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/export.h>
  18 #include <linux/pci.h>
  19 #include <linux/sched.h>
  20 #include <linux/wait.h>
  21 #include <linux/delay.h>
  22
  23 #include <linux/mei.h>
  24
  25 #include "mei_dev.h"
  26 #include "hbm.h"
  27 #include "client.h"
  28
  29 const char *mei_dev_state_str(int state)
  30 {
  31 #define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
  32         switch (state) {
  33         MEI_DEV_STATE(INITIALIZING);
  34         MEI_DEV_STATE(INIT_CLIENTS);
  35         MEI_DEV_STATE(ENABLED);
  36         MEI_DEV_STATE(RESETTING);
  37         MEI_DEV_STATE(DISABLED);
  38         MEI_DEV_STATE(POWER_DOWN);
  39         MEI_DEV_STATE(POWER_UP);
  40         default:
  41                 return "unknown";
  42         }
  43 #undef MEI_DEV_STATE
  44 }
  45
  46 void mei_device_init(struct mei_device *dev)
  47 {
  48         /* setup our list array */
  49         INIT_LIST_HEAD(&dev->file_list);
  50         INIT_LIST_HEAD(&dev->device_list);
  51         mutex_init(&dev->device_lock);
  52         init_waitqueue_head(&dev->wait_hw_ready);
  53         init_waitqueue_head(&dev->wait_recvd_msg);
  54         init_waitqueue_head(&dev->wait_stop_wd);
  55         dev->dev_state = MEI_DEV_INITIALIZING;
  56
  57         mei_io_list_init(&dev->read_list);
  58         mei_io_list_init(&dev->write_list);
  59         mei_io_list_init(&dev->write_waiting_list);
  60         mei_io_list_init(&dev->ctrl_wr_list);
  61         mei_io_list_init(&dev->ctrl_rd_list);
  62
  63         INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
  64         INIT_WORK(&dev->init_work, mei_host_client_init);
  65
  66         INIT_LIST_HEAD(&dev->wd_cl.link);
  67         INIT_LIST_HEAD(&dev->iamthif_cl.link);
  68         mei_io_list_init(&dev->amthif_cmd_list);
  69         mei_io_list_init(&dev->amthif_rd_complete_list);
  70
  71         bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
  72         dev->open_handle_count = 0;
  73
  74         /*
  75          * Reserving the first client ID
  76          * 0: Reserved for MEI Bus Message communications
  77          */
  78         bitmap_set(dev->host_clients_map, 0, 1);
  79 }
  80 EXPORT_SYMBOL_GPL(mei_device_init);
  81
  82 /**
  83  * mei_start - initializes host and fw to start work.
  84  *
  85  * @dev: the device structure
  86  *
  87  * returns 0 on success, <0 on failure.
  88  */
  89 int mei_start(struct mei_device *dev)
  90 {
  91         mutex_lock(&dev->device_lock);
  92
  93         /* acknowledge interrupt and stop interupts */
  94         mei_clear_interrupts(dev);
  95
  96         mei_hw_config(dev);
  97
  98         dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");
  99
 100         mei_reset(dev, 1);
 101
 102         if (mei_hbm_start_wait(dev)) {
 103                 dev_err(&dev->pdev->dev, "HBM haven't started");
 104                 goto err;
 105         }
 106
 107         if (!mei_host_is_ready(dev)) {
 108                 dev_err(&dev->pdev->dev, "host is not ready.\n");
 109                 goto err;
 110         }
 111
 112         if (!mei_hw_is_ready(dev)) {
 113                 dev_err(&dev->pdev->dev, "ME is not ready.\n");
 114                 goto err;
 115         }
 116
 117         if (!mei_hbm_version_is_supported(dev)) {
 118                 dev_dbg(&dev->pdev->dev, "MEI start failed.\n");
 119                 goto err;
 120         }
 121
 122         dev_dbg(&dev->pdev->dev, "link layer has been established.\n");
 123
 124         mutex_unlock(&dev->device_lock);
 125         return 0;
 126 err:
 127         dev_err(&dev->pdev->dev, "link layer initialization failed.\n");
 128         dev->dev_state = MEI_DEV_DISABLED;
 129         mutex_unlock(&dev->device_lock);
 130         return -ENODEV;
 131 }
 132 EXPORT_SYMBOL_GPL(mei_start);
 133
 134
 135 void mei_cancel_work(struct mei_device *dev)
 136 {
 137         cancel_work_sync(&dev->init_work);
 138
 139         cancel_delayed_work(&dev->timer_work);
 140 }
 141 EXPORT_SYMBOL_GPL(mei_cancel_work);
 142
 143 /**
 144  * mei_reset - resets host and fw.
 145  *
 146  * @dev: the device structure
 147  * @interrupts_enabled: if interrupt should be enabled after reset.
 148  */
 149 void mei_reset(struct mei_device *dev, int interrupts_enabled)
 150 {
 151         bool unexpected;
 152         int ret;
 153
 154         unexpected = (dev->dev_state != MEI_DEV_INITIALIZING &&
 155                         dev->dev_state != MEI_DEV_DISABLED &&
 156                         dev->dev_state != MEI_DEV_POWER_DOWN &&
 157                         dev->dev_state != MEI_DEV_POWER_UP);
 158
 159         if (unexpected)
 160                 dev_warn(&dev->pdev->dev, "unexpected reset: dev_state = %s\n",
 161                          mei_dev_state_str(dev->dev_state));
 162
 163         ret = mei_hw_reset(dev, interrupts_enabled);
 164         if (ret) {
 165                 dev_err(&dev->pdev->dev, "hw reset failed disabling the device\n");
 166                 interrupts_enabled = false;
 167                 dev->dev_state = MEI_DEV_DISABLED;
 168         }
 169
 170         dev->hbm_state = MEI_HBM_IDLE;
 171
 172         if (dev->dev_state != MEI_DEV_INITIALIZING &&
 173             dev->dev_state != MEI_DEV_POWER_UP) {
 174                 if (dev->dev_state != MEI_DEV_DISABLED &&
 175                     dev->dev_state != MEI_DEV_POWER_DOWN)
 176                         dev->dev_state = MEI_DEV_RESETTING;
 177
 178                 /* remove all waiting requests */
 179                 mei_cl_all_write_clear(dev);
 180
 181                 mei_cl_all_disconnect(dev);
 182
 183                 /* wake up all readings so they can be interrupted */
 184                 mei_cl_all_wakeup(dev);
 185
 186                 /* remove entry if already in list */
 187                 dev_dbg(&dev->pdev->dev, "remove iamthif and wd from the file list.\n");
 188                 mei_cl_unlink(&dev->wd_cl);
 189                 mei_cl_unlink(&dev->iamthif_cl);
 190                 mei_amthif_reset_params(dev);
 191                 memset(&dev->wr_ext_msg, 0, sizeof(dev->wr_ext_msg));
 192         }
 193
 194         /* we're already in reset, cancel the init timer */
 195         dev->init_clients_timer = 0;
 196
 197         dev->me_clients_num = 0;
 198         dev->rd_msg_hdr = 0;
 199         dev->wd_pending = false;
 200
 201         if (!interrupts_enabled) {
 202                 dev_dbg(&dev->pdev->dev, "intr not enabled end of reset\n");
 203                 return;
 204         }
 205
 206         ret = mei_hw_start(dev);
 207         if (ret) {
 208                 dev_err(&dev->pdev->dev, "hw_start failed disabling the device\n");
 209                 dev->dev_state = MEI_DEV_DISABLED;
 210                 return;
 211         }
 212
 213         dev_dbg(&dev->pdev->dev, "link is established start sending messages.\n");
 214         /* link is established * start sending messages.  */
 215
 216         dev->dev_state = MEI_DEV_INIT_CLIENTS;
 217
 218         mei_hbm_start_req(dev);
 219
 220 }
 221 EXPORT_SYMBOL_GPL(mei_reset);
 222
 223 void mei_stop(struct mei_device *dev)
 224 {
 225         dev_dbg(&dev->pdev->dev, "stopping the device.\n");
 226
 227         mei_cancel_work(dev);
 228
 229         mei_nfc_host_exit(dev);
 230
 231         mutex_lock(&dev->device_lock);
 232
 233         mei_wd_stop(dev);
 234
 235         dev->dev_state = MEI_DEV_POWER_DOWN;
 236         mei_reset(dev, 0);
 237
 238         mutex_unlock(&dev->device_lock);
 239
 240         mei_watchdog_unregister(dev);
 241 }
 242 EXPORT_SYMBOL_GPL(mei_stop);
 243
 244
 245