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authorDexuan Cui <decui@microsoft.com>2019-07-04 02:43:32 +0000
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-07-06 09:49:22 +0200
commitad5a449b707b909a91ed59109f421a1b965c6004 (patch)
treee1e7337706961e874ae2225a5f34e0ad7c9383fc
parentf850a48a07996bfd7bd1b2e52f57b5ee55125482 (diff)
downloadlinux-ad5a449b707b909a91ed59109f421a1b965c6004.tar.bz2
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.c2
-rw-r--r--include/acpi/acpi_bus.h6
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