/*
*
* Intel Management Engine Interface (Intel MEI) Linux driver
* Copyright (c) 2003-2012, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
*/
#include <linux/export.h>
#include <linux/pci.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/mei.h>
#include "mei_dev.h"
#include "hbm.h"
#include "client.h"
const char *mei_dev_state_str(int state)
{
#define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
switch (state) {
MEI_DEV_STATE(INITIALIZING);
MEI_DEV_STATE(INIT_CLIENTS);
MEI_DEV_STATE(ENABLED);
MEI_DEV_STATE(RESETTING);
MEI_DEV_STATE(DISABLED);
MEI_DEV_STATE(POWER_DOWN);
MEI_DEV_STATE(POWER_UP);
default:
return "unknown";
}
#undef MEI_DEV_STATE
}
/**
* mei_start - initializes host and fw to start work.
*
* @dev: the device structure
*
* returns 0 on success, <0 on failure.
*/
int mei_start(struct mei_device *dev)
{
mutex_lock(&dev->device_lock);
/* acknowledge interrupt and stop interupts */
mei_clear_interrupts(dev);
mei_hw_config(dev);
dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");
mei_reset(dev, 1);
if (mei_hbm_start_wait(dev)) {
dev_err(&dev->pdev->dev, "HBM haven't started");
goto err;
}
if (!mei_host_is_ready(dev)) {
dev_err(&dev->pdev->dev, "host is not ready.\n");
goto err;
}
if (!mei_hw_is_ready(dev)) {
dev_err(&dev->pdev->dev, "ME is not ready.\n");
goto err;
}
if (!mei_hbm_version_is_supported(dev)) {
dev_dbg(&dev->pdev->dev, "MEI start failed.\n");
goto err;
}
dev_dbg(&dev->pdev->dev, "link layer has been established.\n");
mutex_unlock(&dev->device_lock);
return 0;
err:
dev_err(&dev->pdev->dev, "link layer initialization failed.\n");
dev->dev_state = MEI_DEV_DISABLED;
mutex_unlock(&dev->device_lock);
return -ENODEV;
}
EXPORT_SYMBOL_GPL(mei_start);
/**
* mei_cancel_work. Cancel mei background jobs
*
* @dev: the device structure
*/
void mei_cancel_work(struct mei_device *dev)
{
cancel_work_sync(&dev->init_work);
cancel_work_sync(&dev->reset_work);
cancel_delayed_work(&dev->timer_work);
}
EXPORT_SYMBOL_GPL(mei_cancel_work);
/**
* mei_reset - resets host and fw.
*
* @dev: the device structure
* @interrupts_enabled: if interrupt should be enabled after reset.
*/
void mei_reset(struct mei_device *dev, int interrupts_enabled)
{
bool unexpected;
int ret;
unexpected = (dev->dev_state != MEI_DEV_INITIALIZING &&
dev->dev_state != MEI_DEV_DISABLED &&
dev->dev_state != MEI_DEV_POWER_DOWN &&
dev->dev_state != MEI_DEV_POWER_UP);
if (unexpected)
dev_warn(&dev->pdev->dev, "unexpected reset: dev_state = %s\n",
mei_dev_state_str(dev->dev_state));
/* we're already in reset, cancel the init timer
* if the reset was called due the hbm protocol error
* we need to call it before hw start
* so the hbm watchdog won't kick in
*/
mei_hbm_idle(dev);
ret = mei_hw_reset(dev, interrupts_enabled);
if (ret) {
dev_err(&dev->pdev->dev, "hw reset failed disabling the device\n");
interrupts_enabled = false;
}
if (dev->dev_state != MEI_DEV_INITIALIZING &&
dev->dev_state != MEI_DEV_POWER_UP) {
if (dev->dev_state != MEI_DEV_DISABLED &&
dev->dev_state != MEI_DEV_POWER_DOWN)
dev->dev_state = MEI_DEV_RESETTING;
/* remove all waiting requests */
mei_cl_all_write_clear(dev);
mei_cl_all_disconnect(dev);
/* wake up all readings so they can be interrupted */
mei_cl_all_wakeup(dev);
/* remove entry if already in list */
dev_dbg(&dev->pdev->dev, "remove iamthif and wd from the file list.\n");
mei_cl_unlink(&dev->wd_cl);
mei_cl_unlink(&dev->iamthif_cl);
mei_amthif_reset_params(dev);
memset(&dev->wr_ext_msg, 0, sizeof(dev->wr_ext_msg));
}
dev->me_clients_num = 0;
dev->rd_msg_hdr = 0;
dev->wd_pending = false;
if (!interrupts_enabled) {
dev_dbg(&dev->pdev->dev, "intr not enabled end of reset\n");
dev->dev_state = MEI_DEV_DISABLED;
return;
}
ret = mei_hw_start(dev);
if (ret) {
dev_err(&dev->pdev->dev, "hw_start failed disabling the device\n");
dev->dev_state = MEI_DEV_DISABLED;
return;
}
dev_dbg(&dev->pdev->dev, "link is established start sending messages.\n");
/* link is established * start sending messages. */
dev->dev_state = MEI_DEV_INIT_CLIENTS;
ret = mei_hbm_start_req(dev);
if (ret) {
dev_err(&dev->pdev->dev, "hbm_start failed disabling the device\n");
dev->dev_state = MEI_DEV_DISABLED;
return;
}
}
EXPORT_SYMBOL_GPL(mei_reset);
static void mei_reset_work(struct work_struct *work)
{
struct mei_device *dev =
container_of(work, struct mei_device, reset_work);
mutex_lock(&dev->device_lock);
mei_reset(dev, true);
mutex_unlock(&dev->device_lock);
}
void mei_stop(struct mei_device *dev)
{
dev_dbg(&dev->pdev->dev, "stopping the device.\n");
mei_cancel_work(dev);
mei_nfc_host_exit(dev);
mutex_lock(&dev->device_lock);
mei_wd_stop(dev);
dev->dev_state = MEI_DEV_POWER_DOWN;
mei_reset(dev, 0);
mutex_unlock(&dev->device_lock);
mei_watchdog_unregister(dev);
}
EXPORT_SYMBOL_GPL(mei_stop);
void mei_device_init(struct mei_device *dev)
{
/* setup our list array */
INIT_LIST_HEAD(&dev->file_list);
INIT_LIST_HEAD(&dev->device_list);
mutex_init(&dev->device_lock);
init_waitqueue_head(&dev->wait_hw_ready);
init_waitqueue_head(&dev->wait_recvd_msg);
init_waitqueue_head(&dev->wait_stop_wd);
dev->dev_state = MEI_DEV_INITIALIZING;
mei_io_list_init(&dev->read_list);
mei_io_list_init(&dev->write_list);
mei_io_list_init(&dev->write_waiting_list);
mei_io_list_init(&dev->ctrl_wr_list);
mei_io_list_init(&dev->ctrl_rd_list);
INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
INIT_WORK(&dev->init_work, mei_host_client_init);
INIT_WORK(&dev->reset_work, mei_reset_work);
INIT_LIST_HEAD(&dev->wd_cl.link);
INIT_LIST_HEAD(&dev->iamthif_cl.link);
mei_io_list_init(&dev->amthif_cmd_list);
mei_io_list_init(&dev->amthif_rd_complete_list);
bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
dev->open_handle_count = 0;
/*
* Reserving the first client ID
* 0: Reserved for MEI Bus Message communications
*/
bitmap_set(dev->host_clients_map, 0, 1);
}
EXPORT_SYMBOL_GPL(mei_device_init);
