[PATCH] ACPI / PM: Move processor suspend/resume to syscore_ops

From: Rafael J. Wysocki
Date: Tue Apr 30 2013 - 18:10:22 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

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@xxxxxxxxx>
---
drivers/acpi/processor_driver.c | 8 ++++----
drivers/acpi/processor_idle.c | 29 +++++++++++++++++++----------
include/acpi/processor.h | 10 ++++++++--
3 files changed, 31 insertions(+), 16 deletions(-)

Index: linux-pm/drivers/acpi/processor_driver.c
===================================================================
--- linux-pm.orig/drivers/acpi/processor_driver.c
+++ linux-pm/drivers/acpi/processor_driver.c
@@ -95,9 +95,6 @@ static const struct acpi_device_id proce
};
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
.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(vo
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(v

acpi_processor_uninstall_hotplug_notify();

+ acpi_processor_syscore_exit();
+
acpi_bus_unregister_driver(&acpi_processor_driver);

return;
Index: linux-pm/drivers/acpi/processor_idle.c
===================================================================
--- linux-pm.orig/drivers/acpi/processor_idle.c
+++ linux-pm/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(

#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)
Index: linux-pm/include/acpi/processor.h
===================================================================
--- linux-pm.orig/include/acpi/processor.h
+++ linux-pm/include/acpi/processor.h
@@ -329,10 +329,16 @@ int acpi_processor_power_init(struct acp
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;

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