diff options
| -rw-r--r-- | Documentation/misc-devices/mei/mei.txt | 12 | ||||
| -rw-r--r-- | MAINTAINERS | 1 | ||||
| -rw-r--r-- | drivers/watchdog/Kconfig | 15 | ||||
| -rw-r--r-- | drivers/watchdog/Makefile | 1 | ||||
| -rw-r--r-- | drivers/watchdog/mei_wdt.c | 404 |
5 files changed, 427 insertions, 6 deletions
diff --git a/Documentation/misc-devices/mei/mei.txt b/Documentation/misc-devices/mei/mei.txt index 91c1fa34f48b..2b80a0cd621f 100644 --- a/Documentation/misc-devices/mei/mei.txt +++ b/Documentation/misc-devices/mei/mei.txt @@ -231,15 +231,15 @@ IT knows when a platform crashes even when there is a hard failure on the host. The Intel AMT Watchdog is composed of two parts: 1) Firmware feature - receives the heartbeats and sends an event when the heartbeats stop. - 2) Intel MEI driver - connects to the watchdog feature, configures the - watchdog and sends the heartbeats. + 2) Intel MEI iAMT watchdog driver - connects to the watchdog feature, + configures the watchdog and sends the heartbeats. -The Intel MEI driver uses the kernel watchdog API to configure the Intel AMT -Watchdog and to send heartbeats to it. The default timeout of the +The Intel iAMT watchdog MEI driver uses the kernel watchdog API to configure +the Intel AMT Watchdog and to send heartbeats to it. The default timeout of the watchdog is 120 seconds. -If the Intel AMT Watchdog feature does not exist (i.e. the connection failed), -the Intel MEI driver will disable the sending of heartbeats. +If the Intel AMT is not enabled in the firmware then the watchdog client won't enumerate +on the me client bus and watchdog devices won't be exposed. Supported Chipsets diff --git a/MAINTAINERS b/MAINTAINERS index 30aca4aa5467..d63b3c773c7d 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5751,6 +5751,7 @@ S: Supported F: include/uapi/linux/mei.h F: include/linux/mei_cl_bus.h F: drivers/misc/mei/* +F: drivers/watchdog/mei_wdt.c F: Documentation/misc-devices/mei/* INTEL MIC DRIVERS (mic) diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 4f0e7be0da34..57f872122b16 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1212,6 +1212,21 @@ config SBC_EPX_C3_WATCHDOG To compile this driver as a module, choose M here: the module will be called sbc_epx_c3. +config INTEL_MEI_WDT + tristate "Intel MEI iAMT Watchdog" + depends on INTEL_MEI && X86 + select WATCHDOG_CORE + ---help--- + A device driver for the Intel MEI iAMT watchdog. + + The Intel AMT Watchdog is an OS Health (Hang/Crash) watchdog. + Whenever the OS hangs or crashes, iAMT will send an event + to any subscriber to this event. The watchdog doesn't reset the + the platform. + + To compile this driver as a module, choose M here: + the module will be called mei_wdt. + # M32R Architecture # M68K Architecture diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index f566753256ab..efc4f788e0f2 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -126,6 +126,7 @@ obj-$(CONFIG_MACHZ_WDT) += machzwd.o obj-$(CONFIG_SBC_EPX_C3_WATCHDOG) += sbc_epx_c3.o obj-$(CONFIG_INTEL_SCU_WATCHDOG) += intel_scu_watchdog.o obj-$(CONFIG_INTEL_MID_WATCHDOG) += intel-mid_wdt.o +obj-$(CONFIG_INTEL_MEI_WDT) += mei_wdt.o # M32R Architecture diff --git a/drivers/watchdog/mei_wdt.c b/drivers/watchdog/mei_wdt.c new file mode 100644 index 000000000000..32e3e1d55ef3 --- /dev/null +++ b/drivers/watchdog/mei_wdt.c @@ -0,0 +1,404 @@ +/* + * Intel Management Engine Interface (Intel MEI) Linux driver + * Copyright (c) 2015, 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/module.h> +#include <linux/slab.h> +#include <linux/interrupt.h> +#include <linux/watchdog.h> + +#include <linux/uuid.h> +#include <linux/mei_cl_bus.h> + +/* + * iAMT Watchdog Device + */ +#define INTEL_AMT_WATCHDOG_ID "iamt_wdt" + +#define MEI_WDT_DEFAULT_TIMEOUT 120 /* seconds */ +#define MEI_WDT_MIN_TIMEOUT 120 /* seconds */ +#define MEI_WDT_MAX_TIMEOUT 65535 /* seconds */ + +/* Commands */ +#define MEI_MANAGEMENT_CONTROL 0x02 + +/* MEI Management Control version number */ +#define MEI_MC_VERSION_NUMBER 0x10 + +/* Sub Commands */ +#define MEI_MC_START_WD_TIMER_REQ 0x13 +#define MEI_MC_STOP_WD_TIMER_REQ 0x14 + +/** + * enum mei_wdt_state - internal watchdog state + * + * @MEI_WDT_IDLE: wd is idle and not opened + * @MEI_WDT_START: wd was opened, start was called + * @MEI_WDT_RUNNING: wd is expecting keep alive pings + * @MEI_WDT_STOPPING: wd is stopping and will move to IDLE + */ +enum mei_wdt_state { + MEI_WDT_IDLE, + MEI_WDT_START, + MEI_WDT_RUNNING, + MEI_WDT_STOPPING, +}; + +/** + * struct mei_wdt - mei watchdog driver + * @wdd: watchdog device + * + * @cldev: mei watchdog client device + * @state: watchdog internal state + * @timeout: watchdog current timeout + */ +struct mei_wdt { + struct watchdog_device wdd; + + struct mei_cl_device *cldev; + enum mei_wdt_state state; + u16 timeout; +}; + +/* + * struct mei_mc_hdr - Management Control Command Header + * + * @command: Management Control (0x2) + * @bytecount: Number of bytes in the message beyond this byte + * @subcommand: Management Control Subcommand + * @versionnumber: Management Control Version (0x10) + */ +struct mei_mc_hdr { + u8 command; + u8 bytecount; + u8 subcommand; + u8 versionnumber; +}; + +/** + * struct mei_wdt_start_request watchdog start/ping + * + * @hdr: Management Control Command Header + * @timeout: timeout value + * @reserved: reserved (legacy) + */ +struct mei_wdt_start_request { + struct mei_mc_hdr hdr; + u16 timeout; + u8 reserved[17]; +} __packed; + +/** + * struct mei_wdt_stop_request - watchdog stop + * + * @hdr: Management Control Command Header + */ +struct mei_wdt_stop_request { + struct mei_mc_hdr hdr; +} __packed; + +/** + * mei_wdt_ping - send wd start/ping command + * + * @wdt: mei watchdog device + * + * Return: 0 on success, + * negative errno code on failure + */ +static int mei_wdt_ping(struct mei_wdt *wdt) +{ + struct mei_wdt_start_request req; + const size_t req_len = sizeof(req); + int ret; + + memset(&req, 0, req_len); + req.hdr.command = MEI_MANAGEMENT_CONTROL; + req.hdr.bytecount = req_len - offsetof(struct mei_mc_hdr, subcommand); + req.hdr.subcommand = MEI_MC_START_WD_TIMER_REQ; + req.hdr.versionnumber = MEI_MC_VERSION_NUMBER; + req.timeout = wdt->timeout; + + ret = mei_cldev_send(wdt->cldev, (u8 *)&req, req_len); + if (ret < 0) + return ret; + + return 0; +} + +/** + * mei_wdt_stop - send wd stop command + * + * @wdt: mei watchdog device + * + * Return: 0 on success, + * negative errno code on failure + */ +static int mei_wdt_stop(struct mei_wdt *wdt) +{ + struct mei_wdt_stop_request req; + const size_t req_len = sizeof(req); + int ret; + + memset(&req, 0, req_len); + req.hdr.command = MEI_MANAGEMENT_CONTROL; + req.hdr.bytecount = req_len - offsetof(struct mei_mc_hdr, subcommand); + req.hdr.subcommand = MEI_MC_STOP_WD_TIMER_REQ; + req.hdr.versionnumber = MEI_MC_VERSION_NUMBER; + + ret = mei_cldev_send(wdt->cldev, (u8 *)&req, req_len); + if (ret < 0) + return ret; + + return 0; +} + +/** + * mei_wdt_ops_start - wd start command from the watchdog core. + * + * @wdd: watchdog device + * + * Return: 0 on success or -ENODEV; + */ +static int mei_wdt_ops_start(struct watchdog_device *wdd) +{ + struct mei_wdt *wdt = watchdog_get_drvdata(wdd); + + wdt->state = MEI_WDT_START; + wdd->timeout = wdt->timeout; + return 0; +} + +/** + * mei_wdt_ops_stop - wd stop command from the watchdog core. + * + * @wdd: watchdog device + * + * Return: 0 if success, negative errno code for failure + */ +static int mei_wdt_ops_stop(struct watchdog_device *wdd) +{ + struct mei_wdt *wdt = watchdog_get_drvdata(wdd); + int ret; + + if (wdt->state != MEI_WDT_RUNNING) + return 0; + + wdt->state = MEI_WDT_STOPPING; + + ret = mei_wdt_stop(wdt); + if (ret) + return ret; + + wdt->state = MEI_WDT_IDLE; + + return 0; +} + +/** + * mei_wdt_ops_ping - wd ping command from the watchdog core. + * + * @wdd: watchdog device + * + * Return: 0 if success, negative errno code on failure + */ +static int mei_wdt_ops_ping(struct watchdog_device *wdd) +{ + struct mei_wdt *wdt = watchdog_get_drvdata(wdd); + int ret; + + if (wdt->state != MEI_WDT_START && wdt->state != MEI_WDT_RUNNING) + return 0; + + ret = mei_wdt_ping(wdt); + if (ret) + return ret; + + wdt->state = MEI_WDT_RUNNING; + + return 0; +} + +/** + * mei_wdt_ops_set_timeout - wd set timeout command from the watchdog core. + * + * @wdd: watchdog device + * @timeout: timeout value to set + * + * Return: 0 if success, negative errno code for failure + */ +static int mei_wdt_ops_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + + struct mei_wdt *wdt = watchdog_get_drvdata(wdd); + + /* valid value is already checked by the caller */ + wdt->timeout = timeout; + wdd->timeout = timeout; + + return 0; +} + +static const struct watchdog_ops wd_ops = { + .owner = THIS_MODULE, + .start = mei_wdt_ops_start, + .stop = mei_wdt_ops_stop, + .ping = mei_wdt_ops_ping, + .set_timeout = mei_wdt_ops_set_timeout, +}; + +/* not const as the firmware_version field need to be retrieved */ +static struct watchdog_info wd_info = { + .identity = INTEL_AMT_WATCHDOG_ID, + .options = WDIOF_KEEPALIVEPING | + WDIOF_SETTIMEOUT | + WDIOF_ALARMONLY, +}; + +/** + * mei_wdt_unregister - unregister from the watchdog subsystem + * + * @wdt: mei watchdog device + */ +static void mei_wdt_unregister(struct mei_wdt *wdt) +{ + watchdog_unregister_device(&wdt->wdd); + watchdog_set_drvdata(&wdt->wdd, NULL); +} + +/** + * mei_wdt_register - register with the watchdog subsystem + * + * @wdt: mei watchdog device + * + * Return: 0 if success, negative errno code for failure + */ +static int mei_wdt_register(struct mei_wdt *wdt) +{ + struct device *dev; + int ret; + + if (!wdt || !wdt->cldev) + return -EINVAL; + + dev = &wdt->cldev->dev; + + wdt->wdd.info = &wd_info; + wdt->wdd.ops = &wd_ops; + wdt->wdd.parent = dev; + wdt->wdd.timeout = MEI_WDT_DEFAULT_TIMEOUT; + wdt->wdd.min_timeout = MEI_WDT_MIN_TIMEOUT; + wdt->wdd.max_timeout = MEI_WDT_MAX_TIMEOUT; + + watchdog_set_drvdata(&wdt->wdd, wdt); + ret = watchdog_register_device(&wdt->wdd); + if (ret) { + dev_err(dev, "unable to register watchdog device = %d.\n", ret); + watchdog_set_drvdata(&wdt->wdd, NULL); + } + + return ret; +} + +static int mei_wdt_probe(struct mei_cl_device *cldev, + const struct mei_cl_device_id *id) +{ + struct mei_wdt *wdt; + int ret; + + wdt = kzalloc(sizeof(struct mei_wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + wdt->timeout = MEI_WDT_DEFAULT_TIMEOUT; + wdt->state = MEI_WDT_IDLE; + wdt->cldev = cldev; + mei_cldev_set_drvdata(cldev, wdt); + + ret = mei_cldev_enable(cldev); + if (ret < 0) { + dev_err(&cldev->dev, "Could not enable cl device\n"); + goto err_out; + } + + wd_info.firmware_version = mei_cldev_ver(cldev); + + ret = mei_wdt_register(wdt); + if (ret) + goto err_disable; + + return 0; + +err_disable: + mei_cldev_disable(cldev); + +err_out: + kfree(wdt); + + return ret; +} + +static int mei_wdt_remove(struct mei_cl_device *cldev) +{ + struct mei_wdt *wdt = mei_cldev_get_drvdata(cldev); + + mei_wdt_unregister(wdt); + + mei_cldev_disable(cldev); + + kfree(wdt); + + return 0; +} + +#define MEI_UUID_WD UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, \ + 0x89, 0x9D, 0xA9, 0x15, 0x14, 0xCB, 0x32, 0xAB) + +static struct mei_cl_device_id mei_wdt_tbl[] = { + { .uuid = MEI_UUID_WD, .version = 0x1}, + /* required last entry */ + { } +}; +MODULE_DEVICE_TABLE(mei, mei_wdt_tbl); + +static struct mei_cl_driver mei_wdt_driver = { + .id_table = mei_wdt_tbl, + .name = KBUILD_MODNAME, + + .probe = mei_wdt_probe, + .remove = mei_wdt_remove, +}; + +static int __init mei_wdt_init(void) +{ + int ret; + + ret = mei_cldev_driver_register(&mei_wdt_driver); + if (ret) { + pr_err(KBUILD_MODNAME ": module registration failed\n"); + return ret; + } + return 0; +} + +static void __exit mei_wdt_exit(void) +{ + mei_cldev_driver_unregister(&mei_wdt_driver); +} + +module_init(mei_wdt_init); +module_exit(mei_wdt_exit); + +MODULE_AUTHOR("Intel Corporation"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Device driver for Intel MEI iAMT watchdog"); |