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 /*
  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 void mei_wd_set_start_timeout(struct mei_device *dev, u16 timeout)
  49 {
  50         dev_dbg(&dev->pdev->dev, "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,
  53                         &timeout, sizeof(u16));
  54 }
  55
  56 /**
  57  * host_init_wd - mei initialization wd.
  58  *
  59  * @dev: the device structure
  60  */
  61 bool mei_wd_host_init(struct mei_device *dev)
  62 {
  63         bool ret = false;
  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 = AMT_WD_DEFAULT_TIMEOUT;
  70
  71         /* find ME WD client */
  72         mei_find_me_client_update_filext(dev, &dev->wd_cl,
  73                                 &mei_wd_guid, MEI_WD_HOST_CLIENT_ID);
  74
  75         dev_dbg(&dev->pdev->dev, "check wd_cl\n");
  76         if (MEI_FILE_CONNECTING == dev->wd_cl.state) {
  77                 if (!mei_connect(dev, &dev->wd_cl)) {
  78                         dev_dbg(&dev->pdev->dev, "Failed to connect to WD client\n");
  79                         dev->wd_cl.state = MEI_FILE_DISCONNECTED;
  80                         dev->wd_cl.host_client_id = 0;
  81                         ret = false;
  82                         goto end;
  83                 } else {
  84                         dev->wd_cl.timer_count = CONNECT_TIMEOUT;
  85                 }
  86         } else {
  87                 dev_dbg(&dev->pdev->dev, "Failed to find WD client\n");
  88                 ret = false;
  89                 goto end;
  90         }
  91
  92 end:
  93         return ret;
  94 }
  95
  96 /**
  97  * mei_wd_send - sends watch dog message to fw.
  98  *
  99  * @dev: the device structure
 100  *
 101  * returns 0 if success,
 102  *      -EIO when message send fails
 103  *      -EINVAL when invalid message is to be sent
 104  */
 105 int mei_wd_send(struct mei_device *dev)
 106 {
 107         struct mei_msg_hdr *mei_hdr;
 108
 109         mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
 110         mei_hdr->host_addr = dev->wd_cl.host_client_id;
 111         mei_hdr->me_addr = dev->wd_cl.me_client_id;
 112         mei_hdr->msg_complete = 1;
 113         mei_hdr->reserved = 0;
 114
 115         if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_PARAMS_SIZE))
 116                 mei_hdr->length = MEI_START_WD_DATA_SIZE;
 117         else if (!memcmp(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE))
 118                 mei_hdr->length = MEI_WD_PARAMS_SIZE;
 119         else
 120                 return -EINVAL;
 121
 122         if (mei_write_message(dev, mei_hdr, dev->wd_data, mei_hdr->length))
 123                 return 0;
 124         return -EIO;
 125 }
 126
 127 /**
 128  * mei_wd_stop - sends watchdog stop message to fw.
 129  *
 130  * @dev: the device structure
 131  * @preserve: indicate if to keep the timeout value
 132  *
 133  * returns 0 if success,
 134  *      -EIO when message send fails
 135  *      -EINVAL when invalid message is to be sent
 136  */
 137 int mei_wd_stop(struct mei_device *dev, bool preserve)
 138 {
 139         int ret;
 140         u16 wd_timeout = dev->wd_timeout;
 141
 142         cancel_delayed_work(&dev->timer_work);
 143         if (dev->wd_cl.state != MEI_FILE_CONNECTED || !dev->wd_timeout)
 144                 return 0;
 145
 146         dev->wd_timeout = 0;
 147         dev->wd_due_counter = 0;
 148         memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE);
 149         dev->stop = true;
 150
 151         ret = mei_flow_ctrl_creds(dev, &dev->wd_cl);
 152         if (ret < 0)
 153                 goto out;
 154
 155         if (ret && dev->mei_host_buffer_is_empty) {
 156                 ret = 0;
 157                 dev->mei_host_buffer_is_empty = false;
 158
 159                 if (!mei_wd_send(dev)) {
 160                         ret = mei_flow_ctrl_reduce(dev, &dev->wd_cl);
 161                         if (ret)
 162                                 goto out;
 163                 } else {
 164                         dev_dbg(&dev->pdev->dev, "send stop WD failed\n");
 165                 }
 166
 167                 dev->wd_pending = false;
 168         } else {
 169                 dev->wd_pending = true;
 170         }
 171         dev->wd_stopped = false;
 172         mutex_unlock(&dev->device_lock);
 173
 174         ret = wait_event_interruptible_timeout(dev->wait_stop_wd,
 175                                         dev->wd_stopped, 10 * HZ);
 176         mutex_lock(&dev->device_lock);
 177         if (dev->wd_stopped) {
 178                 dev_dbg(&dev->pdev->dev, "stop wd complete ret=%d.\n", ret);
 179                 ret = 0;
 180         } else {
 181                 if (!ret)
 182                         ret = -ETIMEDOUT;
 183                 dev_warn(&dev->pdev->dev,
 184                         "stop wd failed to complete ret=%d.\n", ret);
 185         }
 186
 187         if (preserve)
 188                 dev->wd_timeout = wd_timeout;
 189
 190 out:
 191         return ret;
 192 }
 193
 194 /*
 195  * mei_wd_ops_start - wd start command from the watchdog core.
 196  *
 197  * @wd_dev - watchdog device struct
 198  *
 199  * returns 0 if success, negative errno code for failure
 200  */
 201 static int mei_wd_ops_start(struct watchdog_device *wd_dev)
 202 {
 203         int err = -ENODEV;
 204         struct mei_device *dev;
 205
 206         dev = pci_get_drvdata(mei_device);
 207         if (!dev)
 208                 return -ENODEV;
 209
 210         mutex_lock(&dev->device_lock);
 211
 212         if (dev->mei_state != MEI_ENABLED) {
 213                 dev_dbg(&dev->pdev->dev, "mei_state != MEI_ENABLED  mei_state= %d\n",
 214                     dev->mei_state);
 215                 goto end_unlock;
 216         }
 217
 218         if (dev->wd_cl.state != MEI_FILE_CONNECTED)     {
 219                 dev_dbg(&dev->pdev->dev, "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         dev = pci_get_drvdata(mei_device);
 242
 243         if (!dev)
 244                 return -ENODEV;
 245
 246         mutex_lock(&dev->device_lock);
 247         mei_wd_stop(dev, false);
 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         dev = pci_get_drvdata(mei_device);
 265
 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_dbg(&dev->pdev->dev, "wd is not connected.\n");
 273                 ret = -ENODEV;
 274                 goto end;
 275         }
 276
 277         /* Check if we can send the ping to HW*/
 278         if (dev->mei_host_buffer_is_empty &&
 279                 mei_flow_ctrl_creds(dev, &dev->wd_cl) > 0) {
 280
 281                 dev->mei_host_buffer_is_empty = false;
 282                 dev_dbg(&dev->pdev->dev, "sending watchdog ping\n");
 283
 284                 if (mei_wd_send(dev)) {
 285                         dev_dbg(&dev->pdev->dev, "wd send failed.\n");
 286                         ret = -EIO;
 287                         goto end;
 288                 }
 289
 290                 if (mei_flow_ctrl_reduce(dev, &dev->wd_cl)) {
 291                         dev_dbg(&dev->pdev->dev, "mei_flow_ctrl_reduce() failed.\n");
 292                         ret = -EIO;
 293                         goto end;
 294                 }
 295
 296         } else {
 297                 dev->wd_pending = true;
 298         }
 299
 300 end:
 301         mutex_unlock(&dev->device_lock);
 302         return ret;
 303 }
 304
 305 /*
 306  * mei_wd_ops_set_timeout - wd set timeout command from the watchdog core.
 307  *
 308  * @wd_dev - watchdog device struct
 309  * @timeout - timeout value to set
 310  *
 311  * returns 0 if success, negative errno code for failure
 312  */
 313 static int mei_wd_ops_set_timeout(struct watchdog_device *wd_dev, unsigned int timeout)
 314 {
 315         struct mei_device *dev;
 316         dev = pci_get_drvdata(mei_device);
 317
 318         if (!dev)
 319                 return -ENODEV;
 320
 321         /* Check Timeout value */
 322         if (timeout < AMT_WD_MIN_TIMEOUT || timeout > AMT_WD_MAX_TIMEOUT)
 323                 return -EINVAL;
 324
 325         mutex_lock(&dev->device_lock);
 326
 327         dev->wd_timeout = timeout;
 328         mei_wd_set_start_timeout(dev, dev->wd_timeout);
 329
 330         mutex_unlock(&dev->device_lock);
 331
 332         return 0;
 333 }
 334
 335 /*
 336  * Watchdog Device structs
 337  */
 338 static const struct watchdog_ops wd_ops = {
 339                 .owner = THIS_MODULE,
 340                 .start = mei_wd_ops_start,
 341                 .stop = mei_wd_ops_stop,
 342                 .ping = mei_wd_ops_ping,
 343                 .set_timeout = mei_wd_ops_set_timeout,
 344 };
 345 static const struct watchdog_info wd_info = {
 346                 .identity = INTEL_AMT_WATCHDOG_ID,
 347                 .options = WDIOF_KEEPALIVEPING,
 348 };
 349
 350 struct watchdog_device amt_wd_dev = {
 351                 .info = &wd_info,
 352                 .ops = &wd_ops,
 353                 .timeout = AMT_WD_DEFAULT_TIMEOUT,
 354                 .min_timeout = AMT_WD_MIN_TIMEOUT,
 355                 .max_timeout = AMT_WD_MAX_TIMEOUT,
 356 };
 357
 358
 359 void  mei_watchdog_register(struct mei_device *dev)
 360 {
 361         dev_dbg(&dev->pdev->dev, "dev->wd_timeout =%d.\n", dev->wd_timeout);
 362
 363         dev->wd_due_counter = !!dev->wd_timeout;
 364
 365         if (watchdog_register_device(&amt_wd_dev)) {
 366                 dev_err(&dev->pdev->dev, "unable to register watchdog device.\n");
 367                 dev->wd_interface_reg = false;
 368         } else {
 369                 dev_dbg(&dev->pdev->dev, "successfully register watchdog interface.\n");
 370                 dev->wd_interface_reg = true;
 371         }
 372 }
 373
 374 void mei_watchdog_unregister(struct mei_device *dev)
 375 {
 376         if (dev->wd_interface_reg)
 377                 watchdog_unregister_device(&amt_wd_dev);
 378         dev->wd_interface_reg = false;
 379 }
 380