ACPI / PM: Move processor suspend/resume to syscore_ops

The system suspend routine of the ACPI processor driver saves
the BUS_MASTER_RLD register and its resume routine restores it.
However, there can be only one such register in the system and it
really should be saved after non-boot CPUs have been offlined and
restored before they are put back online during resume.

For this reason, move the saving and restoration of BUS_MASTER_RLD
to syscore suspend and syscore resume, respectively, and drop the no
longer necessary suspend/resume callbacks from the ACPI processor
driver.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

3 files changed, 31 insertions, 16 deletions

diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index bec717ffd25f..c266cdc11784 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -95,9 +95,6 @@ static const struct acpi_device_id processor_device_ids[] = {
 };
 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
 
-static SIMPLE_DEV_PM_OPS(acpi_processor_pm,
-                         acpi_processor_suspend, acpi_processor_resume);
-
 static struct acpi_driver acpi_processor_driver = {
         .name = "processor",
         .class = ACPI_PROCESSOR_CLASS,
@@ -107,7 +104,6 @@ static struct acpi_driver acpi_processor_driver = {
                 .remove = acpi_processor_remove,
                 .notify = acpi_processor_notify,
                 },
-        .drv.pm = &acpi_processor_pm,
 };
 
 #define INSTALL_NOTIFY_HANDLER          1
@@ -934,6 +930,8 @@ static int __init acpi_processor_init(void)
         if (result < 0)
                 return result;
 
+        acpi_processor_syscore_init();
+
         acpi_processor_install_hotplug_notify();
 
         acpi_thermal_cpufreq_init();
@@ -956,6 +954,8 @@ static void __exit acpi_processor_exit(void)
 
         acpi_processor_uninstall_hotplug_notify();
 
+        acpi_processor_syscore_exit();
+
         acpi_bus_unregister_driver(&acpi_processor_driver);
 
         return;
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index f0df2c9434d2..eb133c77aadb 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -34,6 +34,7 @@
 #include <linux/sched.h>       /* need_resched() */
 #include <linux/clockchips.h>
 #include <linux/cpuidle.h>
+#include <linux/syscore_ops.h>
 
 /*
  * Include the apic definitions for x86 to have the APIC timer related defines
@@ -210,33 +211,41 @@ static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 
 #endif
 
+#ifdef CONFIG_PM_SLEEP
 static u32 saved_bm_rld;
 
-static void acpi_idle_bm_rld_save(void)
+int acpi_processor_suspend(void)
 {
         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
+        return 0;
 }
-static void acpi_idle_bm_rld_restore(void)
+
+void acpi_processor_resume(void)
 {
         u32 resumed_bm_rld;
 
         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
+        if (resumed_bm_rld == saved_bm_rld)
+                return;
 
-        if (resumed_bm_rld != saved_bm_rld)
-                acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
+        acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
 }
 
-int acpi_processor_suspend(struct device *dev)
+static struct syscore_ops acpi_processor_syscore_ops = {
+        .suspend = acpi_processor_suspend,
+        .resume = acpi_processor_resume,
+};
+
+void acpi_processor_syscore_init(void)
 {
-        acpi_idle_bm_rld_save();
-        return 0;
+        register_syscore_ops(&acpi_processor_syscore_ops);
 }
 
-int acpi_processor_resume(struct device *dev)
+void acpi_processor_syscore_exit(void)
 {
-        acpi_idle_bm_rld_restore();
-        return 0;
+        unregister_syscore_ops(&acpi_processor_syscore_ops);
 }
+#endif /* CONFIG_PM_SLEEP */
 
 #if defined(CONFIG_X86)
 static void tsc_check_state(int state)
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index b327b5a9296d..ea69367fdd3b 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -329,10 +329,16 @@ int acpi_processor_power_init(struct acpi_processor *pr);
 int acpi_processor_power_exit(struct acpi_processor *pr);
 int acpi_processor_cst_has_changed(struct acpi_processor *pr);
 int acpi_processor_hotplug(struct acpi_processor *pr);
-int acpi_processor_suspend(struct device *dev);
-int acpi_processor_resume(struct device *dev);
 extern struct cpuidle_driver acpi_idle_driver;
 
+#ifdef CONFIG_PM_SLEEP
+void acpi_processor_syscore_init(void);
+void acpi_processor_syscore_exit(void);
+#else
+static inline void acpi_processor_syscore_init(void) {}
+static inline void acpi_processor_syscore_exit(void) {}
+#endif
+
 /* in processor_thermal.c */
 int acpi_processor_get_limit_info(struct acpi_processor *pr);
 extern const struct thermal_cooling_device_ops processor_cooling_ops;