drivers/staging/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 "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         return mei_write_message(dev, mei_hdr, dev->wd_data, mei_hdr->length);
 123 }
 124
 125 /**
 126  * mei_wd_stop - sends watchdog stop message to fw.
 127  *
 128  * @dev: the device structure
 129  * @preserve: indicate if to keep the timeout value
 130  *
 131  * returns 0 if success,
 132  *      -EIO when message send fails
 133  *      -EINVAL when invalid message is to be sent
 134  */
 135 int mei_wd_stop(struct mei_device *dev, bool preserve)
 136 {
 137         int ret;
 138         u16 wd_timeout = dev->wd_timeout;
 139
 140         cancel_delayed_work(&dev->timer_work);
 141         if (dev->wd_cl.state != MEI_FILE_CONNECTED || !dev->wd_timeout)
 142                 return 0;
 143
 144         dev->wd_timeout = 0;
 145         dev->wd_due_counter = 0;
 146         memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE);
 147         dev->stop = true;
 148
 149         ret = mei_flow_ctrl_creds(dev, &dev->wd_cl);
 150         if (ret < 0)
 151                 goto out;
 152
 153         if (ret && dev->mei_host_buffer_is_empty) {
 154                 ret = 0;
 155                 dev->mei_host_buffer_is_empty = false;
 156
 157                 if (!mei_wd_send(dev)) {
 158                         ret = mei_flow_ctrl_reduce(dev, &dev->wd_cl);
 159                         if (ret)
 160                                 goto out;
 161                 } else {
 162                         dev_dbg(&dev->pdev->dev, "send stop WD failed\n");
 163                 }
 164
 165                 dev->wd_pending = false;
 166         } else {
 167                 dev->wd_pending = true;
 168         }
 169         dev->wd_stopped = false;
 170         mutex_unlock(&dev->device_lock);
 171
 172         ret = wait_event_interruptible_timeout(dev->wait_stop_wd,
 173                                         dev->wd_stopped, 10 * HZ);
 174         mutex_lock(&dev->device_lock);
 175         if (dev->wd_stopped) {
 176                 dev_dbg(&dev->pdev->dev, "stop wd complete ret=%d.\n", ret);
 177                 ret = 0;
 178         } else {
 179                 if (!ret)
 180                         ret = -ETIMEDOUT;
 181                 dev_warn(&dev->pdev->dev,
 182                         "stop wd failed to complete ret=%d.\n", ret);
 183         }
 184
 185         if (preserve)
 186                 dev->wd_timeout = wd_timeout;
 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 = pci_get_drvdata(mei_device);
 205         if (!dev)
 206                 return -ENODEV;
 207
 208         mutex_lock(&dev->device_lock);
 209
 210         if (dev->mei_state != MEI_ENABLED) {
 211                 dev_dbg(&dev->pdev->dev, "mei_state != MEI_ENABLED  mei_state= %d\n",
 212                     dev->mei_state);
 213                 goto end_unlock;
 214         }
 215
 216         if (dev->wd_cl.state != MEI_FILE_CONNECTED)     {
 217                 dev_dbg(&dev->pdev->dev, "MEI Driver is not connected to Watchdog Client\n");
 218                 goto end_unlock;
 219         }
 220
 221         mei_wd_set_start_timeout(dev, dev->wd_timeout);
 222
 223         err = 0;
 224 end_unlock:
 225         mutex_unlock(&dev->device_lock);
 226         return err;
 227 }
 228
 229 /*
 230  * mei_wd_ops_stop -  wd stop command from the watchdog core.
 231  *
 232  * @wd_dev - watchdog device struct
 233  *
 234  * returns 0 if success, negative errno code for failure
 235  */
 236 static int mei_wd_ops_stop(struct watchdog_device *wd_dev)
 237 {
 238         struct mei_device *dev;
 239         dev = pci_get_drvdata(mei_device);
 240
 241         if (!dev)
 242                 return -ENODEV;
 243
 244         mutex_lock(&dev->device_lock);
 245         mei_wd_stop(dev, false);
 246         mutex_unlock(&dev->device_lock);
 247
 248         return 0;
 249 }
 250
 251 /*
 252  * mei_wd_ops_ping - wd ping command from the watchdog core.
 253  *
 254  * @wd_dev - watchdog device struct
 255  *
 256  * returns 0 if success, negative errno code for failure
 257  */
 258 static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
 259 {
 260         int ret = 0;
 261         struct mei_device *dev;
 262         dev = pci_get_drvdata(mei_device);
 263
 264         if (!dev)
 265                 return -ENODEV;
 266
 267         mutex_lock(&dev->device_lock);
 268
 269         if (dev->wd_cl.state != MEI_FILE_CONNECTED) {
 270                 dev_dbg(&dev->pdev->dev, "wd is not connected.\n");
 271                 ret = -ENODEV;
 272                 goto end;
 273         }
 274
 275         /* Check if we can send the ping to HW*/
 276         if (dev->mei_host_buffer_is_empty &&
 277                 mei_flow_ctrl_creds(dev, &dev->wd_cl) > 0) {
 278
 279                 dev->mei_host_buffer_is_empty = false;
 280                 dev_dbg(&dev->pdev->dev, "sending watchdog ping\n");
 281
 282                 if (mei_wd_send(dev)) {
 283                         dev_dbg(&dev->pdev->dev, "wd send failed.\n");
 284                         ret = -EIO;
 285                         goto end;
 286                 }
 287
 288                 if (mei_flow_ctrl_reduce(dev, &dev->wd_cl)) {
 289                         dev_dbg(&dev->pdev->dev, "mei_flow_ctrl_reduce() failed.\n");
 290                         ret = -EIO;
 291                         goto end;
 292                 }
 293
 294         } else {
 295                 dev->wd_pending = true;
 296         }
 297
 298 end:
 299         mutex_unlock(&dev->device_lock);
 300         return ret;
 301 }
 302
 303 /*
 304  * mei_wd_ops_set_timeout - wd set timeout command from the watchdog core.
 305  *
 306  * @wd_dev - watchdog device struct
 307  * @timeout - timeout value to set
 308  *
 309  * returns 0 if success, negative errno code for failure
 310  */
 311 static int mei_wd_ops_set_timeout(struct watchdog_device *wd_dev, unsigned int timeout)
 312 {
 313         struct mei_device *dev;
 314         dev = pci_get_drvdata(mei_device);
 315
 316         if (!dev)
 317                 return -ENODEV;
 318
 319         /* Check Timeout value */
 320         if (timeout < AMT_WD_MIN_TIMEOUT || timeout > AMT_WD_MAX_TIMEOUT)
 321                 return -EINVAL;
 322
 323         mutex_lock(&dev->device_lock);
 324
 325         dev->wd_timeout = timeout;
 326         mei_wd_set_start_timeout(dev, dev->wd_timeout);
 327
 328         mutex_unlock(&dev->device_lock);
 329
 330         return 0;
 331 }
 332
 333 /*
 334  * Watchdog Device structs
 335  */
 336 static const struct watchdog_ops wd_ops = {
 337                 .owner = THIS_MODULE,
 338                 .start = mei_wd_ops_start,
 339                 .stop = mei_wd_ops_stop,
 340                 .ping = mei_wd_ops_ping,
 341                 .set_timeout = mei_wd_ops_set_timeout,
 342 };
 343 static const struct watchdog_info wd_info = {
 344                 .identity = INTEL_AMT_WATCHDOG_ID,
 345                 .options = WDIOF_KEEPALIVEPING,
 346 };
 347
 348 struct watchdog_device amt_wd_dev = {
 349                 .info = &wd_info,
 350                 .ops = &wd_ops,
 351                 .timeout = AMT_WD_DEFAULT_TIMEOUT,
 352                 .min_timeout = AMT_WD_MIN_TIMEOUT,
 353                 .max_timeout = AMT_WD_MAX_TIMEOUT,
 354 };
 355
 356
 357 void  mei_watchdog_register(struct mei_device *dev)
 358 {
 359         dev_dbg(&dev->pdev->dev, "dev->wd_timeout =%d.\n", dev->wd_timeout);
 360
 361         dev->wd_due_counter = !!dev->wd_timeout;
 362
 363         if (watchdog_register_device(&amt_wd_dev)) {
 364                 dev_err(&dev->pdev->dev, "unable to register watchdog device.\n");
 365                 dev->wd_interface_reg = false;
 366         } else {
 367                 dev_dbg(&dev->pdev->dev, "successfully register watchdog interface.\n");
 368                 dev->wd_interface_reg = true;
 369         }
 370 }
 371
 372 void mei_watchdog_unregister(struct mei_device *dev)
 373 {
 374         if (dev->wd_interface_reg)
 375                 watchdog_unregister_device(&amt_wd_dev);
 376         dev->wd_interface_reg = false;
 377 }
 378