PM / Core: Introduce struct syscore_ops for core subsystems PM

Some subsystems need to carry out suspend/resume and shutdown
operations with one CPU on-line and interrupts disabled.  The only
way to register such operations is to define a sysdev class and
a sysdev specifically for this purpose which is cumbersome and
inefficient.  Moreover, the arguments taken by sysdev suspend,
resume and shutdown callbacks are practically never necessary.

For this reason, introduce a simpler interface allowing subsystems
to register operations to be executed very late during system suspend
and shutdown and very early during resume in the form of
strcut syscore_ops objects.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Rafael J. Wysocki 2011-03-15 00:43:46 +01:00
parent f9b9e806ae
commit 40dc166cb5
6 changed files with 164 additions and 1 deletions

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@ -1,6 +1,6 @@
# Makefile for the Linux device tree
obj-y := core.o sys.o bus.o dd.o \
obj-y := core.o sys.o bus.o dd.o syscore.o \
driver.o class.o platform.o \
cpu.o firmware.o init.o map.o devres.o \
attribute_container.o transport_class.o

117
drivers/base/syscore.c Normal file
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@ -0,0 +1,117 @@
/*
* syscore.c - Execution of system core operations.
*
* Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
*
* This file is released under the GPLv2.
*/
#include <linux/syscore_ops.h>
#include <linux/mutex.h>
#include <linux/module.h>
static LIST_HEAD(syscore_ops_list);
static DEFINE_MUTEX(syscore_ops_lock);
/**
* register_syscore_ops - Register a set of system core operations.
* @ops: System core operations to register.
*/
void register_syscore_ops(struct syscore_ops *ops)
{
mutex_lock(&syscore_ops_lock);
list_add_tail(&ops->node, &syscore_ops_list);
mutex_unlock(&syscore_ops_lock);
}
EXPORT_SYMBOL_GPL(register_syscore_ops);
/**
* unregister_syscore_ops - Unregister a set of system core operations.
* @ops: System core operations to unregister.
*/
void unregister_syscore_ops(struct syscore_ops *ops)
{
mutex_lock(&syscore_ops_lock);
list_del(&ops->node);
mutex_unlock(&syscore_ops_lock);
}
EXPORT_SYMBOL_GPL(unregister_syscore_ops);
#ifdef CONFIG_PM_SLEEP
/**
* syscore_suspend - Execute all the registered system core suspend callbacks.
*
* This function is executed with one CPU on-line and disabled interrupts.
*/
int syscore_suspend(void)
{
struct syscore_ops *ops;
int ret = 0;
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled before system core suspend.\n");
list_for_each_entry_reverse(ops, &syscore_ops_list, node)
if (ops->suspend) {
if (initcall_debug)
pr_info("PM: Calling %pF\n", ops->suspend);
ret = ops->suspend();
if (ret)
goto err_out;
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled after %pF\n", ops->suspend);
}
return 0;
err_out:
pr_err("PM: System core suspend callback %pF failed.\n", ops->suspend);
list_for_each_entry_continue(ops, &syscore_ops_list, node)
if (ops->resume)
ops->resume();
return ret;
}
/**
* syscore_resume - Execute all the registered system core resume callbacks.
*
* This function is executed with one CPU on-line and disabled interrupts.
*/
void syscore_resume(void)
{
struct syscore_ops *ops;
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled before system core resume.\n");
list_for_each_entry(ops, &syscore_ops_list, node)
if (ops->resume) {
if (initcall_debug)
pr_info("PM: Calling %pF\n", ops->resume);
ops->resume();
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled after %pF\n", ops->resume);
}
}
#endif /* CONFIG_PM_SLEEP */
/**
* syscore_shutdown - Execute all the registered system core shutdown callbacks.
*/
void syscore_shutdown(void)
{
struct syscore_ops *ops;
mutex_lock(&syscore_ops_lock);
list_for_each_entry_reverse(ops, &syscore_ops_list, node)
if (ops->shutdown) {
if (initcall_debug)
pr_info("PM: Calling %pF\n", ops->shutdown);
ops->shutdown();
}
mutex_unlock(&syscore_ops_lock);
}

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@ -0,0 +1,29 @@
/*
* syscore_ops.h - System core operations.
*
* Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
*
* This file is released under the GPLv2.
*/
#ifndef _LINUX_SYSCORE_OPS_H
#define _LINUX_SYSCORE_OPS_H
#include <linux/list.h>
struct syscore_ops {
struct list_head node;
int (*suspend)(void);
void (*resume)(void);
void (*shutdown)(void);
};
extern void register_syscore_ops(struct syscore_ops *ops);
extern void unregister_syscore_ops(struct syscore_ops *ops);
#ifdef CONFIG_PM_SLEEP
extern int syscore_suspend(void);
extern void syscore_resume(void);
#endif
extern void syscore_shutdown(void);
#endif

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@ -23,6 +23,7 @@
#include <linux/cpu.h>
#include <linux/freezer.h>
#include <linux/gfp.h>
#include <linux/syscore_ops.h>
#include <scsi/scsi_scan.h>
#include <asm/suspend.h>
@ -272,6 +273,8 @@ static int create_image(int platform_mode)
local_irq_disable();
error = sysdev_suspend(PMSG_FREEZE);
if (!error)
error = syscore_suspend();
if (error) {
printk(KERN_ERR "PM: Some system devices failed to power down, "
"aborting hibernation\n");
@ -295,6 +298,7 @@ static int create_image(int platform_mode)
}
Power_up:
syscore_resume();
sysdev_resume();
/* NOTE: dpm_resume_noirq() is just a resume() for devices
* that suspended with irqs off ... no overall powerup.
@ -403,6 +407,8 @@ static int resume_target_kernel(bool platform_mode)
local_irq_disable();
error = sysdev_suspend(PMSG_QUIESCE);
if (!error)
error = syscore_suspend();
if (error)
goto Enable_irqs;
@ -429,6 +435,7 @@ static int resume_target_kernel(bool platform_mode)
restore_processor_state();
touch_softlockup_watchdog();
syscore_resume();
sysdev_resume();
Enable_irqs:
@ -516,6 +523,7 @@ int hibernation_platform_enter(void)
local_irq_disable();
sysdev_suspend(PMSG_HIBERNATE);
syscore_suspend();
if (pm_wakeup_pending()) {
error = -EAGAIN;
goto Power_up;
@ -526,6 +534,7 @@ int hibernation_platform_enter(void)
while (1);
Power_up:
syscore_resume();
sysdev_resume();
local_irq_enable();
enable_nonboot_cpus();

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@ -22,6 +22,7 @@
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/suspend.h>
#include <linux/syscore_ops.h>
#include <trace/events/power.h>
#include "power.h"
@ -163,11 +164,14 @@ static int suspend_enter(suspend_state_t state)
BUG_ON(!irqs_disabled());
error = sysdev_suspend(PMSG_SUSPEND);
if (!error)
error = syscore_suspend();
if (!error) {
if (!(suspend_test(TEST_CORE) || pm_wakeup_pending())) {
error = suspend_ops->enter(state);
events_check_enabled = false;
}
syscore_resume();
sysdev_resume();
}

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@ -37,6 +37,7 @@
#include <linux/ptrace.h>
#include <linux/fs_struct.h>
#include <linux/gfp.h>
#include <linux/syscore_ops.h>
#include <linux/compat.h>
#include <linux/syscalls.h>
@ -298,6 +299,7 @@ void kernel_restart_prepare(char *cmd)
system_state = SYSTEM_RESTART;
device_shutdown();
sysdev_shutdown();
syscore_shutdown();
}
/**
@ -336,6 +338,7 @@ void kernel_halt(void)
{
kernel_shutdown_prepare(SYSTEM_HALT);
sysdev_shutdown();
syscore_shutdown();
printk(KERN_EMERG "System halted.\n");
kmsg_dump(KMSG_DUMP_HALT);
machine_halt();
@ -355,6 +358,7 @@ void kernel_power_off(void)
pm_power_off_prepare();
disable_nonboot_cpus();
sysdev_shutdown();
syscore_shutdown();
printk(KERN_EMERG "Power down.\n");
kmsg_dump(KMSG_DUMP_POWEROFF);
machine_power_off();