drivers/misc/mei/init.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
  17 #include <linux/pci.h>
  18 #include <linux/sched.h>
  19 #include <linux/wait.h>
  20 #include <linux/delay.h>
  21
  22 #include <linux/mei.h>
  23
  24 #include "mei_dev.h"
  25 #include "client.h"
  26
  27 const char *mei_dev_state_str(int state)
  28 {
  29 #define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
  30         switch (state) {
  31         MEI_DEV_STATE(INITIALIZING);
  32         MEI_DEV_STATE(INIT_CLIENTS);
  33         MEI_DEV_STATE(ENABLED);
  34         MEI_DEV_STATE(RESETING);
  35         MEI_DEV_STATE(DISABLED);
  36         MEI_DEV_STATE(RECOVERING_FROM_RESET);
  37         MEI_DEV_STATE(POWER_DOWN);
  38         MEI_DEV_STATE(POWER_UP);
  39         default:
  40                 return "unkown";
  41         }
  42 #undef MEI_DEV_STATE
  43 }
  44
  45 void mei_device_init(struct mei_device *dev)
  46 {
  47         /* setup our list array */
  48         INIT_LIST_HEAD(&dev->file_list);
  49         mutex_init(&dev->device_lock);
  50         init_waitqueue_head(&dev->wait_recvd_msg);
  51         init_waitqueue_head(&dev->wait_stop_wd);
  52         dev->dev_state = MEI_DEV_INITIALIZING;
  53
  54         mei_io_list_init(&dev->read_list);
  55         mei_io_list_init(&dev->write_list);
  56         mei_io_list_init(&dev->write_waiting_list);
  57         mei_io_list_init(&dev->ctrl_wr_list);
  58         mei_io_list_init(&dev->ctrl_rd_list);
  59 }
  60
  61 /**
  62  * mei_hw_init - initializes host and fw to start work.
  63  *
  64  * @dev: the device structure
  65  *
  66  * returns 0 on success, <0 on failure.
  67  */
  68 int mei_hw_init(struct mei_device *dev)
  69 {
  70         int ret = 0;
  71
  72         mutex_lock(&dev->device_lock);
  73
  74         /* acknowledge interrupt and stop interupts */
  75         mei_clear_interrupts(dev);
  76
  77         mei_hw_config(dev);
  78
  79         dev->recvd_msg = false;
  80         dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");
  81
  82         mei_reset(dev, 1);
  83
  84         /* wait for ME to turn on ME_RDY */
  85         if (!dev->recvd_msg) {
  86                 mutex_unlock(&dev->device_lock);
  87                 ret = wait_event_interruptible_timeout(dev->wait_recvd_msg,
  88                         dev->recvd_msg,
  89                         mei_secs_to_jiffies(MEI_INTEROP_TIMEOUT));
  90                 mutex_lock(&dev->device_lock);
  91         }
  92
  93         if (ret <= 0 && !dev->recvd_msg) {
  94                 dev->dev_state = MEI_DEV_DISABLED;
  95                 dev_dbg(&dev->pdev->dev,
  96                         "wait_event_interruptible_timeout failed"
  97                         "on wait for ME to turn on ME_RDY.\n");
  98                 goto err;
  99         }
 100
 101
 102         if (!mei_host_is_ready(dev)) {
 103                 dev_err(&dev->pdev->dev, "host is not ready.\n");
 104                 goto err;
 105         }
 106
 107         if (!mei_hw_is_ready(dev)) {
 108                 dev_err(&dev->pdev->dev, "ME is not ready.\n");
 109                 goto err;
 110         }
 111
 112         if (dev->version.major_version != HBM_MAJOR_VERSION ||
 113             dev->version.minor_version != HBM_MINOR_VERSION) {
 114                 dev_dbg(&dev->pdev->dev, "MEI start failed.\n");
 115                 goto err;
 116         }
 117
 118         dev->recvd_msg = false;
 119         dev_dbg(&dev->pdev->dev, "link layer has been established.\n");
 120
 121         mutex_unlock(&dev->device_lock);
 122         return 0;
 123 err:
 124         dev_err(&dev->pdev->dev, "link layer initialization failed.\n");
 125         dev->dev_state = MEI_DEV_DISABLED;
 126         mutex_unlock(&dev->device_lock);
 127         return -ENODEV;
 128 }
 129
 130 /**
 131  * mei_reset - resets host and fw.
 132  *
 133  * @dev: the device structure
 134  * @interrupts_enabled: if interrupt should be enabled after reset.
 135  */
 136 void mei_reset(struct mei_device *dev, int interrupts_enabled)
 137 {
 138         bool unexpected;
 139
 140         if (dev->dev_state == MEI_DEV_RECOVERING_FROM_RESET)
 141                 return;
 142
 143         unexpected = (dev->dev_state != MEI_DEV_INITIALIZING &&
 144                         dev->dev_state != MEI_DEV_DISABLED &&
 145                         dev->dev_state != MEI_DEV_POWER_DOWN &&
 146                         dev->dev_state != MEI_DEV_POWER_UP);
 147
 148         mei_hw_reset(dev, interrupts_enabled);
 149
 150
 151         if (dev->dev_state != MEI_DEV_INITIALIZING) {
 152                 if (dev->dev_state != MEI_DEV_DISABLED &&
 153                     dev->dev_state != MEI_DEV_POWER_DOWN)
 154                         dev->dev_state = MEI_DEV_RESETING;
 155
 156                 mei_cl_all_disconnect(dev);
 157
 158                 /* remove entry if already in list */
 159                 dev_dbg(&dev->pdev->dev, "remove iamthif and wd from the file list.\n");
 160                 mei_cl_unlink(&dev->wd_cl);
 161                 if (dev->open_handle_count > 0)
 162                         dev->open_handle_count--;
 163                 mei_cl_unlink(&dev->iamthif_cl);
 164                 if (dev->open_handle_count > 0)
 165                         dev->open_handle_count--;
 166
 167                 mei_amthif_reset_params(dev);
 168                 memset(&dev->wr_ext_msg, 0, sizeof(dev->wr_ext_msg));
 169         }
 170
 171         dev->me_clients_num = 0;
 172         dev->rd_msg_hdr = 0;
 173         dev->wd_pending = false;
 174
 175         if (unexpected)
 176                 dev_warn(&dev->pdev->dev, "unexpected reset: dev_state = %s\n",
 177                          mei_dev_state_str(dev->dev_state));
 178
 179         /* wake up all readings so they can be interrupted */
 180         mei_cl_all_read_wakeup(dev);
 181
 182         /* remove all waiting requests */
 183         mei_cl_all_write_clear(dev);
 184 }
 185
 186
 187
 188