From 48001ea50d17f3eb06a552e9ecf21f7fc01b25da Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 20 Jul 2020 15:08:18 -0700 Subject: PM, libnvdimm: Add runtime firmware activation support Abstract platform specific mechanics for nvdimm firmware activation behind a handful of generic ops. At the bus level ->activate_state() indicates the unified state (idle, busy, armed) of all DIMMs on the bus, and ->capability() indicates the system state expectations for activate. At the DIMM level ->activate_state() indicates the per-DIMM state, ->activate_result() indicates the outcome of the last activation attempt, and ->arm() attempts to transition the DIMM from 'idle' to 'armed'. A new hibernate_quiet_exec() facility is added to support firmware activation in an OS defined system quiesce state. It leverages the fact that the hibernate-freeze state wants to assert that a memory hibernation snapshot can be taken. This is in contrast to a platform firmware defined quiesce state that may forcefully quiet the memory controller independent of whether an individual device-driver properly supports hibernate-freeze. The libnvdimm sysfs interface is extended to support detection of a firmware activate capability. The mechanism supports enumeration and triggering of firmware activate, optionally in the hibernate_quiet_exec() context. [rafael: hibernate_quiet_exec() proposal] [vishal: fix up sparse warning, grammar in Documentation/] Cc: Pavel Machek Cc: Ira Weiny Cc: Len Brown Cc: Jonathan Corbet Cc: Dave Jiang Cc: Vishal Verma Reported-by: kernel test robot Co-developed-by: "Rafael J. Wysocki" Signed-off-by: "Rafael J. Wysocki" Signed-off-by: Dan Williams Signed-off-by: Vishal Verma --- kernel/power/hibernate.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) (limited to 'kernel/power') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 02ec716a4927..e6fab3f09c98 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -795,6 +795,103 @@ int hibernate(void) return error; } +/** + * hibernate_quiet_exec - Execute a function with all devices frozen. + * @func: Function to execute. + * @data: Data pointer to pass to @func. + * + * Return the @func return value or an error code if it cannot be executed. + */ +int hibernate_quiet_exec(int (*func)(void *data), void *data) +{ + int error, nr_calls = 0; + + lock_system_sleep(); + + if (!hibernate_acquire()) { + error = -EBUSY; + goto unlock; + } + + pm_prepare_console(); + + error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls); + if (error) { + nr_calls--; + goto exit; + } + + error = freeze_processes(); + if (error) + goto exit; + + lock_device_hotplug(); + + pm_suspend_clear_flags(); + + error = platform_begin(true); + if (error) + goto thaw; + + error = freeze_kernel_threads(); + if (error) + goto thaw; + + error = dpm_prepare(PMSG_FREEZE); + if (error) + goto dpm_complete; + + suspend_console(); + + error = dpm_suspend(PMSG_FREEZE); + if (error) + goto dpm_resume; + + error = dpm_suspend_end(PMSG_FREEZE); + if (error) + goto dpm_resume; + + error = platform_pre_snapshot(true); + if (error) + goto skip; + + error = func(data); + +skip: + platform_finish(true); + + dpm_resume_start(PMSG_THAW); + +dpm_resume: + dpm_resume(PMSG_THAW); + + resume_console(); + +dpm_complete: + dpm_complete(PMSG_THAW); + + thaw_kernel_threads(); + +thaw: + platform_end(true); + + unlock_device_hotplug(); + + thaw_processes(); + +exit: + __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL); + + pm_restore_console(); + + hibernate_release(); + +unlock: + unlock_system_sleep(); + + return error; +} +EXPORT_SYMBOL_GPL(hibernate_quiet_exec); /** * software_resume - Resume from a saved hibernation image. -- cgit v1.2.3