diff options
| author | Dexuan Cui <decui@microsoft.com> | 2019-07-04 04:43:32 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-07-06 09:49:22 +0200 |
| commit | ad5a449b707b909a91ed59109f421a1b965c6004 (patch) | |
| tree | e1e7337706961e874ae2225a5f34e0ad7c9383fc | |
| parent | ACPI: PM: Allow transitions to D0 to occur in special cases (diff) | |
| download | linux-ad5a449b707b909a91ed59109f421a1b965c6004.tar.xz linux-ad5a449b707b909a91ed59109f421a1b965c6004.zip | |
ACPI: PM: Make acpi_sleep_state_supported() non-static
With some upcoming patches to save/restore the Hyper-V drivers related
states, a Linux VM running on Hyper-V will be able to hibernate. When
a Linux VM hibernates, unluckily we must disable the memory hot-add/remove
and balloon up/down capabilities in the hv_balloon driver
(drivers/hv/hv_balloon.c), because these can not really work according to
the design of the related back-end driver on the host.
By default, Hyper-V does not enable the virtual ACPI S4 state for a VM;
on recent Hyper-V hosts, the administrator is able to enable the virtual
ACPI S4 state for a VM, so we hope to use the presence of the virtual ACPI
S4 state as a hint for hv_balloon to disable the aforementioned
capabilities. In this way, hibernation will work more reliably, from the
user's perspective.
By marking acpi_sleep_state_supported() non-static, we'll be able to
implement a hv_is_hibernation_supported() API in the always-built-in
module arch/x86/hyperv/hv_init.c, and the API will be called by hv_balloon.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | drivers/acpi/sleep.c | 2 | ||||
| -rw-r--r-- | include/acpi/acpi_bus.h | 6 |
2 files changed, 7 insertions, 1 deletions
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c index e21a0f5fdadd..a64b81719611 100644 --- a/drivers/acpi/sleep.c +++ b/drivers/acpi/sleep.c @@ -79,7 +79,7 @@ static int acpi_sleep_prepare(u32 acpi_state) return 0; } -static bool acpi_sleep_state_supported(u8 sleep_state) +bool acpi_sleep_state_supported(u8 sleep_state) { acpi_status status; u8 type_a, type_b; diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index 52d4375bde9d..37c0bac4ad6a 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -664,6 +664,12 @@ static inline int acpi_pm_set_bridge_wakeup(struct device *dev, bool enable) } #endif +#ifdef CONFIG_ACPI_SYSTEM_POWER_STATES_SUPPORT +bool acpi_sleep_state_supported(u8 sleep_state); +#else +static inline bool acpi_sleep_state_supported(u8 sleep_state) { return false; } +#endif + #ifdef CONFIG_ACPI_SLEEP u32 acpi_target_system_state(void); #else |