drivers/staging/mei/wd.c

   1 /*
   2  *
   3  * Intel Management Engine Interface (Intel MEI) Linux driver
   4  * Copyright (c) 2003-2011, 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 "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 /* 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
  44 void mei_wd_set_start_timeout(struct mei_device *dev, u16 timeout)
  45 {
  46         dev_dbg(&dev->pdev->dev, "timeout=%d.\n", timeout);
  47         memcpy(dev->wd_data, mei_start_wd_params, MEI_WD_PARAMS_SIZE);
  48         memcpy(dev->wd_data + MEI_WD_PARAMS_SIZE,
  49                         &timeout, sizeof(u16));
  50 }
  51
  52 /**
  53  * host_init_wd - mei initialization wd.
  54  *
  55  * @dev: the device structure
  56  */
  57 bool mei_wd_host_init(struct mei_device *dev)
  58 {
  59         bool ret = false;
  60
  61         mei_cl_init(&dev->wd_cl, dev);
  62
  63         /* look for WD client and connect to it */
  64         dev->wd_cl.state = MEI_FILE_DISCONNECTED;
  65         dev->wd_timeout = AMT_WD_DEFAULT_TIMEOUT;
  66
  67         /* find ME WD client */
  68         mei_find_me_client_update_filext(dev, &dev->wd_cl,
  69                                 &mei_wd_guid, MEI_WD_HOST_CLIENT_ID);
  70
  71         dev_dbg(&dev->pdev->dev, "check wd_cl\n");
  72         if (MEI_FILE_CONNECTING == dev->wd_cl.state) {
  73                 if (!mei_connect(dev, &dev->wd_cl)) {
  74                         dev_dbg(&dev->pdev->dev, "Failed to connect to WD client\n");
  75                         dev->wd_cl.state = MEI_FILE_DISCONNECTED;
  76                         dev->wd_cl.host_client_id = 0;
  77                         ret = false;
  78                         goto end;
  79                 } else {
  80                         dev->wd_cl.timer_count = CONNECT_TIMEOUT;
  81                 }
  82         } else {
  83                 dev_dbg(&dev->pdev->dev, "Failed to find WD client\n");
  84                 ret = false;
  85                 goto end;
  86         }
  87
  88 end:
  89         return ret;
  90 }
  91
  92 /**
  93  * mei_wd_send - sends watch dog message to fw.
  94  *
  95  * @dev: the device structure
  96  *
  97  * returns 0 if success,
  98  *      -EIO when message send fails
  99  *      -EINVAL when invalid message is to be sent
 100  */
 101 int mei_wd_send(struct mei_device *dev)
 102 {
 103         struct mei_msg_hdr *mei_hdr;
 104
 105         mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
 106         mei_hdr->host_addr = dev->wd_cl.host_client_id;
 107         mei_hdr->me_addr = dev->wd_cl.me_client_id;
 108         mei_hdr->msg_complete = 1;
 109         mei_hdr->reserved = 0;
 110
 111         if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_PARAMS_SIZE))
 112                 mei_hdr->length = MEI_START_WD_DATA_SIZE;
 113         else if (!memcmp(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE))
 114                 mei_hdr->length = MEI_WD_PARAMS_SIZE;
 115         else
 116                 return -EINVAL;
 117
 118         if (mei_write_message(dev, mei_hdr, dev->wd_data, mei_hdr->length))
 119                 return 0;
 120         return -EIO;
 121 }
 122
 123 /**
 124  * mei_wd_stop - sends watchdog stop message to fw.
 125  *
 126  * @dev: the device structure
 127  * @preserve: indicate if to keep the timeout value
 128  *
 129  * returns 0 if success,
 130  *      -EIO when message send fails
 131  *      -EINVAL when invalid message is to be sent
 132  */
 133 int mei_wd_stop(struct mei_device *dev, bool preserve)
 134 {
 135         int ret;
 136         u16 wd_timeout = dev->wd_timeout;
 137
 138         cancel_delayed_work(&dev->timer_work);
 139         if (dev->wd_cl.state != MEI_FILE_CONNECTED || !dev->wd_timeout)
 140                 return 0;
 141
 142         dev->wd_timeout = 0;
 143         dev->wd_due_counter = 0;
 144         memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE);
 145         dev->stop = true;
 146
 147         ret = mei_flow_ctrl_creds(dev, &dev->wd_cl);
 148         if (ret < 0)
 149                 goto out;
 150
 151         if (ret && dev->mei_host_buffer_is_empty) {
 152                 ret = 0;
 153                 dev->mei_host_buffer_is_empty = false;
 154
 155                 if (!mei_wd_send(dev)) {
 156                         ret = mei_flow_ctrl_reduce(dev, &dev->wd_cl);
 157                         if (ret)
 158                                 goto out;
 159                 } else {
 160                         dev_dbg(&dev->pdev->dev, "send stop WD failed\n");
 161                 }
 162
 163                 dev->wd_pending = false;
 164         } else {
 165                 dev->wd_pending = true;
 166         }
 167         dev->wd_stopped = false;
 168         mutex_unlock(&dev->device_lock);
 169
 170         ret = wait_event_interruptible_timeout(dev->wait_stop_wd,
 171                                         dev->wd_stopped, 10 * HZ);
 172         mutex_lock(&dev->device_lock);
 173         if (dev->wd_stopped) {
 174                 dev_dbg(&dev->pdev->dev, "stop wd complete ret=%d.\n", ret);
 175                 ret = 0;
 176         } else {
 177                 if (!ret)
 178                         ret = -ETIMEDOUT;
 179                 dev_warn(&dev->pdev->dev,
 180                         "stop wd failed to complete ret=%d.\n", ret);
 181         }
 182
 183         if (preserve)
 184                 dev->wd_timeout = wd_timeout;
 185
 186 out:
 187         return ret;
 188 }
 189
 190 /*
 191  * mei_wd_ops_start - wd start command from the watchdog core.
 192  *
 193  * @wd_dev - watchdog device struct
 194  *
 195  * returns 0 if success, negative errno code for failure
 196  */
 197 static int mei_wd_ops_start(struct watchdog_device *wd_dev)
 198 {
 199         int err = -ENODEV;
 200         struct mei_device *dev;
 201
 202         dev = pci_get_drvdata(mei_device);
 203         if (!dev)
 204                 return -ENODEV;
 205
 206         mutex_lock(&dev->device_lock);
 207
 208         if (dev->mei_state != MEI_ENABLED) {
 209                 dev_dbg(&dev->pdev->dev, "mei_state != MEI_ENABLED  mei_state= %d\n",
 210                     dev->mei_state);
 211                 goto end_unlock;
 212         }
 213
 214         if (dev->wd_cl.state != MEI_FILE_CONNECTED)     {
 215                 dev_dbg(&dev->pdev->dev, "MEI Driver is not connected to Watchdog Client\n");
 216                 goto end_unlock;
 217         }
 218
 219         mei_wd_set_start_timeout(dev, dev->wd_timeout);
 220
 221         err = 0;
 222 end_unlock:
 223         mutex_unlock(&dev->device_lock);
 224         return err;
 225 }
 226
 227 /*
 228  * mei_wd_ops_stop -  wd stop command from the watchdog core.
 229  *
 230  * @wd_dev - watchdog device struct
 231  *
 232  * returns 0 if success, negative errno code for failure
 233  */
 234 static int mei_wd_ops_stop(struct watchdog_device *wd_dev)
 235 {
 236         struct mei_device *dev;
 237         dev = pci_get_drvdata(mei_device);
 238
 239         if (!dev)
 240                 return -ENODEV;
 241
 242         mutex_lock(&dev->device_lock);
 243         mei_wd_stop(dev, false);
 244         mutex_unlock(&dev->device_lock);
 245
 246         return 0;
 247 }
 248
 249 /*
 250  * mei_wd_ops_ping - wd ping command from the watchdog core.
 251  *
 252  * @wd_dev - watchdog device struct
 253  *
 254  * returns 0 if success, negative errno code for failure
 255  */
 256 static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
 257 {
 258         int ret = 0;
 259         struct mei_device *dev;
 260         dev = pci_get_drvdata(mei_device);
 261
 262         if (!dev)
 263                 return -ENODEV;
 264
 265         mutex_lock(&dev->device_lock);
 266
 267         if (dev->wd_cl.state != MEI_FILE_CONNECTED) {
 268                 dev_dbg(&dev->pdev->dev, "wd is not connected.\n");
 269                 ret = -ENODEV;
 270                 goto end;
 271         }
 272
 273         /* Check if we can send the ping to HW*/
 274         if (dev->mei_host_buffer_is_empty &&
 275                 mei_flow_ctrl_creds(dev, &dev->wd_cl) > 0) {
 276
 277                 dev->mei_host_buffer_is_empty = false;
 278                 dev_dbg(&dev->pdev->dev, "sending watchdog ping\n");
 279
 280                 if (mei_wd_send(dev)) {
 281                         dev_dbg(&dev->pdev->dev, "wd send failed.\n");
 282                         ret = -EIO;
 283                         goto end;
 284                 }
 285
 286                 if (mei_flow_ctrl_reduce(dev, &dev->wd_cl)) {
 287                         dev_dbg(&dev->pdev->dev, "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         mei_wd_set_start_timeout(dev, dev->wd_timeout);
 325
 326         mutex_unlock(&dev->device_lock);
 327
 328         return 0;
 329 }
 330
 331 /*
 332  * Watchdog Device structs
 333  */
 334 const struct watchdog_ops wd_ops = {
 335                 .owner = THIS_MODULE,
 336                 .start = mei_wd_ops_start,
 337                 .stop = mei_wd_ops_stop,
 338                 .ping = mei_wd_ops_ping,
 339                 .set_timeout = mei_wd_ops_set_timeout,
 340 };
 341 const struct watchdog_info wd_info = {
 342                 .identity = INTEL_AMT_WATCHDOG_ID,
 343                 .options = WDIOF_KEEPALIVEPING,
 344 };
 345
 346 struct watchdog_device amt_wd_dev = {
 347                 .info = &wd_info,
 348                 .ops = &wd_ops,
 349                 .timeout = AMT_WD_DEFAULT_TIMEOUT,
 350                 .min_timeout = AMT_WD_MIN_TIMEOUT,
 351                 .max_timeout = AMT_WD_MAX_TIMEOUT,
 352 };
 353
 354