| /* |
| * kernel/power/suspend.c - Suspend to RAM and standby functionality. |
| * |
| * Copyright (c) 2003 Patrick Mochel |
| * Copyright (c) 2003 Open Source Development Lab |
| * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. |
| * |
| * This file is released under the GPLv2. |
| */ |
| |
| #include <linux/string.h> |
| #include <linux/delay.h> |
| #include <linux/errno.h> |
| #include <linux/init.h> |
| #include <linux/console.h> |
| #include <linux/cpu.h> |
| #include <linux/syscalls.h> |
| #include <linux/gfp.h> |
| #include <linux/io.h> |
| #include <linux/kernel.h> |
| #include <linux/list.h> |
| #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" |
| |
| const char *const pm_states[PM_SUSPEND_MAX] = { |
| [PM_SUSPEND_STANDBY] = "standby", |
| [PM_SUSPEND_MEM] = "mem", |
| }; |
| |
| static const struct platform_suspend_ops *suspend_ops; |
| |
| /** |
| * suspend_set_ops - Set the global suspend method table. |
| * @ops: Pointer to ops structure. |
| */ |
| void suspend_set_ops(const struct platform_suspend_ops *ops) |
| { |
| mutex_lock(&pm_mutex); |
| suspend_ops = ops; |
| mutex_unlock(&pm_mutex); |
| } |
| |
| bool valid_state(suspend_state_t state) |
| { |
| /* |
| * All states need lowlevel support and need to be valid to the lowlevel |
| * implementation, no valid callback implies that none are valid. |
| */ |
| return suspend_ops && suspend_ops->valid && suspend_ops->valid(state); |
| } |
| |
| /** |
| * suspend_valid_only_mem - generic memory-only valid callback |
| * |
| * Platform drivers that implement mem suspend only and only need |
| * to check for that in their .valid callback can use this instead |
| * of rolling their own .valid callback. |
| */ |
| int suspend_valid_only_mem(suspend_state_t state) |
| { |
| return state == PM_SUSPEND_MEM; |
| } |
| |
| static int suspend_test(int level) |
| { |
| #ifdef CONFIG_PM_DEBUG |
| if (pm_test_level == level) { |
| printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n"); |
| mdelay(5000); |
| return 1; |
| } |
| #endif /* !CONFIG_PM_DEBUG */ |
| return 0; |
| } |
| |
| /** |
| * suspend_prepare - Do prep work before entering low-power state. |
| * |
| * This is common code that is called for each state that we're entering. |
| * Run suspend notifiers, allocate a console and stop all processes. |
| */ |
| static int suspend_prepare(void) |
| { |
| int error; |
| |
| if (!suspend_ops || !suspend_ops->enter) |
| return -EPERM; |
| |
| pm_prepare_console(); |
| |
| error = pm_notifier_call_chain(PM_SUSPEND_PREPARE); |
| if (error) |
| goto Finish; |
| |
| error = usermodehelper_disable(); |
| if (error) |
| goto Finish; |
| |
| error = suspend_freeze_processes(); |
| if (!error) |
| return 0; |
| |
| suspend_thaw_processes(); |
| usermodehelper_enable(); |
| Finish: |
| pm_notifier_call_chain(PM_POST_SUSPEND); |
| pm_restore_console(); |
| return error; |
| } |
| |
| /* default implementation */ |
| void __attribute__ ((weak)) arch_suspend_disable_irqs(void) |
| { |
| local_irq_disable(); |
| } |
| |
| /* default implementation */ |
| void __attribute__ ((weak)) arch_suspend_enable_irqs(void) |
| { |
| local_irq_enable(); |
| } |
| |
| /** |
| * suspend_enter - enter the desired system sleep state. |
| * @state: state to enter |
| * |
| * This function should be called after devices have been suspended. |
| */ |
| static int suspend_enter(suspend_state_t state) |
| { |
| int error; |
| |
| if (suspend_ops->prepare) { |
| error = suspend_ops->prepare(); |
| if (error) |
| goto Platform_finish; |
| } |
| |
| error = dpm_suspend_noirq(PMSG_SUSPEND); |
| if (error) { |
| printk(KERN_ERR "PM: Some devices failed to power down\n"); |
| goto Platform_finish; |
| } |
| |
| if (suspend_ops->prepare_late) { |
| error = suspend_ops->prepare_late(); |
| if (error) |
| goto Platform_wake; |
| } |
| |
| if (suspend_test(TEST_PLATFORM)) |
| goto Platform_wake; |
| |
| error = disable_nonboot_cpus(); |
| if (error || suspend_test(TEST_CPUS)) |
| goto Enable_cpus; |
| |
| arch_suspend_disable_irqs(); |
| BUG_ON(!irqs_disabled()); |
| |
| error = sysdev_suspend(PMSG_SUSPEND); |
| if (!error) { |
| error = syscore_suspend(); |
| if (error) |
| sysdev_resume(); |
| } |
| if (!error) { |
| if (!(suspend_test(TEST_CORE) || pm_wakeup_pending())) { |
| error = suspend_ops->enter(state); |
| events_check_enabled = false; |
| } |
| syscore_resume(); |
| sysdev_resume(); |
| } |
| |
| arch_suspend_enable_irqs(); |
| BUG_ON(irqs_disabled()); |
| |
| Enable_cpus: |
| enable_nonboot_cpus(); |
| |
| Platform_wake: |
| if (suspend_ops->wake) |
| suspend_ops->wake(); |
| |
| dpm_resume_noirq(PMSG_RESUME); |
| |
| Platform_finish: |
| if (suspend_ops->finish) |
| suspend_ops->finish(); |
| |
| return error; |
| } |
| |
| /** |
| * suspend_devices_and_enter - suspend devices and enter the desired system |
| * sleep state. |
| * @state: state to enter |
| */ |
| int suspend_devices_and_enter(suspend_state_t state) |
| { |
| int error; |
| |
| if (!suspend_ops) |
| return -ENOSYS; |
| |
| trace_machine_suspend(state); |
| if (suspend_ops->begin) { |
| error = suspend_ops->begin(state); |
| if (error) |
| goto Close; |
| } |
| suspend_console(); |
| suspend_test_start(); |
| error = dpm_suspend_start(PMSG_SUSPEND); |
| if (error) { |
| printk(KERN_ERR "PM: Some devices failed to suspend\n"); |
| goto Recover_platform; |
| } |
| suspend_test_finish("suspend devices"); |
| if (suspend_test(TEST_DEVICES)) |
| goto Recover_platform; |
| |
| suspend_enter(state); |
| |
| Resume_devices: |
| suspend_test_start(); |
| dpm_resume_end(PMSG_RESUME); |
| suspend_test_finish("resume devices"); |
| resume_console(); |
| Close: |
| if (suspend_ops->end) |
| suspend_ops->end(); |
| trace_machine_suspend(PWR_EVENT_EXIT); |
| return error; |
| |
| Recover_platform: |
| if (suspend_ops->recover) |
| suspend_ops->recover(); |
| goto Resume_devices; |
| } |
| |
| /** |
| * suspend_finish - Do final work before exiting suspend sequence. |
| * |
| * Call platform code to clean up, restart processes, and free the |
| * console that we've allocated. This is not called for suspend-to-disk. |
| */ |
| static void suspend_finish(void) |
| { |
| suspend_thaw_processes(); |
| usermodehelper_enable(); |
| pm_notifier_call_chain(PM_POST_SUSPEND); |
| pm_restore_console(); |
| } |
| |
| /** |
| * enter_state - Do common work of entering low-power state. |
| * @state: pm_state structure for state we're entering. |
| * |
| * Make sure we're the only ones trying to enter a sleep state. Fail |
| * if someone has beat us to it, since we don't want anything weird to |
| * happen when we wake up. |
| * Then, do the setup for suspend, enter the state, and cleaup (after |
| * we've woken up). |
| */ |
| int enter_state(suspend_state_t state) |
| { |
| int error; |
| |
| if (!valid_state(state)) |
| return -ENODEV; |
| |
| if (!mutex_trylock(&pm_mutex)) |
| return -EBUSY; |
| |
| printk(KERN_INFO "PM: Syncing filesystems ... "); |
| sys_sync(); |
| printk("done.\n"); |
| |
| pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); |
| error = suspend_prepare(); |
| if (error) |
| goto Unlock; |
| |
| if (suspend_test(TEST_FREEZER)) |
| goto Finish; |
| |
| pr_debug("PM: Entering %s sleep\n", pm_states[state]); |
| pm_restrict_gfp_mask(); |
| error = suspend_devices_and_enter(state); |
| pm_restore_gfp_mask(); |
| |
| Finish: |
| pr_debug("PM: Finishing wakeup.\n"); |
| suspend_finish(); |
| Unlock: |
| mutex_unlock(&pm_mutex); |
| return error; |
| } |
| |
| /** |
| * pm_suspend - Externally visible function for suspending system. |
| * @state: Enumerated value of state to enter. |
| * |
| * Determine whether or not value is within range, get state |
| * structure, and enter (above). |
| */ |
| int pm_suspend(suspend_state_t state) |
| { |
| if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) |
| return enter_state(state); |
| return -EINVAL; |
| } |
| EXPORT_SYMBOL(pm_suspend); |