staging/mei: AMT Watchdog

/*

 *

 * Intel Management Engine Interface (Intel MEI) Linux driver

 * Copyright (c) 2003-2011, 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/kernel.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/device.h>

#include <linux/pci.h>

#include <linux/sched.h>

#include "mei_dev.h"

#include "hw.h"

#include "interface.h"

#include "mei.h"

/*

 * MEI Watchdog Module Parameters

 */

static u16 watchdog_timeout = AMT_WD_VALUE;

module_param(watchdog_timeout, ushort, 0);

MODULE_PARM_DESC(watchdog_timeout,

		"Intel(R) AMT Watchdog timeout value in seconds. (default="

					__MODULE_STRING(AMT_WD_VALUE)

					", disable=0)");

static const u8 mei_start_wd_params[] = { 0x02, 0x12, 0x13, 0x10 };

static const u8 mei_stop_wd_params[] = { 0x02, 0x02, 0x14, 0x10 };

const u8 mei_wd_state_independence_msg[3][4] = {

	{0x05, 0x02, 0x51, 0x10},

	{0x05, 0x02, 0x52, 0x10},

	{0x07, 0x02, 0x01, 0x10}

};

/* UUIDs for AMT F/W clients */

const uuid_le mei_wd_guid = UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, 0x89,

						0x9D, 0xA9, 0x15, 0x14, 0xCB,

						0x32, 0xAB);

void mei_wd_start_setup(struct mei_device *dev)

{

	dev_dbg(&dev->pdev->dev, "dev->wd_timeout=%d.\n", dev->wd_timeout);

	memcpy(dev->wd_data, mei_start_wd_params, MEI_WD_PARAMS_SIZE);

	memcpy(dev->wd_data + MEI_WD_PARAMS_SIZE,

		&dev->wd_timeout, sizeof(u16));

}

/**

 * host_init_wd - mei initialization wd.

 *

 * @dev: the device structure

 */

void mei_wd_host_init(struct mei_device *dev)

{

	mei_init_file_private(&dev->wd_cl, dev);

	/* look for WD client and connect to it */

	dev->wd_cl.state = MEI_FILE_DISCONNECTED;

	dev->wd_timeout = watchdog_timeout;

	if (dev->wd_timeout > 0) {

		mei_wd_start_setup(dev);

		/* find ME WD client */

		mei_find_me_client_update_filext(dev, &dev->wd_cl,

					&mei_wd_guid, MEI_WD_HOST_CLIENT_ID);

		dev_dbg(&dev->pdev->dev, "check wd_cl\n");

		if (MEI_FILE_CONNECTING == dev->wd_cl.state) {

			if (!mei_connect(dev, &dev->wd_cl)) {

				dev_dbg(&dev->pdev->dev, "Failed to connect to WD client\n");

				dev->wd_cl.state = MEI_FILE_DISCONNECTED;

				dev->wd_cl.host_client_id = 0;

				host_init_iamthif(dev) ;

			} else {

				dev->wd_cl.timer_count = CONNECT_TIMEOUT;

			}

		} else {

			dev_dbg(&dev->pdev->dev, "Failed to find WD client\n");

			host_init_iamthif(dev) ;

		}

	} else {

		dev->wd_bypass = true;

		dev_dbg(&dev->pdev->dev, "WD requested to be disabled\n");

		host_init_iamthif(dev) ;

	}

}

/**

 * mei_wd_send - sends watch dog message to fw.

 *

 * @dev: the device structure

 *

 * returns 0 if success,

 *	-EIO when message send fails

 *	-EINVAL when invalid message is to be sent

 */

int mei_wd_send(struct mei_device *dev)

{

	struct mei_msg_hdr *mei_hdr;

	mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];

	mei_hdr->host_addr = dev->wd_cl.host_client_id;

	mei_hdr->me_addr = dev->wd_cl.me_client_id;

	mei_hdr->msg_complete = 1;

	mei_hdr->reserved = 0;

	if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_PARAMS_SIZE))

		mei_hdr->length = MEI_START_WD_DATA_SIZE;

	else if (!memcmp(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE))

		mei_hdr->length = MEI_WD_PARAMS_SIZE;

	else

		return -EINVAL;

	if (mei_write_message(dev, mei_hdr, dev->wd_data, mei_hdr->length))

		return 0;

	return -EIO;

}

int mei_wd_stop(struct mei_device *dev, bool preserve)

{

	int ret;

	u16 wd_timeout = dev->wd_timeout;

	cancel_delayed_work(&dev->wd_work);

	if (dev->wd_cl.state != MEI_FILE_CONNECTED || !dev->wd_timeout)

		return 0;

	dev->wd_timeout = 0;

	dev->wd_due_counter = 0;

	memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE);

	dev->stop = 1;

	ret = mei_flow_ctrl_creds(dev, &dev->wd_cl);

	if (ret < 0)

		goto out;

	if (ret && dev->mei_host_buffer_is_empty) {

		ret = 0;

		dev->mei_host_buffer_is_empty = 0;

		if (!mei_wd_send(dev)) {

			ret = mei_flow_ctrl_reduce(dev, &dev->wd_cl);

			if (ret)

				goto out;

		} else {

			dev_dbg(&dev->pdev->dev, "send stop WD failed\n");

		}

		dev->wd_pending = 0;

	} else {

		dev->wd_pending = 1;

	}

	dev->wd_stopped = 0;

	mutex_unlock(&dev->device_lock);

	ret = wait_event_interruptible_timeout(dev->wait_stop_wd,

					dev->wd_stopped, 10 * HZ);

	mutex_lock(&dev->device_lock);

	if (!dev->wd_stopped)

		dev_dbg(&dev->pdev->dev, "stop wd failed to complete.\n");

	else

		dev_dbg(&dev->pdev->dev, "stop wd complete.\n");

	if (preserve)

		dev->wd_timeout = wd_timeout;

out:

	return ret;

}