From ad5a449b707b909a91ed59109f421a1b965c6004 Mon Sep 17 00:00:00 2001 From: Dexuan Cui Date: Thu, 4 Jul 2019 02:43:32 +0000 Subject: 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 Signed-off-by: Rafael J. Wysocki --- include/acpi/acpi_bus.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/acpi') 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 -- cgit v1.2.3