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 "mei_dev.h"
  25 #include "hw.h"
  26 #include "interface.h"
  27 #include <linux/mei.h>
  28
  29 static const u8 mei_start_wd_params[] = { 0x02, 0x12, 0x13, 0x10 };
  30 static const u8 mei_stop_wd_params[] = { 0x02, 0x02, 0x14, 0x10 };
  31
  32 const u8 mei_wd_state_independence_msg[3][4] = {
  33         {0x05, 0x02, 0x51, 0x10},
  34         {0x05, 0x02, 0x52, 0x10},
  35         {0x07, 0x02, 0x01, 0x10}
  36 };
  37
  38 /*
  39  * AMT Watchdog Device
  40  */
  41 #define INTEL_AMT_WATCHDOG_ID "INTCAMT"
  42
  43 /* UUIDs for AMT F/W clients */
  44 const uuid_le mei_wd_guid = UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, 0x89,
  45                                                 0x9D, 0xA9, 0x15, 0x14, 0xCB,
  46                                                 0x32, 0xAB);
  47
  48 static void mei_wd_set_start_timeout(struct mei_device *dev, u16 timeout)
  49 {
  50         dev_dbg(&dev->pdev->dev, "wd: set timeout=%d.\n", timeout);
  51         memcpy(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE);
  52         memcpy(dev->wd_data + MEI_WD_HDR_SIZE, &timeout, sizeof(u16));
  53 }
  54
  55 /**
  56  * mei_wd_host_init - connect to the watchdog client
  57  *
  58  * @dev: the device structure
  59  * returns -ENENT if wd client cannot be found
  60  *         -EIO if write has failed
  61  *         0 on success
  62  */
  63 int mei_wd_host_init(struct mei_device *dev)
  64 {
  65         mei_cl_init(&dev->wd_cl, dev);
  66
  67         /* look for WD client and connect to it */
  68         dev->wd_cl.state = MEI_FILE_DISCONNECTED;
  69         dev->wd_timeout = MEI_WD_DEFAULT_TIMEOUT;
  70         dev->wd_state = MEI_WD_IDLE;
  71
  72         /* find ME WD client */
  73         mei_me_cl_update_filext(dev, &dev->wd_cl,
  74                                 &mei_wd_guid, MEI_WD_HOST_CLIENT_ID);
  75
  76         dev_dbg(&dev->pdev->dev, "wd: check client\n");
  77         if (MEI_FILE_CONNECTING != dev->wd_cl.state) {
  78                 dev_info(&dev->pdev->dev, "wd: failed to find the client\n");
  79                 return -ENOENT;
  80         }
  81
  82         if (mei_connect(dev, &dev->wd_cl)) {
  83                 dev_err(&dev->pdev->dev, "wd: failed to connect to the client\n");
  84                 dev->wd_cl.state = MEI_FILE_DISCONNECTED;
  85                 dev->wd_cl.host_client_id = 0;
  86                 return -EIO;
  87         }
  88         dev->wd_cl.timer_count = CONNECT_TIMEOUT;
  89
  90         return 0;
  91 }
  92
  93 /**
  94  * mei_wd_send - sends watch dog message to fw.
  95  *
  96  * @dev: the device structure
  97  *
  98  * returns 0 if success,
  99  *      -EIO when message send fails
 100  *      -EINVAL when invalid message is to be sent
 101  */
 102 int mei_wd_send(struct mei_device *dev)
 103 {
 104         struct mei_msg_hdr *mei_hdr;
 105
 106         mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
 107         mei_hdr->host_addr = dev->wd_cl.host_client_id;
 108         mei_hdr->me_addr = dev->wd_cl.me_client_id;
 109         mei_hdr->msg_complete = 1;
 110         mei_hdr->reserved = 0;
 111
 112         if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE))
 113                 mei_hdr->length = MEI_WD_START_MSG_SIZE;
 114         else if (!memcmp(dev->wd_data, mei_stop_wd_params, MEI_WD_HDR_SIZE))
 115                 mei_hdr->length = MEI_WD_STOP_MSG_SIZE;
 116         else
 117                 return -EINVAL;
 118
 119         return mei_write_message(dev, mei_hdr, dev->wd_data, mei_hdr->length);
 120 }
 121
 122 /**
 123  * mei_wd_stop - sends watchdog stop message to fw.
 124  *
 125  * @dev: the device structure
 126  * @preserve: indicate if to keep the timeout value
 127  *
 128  * returns 0 if success,
 129  *      -EIO when message send fails
 130  *      -EINVAL when invalid message is to be sent
 131  */
 132 int mei_wd_stop(struct mei_device *dev)
 133 {
 134         int ret;
 135
 136         if (dev->wd_cl.state != MEI_FILE_CONNECTED ||
 137             dev->wd_state != MEI_WD_RUNNING)
 138                 return 0;
 139
 140         memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_STOP_MSG_SIZE);
 141
 142         dev->wd_state = MEI_WD_STOPPING;
 143
 144         ret = mei_flow_ctrl_creds(dev, &dev->wd_cl);
 145         if (ret < 0)
 146                 goto out;
 147
 148         if (ret && dev->mei_host_buffer_is_empty) {
 149                 ret = 0;
 150                 dev->mei_host_buffer_is_empty = false;
 151
 152                 if (!mei_wd_send(dev)) {
 153                         ret = mei_flow_ctrl_reduce(dev, &dev->wd_cl);
 154                         if (ret)
 155                                 goto out;
 156                 } else {
 157                         dev_err(&dev->pdev->dev, "wd: send stop failed\n");
 158                 }
 159
 160                 dev->wd_pending = false;
 161         } else {
 162                 dev->wd_pending = true;
 163         }
 164
 165         mutex_unlock(&dev->device_lock);
 166
 167         ret = wait_event_interruptible_timeout(dev->wait_stop_wd,
 168                                         dev->wd_state == MEI_WD_IDLE,
 169                                         msecs_to_jiffies(MEI_WD_STOP_TIMEOUT));
 170         mutex_lock(&dev->device_lock);
 171         if (dev->wd_state == MEI_WD_IDLE) {
 172                 dev_dbg(&dev->pdev->dev, "wd: stop completed ret=%d.\n", ret);
 173                 ret = 0;
 174         } else {
 175                 if (!ret)
 176                         ret = -ETIMEDOUT;
 177                 dev_warn(&dev->pdev->dev,
 178                         "wd: stop failed to complete ret=%d.\n", ret);
 179         }
 180
 181 out:
 182         return ret;
 183 }
 184
 185 /*
 186  * mei_wd_ops_start - wd start command from the watchdog core.
 187  *
 188  * @wd_dev - watchdog device struct
 189  *
 190  * returns 0 if success, negative errno code for failure
 191  */
 192 static int mei_wd_ops_start(struct watchdog_device *wd_dev)
 193 {
 194         int err = -ENODEV;
 195         struct mei_device *dev;
 196
 197         dev = watchdog_get_drvdata(wd_dev);
 198         if (!dev)
 199                 return -ENODEV;
 200
 201         mutex_lock(&dev->device_lock);
 202
 203         if (dev->dev_state != MEI_DEV_ENABLED) {
 204                 dev_dbg(&dev->pdev->dev,
 205                         "wd: dev_state != MEI_DEV_ENABLED  dev_state = %s\n",
 206                         mei_dev_state_str(dev->dev_state));
 207                 goto end_unlock;
 208         }
 209
 210         if (dev->wd_cl.state != MEI_FILE_CONNECTED)     {
 211                 dev_dbg(&dev->pdev->dev,
 212                         "MEI Driver is not connected to Watchdog Client\n");
 213                 goto end_unlock;
 214         }
 215
 216         mei_wd_set_start_timeout(dev, dev->wd_timeout);
 217
 218         err = 0;
 219 end_unlock:
 220         mutex_unlock(&dev->device_lock);
 221         return err;
 222 }
 223
 224 /*
 225  * mei_wd_ops_stop -  wd stop command from the watchdog core.
 226  *
 227  * @wd_dev - watchdog device struct
 228  *
 229  * returns 0 if success, negative errno code for failure
 230  */
 231 static int mei_wd_ops_stop(struct watchdog_device *wd_dev)
 232 {
 233         struct mei_device *dev;
 234
 235         dev = watchdog_get_drvdata(wd_dev);
 236         if (!dev)
 237                 return -ENODEV;
 238
 239         mutex_lock(&dev->device_lock);
 240         mei_wd_stop(dev);
 241         mutex_unlock(&dev->device_lock);
 242
 243         return 0;
 244 }
 245
 246 /*
 247  * mei_wd_ops_ping - wd ping command from the watchdog core.
 248  *
 249  * @wd_dev - watchdog device struct
 250  *
 251  * returns 0 if success, negative errno code for failure
 252  */
 253 static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
 254 {
 255         int ret = 0;
 256         struct mei_device *dev;
 257
 258         dev = watchdog_get_drvdata(wd_dev);
 259         if (!dev)
 260                 return -ENODEV;
 261
 262         mutex_lock(&dev->device_lock);
 263
 264         if (dev->wd_cl.state != MEI_FILE_CONNECTED) {
 265                 dev_err(&dev->pdev->dev, "wd: not connected.\n");
 266                 ret = -ENODEV;
 267                 goto end;
 268         }
 269
 270         dev->wd_state = MEI_WD_RUNNING;
 271
 272         /* Check if we can send the ping to HW*/
 273         if (dev->mei_host_buffer_is_empty &&
 274                 mei_flow_ctrl_creds(dev, &dev->wd_cl) > 0) {
 275
 276                 dev->mei_host_buffer_is_empty = false;
 277                 dev_dbg(&dev->pdev->dev, "wd: sending ping\n");
 278
 279                 if (mei_wd_send(dev)) {
 280                         dev_err(&dev->pdev->dev, "wd: send failed.\n");
 281                         ret = -EIO;
 282                         goto end;
 283                 }
 284
 285                 if (mei_flow_ctrl_reduce(dev, &dev->wd_cl)) {
 286                         dev_err(&dev->pdev->dev,
 287                                 "wd: mei_flow_ctrl_reduce() failed.\n");
 288                         ret = -EIO;
 289                         goto end;
 290                 }
 291
 292         } else {
 293                 dev->wd_pending = true;
 294         }
 295
 296 end:
 297         mutex_unlock(&dev->device_lock);
 298         return ret;
 299 }
 300
 301 /*
 302  * mei_wd_ops_set_timeout - wd set timeout command from the watchdog core.
 303  *
 304  * @wd_dev - watchdog device struct
 305  * @timeout - timeout value to set
 306  *
 307  * returns 0 if success, negative errno code for failure
 308  */
 309 static int mei_wd_ops_set_timeout(struct watchdog_device *wd_dev, unsigned int timeout)
 310 {
 311         struct mei_device *dev;
 312
 313         dev = watchdog_get_drvdata(wd_dev);
 314         if (!dev)
 315                 return -ENODEV;
 316
 317         /* Check Timeout value */
 318         if (timeout < MEI_WD_MIN_TIMEOUT || timeout > MEI_WD_MAX_TIMEOUT)
 319                 return -EINVAL;
 320
 321         mutex_lock(&dev->device_lock);
 322
 323         dev->wd_timeout = timeout;
 324         wd_dev->timeout = timeout;
 325         mei_wd_set_start_timeout(dev, dev->wd_timeout);
 326
 327         mutex_unlock(&dev->device_lock);
 328
 329         return 0;
 330 }
 331
 332 /*
 333  * Watchdog Device structs
 334  */
 335 static const struct watchdog_ops wd_ops = {
 336                 .owner = THIS_MODULE,
 337                 .start = mei_wd_ops_start,
 338                 .stop = mei_wd_ops_stop,
 339                 .ping = mei_wd_ops_ping,
 340                 .set_timeout = mei_wd_ops_set_timeout,
 341 };
 342 static const struct watchdog_info wd_info = {
 343                 .identity = INTEL_AMT_WATCHDOG_ID,
 344                 .options = WDIOF_KEEPALIVEPING |
 345                            WDIOF_SETTIMEOUT |
 346                            WDIOF_ALARMONLY,
 347 };
 348
 349 static struct watchdog_device amt_wd_dev = {
 350                 .info = &wd_info,
 351                 .ops = &wd_ops,
 352                 .timeout = MEI_WD_DEFAULT_TIMEOUT,
 353                 .min_timeout = MEI_WD_MIN_TIMEOUT,
 354                 .max_timeout = MEI_WD_MAX_TIMEOUT,
 355 };
 356
 357
 358 void mei_watchdog_register(struct mei_device *dev)
 359 {
 360         if (watchdog_register_device(&amt_wd_dev)) {
 361                 dev_err(&dev->pdev->dev,
 362                         "wd: unable to register watchdog device.\n");
 363                 dev->wd_interface_reg = false;
 364                 return;
 365         }
 366
 367         dev_dbg(&dev->pdev->dev,
 368                 "wd: successfully register watchdog interface.\n");
 369         dev->wd_interface_reg = true;
 370         watchdog_set_drvdata(&amt_wd_dev, dev);
 371 }
 372
 373 void mei_watchdog_unregister(struct mei_device *dev)
 374 {
 375         if (!dev->wd_interface_reg)
 376                 return;
 377
 378         watchdog_set_drvdata(&amt_wd_dev, NULL);
 379         watchdog_unregister_device(&amt_wd_dev);
 380         dev->wd_interface_reg = false;
 381 }
 382