| Message ID | 20220713202335.1217647-5-cheloha@linux.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | pseries-wdt: initial support for H_WATCHDOG-based watchdog timers | expand |
On 7/13/22 13:23, Scott Cheloha wrote: > PAPR v2.12 defines a new hypercall, H_WATCHDOG. The hypercall permits > guest control of one or more virtual watchdog timers. The timers have > millisecond granularity. The guest is terminated when a timer > expires. > > This patch adds a watchdog driver for these timers, "pseries-wdt". > > pseries_wdt_probe() currently assumes the existence of only one > platform device and always assigns it watchdogNumber 1. If we ever > expose more than one timer to userspace we will need to devise a way > to assign a distinct watchdogNumber to each platform device at device > registration time. > > Signed-off-by: Scott Cheloha <cheloha@linux.ibm.com> Acked-by: Guenter Roeck <linux@roeck-us.net> > --- > .../watchdog/watchdog-parameters.rst | 12 + > drivers/watchdog/Kconfig | 8 + > drivers/watchdog/Makefile | 1 + > drivers/watchdog/pseries-wdt.c | 239 ++++++++++++++++++ > 4 files changed, 260 insertions(+) > create mode 100644 drivers/watchdog/pseries-wdt.c > > diff --git a/Documentation/watchdog/watchdog-parameters.rst b/Documentation/watchdog/watchdog-parameters.rst > index 223c99361a30..29153eed6689 100644 > --- a/Documentation/watchdog/watchdog-parameters.rst > +++ b/Documentation/watchdog/watchdog-parameters.rst > @@ -425,6 +425,18 @@ pnx833x_wdt: > > ------------------------------------------------- > > +pseries-wdt: > + action: > + Action taken when watchdog expires: 0 (power off), 1 (restart), > + 2 (dump and restart). (default=1) > + timeout: > + Initial watchdog timeout in seconds. (default=60) > + nowayout: > + Watchdog cannot be stopped once started. > + (default=kernel config parameter) > + > +------------------------------------------------- > + > rc32434_wdt: > timeout: > Watchdog timeout value, in seconds (default=20) > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 32fd37698932..a2429604a4ab 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -1962,6 +1962,14 @@ config MEN_A21_WDT > > # PPC64 Architecture > > +config PSERIES_WDT > + tristate "POWER Architecture Platform Watchdog Timer" > + depends on PPC_PSERIES > + select WATCHDOG_CORE > + help > + Driver for virtual watchdog timers provided by PAPR > + hypervisors (e.g. PowerVM, KVM). > + > config WATCHDOG_RTAS > tristate "RTAS watchdog" > depends on PPC_RTAS > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index c324e9d820e9..cdeb119e6e61 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -187,6 +187,7 @@ obj-$(CONFIG_BOOKE_WDT) += booke_wdt.o > obj-$(CONFIG_MEN_A21_WDT) += mena21_wdt.o > > # PPC64 Architecture > +obj-$(CONFIG_PSERIES_WDT) += pseries-wdt.o > obj-$(CONFIG_WATCHDOG_RTAS) += wdrtas.o > > # S390 Architecture > diff --git a/drivers/watchdog/pseries-wdt.c b/drivers/watchdog/pseries-wdt.c > new file mode 100644 > index 000000000000..7f53b5293409 > --- /dev/null > +++ b/drivers/watchdog/pseries-wdt.c > @@ -0,0 +1,239 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Copyright (c) 2022 International Business Machines, Inc. > + */ > + > +#include <linux/bitops.h> > +#include <linux/kernel.h> > +#include <linux/limits.h> > +#include <linux/math.h> > +#include <linux/mod_devicetable.h> > +#include <linux/module.h> > +#include <linux/moduleparam.h> > +#include <linux/platform_device.h> > +#include <linux/time64.h> > +#include <linux/watchdog.h> > + > +#define DRV_NAME "pseries-wdt" > + > +/* > + * H_WATCHDOG Input > + * > + * R4: "flags": > + * > + * Bits 48-55: "operation" > + */ > +#define PSERIES_WDTF_OP_START 0x100UL /* start timer */ > +#define PSERIES_WDTF_OP_STOP 0x200UL /* stop timer */ > +#define PSERIES_WDTF_OP_QUERY 0x300UL /* query timer capabilities */ > + > +/* > + * Bits 56-63: "timeoutAction" (for "Start Watchdog" only) > + */ > +#define PSERIES_WDTF_ACTION_HARD_POWEROFF 0x1UL /* poweroff */ > +#define PSERIES_WDTF_ACTION_HARD_RESTART 0x2UL /* restart */ > +#define PSERIES_WDTF_ACTION_DUMP_RESTART 0x3UL /* dump + restart */ > + > +/* > + * H_WATCHDOG Output > + * > + * R3: Return code > + * > + * H_SUCCESS The operation completed. > + * > + * H_BUSY The hypervisor is too busy; retry the operation. > + * > + * H_PARAMETER The given "flags" are somehow invalid. Either the > + * "operation" or "timeoutAction" is invalid, or a > + * reserved bit is set. > + * > + * H_P2 The given "watchdogNumber" is zero or exceeds the > + * supported maximum value. > + * > + * H_P3 The given "timeoutInMs" is below the supported > + * minimum value. > + * > + * H_NOOP The given "watchdogNumber" is already stopped. > + * > + * H_HARDWARE The operation failed for ineffable reasons. > + * > + * H_FUNCTION The H_WATCHDOG hypercall is not supported by this > + * hypervisor. > + * > + * R4: > + * > + * - For the "Query Watchdog Capabilities" operation, a 64-bit > + * structure: > + */ > +#define PSERIES_WDTQ_MIN_TIMEOUT(cap) (((cap) >> 48) & 0xffff) > +#define PSERIES_WDTQ_MAX_NUMBER(cap) (((cap) >> 32) & 0xffff) > + > +static const unsigned long pseries_wdt_action[] = { > + [0] = PSERIES_WDTF_ACTION_HARD_POWEROFF, > + [1] = PSERIES_WDTF_ACTION_HARD_RESTART, > + [2] = PSERIES_WDTF_ACTION_DUMP_RESTART, > +}; > + > +#define WATCHDOG_ACTION 1 > +static unsigned int action = WATCHDOG_ACTION; > +module_param(action, uint, 0444); > +MODULE_PARM_DESC(action, "Action taken when watchdog expires (default=" > + __MODULE_STRING(WATCHDOG_ACTION) ")"); > + > +static bool nowayout = WATCHDOG_NOWAYOUT; > +module_param(nowayout, bool, 0444); > +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" > + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); > + > +#define WATCHDOG_TIMEOUT 60 > +static unsigned int timeout = WATCHDOG_TIMEOUT; > +module_param(timeout, uint, 0444); > +MODULE_PARM_DESC(timeout, "Initial watchdog timeout in seconds (default=" > + __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); > + > +struct pseries_wdt { > + struct watchdog_device wd; > + unsigned long action; > + unsigned long num; /* Watchdog numbers are 1-based */ > +}; > + > +static int pseries_wdt_start(struct watchdog_device *wdd) > +{ > + struct pseries_wdt *pw = watchdog_get_drvdata(wdd); > + struct device *dev = wdd->parent; > + unsigned long flags, msecs; > + long rc; > + > + flags = pw->action | PSERIES_WDTF_OP_START; > + msecs = wdd->timeout * MSEC_PER_SEC; > + rc = plpar_hcall_norets(H_WATCHDOG, flags, pw->num, msecs); > + if (rc != H_SUCCESS) { > + dev_crit(dev, "H_WATCHDOG: %ld: failed to start timer %lu", > + rc, pw->num); > + return -EIO; > + } > + return 0; > +} > + > +static int pseries_wdt_stop(struct watchdog_device *wdd) > +{ > + struct pseries_wdt *pw = watchdog_get_drvdata(wdd); > + struct device *dev = wdd->parent; > + long rc; > + > + rc = plpar_hcall_norets(H_WATCHDOG, PSERIES_WDTF_OP_STOP, pw->num); > + if (rc != H_SUCCESS && rc != H_NOOP) { > + dev_crit(dev, "H_WATCHDOG: %ld: failed to stop timer %lu", > + rc, pw->num); > + return -EIO; > + } > + return 0; > +} > + > +static struct watchdog_info pseries_wdt_info = { > + .identity = DRV_NAME, > + .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT > + | WDIOF_PRETIMEOUT, > +}; > + > +static const struct watchdog_ops pseries_wdt_ops = { > + .owner = THIS_MODULE, > + .start = pseries_wdt_start, > + .stop = pseries_wdt_stop, > +}; > + > +static int pseries_wdt_probe(struct platform_device *pdev) > +{ > + unsigned long ret[PLPAR_HCALL_BUFSIZE] = { 0 }; > + struct pseries_wdt *pw; > + unsigned long cap; > + long msecs, rc; > + int err; > + > + rc = plpar_hcall(H_WATCHDOG, ret, PSERIES_WDTF_OP_QUERY); > + if (rc == H_FUNCTION) > + return -ENODEV; > + if (rc != H_SUCCESS) > + return -EIO; > + cap = ret[0]; > + > + pw = devm_kzalloc(&pdev->dev, sizeof(*pw), GFP_KERNEL); > + if (!pw) > + return -ENOMEM; > + > + /* > + * Assume watchdogNumber 1 for now. If we ever support > + * multiple timers we will need to devise a way to choose a > + * distinct watchdogNumber for each platform device at device > + * registration time. > + */ > + pw->num = 1; > + if (PSERIES_WDTQ_MAX_NUMBER(cap) < pw->num) > + return -ENODEV; > + > + if (action >= ARRAY_SIZE(pseries_wdt_action)) > + return -EINVAL; > + pw->action = pseries_wdt_action[action]; > + > + pw->wd.parent = &pdev->dev; > + pw->wd.info = &pseries_wdt_info; > + pw->wd.ops = &pseries_wdt_ops; > + msecs = PSERIES_WDTQ_MIN_TIMEOUT(cap); > + pw->wd.min_timeout = DIV_ROUND_UP(msecs, MSEC_PER_SEC); > + pw->wd.max_timeout = UINT_MAX / 1000; /* from linux/watchdog.h */ > + pw->wd.timeout = timeout; > + if (watchdog_init_timeout(&pw->wd, 0, NULL)) > + return -EINVAL; > + watchdog_set_nowayout(&pw->wd, nowayout); > + watchdog_stop_on_reboot(&pw->wd); > + watchdog_stop_on_unregister(&pw->wd); > + watchdog_set_drvdata(&pw->wd, pw); > + > + err = devm_watchdog_register_device(&pdev->dev, &pw->wd); > + if (err) > + return err; > + > + platform_set_drvdata(pdev, &pw->wd); > + > + return 0; > +} > + > +static int pseries_wdt_suspend(struct platform_device *pdev, pm_message_t state) > +{ > + struct watchdog_device *wd = platform_get_drvdata(pdev); > + > + if (watchdog_active(wd)) > + return pseries_wdt_stop(wd); > + return 0; > +} > + > +static int pseries_wdt_resume(struct platform_device *pdev) > +{ > + struct watchdog_device *wd = platform_get_drvdata(pdev); > + > + if (watchdog_active(wd)) > + return pseries_wdt_start(wd); > + return 0; > +} > + > +static const struct platform_device_id pseries_wdt_id[] = { > + { .name = "pseries-wdt" }, > + {} > +}; > +MODULE_DEVICE_TABLE(platform, pseries_wdt_id); > + > +static struct platform_driver pseries_wdt_driver = { > + .driver = { > + .name = DRV_NAME, > + }, > + .id_table = pseries_wdt_id, > + .probe = pseries_wdt_probe, > + .resume = pseries_wdt_resume, > + .suspend = pseries_wdt_suspend, > +}; > +module_platform_driver(pseries_wdt_driver); > + > +MODULE_AUTHOR("Alexey Kardashevskiy"); > +MODULE_AUTHOR("Scott Cheloha"); > +MODULE_DESCRIPTION("POWER Architecture Platform Watchdog Driver"); > +MODULE_LICENSE("GPL");
On Wed, Jul 13, 2022 at 01:50:14PM -0700, Guenter Roeck wrote: > On 7/13/22 13:23, Scott Cheloha wrote: > > PAPR v2.12 defines a new hypercall, H_WATCHDOG. The hypercall permits > > guest control of one or more virtual watchdog timers. The timers have > > millisecond granularity. The guest is terminated when a timer > > expires. > > > > This patch adds a watchdog driver for these timers, "pseries-wdt". > > > > pseries_wdt_probe() currently assumes the existence of only one > > platform device and always assigns it watchdogNumber 1. If we ever > > expose more than one timer to userspace we will need to devise a way > > to assign a distinct watchdogNumber to each platform device at device > > registration time. > > > > Signed-off-by: Scott Cheloha <cheloha@linux.ibm.com> > > Acked-by: Guenter Roeck <linux@roeck-us.net> Guenter, Michael, Which tree is taking this series? watchdog-next or PPC development? -Scott
On Mon, Jul 25, 2022 at 11:11:41AM -0500, Scott Cheloha wrote: > On Wed, Jul 13, 2022 at 01:50:14PM -0700, Guenter Roeck wrote: > > On 7/13/22 13:23, Scott Cheloha wrote: > > > PAPR v2.12 defines a new hypercall, H_WATCHDOG. The hypercall permits > > > guest control of one or more virtual watchdog timers. The timers have > > > millisecond granularity. The guest is terminated when a timer > > > expires. > > > > > > This patch adds a watchdog driver for these timers, "pseries-wdt". > > > > > > pseries_wdt_probe() currently assumes the existence of only one > > > platform device and always assigns it watchdogNumber 1. If we ever > > > expose more than one timer to userspace we will need to devise a way > > > to assign a distinct watchdogNumber to each platform device at device > > > registration time. > > > > > > Signed-off-by: Scott Cheloha <cheloha@linux.ibm.com> > > > > Acked-by: Guenter Roeck <linux@roeck-us.net> > > Guenter, Michael, > > Which tree is taking this series? > The series includes non-watchdog changes, so my expectation was that some other tree would take it. Guenter > watchdog-next or PPC development? > > -Scott
Guenter Roeck <linux@roeck-us.net> writes: > On Mon, Jul 25, 2022 at 11:11:41AM -0500, Scott Cheloha wrote: >> On Wed, Jul 13, 2022 at 01:50:14PM -0700, Guenter Roeck wrote: >> > On 7/13/22 13:23, Scott Cheloha wrote: >> > > PAPR v2.12 defines a new hypercall, H_WATCHDOG. The hypercall permits >> > > guest control of one or more virtual watchdog timers. The timers have >> > > millisecond granularity. The guest is terminated when a timer >> > > expires. >> > > >> > > This patch adds a watchdog driver for these timers, "pseries-wdt". >> > > >> > > pseries_wdt_probe() currently assumes the existence of only one >> > > platform device and always assigns it watchdogNumber 1. If we ever >> > > expose more than one timer to userspace we will need to devise a way >> > > to assign a distinct watchdogNumber to each platform device at device >> > > registration time. >> > > >> > > Signed-off-by: Scott Cheloha <cheloha@linux.ibm.com> >> > >> > Acked-by: Guenter Roeck <linux@roeck-us.net> >> >> Guenter, Michael, >> >> Which tree is taking this series? powerpc. It's been in next-test/next for about a week. It's in linux-next today. > The series includes non-watchdog changes, so my expectation was that some > other tree would take it. Yep, thanks for the ack. cheers
diff --git a/Documentation/watchdog/watchdog-parameters.rst b/Documentation/watchdog/watchdog-parameters.rst index 223c99361a30..29153eed6689 100644 --- a/Documentation/watchdog/watchdog-parameters.rst +++ b/Documentation/watchdog/watchdog-parameters.rst @@ -425,6 +425,18 @@ pnx833x_wdt: ------------------------------------------------- +pseries-wdt: + action: + Action taken when watchdog expires: 0 (power off), 1 (restart), + 2 (dump and restart). (default=1) + timeout: + Initial watchdog timeout in seconds. (default=60) + nowayout: + Watchdog cannot be stopped once started. + (default=kernel config parameter) + +------------------------------------------------- + rc32434_wdt: timeout: Watchdog timeout value, in seconds (default=20) diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 32fd37698932..a2429604a4ab 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1962,6 +1962,14 @@ config MEN_A21_WDT # PPC64 Architecture +config PSERIES_WDT + tristate "POWER Architecture Platform Watchdog Timer" + depends on PPC_PSERIES + select WATCHDOG_CORE + help + Driver for virtual watchdog timers provided by PAPR + hypervisors (e.g. PowerVM, KVM). + config WATCHDOG_RTAS tristate "RTAS watchdog" depends on PPC_RTAS diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index c324e9d820e9..cdeb119e6e61 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -187,6 +187,7 @@ obj-$(CONFIG_BOOKE_WDT) += booke_wdt.o obj-$(CONFIG_MEN_A21_WDT) += mena21_wdt.o # PPC64 Architecture +obj-$(CONFIG_PSERIES_WDT) += pseries-wdt.o obj-$(CONFIG_WATCHDOG_RTAS) += wdrtas.o # S390 Architecture diff --git a/drivers/watchdog/pseries-wdt.c b/drivers/watchdog/pseries-wdt.c new file mode 100644 index 000000000000..7f53b5293409 --- /dev/null +++ b/drivers/watchdog/pseries-wdt.c @@ -0,0 +1,239 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2022 International Business Machines, Inc. + */ + +#include <linux/bitops.h> +#include <linux/kernel.h> +#include <linux/limits.h> +#include <linux/math.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/platform_device.h> +#include <linux/time64.h> +#include <linux/watchdog.h> + +#define DRV_NAME "pseries-wdt" + +/* + * H_WATCHDOG Input + * + * R4: "flags": + * + * Bits 48-55: "operation" + */ +#define PSERIES_WDTF_OP_START 0x100UL /* start timer */ +#define PSERIES_WDTF_OP_STOP 0x200UL /* stop timer */ +#define PSERIES_WDTF_OP_QUERY 0x300UL /* query timer capabilities */ + +/* + * Bits 56-63: "timeoutAction" (for "Start Watchdog" only) + */ +#define PSERIES_WDTF_ACTION_HARD_POWEROFF 0x1UL /* poweroff */ +#define PSERIES_WDTF_ACTION_HARD_RESTART 0x2UL /* restart */ +#define PSERIES_WDTF_ACTION_DUMP_RESTART 0x3UL /* dump + restart */ + +/* + * H_WATCHDOG Output + * + * R3: Return code + * + * H_SUCCESS The operation completed. + * + * H_BUSY The hypervisor is too busy; retry the operation. + * + * H_PARAMETER The given "flags" are somehow invalid. Either the + * "operation" or "timeoutAction" is invalid, or a + * reserved bit is set. + * + * H_P2 The given "watchdogNumber" is zero or exceeds the + * supported maximum value. + * + * H_P3 The given "timeoutInMs" is below the supported + * minimum value. + * + * H_NOOP The given "watchdogNumber" is already stopped. + * + * H_HARDWARE The operation failed for ineffable reasons. + * + * H_FUNCTION The H_WATCHDOG hypercall is not supported by this + * hypervisor. + * + * R4: + * + * - For the "Query Watchdog Capabilities" operation, a 64-bit + * structure: + */ +#define PSERIES_WDTQ_MIN_TIMEOUT(cap) (((cap) >> 48) & 0xffff) +#define PSERIES_WDTQ_MAX_NUMBER(cap) (((cap) >> 32) & 0xffff) + +static const unsigned long pseries_wdt_action[] = { + [0] = PSERIES_WDTF_ACTION_HARD_POWEROFF, + [1] = PSERIES_WDTF_ACTION_HARD_RESTART, + [2] = PSERIES_WDTF_ACTION_DUMP_RESTART, +}; + +#define WATCHDOG_ACTION 1 +static unsigned int action = WATCHDOG_ACTION; +module_param(action, uint, 0444); +MODULE_PARM_DESC(action, "Action taken when watchdog expires (default=" + __MODULE_STRING(WATCHDOG_ACTION) ")"); + +static bool nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, bool, 0444); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +#define WATCHDOG_TIMEOUT 60 +static unsigned int timeout = WATCHDOG_TIMEOUT; +module_param(timeout, uint, 0444); +MODULE_PARM_DESC(timeout, "Initial watchdog timeout in seconds (default=" + __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); + +struct pseries_wdt { + struct watchdog_device wd; + unsigned long action; + unsigned long num; /* Watchdog numbers are 1-based */ +}; + +static int pseries_wdt_start(struct watchdog_device *wdd) +{ + struct pseries_wdt *pw = watchdog_get_drvdata(wdd); + struct device *dev = wdd->parent; + unsigned long flags, msecs; + long rc; + + flags = pw->action | PSERIES_WDTF_OP_START; + msecs = wdd->timeout * MSEC_PER_SEC; + rc = plpar_hcall_norets(H_WATCHDOG, flags, pw->num, msecs); + if (rc != H_SUCCESS) { + dev_crit(dev, "H_WATCHDOG: %ld: failed to start timer %lu", + rc, pw->num); + return -EIO; + } + return 0; +} + +static int pseries_wdt_stop(struct watchdog_device *wdd) +{ + struct pseries_wdt *pw = watchdog_get_drvdata(wdd); + struct device *dev = wdd->parent; + long rc; + + rc = plpar_hcall_norets(H_WATCHDOG, PSERIES_WDTF_OP_STOP, pw->num); + if (rc != H_SUCCESS && rc != H_NOOP) { + dev_crit(dev, "H_WATCHDOG: %ld: failed to stop timer %lu", + rc, pw->num); + return -EIO; + } + return 0; +} + +static struct watchdog_info pseries_wdt_info = { + .identity = DRV_NAME, + .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT + | WDIOF_PRETIMEOUT, +}; + +static const struct watchdog_ops pseries_wdt_ops = { + .owner = THIS_MODULE, + .start = pseries_wdt_start, + .stop = pseries_wdt_stop, +}; + +static int pseries_wdt_probe(struct platform_device *pdev) +{ + unsigned long ret[PLPAR_HCALL_BUFSIZE] = { 0 }; + struct pseries_wdt *pw; + unsigned long cap; + long msecs, rc; + int err; + + rc = plpar_hcall(H_WATCHDOG, ret, PSERIES_WDTF_OP_QUERY); + if (rc == H_FUNCTION) + return -ENODEV; + if (rc != H_SUCCESS) + return -EIO; + cap = ret[0]; + + pw = devm_kzalloc(&pdev->dev, sizeof(*pw), GFP_KERNEL); + if (!pw) + return -ENOMEM; + + /* + * Assume watchdogNumber 1 for now. If we ever support + * multiple timers we will need to devise a way to choose a + * distinct watchdogNumber for each platform device at device + * registration time. + */ + pw->num = 1; + if (PSERIES_WDTQ_MAX_NUMBER(cap) < pw->num) + return -ENODEV; + + if (action >= ARRAY_SIZE(pseries_wdt_action)) + return -EINVAL; + pw->action = pseries_wdt_action[action]; + + pw->wd.parent = &pdev->dev; + pw->wd.info = &pseries_wdt_info; + pw->wd.ops = &pseries_wdt_ops; + msecs = PSERIES_WDTQ_MIN_TIMEOUT(cap); + pw->wd.min_timeout = DIV_ROUND_UP(msecs, MSEC_PER_SEC); + pw->wd.max_timeout = UINT_MAX / 1000; /* from linux/watchdog.h */ + pw->wd.timeout = timeout; + if (watchdog_init_timeout(&pw->wd, 0, NULL)) + return -EINVAL; + watchdog_set_nowayout(&pw->wd, nowayout); + watchdog_stop_on_reboot(&pw->wd); + watchdog_stop_on_unregister(&pw->wd); + watchdog_set_drvdata(&pw->wd, pw); + + err = devm_watchdog_register_device(&pdev->dev, &pw->wd); + if (err) + return err; + + platform_set_drvdata(pdev, &pw->wd); + + return 0; +} + +static int pseries_wdt_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct watchdog_device *wd = platform_get_drvdata(pdev); + + if (watchdog_active(wd)) + return pseries_wdt_stop(wd); + return 0; +} + +static int pseries_wdt_resume(struct platform_device *pdev) +{ + struct watchdog_device *wd = platform_get_drvdata(pdev); + + if (watchdog_active(wd)) + return pseries_wdt_start(wd); + return 0; +} + +static const struct platform_device_id pseries_wdt_id[] = { + { .name = "pseries-wdt" }, + {} +}; +MODULE_DEVICE_TABLE(platform, pseries_wdt_id); + +static struct platform_driver pseries_wdt_driver = { + .driver = { + .name = DRV_NAME, + }, + .id_table = pseries_wdt_id, + .probe = pseries_wdt_probe, + .resume = pseries_wdt_resume, + .suspend = pseries_wdt_suspend, +}; +module_platform_driver(pseries_wdt_driver); + +MODULE_AUTHOR("Alexey Kardashevskiy"); +MODULE_AUTHOR("Scott Cheloha"); +MODULE_DESCRIPTION("POWER Architecture Platform Watchdog Driver"); +MODULE_LICENSE("GPL");
PAPR v2.12 defines a new hypercall, H_WATCHDOG. The hypercall permits guest control of one or more virtual watchdog timers. The timers have millisecond granularity. The guest is terminated when a timer expires. This patch adds a watchdog driver for these timers, "pseries-wdt". pseries_wdt_probe() currently assumes the existence of only one platform device and always assigns it watchdogNumber 1. If we ever expose more than one timer to userspace we will need to devise a way to assign a distinct watchdogNumber to each platform device at device registration time. Signed-off-by: Scott Cheloha <cheloha@linux.ibm.com> --- .../watchdog/watchdog-parameters.rst | 12 + drivers/watchdog/Kconfig | 8 + drivers/watchdog/Makefile | 1 + drivers/watchdog/pseries-wdt.c | 239 ++++++++++++++++++ 4 files changed, 260 insertions(+) create mode 100644 drivers/watchdog/pseries-wdt.c