1/*
  2 *
  3 * Intel Management Engine Interface (Intel MEI) Linux driver
  4 * Copyright (c) 2003-2011, 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#include <linux/kernel.h>
 17#include <linux/module.h>
 18#include <linux/moduleparam.h>
 19#include <linux/device.h>
 20#include <linux/pci.h>
 21#include <linux/sched.h>
 22
 23#include "mei_dev.h"
 24#include "hw.h"
 25#include "interface.h"
 26#include "mei.h"
 27
 28/*
 29 * MEI Watchdog Module Parameters
 30 */
 31static u16 watchdog_timeout = AMT_WD_VALUE;
 32module_param(watchdog_timeout, ushort, 0);
 33MODULE_PARM_DESC(watchdog_timeout,
 34		"Intel(R) AMT Watchdog timeout value in seconds. (default="
 35					__MODULE_STRING(AMT_WD_VALUE)
 36					", disable=0)");
 37
 38static const u8 mei_start_wd_params[] = { 0x02, 0x12, 0x13, 0x10 };
 39static const u8 mei_stop_wd_params[] = { 0x02, 0x02, 0x14, 0x10 };
 40
 41const u8 mei_wd_state_independence_msg[3][4] = {
 42	{0x05, 0x02, 0x51, 0x10},
 43	{0x05, 0x02, 0x52, 0x10},
 44	{0x07, 0x02, 0x01, 0x10}
 45};
 46
 47/* UUIDs for AMT F/W clients */
 48const uuid_le mei_wd_guid = UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, 0x89,
 49						0x9D, 0xA9, 0x15, 0x14, 0xCB,
 50						0x32, 0xAB);
 51
 52
 53void mei_wd_start_setup(struct mei_device *dev)
 54{
 55	dev_dbg(&dev->pdev->dev, "dev->wd_timeout=%d.\n", dev->wd_timeout);
 56	memcpy(dev->wd_data, mei_start_wd_params, MEI_WD_PARAMS_SIZE);
 57	memcpy(dev->wd_data + MEI_WD_PARAMS_SIZE,
 58		&dev->wd_timeout, sizeof(u16));
 59}
 60
 61/**
 62 * host_init_wd - mei initialization wd.
 63 *
 64 * @dev: the device structure
 65 */
 66void mei_wd_host_init(struct mei_device *dev)
 67{
 68	mei_cl_init(&dev->wd_cl, dev);
 69
 70	/* look for WD client and connect to it */
 71	dev->wd_cl.state = MEI_FILE_DISCONNECTED;
 72	dev->wd_timeout = watchdog_timeout;
 73
 74	if (dev->wd_timeout > 0) {
 75		mei_wd_start_setup(dev);
 76		/* find ME WD client */
 77		mei_find_me_client_update_filext(dev, &dev->wd_cl,
 78					&mei_wd_guid, MEI_WD_HOST_CLIENT_ID);
 79
 80		dev_dbg(&dev->pdev->dev, "check wd_cl\n");
 81		if (MEI_FILE_CONNECTING == dev->wd_cl.state) {
 82			if (!mei_connect(dev, &dev->wd_cl)) {
 83				dev_dbg(&dev->pdev->dev, "Failed to connect to WD client\n");
 84				dev->wd_cl.state = MEI_FILE_DISCONNECTED;
 85				dev->wd_cl.host_client_id = 0;
 86				mei_host_init_iamthif(dev) ;
 87			} else {
 88				dev->wd_cl.timer_count = CONNECT_TIMEOUT;
 89			}
 90		} else {
 91			dev_dbg(&dev->pdev->dev, "Failed to find WD client\n");
 92			mei_host_init_iamthif(dev) ;
 93		}
 94	} else {
 95		dev->wd_bypass = true;
 96		dev_dbg(&dev->pdev->dev, "WD requested to be disabled\n");
 97		mei_host_init_iamthif(dev) ;
 98	}
 99}
100
101/**
102 * mei_wd_send - sends watch dog message to fw.
103 *
104 * @dev: the device structure
105 *
106 * returns 0 if success,
107 *	-EIO when message send fails
108 *	-EINVAL when invalid message is to be sent
109 */
110int mei_wd_send(struct mei_device *dev)
111{
112	struct mei_msg_hdr *mei_hdr;
113
114	mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
115	mei_hdr->host_addr = dev->wd_cl.host_client_id;
116	mei_hdr->me_addr = dev->wd_cl.me_client_id;
117	mei_hdr->msg_complete = 1;
118	mei_hdr->reserved = 0;
119
120	if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_PARAMS_SIZE))
121		mei_hdr->length = MEI_START_WD_DATA_SIZE;
122	else if (!memcmp(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE))
123		mei_hdr->length = MEI_WD_PARAMS_SIZE;
124	else
125		return -EINVAL;
126
127	if (mei_write_message(dev, mei_hdr, dev->wd_data, mei_hdr->length))
128		return 0;
129	return -EIO;
130}
131
132int mei_wd_stop(struct mei_device *dev, bool preserve)
133{
134	int ret;
135	u16 wd_timeout = dev->wd_timeout;
136
137	cancel_delayed_work(&dev->wd_work);
138	if (dev->wd_cl.state != MEI_FILE_CONNECTED || !dev->wd_timeout)
139		return 0;
140
141	dev->wd_timeout = 0;
142	dev->wd_due_counter = 0;
143	memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE);
144	dev->stop = true;
145
146	ret = mei_flow_ctrl_creds(dev, &dev->wd_cl);
147	if (ret < 0)
148		goto out;
149
150	if (ret && dev->mei_host_buffer_is_empty) {
151		ret = 0;
152		dev->mei_host_buffer_is_empty = false;
153
154		if (!mei_wd_send(dev)) {
155			ret = mei_flow_ctrl_reduce(dev, &dev->wd_cl);
156			if (ret)
157				goto out;
158		} else {
159			dev_dbg(&dev->pdev->dev, "send stop WD failed\n");
160		}
161
162		dev->wd_pending = false;
163	} else {
164		dev->wd_pending = true;
165	}
166	dev->wd_stopped = false;
167	mutex_unlock(&dev->device_lock);
168
169	ret = wait_event_interruptible_timeout(dev->wait_stop_wd,
170					dev->wd_stopped, 10 * HZ);
171	mutex_lock(&dev->device_lock);
172	if (dev->wd_stopped) {
173		dev_dbg(&dev->pdev->dev, "stop wd complete ret=%d.\n", ret);
174		ret = 0;
175	} else {
176		if (!ret)
177			ret = -ETIMEDOUT;
178		dev_warn(&dev->pdev->dev,
179			"stop wd failed to complete ret=%d.\n", ret);
180	}
181
182	if (preserve)
183		dev->wd_timeout = wd_timeout;
184
185out:
186	return ret;
187}
188