ACPI / sleep: move acpi_processor_sleep to sleep.c

acpi_processor_sleep is neither related nor used by CPUIdle framework.
It's used in system suspend/resume path as a syscore operation. It makes
more sense to move it to acpi/sleep.c where all the S-state transition
(a.k.a. Linux system suspend/hiberate) related code are present.

Also make it depend on CONFIG_ACPI_SYSTEM_POWER_STATES_SUPPORT so that
it's not compiled on architecture like ARM64 where S-states are not
yet defined in ACPI.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 9cb975200cac..fbfcce3b5227 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -19,6 +19,7 @@
 #include <linux/reboot.h>
 #include <linux/acpi.h>
 #include <linux/module.h>
+#include <linux/syscore_ops.h>
 #include <asm/io.h>
 #include <trace/events/power.h>
 
@@ -677,6 +678,39 @@ static void acpi_sleep_suspend_setup(void)
 static inline void acpi_sleep_suspend_setup(void) {}
 #endif /* !CONFIG_SUSPEND */
 
+#ifdef CONFIG_PM_SLEEP
+static u32 saved_bm_rld;
+
+static int  acpi_save_bm_rld(void)
+{
+        acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
+        return 0;
+}
+
+static void  acpi_restore_bm_rld(void)
+{
+        u32 resumed_bm_rld = 0;
+
+        acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
+        if (resumed_bm_rld == saved_bm_rld)
+                return;
+
+        acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
+}
+
+static struct syscore_ops acpi_sleep_syscore_ops = {
+        .suspend = acpi_save_bm_rld,
+        .resume = acpi_restore_bm_rld,
+};
+
+void acpi_sleep_syscore_init(void)
+{
+        register_syscore_ops(&acpi_sleep_syscore_ops);
+}
+#else
+static inline void acpi_sleep_syscore_init(void) {}
+#endif /* CONFIG_PM_SLEEP */
+
 #ifdef CONFIG_HIBERNATION
 static unsigned long s4_hardware_signature;
 static struct acpi_table_facs *facs;
@@ -839,6 +873,7 @@ int __init acpi_sleep_init(void)
 
         sleep_states[ACPI_STATE_S0] = 1;
 
+        acpi_sleep_syscore_init();
         acpi_sleep_suspend_setup();
         acpi_sleep_hibernate_setup();