suspend.h

Go to the documentation of this file.

#ifndef _LINUX_SUSPEND_H
#define _LINUX_SUSPEND_H

#include <linux/swap.h>
#include <linux/notifier.h>
#include <linux/init.h>
#include <linux/pm.h>
#include <linux/mm.h>
#include <linux/freezer.h>
#include <asm/errno.h>

#ifdef CONFIG_VT
extern void pm_set_vt_switch(int);
#else
static inline void pm_set_vt_switch(int do_switch)
{
}
#endif

#ifdef CONFIG_VT_CONSOLE_SLEEP
extern int pm_prepare_console(void);
extern void pm_restore_console(void);
#else
static inline int pm_prepare_console(void)
{
    return 0;
}

static inline void pm_restore_console(void)
{
}
#endif

typedef int __bitwise suspend_state_t;

#define PM_SUSPEND_ON       ((__force suspend_state_t) 0)
#define PM_SUSPEND_STANDBY  ((__force suspend_state_t) 1)
#define PM_SUSPEND_MEM      ((__force suspend_state_t) 3)
#define PM_SUSPEND_MAX      ((__force suspend_state_t) 4)

enum suspend_stat_step {
    SUSPEND_FREEZE = 1,
    SUSPEND_PREPARE,
    SUSPEND_SUSPEND,
    SUSPEND_SUSPEND_LATE,
    SUSPEND_SUSPEND_NOIRQ,
    SUSPEND_RESUME_NOIRQ,
    SUSPEND_RESUME_EARLY,
    SUSPEND_RESUME
};

struct suspend_stats {
    int success;
    int fail;
    int failed_freeze;
    int failed_prepare;
    int failed_suspend;
    int failed_suspend_late;
    int failed_suspend_noirq;
    int failed_resume;
    int failed_resume_early;
    int failed_resume_noirq;
#define REC_FAILED_NUM  2
    int last_failed_dev;
    char    failed_devs[REC_FAILED_NUM][40];
    int last_failed_errno;
    int errno[REC_FAILED_NUM];
    int last_failed_step;
    enum suspend_stat_step  failed_steps[REC_FAILED_NUM];
};

extern struct suspend_stats suspend_stats;

static inline void dpm_save_failed_dev(const char *name)
{
    strlcpy(suspend_stats.failed_devs[suspend_stats.last_failed_dev],
        name,
        sizeof(suspend_stats.failed_devs[0]));
    suspend_stats.last_failed_dev++;
    suspend_stats.last_failed_dev %= REC_FAILED_NUM;
}

static inline void dpm_save_failed_errno(int err)
{
    suspend_stats.errno[suspend_stats.last_failed_errno] = err;
    suspend_stats.last_failed_errno++;
    suspend_stats.last_failed_errno %= REC_FAILED_NUM;
}

static inline void dpm_save_failed_step(enum suspend_stat_step step)
{
    suspend_stats.failed_steps[suspend_stats.last_failed_step] = step;
    suspend_stats.last_failed_step++;
    suspend_stats.last_failed_step %= REC_FAILED_NUM;
}

struct platform_suspend_ops {
    int (*valid)(suspend_state_t state);
    int (*begin)(suspend_state_t state);
    int (*prepare)(void);
    int (*prepare_late)(void);
    int (*enter)(suspend_state_t state);
    void (*wake)(void);
    void (*finish)(void);
    bool (*suspend_again)(void);
    void (*end)(void);
    void (*recover)(void);
};

#ifdef CONFIG_SUSPEND

extern void suspend_set_ops(const struct platform_suspend_ops *ops);
extern int suspend_valid_only_mem(suspend_state_t state);

extern void arch_suspend_disable_irqs(void);

extern void arch_suspend_enable_irqs(void);

extern int pm_suspend(suspend_state_t state);
#else /* !CONFIG_SUSPEND */
#define suspend_valid_only_mem  NULL

static inline void suspend_set_ops(const struct platform_suspend_ops *ops) {}
static inline int pm_suspend(suspend_state_t state) { return -ENOSYS; }
#endif /* !CONFIG_SUSPEND */

/* struct pbe is used for creating lists of pages that should be restored
 * atomically during the resume from disk, because the page frames they have
 * occupied before the suspend are in use.
 */
struct pbe {
    void *address;      /* address of the copy */
    void *orig_address; /* original address of a page */
    struct pbe *next;
};

/* mm/page_alloc.c */
extern void mark_free_pages(struct zone *zone);

struct platform_hibernation_ops {
    int (*begin)(void);
    void (*end)(void);
    int (*pre_snapshot)(void);
    void (*finish)(void);
    int (*prepare)(void);
    int (*enter)(void);
    void (*leave)(void);
    int (*pre_restore)(void);
    void (*restore_cleanup)(void);
    void (*recover)(void);
};

#ifdef CONFIG_HIBERNATION
/* kernel/power/snapshot.c */
extern void __register_nosave_region(unsigned long b, unsigned long e, int km);
static inline void __init register_nosave_region(unsigned long b, unsigned long e)
{
    __register_nosave_region(b, e, 0);
}
static inline void __init register_nosave_region_late(unsigned long b, unsigned long e)
{
    __register_nosave_region(b, e, 1);
}
extern int swsusp_page_is_forbidden(struct page *);
extern void swsusp_set_page_free(struct page *);
extern void swsusp_unset_page_free(struct page *);
extern unsigned long get_safe_page(gfp_t gfp_mask);

extern void hibernation_set_ops(const struct platform_hibernation_ops *ops);
extern int hibernate(void);
extern bool system_entering_hibernation(void);
#else /* CONFIG_HIBERNATION */
static inline void register_nosave_region(unsigned long b, unsigned long e) {}
static inline void register_nosave_region_late(unsigned long b, unsigned long e) {}
static inline int swsusp_page_is_forbidden(struct page *p) { return 0; }
static inline void swsusp_set_page_free(struct page *p) {}
static inline void swsusp_unset_page_free(struct page *p) {}

static inline void hibernation_set_ops(const struct platform_hibernation_ops *ops) {}
static inline int hibernate(void) { return -ENOSYS; }
static inline bool system_entering_hibernation(void) { return false; }
#endif /* CONFIG_HIBERNATION */

/* Hibernation and suspend events */
#define PM_HIBERNATION_PREPARE  0x0001 /* Going to hibernate */
#define PM_POST_HIBERNATION 0x0002 /* Hibernation finished */
#define PM_SUSPEND_PREPARE  0x0003 /* Going to suspend the system */
#define PM_POST_SUSPEND     0x0004 /* Suspend finished */
#define PM_RESTORE_PREPARE  0x0005 /* Going to restore a saved image */
#define PM_POST_RESTORE     0x0006 /* Restore failed */

extern struct mutex pm_mutex;

#ifdef CONFIG_PM_SLEEP
void save_processor_state(void);
void restore_processor_state(void);

/* kernel/power/main.c */
extern int register_pm_notifier(struct notifier_block *nb);
extern int unregister_pm_notifier(struct notifier_block *nb);

#define pm_notifier(fn, pri) {              \
    static struct notifier_block fn##_nb =          \
        { .notifier_call = fn, .priority = pri };   \
    register_pm_notifier(&fn##_nb);         \
}

/* drivers/base/power/wakeup.c */
extern bool events_check_enabled;

extern bool pm_wakeup_pending(void);
extern bool pm_get_wakeup_count(unsigned int *count, bool block);
extern bool pm_save_wakeup_count(unsigned int count);
extern void pm_wakep_autosleep_enabled(bool set);

static inline void lock_system_sleep(void)
{
    current->flags |= PF_FREEZER_SKIP;
    mutex_lock(&pm_mutex);
}

static inline void unlock_system_sleep(void)
{
    /*
     * Don't use freezer_count() because we don't want the call to
     * try_to_freeze() here.
     *
     * Reason:
     * Fundamentally, we just don't need it, because freezing condition
     * doesn't come into effect until we release the pm_mutex lock,
     * since the freezer always works with pm_mutex held.
     *
     * More importantly, in the case of hibernation,
     * unlock_system_sleep() gets called in snapshot_read() and
     * snapshot_write() when the freezing condition is still in effect.
     * Which means, if we use try_to_freeze() here, it would make them
     * enter the refrigerator, thus causing hibernation to lockup.
     */
    current->flags &= ~PF_FREEZER_SKIP;
    mutex_unlock(&pm_mutex);
}

#else /* !CONFIG_PM_SLEEP */

static inline int register_pm_notifier(struct notifier_block *nb)
{
    return 0;
}

static inline int unregister_pm_notifier(struct notifier_block *nb)
{
    return 0;
}

#define pm_notifier(fn, pri)    do { (void)(fn); } while (0)

static inline bool pm_wakeup_pending(void) { return false; }

static inline void lock_system_sleep(void) {}
static inline void unlock_system_sleep(void) {}

#endif /* !CONFIG_PM_SLEEP */

#ifdef CONFIG_PM_SLEEP_DEBUG
extern bool pm_print_times_enabled;
#else
#define pm_print_times_enabled  (false)
#endif

#ifdef CONFIG_PM_AUTOSLEEP

/* kernel/power/autosleep.c */
void queue_up_suspend_work(void);

#else /* !CONFIG_PM_AUTOSLEEP */

static inline void queue_up_suspend_work(void) {}

#endif /* !CONFIG_PM_AUTOSLEEP */

#ifdef CONFIG_ARCH_SAVE_PAGE_KEYS
/*
 * The ARCH_SAVE_PAGE_KEYS functions can be used by an architecture
 * to save/restore additional information to/from the array of page
 * frame numbers in the hibernation image. For s390 this is used to
 * save and restore the storage key for each page that is included
 * in the hibernation image.
 */
unsigned long page_key_additional_pages(unsigned long pages);
int page_key_alloc(unsigned long pages);
void page_key_free(void);
void page_key_read(unsigned long *pfn);
void page_key_memorize(unsigned long *pfn);
void page_key_write(void *address);

#else /* !CONFIG_ARCH_SAVE_PAGE_KEYS */

static inline unsigned long page_key_additional_pages(unsigned long pages)
{
    return 0;
}

static inline int  page_key_alloc(unsigned long pages)
{
    return 0;
}

static inline void page_key_free(void) {}
static inline void page_key_read(unsigned long *pfn) {}
static inline void page_key_memorize(unsigned long *pfn) {}
static inline void page_key_write(void *address) {}

#endif /* !CONFIG_ARCH_SAVE_PAGE_KEYS */

#endif /* _LINUX_SUSPEND_H */