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
  23 #include "mei_dev.h"
  24 #include "hw.h"
  25 #include "interface.h"
  26 #include "mei.h"
  27
  28 /*
  29  * MEI Watchdog Module Parameters
  30  */
  31 static u16 watchdog_timeout = AMT_WD_VALUE;
  32 module_param(watchdog_timeout, ushort, 0);
  33 MODULE_PARM_DESC(watchdog_timeout,
  34                 "Intel(R) AMT Watchdog timeout value in seconds. (default="
  35                                         __MODULE_STRING(AMT_WD_VALUE)
  36                                         ", disable=0)");
  37
  38 static const u8 mei_start_wd_params[] = { 0x02, 0x12, 0x13, 0x10 };
  39 static const u8 mei_stop_wd_params[] = { 0x02, 0x02, 0x14, 0x10 };
  40
  41 const u8 mei_wd_state_independence_msg[3][4] = {
  42         {0x05, 0x02, 0x51, 0x10},
  43         {0x05, 0x02, 0x52, 0x10},
  44         {0x07, 0x02, 0x01, 0x10}
  45 };
  46
  47 /* UUIDs for AMT F/W clients */
  48 const uuid_le mei_wd_guid = UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, 0x89,
  49                                                 0x9D, 0xA9, 0x15, 0x14, 0xCB,
  50                                                 0x32, 0xAB);
  51
  52
  53 void mei_wd_start_setup(struct mei_device *dev)
  54 {
  55         dev_dbg(&dev->pdev->dev, "dev->wd_timeout=%d.\n", dev->wd_timeout);
  56         memcpy(dev->wd_data, mei_start_wd_params, MEI_WD_PARAMS_SIZE);
  57         memcpy(dev->wd_data + MEI_WD_PARAMS_SIZE,
  58                 &dev->wd_timeout, sizeof(u16));
  59 }
  60
  61 /**
  62  * host_init_wd - mei initialization wd.
  63  *
  64  * @dev: the device structure
  65  */
  66 void mei_wd_host_init(struct mei_device *dev)
  67 {
  68         mei_init_file_private(&dev->wd_cl, dev);
  69
  70         /* look for WD client and connect to it */
  71         dev->wd_cl.state = MEI_FILE_DISCONNECTED;
  72         dev->wd_timeout = watchdog_timeout;
  73
  74         if (dev->wd_timeout > 0) {
  75                 mei_wd_start_setup(dev);
  76                 /* find ME WD client */
  77                 mei_find_me_client_update_filext(dev, &dev->wd_cl,
  78                                         &mei_wd_guid, MEI_WD_HOST_CLIENT_ID);
  79
  80                 dev_dbg(&dev->pdev->dev, "check wd_cl\n");
  81                 if (MEI_FILE_CONNECTING == dev->wd_cl.state) {
  82                         if (!mei_connect(dev, &dev->wd_cl)) {
  83                                 dev_dbg(&dev->pdev->dev, "Failed to connect to WD client\n");
  84                                 dev->wd_cl.state = MEI_FILE_DISCONNECTED;
  85                                 dev->wd_cl.host_client_id = 0;
  86                                 host_init_iamthif(dev) ;
  87                         } else {
  88                                 dev->wd_cl.timer_count = CONNECT_TIMEOUT;
  89                         }
  90                 } else {
  91                         dev_dbg(&dev->pdev->dev, "Failed to find WD client\n");
  92                         host_init_iamthif(dev) ;
  93                 }
  94         } else {
  95                 dev->wd_bypass = true;
  96                 dev_dbg(&dev->pdev->dev, "WD requested to be disabled\n");
  97                 host_init_iamthif(dev) ;
  98         }
  99 }
 100
 101 /**
 102  * mei_wd_send - sends watch dog message to fw.
 103  *
 104  * @dev: the device structure
 105  *
 106  * returns 0 if success,
 107  *      -EIO when message send fails
 108  *      -EINVAL when invalid message is to be sent
 109  */
 110 int mei_wd_send(struct mei_device *dev)
 111 {
 112         struct mei_msg_hdr *mei_hdr;
 113
 114         mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
 115         mei_hdr->host_addr = dev->wd_cl.host_client_id;
 116         mei_hdr->me_addr = dev->wd_cl.me_client_id;
 117         mei_hdr->msg_complete = 1;
 118         mei_hdr->reserved = 0;
 119
 120         if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_PARAMS_SIZE))
 121                 mei_hdr->length = MEI_START_WD_DATA_SIZE;
 122         else if (!memcmp(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE))
 123                 mei_hdr->length = MEI_WD_PARAMS_SIZE;
 124         else
 125                 return -EINVAL;
 126
 127         if (mei_write_message(dev, mei_hdr, dev->wd_data, mei_hdr->length))
 128                 return 0;
 129         return -EIO;
 130 }
 131
 132 int mei_wd_stop(struct mei_device *dev, bool preserve)
 133 {
 134         int ret;
 135         u16 wd_timeout = dev->wd_timeout;
 136
 137         cancel_delayed_work(&dev->wd_work);
 138         if (dev->wd_cl.state != MEI_FILE_CONNECTED || !dev->wd_timeout)
 139                 return 0;
 140
 141         dev->wd_timeout = 0;
 142         dev->wd_due_counter = 0;
 143         memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE);
 144         dev->stop = 1;
 145
 146         ret = mei_flow_ctrl_creds(dev, &dev->wd_cl);
 147         if (ret < 0)
 148                 goto out;
 149
 150         if (ret && dev->mei_host_buffer_is_empty) {
 151                 ret = 0;
 152                 dev->mei_host_buffer_is_empty = 0;
 153
 154                 if (!mei_wd_send(dev)) {
 155                         ret = mei_flow_ctrl_reduce(dev, &dev->wd_cl);
 156                         if (ret)
 157                                 goto out;
 158                 } else {
 159                         dev_dbg(&dev->pdev->dev, "send stop WD failed\n");
 160                 }
 161
 162                 dev->wd_pending = 0;
 163         } else {
 164                 dev->wd_pending = 1;
 165         }
 166         dev->wd_stopped = 0;
 167         mutex_unlock(&dev->device_lock);
 168
 169         ret = wait_event_interruptible_timeout(dev->wait_stop_wd,
 170                                         dev->wd_stopped, 10 * HZ);
 171         mutex_lock(&dev->device_lock);
 172         if (dev->wd_stopped) {
 173                 dev_dbg(&dev->pdev->dev, "stop wd complete ret=%d.\n", ret);
 174                 ret = 0;
 175         } else {
 176                 if (!ret)
 177                         ret = -ETIMEDOUT;
 178                 dev_warn(&dev->pdev->dev,
 179                         "stop wd failed to complete ret=%d.\n", ret);
 180         }
 181
 182         if (preserve)
 183                 dev->wd_timeout = wd_timeout;
 184
 185 out:
 186         return ret;
 187 }
 188