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 "hw-me.h"
  29 #include "client.h"
  30
  31 static const u8 mei_start_wd_params[] = { 0x02, 0x12, 0x13, 0x10 };
  32 static const u8 mei_stop_wd_params[] = { 0x02, 0x02, 0x14, 0x10 };
  33
  34 const u8 mei_wd_state_independence_msg[3][4] = {
  35         {0x05, 0x02, 0x51, 0x10},
  36         {0x05, 0x02, 0x52, 0x10},
  37         {0x07, 0x02, 0x01, 0x10}
  38 };
  39
  40 /*
  41  * AMT Watchdog Device
  42  */
  43 #define INTEL_AMT_WATCHDOG_ID "INTCAMT"
  44
  45 /* UUIDs for AMT F/W clients */
  46 const uuid_le mei_wd_guid = UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, 0x89,
  47                                                 0x9D, 0xA9, 0x15, 0x14, 0xCB,
  48                                                 0x32, 0xAB);
  49
  50 static void mei_wd_set_start_timeout(struct mei_device *dev, u16 timeout)
  51 {
  52         dev_dbg(&dev->pdev->dev, "wd: set timeout=%d.\n", timeout);
  53         memcpy(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE);
  54         memcpy(dev->wd_data + MEI_WD_HDR_SIZE, &timeout, sizeof(u16));
  55 }
  56
  57 /**
  58  * mei_wd_host_init - connect to the watchdog client
  59  *
  60  * @dev: the device structure
  61  *
  62  * returns -ENENT if wd client cannot be found
  63  *         -EIO if write has failed
  64  *         0 on success
  65  */
  66 int mei_wd_host_init(struct mei_device *dev)
  67 {
  68         struct mei_cl *cl = &dev->wd_cl;
  69         int i;
  70         int ret;
  71
  72         mei_cl_init(cl, dev);
  73
  74         dev->wd_timeout = MEI_WD_DEFAULT_TIMEOUT;
  75         dev->wd_state = MEI_WD_IDLE;
  76
  77
  78         /* check for valid client id */
  79         i = mei_me_cl_by_uuid(dev, &mei_wd_guid);
  80         if (i < 0) {
  81                 dev_info(&dev->pdev->dev, "wd: failed to find the client\n");
  82                 return -ENOENT;
  83         }
  84
  85         cl->me_client_id = dev->me_clients[i].client_id;
  86
  87         ret = mei_cl_link(cl, MEI_WD_HOST_CLIENT_ID);
  88
  89         if (ret < 0) {
  90                 dev_info(&dev->pdev->dev, "wd: failed link client\n");
  91                 return -ENOENT;
  92         }
  93
  94         cl->state = MEI_FILE_CONNECTING;
  95
  96         if (mei_hbm_cl_connect_req(dev, cl)) {
  97                 dev_err(&dev->pdev->dev, "wd: failed to connect to the client\n");
  98                 cl->state = MEI_FILE_DISCONNECTED;
  99                 cl->host_client_id = 0;
 100                 return -EIO;
 101         }
 102         cl->timer_count = MEI_CONNECT_TIMEOUT;
 103
 104         return 0;
 105 }
 106
 107 /**
 108  * mei_wd_send - sends watch dog message to fw.
 109  *
 110  * @dev: the device structure
 111  *
 112  * returns 0 if success,
 113  *      -EIO when message send fails
 114  *      -EINVAL when invalid message is to be sent
 115  */
 116 int mei_wd_send(struct mei_device *dev)
 117 {
 118         struct mei_msg_hdr hdr;
 119
 120         hdr.host_addr = dev->wd_cl.host_client_id;
 121         hdr.me_addr = dev->wd_cl.me_client_id;
 122         hdr.msg_complete = 1;
 123         hdr.reserved = 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                 return -EINVAL;
 131
 132         return mei_write_message(dev, &hdr, dev->wd_data);
 133 }
 134
 135 /**
 136  * mei_wd_stop - sends watchdog stop message to fw.
 137  *
 138  * @dev: the device structure
 139  * @preserve: indicate if to keep the timeout value
 140  *
 141  * returns 0 if success,
 142  *      -EIO when message send fails
 143  *      -EINVAL when invalid message is to be sent
 144  */
 145 int mei_wd_stop(struct mei_device *dev)
 146 {
 147         int ret;
 148
 149         if (dev->wd_cl.state != MEI_FILE_CONNECTED ||
 150             dev->wd_state != MEI_WD_RUNNING)
 151                 return 0;
 152
 153         memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_STOP_MSG_SIZE);
 154
 155         dev->wd_state = MEI_WD_STOPPING;
 156
 157         ret = mei_cl_flow_ctrl_creds(&dev->wd_cl);
 158         if (ret < 0)
 159                 goto out;
 160
 161         if (ret && dev->hbuf_is_ready) {
 162                 ret = 0;
 163                 dev->hbuf_is_ready = false;
 164
 165                 if (!mei_wd_send(dev)) {
 166                         ret = mei_cl_flow_ctrl_reduce(&dev->wd_cl);
 167                         if (ret)
 168                                 goto out;
 169                 } else {
 170                         dev_err(&dev->pdev->dev, "wd: send stop failed\n");
 171                 }
 172
 173                 dev->wd_pending = false;
 174         } else {
 175                 dev->wd_pending = true;
 176         }
 177
 178         mutex_unlock(&dev->device_lock);
 179
 180         ret = wait_event_interruptible_timeout(dev->wait_stop_wd,
 181                                         dev->wd_state == MEI_WD_IDLE,
 182                                         msecs_to_jiffies(MEI_WD_STOP_TIMEOUT));
 183         mutex_lock(&dev->device_lock);
 184         if (dev->wd_state == MEI_WD_IDLE) {
 185                 dev_dbg(&dev->pdev->dev, "wd: stop completed ret=%d.\n", ret);
 186                 ret = 0;
 187         } else {
 188                 if (!ret)
 189                         ret = -ETIMEDOUT;
 190                 dev_warn(&dev->pdev->dev,
 191                         "wd: stop failed to complete ret=%d.\n", ret);
 192         }
 193
 194 out:
 195         return ret;
 196 }
 197
 198 /*
 199  * mei_wd_ops_start - wd start command from the watchdog core.
 200  *
 201  * @wd_dev - watchdog device struct
 202  *
 203  * returns 0 if success, negative errno code for failure
 204  */
 205 static int mei_wd_ops_start(struct watchdog_device *wd_dev)
 206 {
 207         int err = -ENODEV;
 208         struct mei_device *dev;
 209
 210         dev = watchdog_get_drvdata(wd_dev);
 211         if (!dev)
 212                 return -ENODEV;
 213
 214         mutex_lock(&dev->device_lock);
 215
 216         if (dev->dev_state != MEI_DEV_ENABLED) {
 217                 dev_dbg(&dev->pdev->dev,
 218                         "wd: dev_state != MEI_DEV_ENABLED  dev_state = %s\n",
 219                         mei_dev_state_str(dev->dev_state));
 220                 goto end_unlock;
 221         }
 222
 223         if (dev->wd_cl.state != MEI_FILE_CONNECTED)     {
 224                 dev_dbg(&dev->pdev->dev,
 225                         "MEI Driver is not connected to Watchdog Client\n");
 226                 goto end_unlock;
 227         }
 228
 229         mei_wd_set_start_timeout(dev, dev->wd_timeout);
 230
 231         err = 0;
 232 end_unlock:
 233         mutex_unlock(&dev->device_lock);
 234         return err;
 235 }
 236
 237 /*
 238  * mei_wd_ops_stop -  wd stop command from the watchdog core.
 239  *
 240  * @wd_dev - watchdog device struct
 241  *
 242  * returns 0 if success, negative errno code for failure
 243  */
 244 static int mei_wd_ops_stop(struct watchdog_device *wd_dev)
 245 {
 246         struct mei_device *dev;
 247
 248         dev = watchdog_get_drvdata(wd_dev);
 249         if (!dev)
 250                 return -ENODEV;
 251
 252         mutex_lock(&dev->device_lock);
 253         mei_wd_stop(dev);
 254         mutex_unlock(&dev->device_lock);
 255
 256         return 0;
 257 }
 258
 259 /*
 260  * mei_wd_ops_ping - wd ping command from the watchdog core.
 261  *
 262  * @wd_dev - watchdog device struct
 263  *
 264  * returns 0 if success, negative errno code for failure
 265  */
 266 static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
 267 {
 268         int ret = 0;
 269         struct mei_device *dev;
 270
 271         dev = watchdog_get_drvdata(wd_dev);
 272         if (!dev)
 273                 return -ENODEV;
 274
 275         mutex_lock(&dev->device_lock);
 276
 277         if (dev->wd_cl.state != MEI_FILE_CONNECTED) {
 278                 dev_err(&dev->pdev->dev, "wd: not connected.\n");
 279                 ret = -ENODEV;
 280                 goto end;
 281         }
 282
 283         dev->wd_state = MEI_WD_RUNNING;
 284
 285         /* Check if we can send the ping to HW*/
 286         if (dev->hbuf_is_ready && mei_cl_flow_ctrl_creds(&dev->wd_cl) > 0) {
 287
 288                 dev->hbuf_is_ready = false;
 289                 dev_dbg(&dev->pdev->dev, "wd: sending ping\n");
 290
 291                 if (mei_wd_send(dev)) {
 292                         dev_err(&dev->pdev->dev, "wd: send failed.\n");
 293                         ret = -EIO;
 294                         goto end;
 295                 }
 296
 297                 if (mei_cl_flow_ctrl_reduce(&dev->wd_cl)) {
 298                         dev_err(&dev->pdev->dev,
 299                                 "wd: mei_cl_flow_ctrl_reduce() failed.\n");
 300                         ret = -EIO;
 301                         goto end;
 302                 }
 303
 304         } else {
 305                 dev->wd_pending = true;
 306         }
 307
 308 end:
 309         mutex_unlock(&dev->device_lock);
 310         return ret;
 311 }
 312
 313 /*
 314  * mei_wd_ops_set_timeout - wd set timeout command from the watchdog core.
 315  *
 316  * @wd_dev - watchdog device struct
 317  * @timeout - timeout value to set
 318  *
 319  * returns 0 if success, negative errno code for failure
 320  */
 321 static int mei_wd_ops_set_timeout(struct watchdog_device *wd_dev,
 322                 unsigned int timeout)
 323 {
 324         struct mei_device *dev;
 325
 326         dev = watchdog_get_drvdata(wd_dev);
 327         if (!dev)
 328                 return -ENODEV;
 329
 330         /* Check Timeout value */
 331         if (timeout < MEI_WD_MIN_TIMEOUT || timeout > MEI_WD_MAX_TIMEOUT)
 332                 return -EINVAL;
 333
 334         mutex_lock(&dev->device_lock);
 335
 336         dev->wd_timeout = timeout;
 337         wd_dev->timeout = timeout;
 338         mei_wd_set_start_timeout(dev, dev->wd_timeout);
 339
 340         mutex_unlock(&dev->device_lock);
 341
 342         return 0;
 343 }
 344
 345 /*
 346  * Watchdog Device structs
 347  */
 348 static const struct watchdog_ops wd_ops = {
 349                 .owner = THIS_MODULE,
 350                 .start = mei_wd_ops_start,
 351                 .stop = mei_wd_ops_stop,
 352                 .ping = mei_wd_ops_ping,
 353                 .set_timeout = mei_wd_ops_set_timeout,
 354 };
 355 static const struct watchdog_info wd_info = {
 356                 .identity = INTEL_AMT_WATCHDOG_ID,
 357                 .options = WDIOF_KEEPALIVEPING |
 358                            WDIOF_SETTIMEOUT |
 359                            WDIOF_ALARMONLY,
 360 };
 361
 362 static struct watchdog_device amt_wd_dev = {
 363                 .info = &wd_info,
 364                 .ops = &wd_ops,
 365                 .timeout = MEI_WD_DEFAULT_TIMEOUT,
 366                 .min_timeout = MEI_WD_MIN_TIMEOUT,
 367                 .max_timeout = MEI_WD_MAX_TIMEOUT,
 368 };
 369
 370
 371 void mei_watchdog_register(struct mei_device *dev)
 372 {
 373         if (watchdog_register_device(&amt_wd_dev)) {
 374                 dev_err(&dev->pdev->dev,
 375                         "wd: unable to register watchdog device.\n");
 376                 return;
 377         }
 378
 379         dev_dbg(&dev->pdev->dev,
 380                 "wd: successfully register watchdog interface.\n");
 381         watchdog_set_drvdata(&amt_wd_dev, dev);
 382 }
 383
 384 void mei_watchdog_unregister(struct mei_device *dev)
 385 {
 386         if (watchdog_get_drvdata(&amt_wd_dev) == NULL)
 387                 return;
 388
 389         watchdog_set_drvdata(&amt_wd_dev, NULL);
 390         watchdog_unregister_device(&amt_wd_dev);
 391 }
 392