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