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_PARAMS_SIZE);
  52         memcpy(dev->wd_data + MEI_WD_PARAMS_SIZE, &timeout, sizeof(u16));
  53 }
  54
  55 /**
  56  * host_init_wd - mei initialization wd.
  57  *
  58  * @dev: the device structure
  59  * returns -ENENT if wd client cannot be found
  60  *         -EIO if write has failed
  61  */
  62 int mei_wd_host_init(struct mei_device *dev)
  63 {
  64         mei_cl_init(&dev->wd_cl, dev);
  65
  66         /* look for WD client and connect to it */
  67         dev->wd_cl.state = MEI_FILE_DISCONNECTED;
  68         dev->wd_timeout = AMT_WD_DEFAULT_TIMEOUT;
  69
  70         /* find ME WD client */
  71         mei_find_me_client_update_filext(dev, &dev->wd_cl,
  72                                 &mei_wd_guid, MEI_WD_HOST_CLIENT_ID);
  73
  74         dev_dbg(&dev->pdev->dev, "wd: check client\n");
  75         if (MEI_FILE_CONNECTING != dev->wd_cl.state) {
  76                 dev_info(&dev->pdev->dev, "wd: failed to find the client\n");
  77                 return -ENOENT;
  78         }
  79
  80         if (mei_connect(dev, &dev->wd_cl)) {
  81                 dev_err(&dev->pdev->dev, "wd: failed to connect to the client\n");
  82                 dev->wd_cl.state = MEI_FILE_DISCONNECTED;
  83                 dev->wd_cl.host_client_id = 0;
  84                 return -EIO;
  85         }
  86         dev->wd_cl.timer_count = CONNECT_TIMEOUT;
  87
  88         return 0;
  89 }
  90
  91 /**
  92  * mei_wd_send - sends watch dog message to fw.
  93  *
  94  * @dev: the device structure
  95  *
  96  * returns 0 if success,
  97  *      -EIO when message send fails
  98  *      -EINVAL when invalid message is to be sent
  99  */
 100 int mei_wd_send(struct mei_device *dev)
 101 {
 102         struct mei_msg_hdr *mei_hdr;
 103
 104         mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
 105         mei_hdr->host_addr = dev->wd_cl.host_client_id;
 106         mei_hdr->me_addr = dev->wd_cl.me_client_id;
 107         mei_hdr->msg_complete = 1;
 108         mei_hdr->reserved = 0;
 109
 110         if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_PARAMS_SIZE))
 111                 mei_hdr->length = MEI_START_WD_DATA_SIZE;
 112         else if (!memcmp(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE))
 113                 mei_hdr->length = MEI_WD_PARAMS_SIZE;
 114         else
 115                 return -EINVAL;
 116
 117         return mei_write_message(dev, mei_hdr, dev->wd_data, mei_hdr->length);
 118 }
 119
 120 /**
 121  * mei_wd_stop - sends watchdog stop message to fw.
 122  *
 123  * @dev: the device structure
 124  * @preserve: indicate if to keep the timeout value
 125  *
 126  * returns 0 if success,
 127  *      -EIO when message send fails
 128  *      -EINVAL when invalid message is to be sent
 129  */
 130 int mei_wd_stop(struct mei_device *dev, bool preserve)
 131 {
 132         int ret;
 133         u16 wd_timeout = dev->wd_timeout;
 134
 135         cancel_delayed_work(&dev->timer_work);
 136         if (dev->wd_cl.state != MEI_FILE_CONNECTED || !dev->wd_timeout)
 137                 return 0;
 138
 139         dev->wd_timeout = 0;
 140         dev->wd_due_counter = 0;
 141         memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE);
 142         dev->stop = true;
 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         dev->wd_stopped = false;
 165         mutex_unlock(&dev->device_lock);
 166
 167         ret = wait_event_interruptible_timeout(dev->wait_stop_wd,
 168                                         dev->wd_stopped, 10 * HZ);
 169         mutex_lock(&dev->device_lock);
 170         if (dev->wd_stopped) {
 171                 dev_dbg(&dev->pdev->dev, "wd: stop completed ret=%d.\n", ret);
 172                 ret = 0;
 173         } else {
 174                 if (!ret)
 175                         ret = -ETIMEDOUT;
 176                 dev_warn(&dev->pdev->dev,
 177                         "wd: stop failed to complete ret=%d.\n", ret);
 178         }
 179
 180         if (preserve)
 181                 dev->wd_timeout = wd_timeout;
 182
 183 out:
 184         return ret;
 185 }
 186
 187 /*
 188  * mei_wd_ops_start - wd start command from the watchdog core.
 189  *
 190  * @wd_dev - watchdog device struct
 191  *
 192  * returns 0 if success, negative errno code for failure
 193  */
 194 static int mei_wd_ops_start(struct watchdog_device *wd_dev)
 195 {
 196         int err = -ENODEV;
 197         struct mei_device *dev;
 198
 199         dev = pci_get_drvdata(mei_device);
 200         if (!dev)
 201                 return -ENODEV;
 202
 203         mutex_lock(&dev->device_lock);
 204
 205         if (dev->mei_state != MEI_ENABLED) {
 206                 dev_dbg(&dev->pdev->dev,
 207                         "wd: mei_state != MEI_ENABLED  mei_state = %d\n",
 208                         dev->mei_state);
 209                 goto end_unlock;
 210         }
 211
 212         if (dev->wd_cl.state != MEI_FILE_CONNECTED)     {
 213                 dev_dbg(&dev->pdev->dev,
 214                         "MEI Driver is not connected to Watchdog Client\n");
 215                 goto end_unlock;
 216         }
 217
 218         mei_wd_set_start_timeout(dev, dev->wd_timeout);
 219
 220         err = 0;
 221 end_unlock:
 222         mutex_unlock(&dev->device_lock);
 223         return err;
 224 }
 225
 226 /*
 227  * mei_wd_ops_stop -  wd stop command from the watchdog core.
 228  *
 229  * @wd_dev - watchdog device struct
 230  *
 231  * returns 0 if success, negative errno code for failure
 232  */
 233 static int mei_wd_ops_stop(struct watchdog_device *wd_dev)
 234 {
 235         struct mei_device *dev;
 236         dev = pci_get_drvdata(mei_device);
 237
 238         if (!dev)
 239                 return -ENODEV;
 240
 241         mutex_lock(&dev->device_lock);
 242         mei_wd_stop(dev, false);
 243         mutex_unlock(&dev->device_lock);
 244
 245         return 0;
 246 }
 247
 248 /*
 249  * mei_wd_ops_ping - wd ping command from the watchdog core.
 250  *
 251  * @wd_dev - watchdog device struct
 252  *
 253  * returns 0 if success, negative errno code for failure
 254  */
 255 static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
 256 {
 257         int ret = 0;
 258         struct mei_device *dev;
 259         dev = pci_get_drvdata(mei_device);
 260
 261         if (!dev)
 262                 return -ENODEV;
 263
 264         mutex_lock(&dev->device_lock);
 265
 266         if (dev->wd_cl.state != MEI_FILE_CONNECTED) {
 267                 dev_err(&dev->pdev->dev, "wd: not connected.\n");
 268                 ret = -ENODEV;
 269                 goto end;
 270         }
 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         dev = pci_get_drvdata(mei_device);
 313
 314         if (!dev)
 315                 return -ENODEV;
 316
 317         /* Check Timeout value */
 318         if (timeout < AMT_WD_MIN_TIMEOUT || timeout > AMT_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 | WDIOF_ALARMONLY,
 345 };
 346
 347 static struct watchdog_device amt_wd_dev = {
 348                 .info = &wd_info,
 349                 .ops = &wd_ops,
 350                 .timeout = AMT_WD_DEFAULT_TIMEOUT,
 351                 .min_timeout = AMT_WD_MIN_TIMEOUT,
 352                 .max_timeout = AMT_WD_MAX_TIMEOUT,
 353 };
 354
 355
 356 void  mei_watchdog_register(struct mei_device *dev)
 357 {
 358         dev_dbg(&dev->pdev->dev, "dev->wd_timeout =%d.\n", dev->wd_timeout);
 359
 360         dev->wd_due_counter = !!dev->wd_timeout;
 361
 362         if (watchdog_register_device(&amt_wd_dev)) {
 363                 dev_err(&dev->pdev->dev,
 364                         "wd: unable to register watchdog device.\n");
 365                 dev->wd_interface_reg = false;
 366         } else {
 367                 dev_dbg(&dev->pdev->dev,
 368                         "wd: successfully register watchdog interface.\n");
 369                 dev->wd_interface_reg = true;
 370         }
 371 }
 372
 373 void mei_watchdog_unregister(struct mei_device *dev)
 374 {
 375         if (dev->wd_interface_reg)
 376                 watchdog_unregister_device(&amt_wd_dev);
 377         dev->wd_interface_reg = false;
 378 }
 379