init(cl, dev);
  66
  67         dev->wd_timeout = MEI_WD_DEFAULT_TIMEOUT;
  68         dev->wd_state = MEI_WD_IDLE;
  69
  70
  71         /* check for valid client id */
  72         id = mei_me_cl_by_uuid(dev, &mei_wd_guid);
  73         if (id < 0) {
  74                 dev_info(&dev->pdev->dev, "wd: failed to find the client\n");
  75                 return -ENOTTY;
  76         }
  77
  78         cl->me_client_id = dev->me_clients[id].client_id;
  79
  80         ret = mei_cl_link(cl, MEI_WD_HOST_CLIENT_ID);
  81
  82         if (ret < 0) {
  83                 dev_info(&dev->pdev->dev, "wd: failed link client\n");
  84                 return ret;
  85         }
  86
  87         ret = mei_cl_connect(cl, NULL);
  88
  89         if (ret) {
  90                 dev_err(&dev->pdev->dev, "wd: failed to connect = %d\n", ret);
  91                 mei_cl_unlink(cl);
  92                 return ret;
  93         }
  94
  95         ret = mei_watchdog_register(dev);
  96         if (ret) {
  97                 mei_cl_disconnect(cl);
  98                 mei_cl_unlink(cl);
  99         }
 100         return ret;
 101 }
 102
 103 /**
 104  * mei_wd_send - sends watch dog message to fw.
 105  *
 106  * @dev: the device structure
 107  *
 108  * returns 0 if success,
 109  *      -EIO when message send fails
 110  *      -EINVAL when invalid message is to be sent
 111  *      -ENODEV on flow control failure
 112  */
 113 int mei_wd_send(struct mei_device *dev)
 114 {
 115         struct mei_cl *cl = &dev->wd_cl;
 116         struct mei_msg_hdr hdr;
 117         int ret;
 118
 119         hdr.host_addr = cl->host_client_id;
 120         hdr.me_addr = cl->me_client_id;
 121         hdr.msg_complete = 1;
 122         hdr.reserved = 0;
 123         hdr.internal = 0;
 124
 125         if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE))
 126                 hdr.length = MEI_WD_START_MSG_SIZE;
 127         else if (!memcmp(dev->wd_data, mei_stop_wd_params, MEI_WD_HDR_SIZE))
 128                 hdr.length = MEI_WD_STOP_MSG_SIZE;
 129         else {
 130                 dev_err(&dev->pdev->dev, "wd: invalid message is to be sent, aborting\n");
 131                 return -EINVAL;
 132         }
 133
 134         ret = mei_write_message(dev, &hdr, dev->wd_data);
 135         if (ret) {
 136                 dev_err(&dev->pdev->dev, "wd: write message failed\n");
 137                 return ret;
 138         }
 139
 140         ret = mei_cl_flow_ctrl_reduce(cl);
 141         if (ret) {
 142                 dev_err(&dev->pdev->dev, "wd: flow_ctrl_reduce failed.\n");
 143                 return ret;
 144         }
 145
 146         return 0;
 147 }
 148
 149 /**
 150  * mei_wd_stop - sends watchdog stop message to fw.
 151  *
 152  * @dev: the device structure
 153  * @preserve: indicate if to keep the timeout value
 154  *
 155  * returns 0 if success
 156  * on error:
 157  *      -EIO    when message send fails
 158  *      -EINVAL when invalid message is to be sent
 159  *      -ETIME  on message timeout
 160  */
 161 int mei_wd_stop(struct mei_device *dev)
 162 {
 163         int ret;
 164
 165         if (dev->wd_cl.state != MEI_FILE_CONNECTED ||
 166             dev->wd_state != MEI_WD_RUNNING)
 167                 return 0;
 168
 169         memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_STOP_MSG_SIZE);
 170
 171         dev->wd_state = MEI_WD_STOPPING;
 172
 173         ret = mei_cl_flow_ctrl_creds(&dev->wd_cl);
 174         if (ret < 0)
 175                 goto err;
 176
 177         if (ret && mei_hbuf_acquire(dev)) {
 178                 ret = mei_wd_send(dev);
 179                 if (ret)
 180                         goto err;
 181                 dev->wd_pending = false;
 182         } else {
 183                 dev->wd_pending = true;
 184         }
 185
 186         mutex_unlock(&dev->device_lock);
 187
 188         ret = wait_event_timeout(dev->wait_stop_wd,
 189                                 dev->wd_state == MEI_WD_IDLE,
 190                                 msecs_to_jiffies(MEI_WD_STOP_TIMEOUT));
 191         mutex_lock(&dev->device_lock);
 192         if (dev->wd_state != MEI_WD_IDLE) {
 193                 /* timeout */
 194                 ret = -ETIME;
 195                 dev_warn(&dev->pdev->dev,
 196                         "wd: stop failed to complete ret=%d.\n", ret);
 197                 goto err;
 198         }
 199         dev_dbg(&dev->pdev->dev, "wd: stop completed after %u msec\n",
 200                         MEI_WD_STOP_TIMEOUT - jiffies_to_msecs(ret));
 201         return 0;
 202 err:
 203         return ret;
 204 }
 205
 206 /*
 207  * mei_wd_ops_start - wd start command from the watchdog core.
 208  *
 209  * @wd_dev - watchdog device struct
 210  *
 211  * returns 0 if success, negative errno code for failure
 212  */
 213 static int mei_wd_ops_start(struct watchdog_device *wd_dev)
 214 {
 215         int err = -ENODEV;
 216         struct mei_device *dev;
 217
 218         dev = watchdog_get_drvdata(wd_dev);
 219         if (!dev)
 220                 return -ENODEV;
 221
 222         mutex_lock(&dev->device_lock);
 223
 224         if (dev->dev_state != MEI_DEV_ENABLED) {
 225                 dev_dbg(&dev->pdev->dev,
 226                         "wd: dev_state != MEI_DEV_ENABLED  dev_state = %s\n",
 227                         mei_dev_state_str(dev->dev_state));
 228                 goto end_unlock;
 229         }
 230
 231         if (dev->wd_cl.state != MEI_FILE_CONNECTED)     {
 232                 dev_dbg(&dev->pdev->dev,
 233                         "MEI Driver is not connected to Watchdog Client\n");
 234                 goto end_unlock;
 235         }
 236
 237         mei_wd_set_start_timeout(dev, dev->wd_timeout);
 238
 239         err = 0;
 240 end_unlock:
 241         mutex_unlock(&dev->device_lock);
 242         return err;
 243 }
 244
 245 /*
 246  * mei_wd_ops_stop -  wd stop command from the watchdog core.
 247  *
 248  * @wd_dev - watchdog device struct
 249  *
 250  * returns 0 if success, negative errno code for failure
 251  */
 252 static int mei_wd_ops_stop(struct watchdog_device *wd_dev)
 253 {
 254         struct mei_device *dev;
 255
 256         dev = watchdog_get_drvdata(wd_dev);
 257         if (!dev)
 258                 return -ENODEV;
 259
 260         mutex_lock(&dev->device_lock);
 261         mei_wd_stop(dev);
 262         mutex_unlock(&dev->device_lock);
 263
 264         return 0;
 265 }
 266
 267 /*
 268  * mei_wd_ops_ping - wd ping command from the watchdog core.
 269  *
 270  * @wd_dev - watchdog device struct
 271  *
 272  * returns 0 if success, negative errno code for failure
 273  */
 274 static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
 275 {
 276         struct mei_device *dev;
 277         int ret;
 278
 279         dev = watchdog_get_drvdata(wd_dev);
 280         if (!dev)
 281                 return -ENODEV;
 282
 283         mutex_lock(&dev->device_lock);
 284
 285         if (dev->wd_cl.state != MEI_FILE_CONNECTED) {
 286                 dev_err(&dev->pdev->dev, "wd: not connected.\n");
 287                 ret = -ENODEV;
 288                 goto end;
 289         }
 290
 291         dev->wd_state = MEI_WD_RUNNING;
 292
 293         ret = mei_cl_flow_ctrl_creds(&dev->wd_cl);
 294         if (ret < 0)
 295                 goto end;
 296         /* Check if we can send the ping to HW*/
 297         if (ret && mei_hbuf_acquire(dev)) {
 298
 299                 dev_dbg(&dev->pdev->dev, "wd: sending ping\n");
 300
 301                 ret = mei_wd_send(dev);
 302                 if (ret)
 303                         goto end;
 304                 dev->wd_pending = false;
 305         } else {
 306                 dev->wd_pending = true;
 307         }
 308
 309 end:
 310         mutex_unlock(&dev->device_lock);
 311         return ret;
 312 }
 313
 314 /*
 315  * mei_wd_ops_set_timeout - wd set timeout command from the watchdog core.
 316  *
 317  * @wd_dev - watchdog device struct
 318  * @timeout - timeout value to set
 319  *
 320  * returns 0 if success, negative errno code for failure
 321  */
 322 static int mei_wd_ops_set_timeout(struct watchdog_device *wd_dev,
 323                 unsigned int timeout)
 324 {
 325         struct mei_device *dev;
 326
 327         dev = watchdog_get_drvdata(wd_dev);
 328         if (!dev)
 329                 return -ENODEV;
 330
 331         /* Check Timeout value */
 332         if (timeout < MEI_WD_MIN_TIMEOUT || timeout > MEI_WD_MAX_TIMEOUT)
 333                 return -EINVAL;
 334
 335         mutex_lock(&dev->device_lock);
 336
 337         dev->wd_timeout = timeout;
 338         wd_dev->timeout = timeout;
 339         mei_wd_set_start_timeout(dev, dev->wd_timeout);
 340
 341         mutex_unlock(&dev->device_lock);
 342
 343         return 0;
 344 }
 345
 346 /*
 347  * Watchdog Device structs
 348  */
 349 static const struct watchdog_ops wd_ops = {
 350                 .owner = THIS_MODULE,
 351                 .start = mei_wd_ops_start,
 352                 .stop = mei_wd_ops_stop,
 353                 .ping = mei_wd_ops_ping,
 354                 .set_timeout = mei_wd_ops_set_timeout,
 355 };
 356 static const struct watchdog_info wd_info = {
 357                 .identity = INTEL_AMT_WATCHDOG_ID,
 358                 .options = WDIOF_KEEPALIVEPING |
 359                            WDIOF_SETTIMEOUT |
 360                            WDIOF_ALARMONLY,
 361 };
 362
 363 static struct watchdog_device amt_wd_dev = {
 364                 .info = &wd_info,
 365                 .ops = &wd_ops,
 366                 .timeout = MEI_WD_DEFAULT_TIMEOUT,
 367                 .min_timeout = MEI_WD_MIN_TIMEOUT,
 368                 .max_timeout = MEI_WD_MAX_TIMEOUT,
 369 };
 370
 371
 372 int mei_watchdog_register(struct mei_device *dev)
 373 {
 374
 375         int ret;
 376
 377         /* unlock to perserve correct locking order */
 378         mutex_unlock(&dev->device_lock);
 379         ret = watchdog_register_device(&amt_wd_dev);
 380         mutex_lock(&dev->device_lock);
 381         if (ret) {
 382                 dev_err(&dev->pdev->dev, "wd: unable to register watchdog device = %d.\n",
 383                         ret);
 384                 return ret;
 385         }
 386
 387         dev_dbg(&dev->pdev->dev,
 388                 "wd: successfully register watchdog interface.\n");
 389         watchdog_set_drvdata(&amt_wd_dev, dev);
 390         return 0;
 391 }
 392
 393 void mei_watchdog_unregister(struct mei_device *dev)
 394 {
 395         if (watchdog_get_drvdata(&amt_wd_dev) == NULL)
 396                 return;
 397
 398         watchdog_set_drvdata(&amt_wd_dev, NULL);
 399         watchdog_unregister_device(&amt_wd_dev);
 400 }
 401