linux-stable/include/linux/suspend.h
Huang Ying 89081d17f7 kexec jump: save/restore device state
This patch implements devices state save/restore before after kexec.

This patch together with features in kexec_jump patch can be used for
following:

- A simple hibernation implementation without ACPI support.  You can kexec a
  hibernating kernel, save the memory image of original system and shutdown
  the system.  When resuming, you restore the memory image of original system
  via ordinary kexec load then jump back.

- Kernel/system debug through making system snapshot.  You can make system
  snapshot, jump back, do some thing and make another system snapshot.

- Cooperative multi-kernel/system.  With kexec jump, you can switch between
  several kernels/systems quickly without boot process except the first time.
  This appears like swap a whole kernel/system out/in.

- A general method to call program in physical mode (paging turning
  off). This can be used to invoke BIOS code under Linux.

The following user-space tools can be used with kexec jump:

- kexec-tools needs to be patched to support kexec jump. The patches
  and the precompiled kexec can be download from the following URL:
       source: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-src_git_kh10.tar.bz2
       patches: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-patches_git_kh10.tar.bz2
       binary: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec_git_kh10

- makedumpfile with patches are used as memory image saving tool, it
  can exclude free pages from original kernel memory image file. The
  patches and the precompiled makedumpfile can be download from the
  following URL:
       source: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile-src_cvs_kh10.tar.bz2
       patches: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile-patches_cvs_kh10.tar.bz2
       binary: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile_cvs_kh10

- An initramfs image can be used as the root file system of kexeced
  kernel. An initramfs image built with "BuildRoot" can be downloaded
  from the following URL:
       initramfs image: http://khibernation.sourceforge.net/download/release_v10/initramfs/rootfs_cvs_kh10.gz
  All user space tools above are included in the initramfs image.

Usage example of simple hibernation:

1. Compile and install patched kernel with following options selected:

CONFIG_X86_32=y
CONFIG_RELOCATABLE=y
CONFIG_KEXEC=y
CONFIG_CRASH_DUMP=y
CONFIG_PM=y
CONFIG_HIBERNATION=y
CONFIG_KEXEC_JUMP=y

2. Build an initramfs image contains kexec-tool and makedumpfile, or
   download the pre-built initramfs image, called rootfs.gz in
   following text.

3. Prepare a partition to save memory image of original kernel, called
   hibernating partition in following text.

4. Boot kernel compiled in step 1 (kernel A).

5. In the kernel A, load kernel compiled in step 1 (kernel B) with
   /sbin/kexec. The shell command line can be as follow:

   /sbin/kexec --load-preserve-context /boot/bzImage --mem-min=0x100000
     --mem-max=0xffffff --initrd=rootfs.gz

6. Boot the kernel B with following shell command line:

   /sbin/kexec -e

7. The kernel B will boot as normal kexec. In kernel B the memory
   image of kernel A can be saved into hibernating partition as
   follow:

   jump_back_entry=`cat /proc/cmdline | tr ' ' '\n' | grep kexec_jump_back_entry | cut -d '='`
   echo $jump_back_entry > kexec_jump_back_entry
   cp /proc/vmcore dump.elf

   Then you can shutdown the machine as normal.

8. Boot kernel compiled in step 1 (kernel C). Use the rootfs.gz as
   root file system.

9. In kernel C, load the memory image of kernel A as follow:

   /sbin/kexec -l --args-none --entry=`cat kexec_jump_back_entry` dump.elf

10. Jump back to the kernel A as follow:

   /sbin/kexec -e

   Then, kernel A is resumed.

Implementation point:

To support jumping between two kernels, before jumping to (executing)
the new kernel and jumping back to the original kernel, the devices
are put into quiescent state, and the state of devices and CPU is
saved. After jumping back from kexeced kernel and jumping to the new
kernel, the state of devices and CPU are restored accordingly. The
devices/CPU state save/restore code of software suspend is called to
implement corresponding function.

Known issues:

- Because the segment number supported by sys_kexec_load is limited,
  hibernation image with many segments may not be load. This is
  planned to be eliminated by adding a new flag to sys_kexec_load to
  make a image can be loaded with multiple sys_kexec_load invoking.

Now, only the i386 architecture is supported.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:04 -07:00

283 lines
10 KiB
C

#ifndef _LINUX_SUSPEND_H
#define _LINUX_SUSPEND_H
#if defined(CONFIG_X86) || defined(CONFIG_FRV) || defined(CONFIG_PPC32) || defined(CONFIG_PPC64)
#include <asm/suspend.h>
#endif
#include <linux/swap.h>
#include <linux/notifier.h>
#include <linux/init.h>
#include <linux/pm.h>
#include <linux/mm.h>
#include <asm/errno.h>
#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE)
extern void pm_set_vt_switch(int);
extern int pm_prepare_console(void);
extern void pm_restore_console(void);
#else
static inline void pm_set_vt_switch(int do_switch)
{
}
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)
/**
* struct platform_suspend_ops - Callbacks for managing platform dependent
* system sleep states.
*
* @valid: Callback to determine if given system sleep state is supported by
* the platform.
* Valid (ie. supported) states are advertised in /sys/power/state. Note
* that it still may be impossible to enter given system sleep state if the
* conditions aren't right.
* There is the %suspend_valid_only_mem function available that can be
* assigned to this if the platform only supports mem sleep.
*
* @begin: Initialise a transition to given system sleep state.
* @begin() is executed right prior to suspending devices. The information
* conveyed to the platform code by @begin() should be disregarded by it as
* soon as @end() is executed. If @begin() fails (ie. returns nonzero),
* @prepare(), @enter() and @finish() will not be called by the PM core.
* This callback is optional. However, if it is implemented, the argument
* passed to @enter() is redundant and should be ignored.
*
* @prepare: Prepare the platform for entering the system sleep state indicated
* by @begin().
* @prepare() is called right after devices have been suspended (ie. the
* appropriate .suspend() method has been executed for each device) and
* before the nonboot CPUs are disabled (it is executed with IRQs enabled).
* This callback is optional. It returns 0 on success or a negative
* error code otherwise, in which case the system cannot enter the desired
* sleep state (@enter() and @finish() will not be called in that case).
*
* @enter: Enter the system sleep state indicated by @begin() or represented by
* the argument if @begin() is not implemented.
* This callback is mandatory. It returns 0 on success or a negative
* error code otherwise, in which case the system cannot enter the desired
* sleep state.
*
* @finish: Called when the system has just left a sleep state, right after
* the nonboot CPUs have been enabled and before devices are resumed (it is
* executed with IRQs enabled).
* This callback is optional, but should be implemented by the platforms
* that implement @prepare(). If implemented, it is always called after
* @enter() (even if @enter() fails).
*
* @end: Called by the PM core right after resuming devices, to indicate to
* the platform that the system has returned to the working state or
* the transition to the sleep state has been aborted.
* This callback is optional, but should be implemented by the platforms
* that implement @begin(), but platforms implementing @begin() should
* also provide a @end() which cleans up transitions aborted before
* @enter().
*
* @recover: Recover the platform from a suspend failure.
* Called by the PM core if the suspending of devices fails.
* This callback is optional and should only be implemented by platforms
* which require special recovery actions in that situation.
*/
struct platform_suspend_ops {
int (*valid)(suspend_state_t state);
int (*begin)(suspend_state_t state);
int (*prepare)(void);
int (*enter)(suspend_state_t state);
void (*finish)(void);
void (*end)(void);
void (*recover)(void);
};
#ifdef CONFIG_SUSPEND
/**
* suspend_set_ops - set platform dependent suspend operations
* @ops: The new suspend operations to set.
*/
extern void suspend_set_ops(struct platform_suspend_ops *ops);
extern int suspend_valid_only_mem(suspend_state_t state);
/**
* arch_suspend_disable_irqs - disable IRQs for suspend
*
* Disables IRQs (in the default case). This is a weak symbol in the common
* code and thus allows architectures to override it if more needs to be
* done. Not called for suspend to disk.
*/
extern void arch_suspend_disable_irqs(void);
/**
* arch_suspend_enable_irqs - enable IRQs after suspend
*
* Enables IRQs (in the default case). This is a weak symbol in the common
* code and thus allows architectures to override it if more needs to be
* done. Not called for suspend to disk.
*/
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(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 - hibernation platform support
*
* The methods in this structure allow a platform to carry out special
* operations required by it during a hibernation transition.
*
* All the methods below, except for @recover(), must be implemented.
*
* @begin: Tell the platform driver that we're starting hibernation.
* Called right after shrinking memory and before freezing devices.
*
* @end: Called by the PM core right after resuming devices, to indicate to
* the platform that the system has returned to the working state.
*
* @pre_snapshot: Prepare the platform for creating the hibernation image.
* Called right after devices have been frozen and before the nonboot
* CPUs are disabled (runs with IRQs on).
*
* @finish: Restore the previous state of the platform after the hibernation
* image has been created *or* put the platform into the normal operation
* mode after the hibernation (the same method is executed in both cases).
* Called right after the nonboot CPUs have been enabled and before
* thawing devices (runs with IRQs on).
*
* @prepare: Prepare the platform for entering the low power state.
* Called right after the hibernation image has been saved and before
* devices are prepared for entering the low power state.
*
* @enter: Put the system into the low power state after the hibernation image
* has been saved to disk.
* Called after the nonboot CPUs have been disabled and all of the low
* level devices have been shut down (runs with IRQs off).
*
* @leave: Perform the first stage of the cleanup after the system sleep state
* indicated by @set_target() has been left.
* Called right after the control has been passed from the boot kernel to
* the image kernel, before the nonboot CPUs are enabled and before devices
* are resumed. Executed with interrupts disabled.
*
* @pre_restore: Prepare system for the restoration from a hibernation image.
* Called right after devices have been frozen and before the nonboot
* CPUs are disabled (runs with IRQs on).
*
* @restore_cleanup: Clean up after a failing image restoration.
* Called right after the nonboot CPUs have been enabled and before
* thawing devices (runs with IRQs on).
*
* @recover: Recover the platform from a failure to suspend devices.
* Called by the PM core if the suspending of devices during hibernation
* fails. This callback is optional and should only be implemented by
* platforms which require special recovery actions in that situation.
*/
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 register_nosave_region(unsigned long b, unsigned long e)
{
__register_nosave_region(b, e, 0);
}
static inline void 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(struct platform_hibernation_ops *ops);
extern int hibernate(void);
#else /* CONFIG_HIBERNATION */
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(struct platform_hibernation_ops *ops) {}
static inline int hibernate(void) { return -ENOSYS; }
#endif /* CONFIG_HIBERNATION */
#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); \
}
#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)
#endif /* !CONFIG_PM_SLEEP */
#ifndef 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)
{
}
#endif
extern struct mutex pm_mutex;
#endif /* _LINUX_SUSPEND_H */