/*
*
* 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/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/device.h>
#include <linux/pci.h>
#include <linux/sched.h>
#include <linux/watchdog.h>
#include <linux/mei.h>
#include "mei_dev.h"
#include "hbm.h"
#include "client.h"
static const u8 mei_start_wd_params[] = { 0x02, 0x12, 0x13, 0x10 };
static const u8 mei_stop_wd_params[] = { 0x02, 0x02, 0x14, 0x10 };
/*
* AMT Watchdog Device
*/
#define INTEL_AMT_WATCHDOG_ID "INTCAMT"
/* 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);
static void mei_wd_set_start_timeout(struct mei_device *dev, u16 timeout)
{
dev_dbg(&dev->pdev->dev, "wd: set timeout=%d.\n", timeout);
memcpy(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE);
memcpy(dev->wd_data + MEI_WD_HDR_SIZE, &timeout, sizeof(u16));
}
/**
* mei_wd_host_init - connect to the watchdog client
*
* @dev: the device structure
*
* returns -ENOTTY if wd client cannot be found
* -EIO if write has failed
* 0 on success
*/
int mei_wd_host_init(struct mei_device *dev)
{
struct mei_cl *cl = &dev->wd_cl;
int id;
int ret;
mei_cl_init(cl, dev);
dev->wd_timeout = MEI_WD_DEFAULT_TIMEOUT;
dev->wd_state = MEI_WD_IDLE;
/* check for valid client id */
id = mei_me_cl_by_uuid(dev, &mei_wd_guid);
if (id < 0) {
dev_info(&dev->pdev->dev, "wd: failed to find the client\n");
return -ENOTTY;
}
cl->me_client_id = dev->me_clients[id].client_id;
ret = mei_cl_link(cl, MEI_WD_HOST_CLIENT_ID);
if (ret < 0) {
dev_info(&dev->pdev->dev, "wd: failed link client\n");
return ret;
}
ret = mei_cl_connect(cl, NULL);
if (ret) {
dev_err(&dev->pdev->dev, "wd: failed to connect = %d\n", ret);
mei_cl_unlink(cl);
return ret;
}
ret = mei_watchdog_register(dev);
if (ret) {
mei_cl_disconnect(cl);
mei_cl_unlink(cl);
}
return ret;
}
/**
* 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
* -ENODEV on flow control failure
*/
int mei_wd_send(struct mei_device *dev)
{
struct mei_cl *cl = &dev->wd_cl;
struct mei_msg_hdr hdr;
int ret;
hdr.host_addr = cl->host_client_id;
hdr.me_addr = cl->me_client_id;
hdr.msg_complete = 1;
hdr.reserved = 0;
hdr.internal = 0;
if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE))
hdr.length = MEI_WD_START_MSG_SIZE;
else if (!memcmp(dev->wd_data, mei_stop_wd_params, MEI_WD_HDR_SIZE))
hdr.length = MEI_WD_STOP_MSG_SIZE;
else {
dev_err(&dev->pdev->dev, "wd: invalid message is to be sent, aborting\n");
return -EINVAL;
}
ret = mei_write_message(dev, &hdr, dev->wd_data);
if (ret) {
dev_err(&dev->pdev->dev, "wd: write message failed\n");
return ret;
}
ret = mei_cl_flow_ctrl_reduce(cl);
if (ret) {
dev_err(&dev->pdev->dev, "wd: flow_ctrl_reduce failed.\n");
return ret;
}
return 0;
}
/**
* mei_wd_stop - sends watchdog stop message to fw.
*
* @dev: the device structure
* @preserve: indicate if to keep the timeout value
*
* returns 0 if success
* on error:
* -EIO when message send fails
* -EINVAL when invalid message is to be sent
* -ETIME on message timeout
*/
int mei_wd_stop(struct mei_device *dev)
{
int ret;
if (dev->wd_cl.state != MEI_FILE_CONNECTED ||
dev->wd_state != MEI_WD_RUNNING)
return 0;
memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_STOP_MSG_SIZE);
dev->wd_state = MEI_WD_STOPPING;
ret = mei_cl_flow_ctrl_creds(&dev->wd_cl);
if (ret < 0)
goto err;
if (ret && mei_hbuf_acquire(dev)) {
ret = mei_wd_send(dev);
if (ret)
goto err;
dev->wd_pending = false;
} else {
dev->wd_pending = true;
}
mutex_unlock(&dev->device_lock);
ret = wait_event_timeout(dev->wait_stop_wd,
dev->wd_state == MEI_WD_IDLE,
msecs_to_jiffies(MEI_WD_STOP_TIMEOUT));
mutex_lock(&dev->device_lock);
if (dev->wd_state != MEI_WD_IDLE) {
/* timeout */
ret = -ETIME;
dev_warn(&dev->pdev->dev,
"wd: stop failed to complete ret=%d.\n", ret);
goto err;
}
dev_dbg(&dev->pdev->dev, "wd: stop completed after %u msec\n",
MEI_WD_STOP_TIMEOUT - jiffies_to_msecs(ret));
return 0;
err:
return ret;
}
/*
* mei_wd_ops_start - wd start command from the watchdog core.
*
* @wd_dev - watchdog device struct
*
* returns 0 if success, negative errno code for failure
*/
static int mei_wd_ops_start(struct watchdog_device *wd_dev)
{
int err = -ENODEV;
struct mei_device *dev;
dev = watchdog_get_drvdata(wd_dev);
if (!dev)
return -ENODEV;
mutex_lock(&dev->device_lock);
if (dev->dev_state != MEI_DEV_ENABLED) {
dev_dbg(&dev->pdev->dev,
"wd: dev_state != MEI_DEV_ENABLED dev_state = %s\n",
mei_dev_state_str(dev->dev_state));
goto end_unlock;
}
if (dev->wd_cl.state != MEI_FILE_CONNECTED) {
dev_dbg(&dev->pdev->dev,
"MEI Driver is not connected to Watchdog Client\n");
goto end_unlock;
}
mei_wd_set_start_timeout(dev, dev->wd_timeout);
err = 0;
end_unlock:
mutex_unlock(&dev->device_lock);
return err;
}
/*
* mei_wd_ops_stop - wd stop command from the watchdog core.
*
* @wd_dev - watchdog device struct
*
* returns 0 if success, negative errno code for failure
*/
static int mei_wd_ops_stop(struct watchdog_device *wd_dev)
{
struct mei_device *dev;
dev = watchdog_get_drvdata(wd_dev);
if (!dev)
return -ENODEV;
mutex_lock(&dev->device_lock);
mei_wd_stop(dev);
mutex_unlock(&dev->device_lock);
return 0;
}
/*
* mei_wd_ops_ping - wd ping command from the watchdog core.
*
* @wd_dev - watchdog device struct
*
* returns 0 if success, negative errno code for failure
*/
static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
{
struct mei_device *dev;
int ret;
dev = watchdog_get_drvdata(wd_dev);
if (!dev)
return -ENODEV;
mutex_lock(&dev->device_lock);
if (dev->wd_cl.state != MEI_FILE_CONNECTED) {
dev_err(&dev->pdev->dev, "wd: not connected.\n");
ret = -ENODEV;
goto end;
}
dev->wd_state = MEI_WD_RUNNING;
ret = mei_cl_flow_ctrl_creds(&dev->wd_cl);
if (ret < 0)
goto end;
/* Check if we can send the ping to HW*/
if (ret && mei_hbuf_acquire(dev)) {
dev_dbg(&dev->pdev->dev, "wd: sending ping\n");
ret = mei_wd_send(dev);
if (ret)
goto end;
dev->wd_pending = false;
} else {
dev->wd_pending = true;
}
end:
mutex_unlock(&dev->device_lock);
return ret;
}
/*
* mei_wd_ops_set_timeout - wd set timeout command from the watchdog core.
*
* @wd_dev - watchdog device struct
* @timeout - timeout value to set
*
* returns 0 if success, negative errno code for failure
*/
static int mei_wd_ops_set_timeout(struct watchdog_device *wd_dev,
unsigned int timeout)
{
struct mei_device *dev;
dev = watchdog_get_drvdata(wd_dev);
if (!dev)
return -ENODEV;
/* Check Timeout value */
if (timeout < MEI_WD_MIN_TIMEOUT || timeout > MEI_WD_MAX_TIMEOUT)
return -EINVAL;
mutex_lock(&dev->device_lock);
dev->wd_timeout = timeout;
wd_dev->timeout = timeout;
mei_wd_set_start_timeout(dev, dev->wd_timeout);
mutex_unlock(&dev->device_lock);
return 0;
}
/*
* Watchdog Device structs
*/
static const struct watchdog_ops wd_ops = {
.owner = THIS_MODULE,
.start = mei_wd_ops_start,
.stop = mei_wd_ops_stop,
.ping = mei_wd_ops_ping,
.set_timeout = mei_wd_ops_set_timeout,
};
static const struct watchdog_info wd_info = {
.identity = INTEL_AMT_WATCHDOG_ID,
.options = WDIOF_KEEPALIVEPING |
WDIOF_SETTIMEOUT |
WDIOF_ALARMONLY,
};
static struct watchdog_device amt_wd_dev = {
.info = &wd_info,
.ops = &wd_ops,
.timeout = MEI_WD_DEFAULT_TIMEOUT,
.min_timeout = MEI_WD_MIN_TIMEOUT,
.max_timeout = MEI_WD_MAX_TIMEOUT,
};
int mei_watchdog_register(struct mei_device *dev)
{
int ret;
/* unlock to perserve correct locking order */
mutex_unlock(&dev->device_lock);
ret = watchdog_register_device(&amt_wd_dev);
mutex_lock(&dev->device_lock);
if (ret) {
dev_err(&dev->pdev->dev, "wd: unable to register watchdog device = %d.\n",
ret);
return ret;
}
dev_dbg(&dev->pdev->dev,
"wd: successfully register watchdog interface.\n");
watchdog_set_drvdata(&amt_wd_dev, dev);
return 0;
}
void mei_watchdog_unregister(struct mei_device *dev)
{
if (watchdog_get_drvdata(&amt_wd_dev) == NULL)
return;
watchdog_set_drvdata(&amt_wd_dev, NULL);
watchdog_unregister_device(&amt_wd_dev);
}
