diff options
Diffstat (limited to 'drivers/misc/mei/wd.c')
| -rw-r--r-- | drivers/misc/mei/wd.c | 404 |
1 files changed, 404 insertions, 0 deletions
diff --git a/drivers/misc/mei/wd.c b/drivers/misc/mei/wd.c new file mode 100644 index 000000000..2725f865c --- /dev/null +++ b/drivers/misc/mei/wd.c @@ -0,0 +1,404 @@ +/* + * + * 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/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->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 + * + * Return: -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; + struct mei_me_client *me_cl; + 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 */ + me_cl = mei_me_cl_by_uuid(dev, &mei_wd_guid); + if (!me_cl) { + dev_info(dev->dev, "wd: failed to find the client\n"); + return -ENOTTY; + } + + cl->me_client_id = me_cl->client_id; + cl->cl_uuid = me_cl->props.protocol_name; + mei_me_cl_put(me_cl); + + ret = mei_cl_link(cl, MEI_WD_HOST_CLIENT_ID); + + if (ret < 0) { + dev_info(dev->dev, "wd: failed link client\n"); + return ret; + } + + ret = mei_cl_connect(cl, NULL); + + if (ret) { + dev_err(dev->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 + * + * Return: 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->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->dev, "wd: write message failed\n"); + return ret; + } + + ret = mei_cl_flow_ctrl_reduce(cl); + if (ret) { + dev_err(dev->dev, "wd: flow_ctrl_reduce failed.\n"); + return ret; + } + + return 0; +} + +/** + * mei_wd_stop - sends watchdog stop message to fw. + * + * @dev: the device structure + * + * Return: 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) +{ + struct mei_cl *cl = &dev->wd_cl; + int ret; + + if (!mei_cl_is_connected(cl) || + 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(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->dev, "wd: stop failed to complete ret=%d\n", ret); + goto err; + } + dev_dbg(dev->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 + * + * Return: 0 if success, negative errno code for failure + */ +static int mei_wd_ops_start(struct watchdog_device *wd_dev) +{ + struct mei_device *dev; + struct mei_cl *cl; + int err = -ENODEV; + + dev = watchdog_get_drvdata(wd_dev); + if (!dev) + return -ENODEV; + + cl = &dev->wd_cl; + + mutex_lock(&dev->device_lock); + + if (dev->dev_state != MEI_DEV_ENABLED) { + dev_dbg(dev->dev, "wd: dev_state != MEI_DEV_ENABLED dev_state = %s\n", + mei_dev_state_str(dev->dev_state)); + goto end_unlock; + } + + if (!mei_cl_is_connected(cl)) { + cl_dbg(dev, cl, "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 + * + * Return: 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 + * + * Return: 0 if success, negative errno code for failure + */ +static int mei_wd_ops_ping(struct watchdog_device *wd_dev) +{ + struct mei_device *dev; + struct mei_cl *cl; + int ret; + + dev = watchdog_get_drvdata(wd_dev); + if (!dev) + return -ENODEV; + + cl = &dev->wd_cl; + + mutex_lock(&dev->device_lock); + + if (!mei_cl_is_connected(cl)) { + cl_err(dev, cl, "wd: not connected.\n"); + ret = -ENODEV; + goto end; + } + + dev->wd_state = MEI_WD_RUNNING; + + ret = mei_cl_flow_ctrl_creds(cl); + if (ret < 0) + goto end; + + /* Check if we can send the ping to HW*/ + if (ret && mei_hbuf_acquire(dev)) { + dev_dbg(dev->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 + * + * Return: 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->dev, "wd: unable to register watchdog device = %d.\n", + ret); + return ret; + } + + dev_dbg(dev->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); +} + |