diff options
Diffstat (limited to 'Documentation/watchdog')
| -rw-r--r-- | Documentation/watchdog/hpwdt.txt | 56 | ||||
| -rw-r--r-- | Documentation/watchdog/src/watchdog-test.c | 39 | ||||
| -rw-r--r-- | Documentation/watchdog/watchdog-kernel-api.txt | 64 | ||||
| -rw-r--r-- | Documentation/watchdog/watchdog-parameters.txt | 16 |
4 files changed, 120 insertions, 55 deletions
diff --git a/Documentation/watchdog/hpwdt.txt b/Documentation/watchdog/hpwdt.txt index 948807890..7a9f635d0 100644 --- a/Documentation/watchdog/hpwdt.txt +++ b/Documentation/watchdog/hpwdt.txt @@ -1,64 +1,67 @@ -Last reviewed: 06/02/2009 +Last reviewed: 05/20/2016 - HP iLO2 NMI Watchdog Driver - NMI sourcing for iLO2 based ProLiant Servers + HPE iLO NMI Watchdog Driver + NMI sourcing for iLO based ProLiant Servers Documentation and Driver by - Thomas Mingarelli <thomas.mingarelli@hp.com> + Thomas Mingarelli - The HP iLO2 NMI Watchdog driver is a kernel module that provides basic + The HPE iLO NMI Watchdog driver is a kernel module that provides basic watchdog functionality and the added benefit of NMI sourcing. Both the watchdog functionality and the NMI sourcing capability need to be enabled by the user. Remember that the two modes are not dependent on one another. A user can have the NMI sourcing without the watchdog timer and vice-versa. + All references to iLO in this document imply it also works on iLO2 and all + subsequent generations. Watchdog functionality is enabled like any other common watchdog driver. That is, an application needs to be started that kicks off the watchdog timer. A basic application exists in the Documentation/watchdog/src directory called watchdog-test.c. Simply compile the C file and kick it off. If the system - gets into a bad state and hangs, the HP ProLiant iLO 2 timer register will + gets into a bad state and hangs, the HPE ProLiant iLO timer register will not be updated in a timely fashion and a hardware system reset (also known as an Automatic Server Recovery (ASR)) event will occur. - The hpwdt driver also has four (4) module parameters. They are the following: + The hpwdt driver also has three (3) module parameters. They are the following: - soft_margin - allows the user to set the watchdog timer value - allow_kdump - allows the user to save off a kernel dump image after an NMI + soft_margin - allows the user to set the watchdog timer value. + Default value is 30 seconds. + allow_kdump - allows the user to save off a kernel dump image after an NMI. + Default value is 1/ON nowayout - basic watchdog parameter that does not allow the timer to be restarted or an impending ASR to be escaped. - priority - determines whether or not the hpwdt driver is first on the - die_notify list to handle NMIs or last. The default value - for this module parameter is 0 or LAST. If the user wants to - enable NMI sourcing then reload the hpwdt driver with - priority=1 (and boot with nmi_watchdog=0). + Default value is set when compiling the kernel. If it is set + to "Y", then there is no way of disabling the watchdog once + it has been started. NOTE: More information about watchdog drivers in general, including the ioctl interface to /dev/watchdog can be found in Documentation/watchdog/watchdog-api.txt and Documentation/IPMI.txt. - The priority parameter was introduced due to other kernel software that relied - on handling NMIs (like oprofile). Keeping hpwdt's priority at 0 (or LAST) - enables the users of NMIs for non critical events to be work as expected. - The NMI sourcing capability is disabled by default due to the inability to distinguish between "NMI Watchdog Ticks" and "HW generated NMI events" in the Linux kernel. What this means is that the hpwdt nmi handler code is called each time the NMI signal fires off. This could amount to several thousands of NMIs in a matter of seconds. If a user sees the Linux kernel's "dazed and confused" message in the logs or if the system gets into a hung state, then - the hpwdt driver can be reloaded with the "priority" module parameter set - (priority=1). + the hpwdt driver can be reloaded. 1. If the kernel has not been booted with nmi_watchdog turned off then - edit /boot/grub/menu.lst and place the nmi_watchdog=0 at the end of the - currently booting kernel line. + edit and place the nmi_watchdog=0 at the end of the currently booting + kernel line. Depending on your Linux distribution and platform setup: + For non-UEFI systems + /boot/grub/grub.conf or + /boot/grub/menu.lst + For UEFI systems + /boot/efi/EFI/distroname/grub.conf or + /boot/efi/efi/distroname/elilo.conf 2. reboot the sever - 3. Once the system comes up perform a rmmod hpwdt - 4. insmod /lib/modules/`uname -r`/kernel/drivers/char/watchdog/hpwdt.ko priority=1 + 3. Once the system comes up perform a modprobe -r hpwdt + 4. modprobe /lib/modules/`uname -r`/kernel/drivers/watchdog/hpwdt.ko Now, the hpwdt can successfully receive and source the NMI and provide a log - message that details the reason for the NMI (as determined by the HP BIOS). + message that details the reason for the NMI (as determined by the HPE BIOS). - Below is a list of NMIs the HP BIOS understands along with the associated + Below is a list of NMIs the HPE BIOS understands along with the associated code (reason): No source found 00h @@ -92,4 +95,3 @@ Last reviewed: 06/02/2009 -- Tom Mingarelli - (thomas.mingarelli@hp.com) diff --git a/Documentation/watchdog/src/watchdog-test.c b/Documentation/watchdog/src/watchdog-test.c index fcdde8fc9..6983d0509 100644 --- a/Documentation/watchdog/src/watchdog-test.c +++ b/Documentation/watchdog/src/watchdog-test.c @@ -2,6 +2,7 @@ * Watchdog Driver Test Program */ +#include <errno.h> #include <stdio.h> #include <stdlib.h> #include <string.h> @@ -13,6 +14,7 @@ #include <linux/watchdog.h> int fd; +const char v = 'V'; /* * This function simply sends an IOCTL to the driver, which in turn ticks @@ -23,6 +25,7 @@ static void keep_alive(void) { int dummy; + printf("."); ioctl(fd, WDIOC_KEEPALIVE, &dummy); } @@ -33,8 +36,13 @@ static void keep_alive(void) static void term(int sig) { + int ret = write(fd, &v, 1); + close(fd); - fprintf(stderr, "Stopping watchdog ticks...\n"); + if (ret < 0) + printf("\nStopping watchdog ticks failed (%d)...\n", errno); + else + printf("\nStopping watchdog ticks...\n"); exit(0); } @@ -42,12 +50,14 @@ int main(int argc, char *argv[]) { int flags; unsigned int ping_rate = 1; + int ret; + + setbuf(stdout, NULL); fd = open("/dev/watchdog", O_WRONLY); if (fd == -1) { - fprintf(stderr, "Watchdog device not enabled.\n"); - fflush(stderr); + printf("Watchdog device not enabled.\n"); exit(-1); } @@ -55,36 +65,30 @@ int main(int argc, char *argv[]) if (!strncasecmp(argv[1], "-d", 2)) { flags = WDIOS_DISABLECARD; ioctl(fd, WDIOC_SETOPTIONS, &flags); - fprintf(stderr, "Watchdog card disabled.\n"); - fflush(stderr); + printf("Watchdog card disabled.\n"); goto end; } else if (!strncasecmp(argv[1], "-e", 2)) { flags = WDIOS_ENABLECARD; ioctl(fd, WDIOC_SETOPTIONS, &flags); - fprintf(stderr, "Watchdog card enabled.\n"); - fflush(stderr); + printf("Watchdog card enabled.\n"); goto end; } else if (!strncasecmp(argv[1], "-t", 2) && argv[2]) { flags = atoi(argv[2]); ioctl(fd, WDIOC_SETTIMEOUT, &flags); - fprintf(stderr, "Watchdog timeout set to %u seconds.\n", flags); - fflush(stderr); + printf("Watchdog timeout set to %u seconds.\n", flags); goto end; } else if (!strncasecmp(argv[1], "-p", 2) && argv[2]) { ping_rate = strtoul(argv[2], NULL, 0); - fprintf(stderr, "Watchdog ping rate set to %u seconds.\n", ping_rate); - fflush(stderr); + printf("Watchdog ping rate set to %u seconds.\n", ping_rate); } else { - fprintf(stderr, "-d to disable, -e to enable, -t <n> to set " \ + printf("-d to disable, -e to enable, -t <n> to set " \ "the timeout,\n-p <n> to set the ping rate, and \n"); - fprintf(stderr, "run by itself to tick the card.\n"); - fflush(stderr); + printf("run by itself to tick the card.\n"); goto end; } } - fprintf(stderr, "Watchdog Ticking Away!\n"); - fflush(stderr); + printf("Watchdog Ticking Away!\n"); signal(SIGINT, term); @@ -93,6 +97,9 @@ int main(int argc, char *argv[]) sleep(ping_rate); } end: + ret = write(fd, &v, 1); + if (ret < 0) + printf("Stopping watchdog ticks failed (%d)...\n", errno); close(fd); return 0; } diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt index 55120a055..7f31125c1 100644 --- a/Documentation/watchdog/watchdog-kernel-api.txt +++ b/Documentation/watchdog/watchdog-kernel-api.txt @@ -52,6 +52,8 @@ struct watchdog_device { unsigned int timeout; unsigned int min_timeout; unsigned int max_timeout; + unsigned int min_hw_heartbeat_ms; + unsigned int max_hw_heartbeat_ms; struct notifier_block reboot_nb; struct notifier_block restart_nb; void *driver_data; @@ -73,8 +75,22 @@ It contains following fields: additional information about the watchdog timer itself. (Like it's unique name) * ops: a pointer to the list of watchdog operations that the watchdog supports. * timeout: the watchdog timer's timeout value (in seconds). + This is the time after which the system will reboot if user space does + not send a heartbeat request if WDOG_ACTIVE is set. * min_timeout: the watchdog timer's minimum timeout value (in seconds). -* max_timeout: the watchdog timer's maximum timeout value (in seconds). + If set, the minimum configurable value for 'timeout'. +* max_timeout: the watchdog timer's maximum timeout value (in seconds), + as seen from userspace. If set, the maximum configurable value for + 'timeout'. Not used if max_hw_heartbeat_ms is non-zero. +* min_hw_heartbeat_ms: Hardware limit for minimum time between heartbeats, + in milli-seconds. This value is normally 0; it should only be provided + if the hardware can not tolerate lower intervals between heartbeats. +* max_hw_heartbeat_ms: Maximum hardware heartbeat, in milli-seconds. + If set, the infrastructure will send heartbeats to the watchdog driver + if 'timeout' is larger than max_hw_heartbeat_ms, unless WDOG_ACTIVE + is set and userspace failed to send a heartbeat for at least 'timeout' + seconds. max_hw_heartbeat_ms must be set if a driver does not implement + the stop function. * reboot_nb: notifier block that is registered for reboot notifications, for internal use only. If the driver calls watchdog_stop_on_reboot, watchdog core will stop the watchdog on such notifications. @@ -123,17 +139,20 @@ are: device. The routine needs a pointer to the watchdog timer device structure as a parameter. It returns zero on success or a negative errno code for failure. -* stop: with this routine the watchdog timer device is being stopped. - The routine needs a pointer to the watchdog timer device structure as a - parameter. It returns zero on success or a negative errno code for failure. - Some watchdog timer hardware can only be started and not be stopped. The - driver supporting this hardware needs to make sure that a start and stop - routine is being provided. This can be done by using a timer in the driver - that regularly sends a keepalive ping to the watchdog timer hardware. Not all watchdog timer hardware supports the same functionality. That's why all other routines/operations are optional. They only need to be provided if they are supported. These optional routines/operations are: +* stop: with this routine the watchdog timer device is being stopped. + The routine needs a pointer to the watchdog timer device structure as a + parameter. It returns zero on success or a negative errno code for failure. + Some watchdog timer hardware can only be started and not be stopped. A + driver supporting such hardware does not have to implement the stop routine. + If a driver has no stop function, the watchdog core will set WDOG_HW_RUNNING + and start calling the driver's keepalive pings function after the watchdog + device is closed. + If a watchdog driver does not implement the stop function, it must set + max_hw_heartbeat_ms. * ping: this is the routine that sends a keepalive ping to the watchdog timer hardware. The routine needs a pointer to the watchdog timer device structure as a @@ -148,14 +167,27 @@ they are supported. These optional routines/operations are: info structure). * status: this routine checks the status of the watchdog timer device. The status of the device is reported with watchdog WDIOF_* status flags/bits. + WDIOF_MAGICCLOSE and WDIOF_KEEPALIVEPING are reported by the watchdog core; + it is not necessary to report those bits from the driver. Also, if no status + function is provided by the driver, the watchdog core reports the status bits + provided in the bootstatus variable of struct watchdog_device. * set_timeout: this routine checks and changes the timeout of the watchdog timer device. It returns 0 on success, -EINVAL for "parameter out of range" and -EIO for "could not write value to the watchdog". On success this routine should set the timeout value of the watchdog_device to the achieved timeout value (which may be different from the requested one - because the watchdog does not necessarily has a 1 second resolution). + because the watchdog does not necessarily have a 1 second resolution). + Drivers implementing max_hw_heartbeat_ms set the hardware watchdog heartbeat + to the minimum of timeout and max_hw_heartbeat_ms. Those drivers set the + timeout value of the watchdog_device either to the requested timeout value + (if it is larger than max_hw_heartbeat_ms), or to the achieved timeout value. (Note: the WDIOF_SETTIMEOUT needs to be set in the options field of the watchdog's info structure). + If the watchdog driver does not have to perform any action but setting the + watchdog_device.timeout, this callback can be omitted. + If set_timeout is not provided but, WDIOF_SETTIMEOUT is set, the watchdog + infrastructure updates the timeout value of the watchdog_device internally + to the requested value. * get_timeleft: this routines returns the time that's left before a reset. * restart: this routine restarts the machine. It returns 0 on success or a negative errno code for failure. @@ -169,11 +201,19 @@ The 'ref' and 'unref' operations are no longer used and deprecated. The status bits should (preferably) be set with the set_bit and clear_bit alike bit-operations. The status bits that are defined are: * WDOG_ACTIVE: this status bit indicates whether or not a watchdog timer device - is active or not. When the watchdog is active after booting, then you should - set this status bit (Note: when you register the watchdog timer device with - this bit set, then opening /dev/watchdog will skip the start operation) + is active or not from user perspective. User space is expected to send + heartbeat requests to the driver while this flag is set. * WDOG_NO_WAY_OUT: this bit stores the nowayout setting for the watchdog. If this bit is set then the watchdog timer will not be able to stop. +* WDOG_HW_RUNNING: Set by the watchdog driver if the hardware watchdog is + running. The bit must be set if the watchdog timer hardware can not be + stopped. The bit may also be set if the watchdog timer is running after + booting, before the watchdog device is opened. If set, the watchdog + infrastructure will send keepalives to the watchdog hardware while + WDOG_ACTIVE is not set. + Note: when you register the watchdog timer device with this bit set, + then opening /dev/watchdog will skip the start operation but send a keepalive + request instead. To set the WDOG_NO_WAY_OUT status bit (before registering your watchdog timer device) you can either: diff --git a/Documentation/watchdog/watchdog-parameters.txt b/Documentation/watchdog/watchdog-parameters.txt index 4e4b6f10d..a8d364227 100644 --- a/Documentation/watchdog/watchdog-parameters.txt +++ b/Documentation/watchdog/watchdog-parameters.txt @@ -86,6 +86,10 @@ nowayout: Watchdog cannot be stopped once started davinci_wdt: heartbeat: Watchdog heartbeat period in seconds from 1 to 600, default 60 ------------------------------------------------- +ebc-c384_wdt: +timeout: Watchdog timeout in seconds. (1<=timeout<=15300, default=60) +nowayout: Watchdog cannot be stopped once started +------------------------------------------------- ep93xx_wdt: nowayout: Watchdog cannot be stopped once started timeout: Watchdog timeout in seconds. (1<=timeout<=3600, default=TBD) @@ -200,6 +204,11 @@ mv64x60_wdt: nowayout: Watchdog cannot be stopped once started (default=kernel config parameter) ------------------------------------------------- +ni903x_wdt: +timeout: Initial watchdog timeout in seconds (0<timeout<516, default=60) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- nuc900_wdt: heartbeat: Watchdog heartbeats in seconds. (default = 15) @@ -284,6 +293,13 @@ sbc_fitpc2_wdt: margin: Watchdog margin in seconds (default 60s) nowayout: Watchdog cannot be stopped once started ------------------------------------------------- +sbsa_gwdt: +timeout: Watchdog timeout in seconds. (default 10s) +action: Watchdog action at the first stage timeout, + set to 0 to ignore, 1 to panic. (default=0) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- sc1200wdt: isapnp: When set to 0 driver ISA PnP support will be disabled (default=1) io: io port |