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 }
  72 EXPORT_SYMBOL_GPL(mei_device_init);
  73
  74 /**
  75  * mei_start - initializes host and fw to start work.
  76  *
  77  * @dev: the device structure
  78  *
  79  * returns 0 on success, <0 on failure.
  80  */
  81 int mei_start(struct mei_device *dev)
  82 {
  83         mutex_lock(&dev->device_lock);
  84
  85         /* acknowledge interrupt and stop interupts */
  86         mei_clear_interrupts(dev);
  87
  88         mei_hw_config(dev);
  89
  90         dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");
  91
  92         mei_reset(dev, 1);
  93
  94         if (mei_hbm_start_wait(dev)) {
  95                 dev_err(&dev->pdev->dev, "HBM haven't started");
  96                 goto err;
  97         }
  98
  99         if (!mei_host_is_ready(dev)) {
 100                 dev_err(&dev->pdev->dev, "host is not ready.\n");
 101                 goto err;
 102         }
 103
 104         if (!mei_hw_is_ready(dev)) {
 105                 dev_err(&dev->pdev->dev, "ME is not ready.\n");
 106                 goto err;
 107         }
 108
 109         if (!mei_hbm_version_is_supported(dev)) {
 110                 dev_dbg(&dev->pdev->dev, "MEI start failed.\n");
 111                 goto err;
 112         }
 113
 114         dev_dbg(&dev->pdev->dev, "link layer has been established.\n");
 115
 116         mutex_unlock(&dev->device_lock);
 117         return 0;
 118 err:
 119         dev_err(&dev->pdev->dev, "link layer initialization failed.\n");
 120         dev->dev_state = MEI_DEV_DISABLED;
 121         mutex_unlock(&dev->device_lock);
 122         return -ENODEV;
 123 }
 124 EXPORT_SYMBOL_GPL(mei_start);
 125
 126 /**
 127  * mei_reset - resets host and fw.
 128  *
 129  * @dev: the device structure
 130  * @interrupts_enabled: if interrupt should be enabled after reset.
 131  */
 132 void mei_reset(struct mei_device *dev, int interrupts_enabled)
 133 {
 134         bool unexpected;
 135         int ret;
 136
 137         unexpected = (dev->dev_state != MEI_DEV_INITIALIZING &&
 138                         dev->dev_state != MEI_DEV_DISABLED &&
 139                         dev->dev_state != MEI_DEV_POWER_DOWN &&
 140                         dev->dev_state != MEI_DEV_POWER_UP);
 141
 142         ret = mei_hw_reset(dev, interrupts_enabled);
 143         if (ret) {
 144                 dev_err(&dev->pdev->dev, "hw reset failed disabling the device\n");
 145                 interrupts_enabled = false;
 146                 dev->dev_state = MEI_DEV_DISABLED;
 147         }
 148
 149         dev->hbm_state = MEI_HBM_IDLE;
 150
 151         if (dev->dev_state != MEI_DEV_INITIALIZING &&
 152             dev->dev_state != MEI_DEV_POWER_UP) {
 153                 if (dev->dev_state != MEI_DEV_DISABLED &&
 154                     dev->dev_state != MEI_DEV_POWER_DOWN)
 155                         dev->dev_state = MEI_DEV_RESETTING;
 156
 157                 /* remove all waiting requests */
 158                 mei_cl_all_write_clear(dev);
 159
 160                 mei_cl_all_disconnect(dev);
 161
 162                 /* wake up all readings so they can be interrupted */
 163                 mei_cl_all_wakeup(dev);
 164
 165                 /* remove entry if already in list */
 166                 dev_dbg(&dev->pdev->dev, "remove iamthif and wd from the file list.\n");
 167                 mei_cl_unlink(&dev->wd_cl);
 168                 if (dev->open_handle_count > 0)
 169                         dev->open_handle_count--;
 170                 mei_cl_unlink(&dev->iamthif_cl);
 171                 if (dev->open_handle_count > 0)
 172                         dev->open_handle_count--;
 173
 174                 mei_amthif_reset_params(dev);
 175                 memset(&dev->wr_ext_msg, 0, sizeof(dev->wr_ext_msg));
 176         }
 177
 178         /* we're already in reset, cancel the init timer */
 179         dev->init_clients_timer = 0;
 180
 181         dev->me_clients_num = 0;
 182         dev->rd_msg_hdr = 0;
 183         dev->wd_pending = false;
 184
 185         if (unexpected)
 186                 dev_warn(&dev->pdev->dev, "unexpected reset: dev_state = %s\n",
 187                          mei_dev_state_str(dev->dev_state));
 188
 189         if (!interrupts_enabled) {
 190                 dev_dbg(&dev->pdev->dev, "intr not enabled end of reset\n");
 191                 return;
 192         }
 193
 194         ret = mei_hw_start(dev);
 195         if (ret) {
 196                 dev_err(&dev->pdev->dev, "hw_start failed disabling the device\n");
 197                 dev->dev_state = MEI_DEV_DISABLED;
 198                 return;
 199         }
 200
 201         dev_dbg(&dev->pdev->dev, "link is established start sending messages.\n");
 202         /* link is established * start sending messages.  */
 203
 204         dev->dev_state = MEI_DEV_INIT_CLIENTS;
 205
 206         mei_hbm_start_req(dev);
 207
 208 }
 209 EXPORT_SYMBOL_GPL(mei_reset);
 210
 211 void mei_stop(struct mei_device *dev)
 212 {
 213         dev_dbg(&dev->pdev->dev, "stopping the device.\n");
 214
 215         flush_scheduled_work();
 216
 217         mutex_lock(&dev->device_lock);
 218
 219         cancel_delayed_work(&dev->timer_work);
 220
 221         mei_wd_stop(dev);
 222
 223         mei_nfc_host_exit();
 224
 225         dev->dev_state = MEI_DEV_POWER_DOWN;
 226         mei_reset(dev, 0);
 227
 228         mutex_unlock(&dev->device_lock);
 229
 230         mei_watchdog_unregister(dev);
 231 }
 232 EXPORT_SYMBOL_GPL(mei_stop);
 233
 234
 235