[PATCH 2/7] Hibernation: Move low level resume to disk.c

From: Rafael J. Wysocki
Date: Tue Nov 27 2007 - 19:35:09 EST


From: Rafael J. Wysocki <rjw@xxxxxxx>

Move the low level restore code to kernel/power/disk.c , since the
corresponding low level hibernation code is already there.

Make restore fail if device_power_down(PMSG_PRETHAW) returns an
error.

Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
Acked-by: Pavel Machek <pavel@xxxxxx>
---
kernel/power/disk.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++-
kernel/power/power.h | 1 -
kernel/power/swsusp.c | 35 -----------------------------------
3 files changed, 48 insertions(+), 37 deletions(-)

Index: linux-2.6/kernel/power/disk.c
===================================================================
--- linux-2.6.orig/kernel/power/disk.c
+++ linux-2.6/kernel/power/disk.c
@@ -275,6 +275,53 @@ int hibernation_snapshot(int platform_mo
}

/**
+ * resume_target_kernel - prepare devices that need to be suspended with
+ * interrupts off, restore the contents of highmem that have not been
+ * restored yet from the image and run the low level code that will restore
+ * the remaining contents of memory and switch to the just restored target
+ * kernel.
+ */
+
+static int resume_target_kernel(void)
+{
+ int error;
+
+ local_irq_disable();
+ error = device_power_down(PMSG_PRETHAW);
+ if (error) {
+ printk(KERN_ERR "Some devices failed to power down, "
+ "aborting resume\n");
+ goto Enable_irqs;
+ }
+ /* We'll ignore saved state, but this gets preempt count (etc) right */
+ save_processor_state();
+ error = restore_highmem();
+ if (!error) {
+ error = swsusp_arch_resume();
+ /*
+ * The code below is only ever reached in case of a failure.
+ * Otherwise execution continues at place where
+ * swsusp_arch_suspend() was called
+ */
+ BUG_ON(!error);
+ /* This call to restore_highmem() undos the previous one */
+ restore_highmem();
+ }
+ /*
+ * The only reason why swsusp_arch_resume() can fail is memory being
+ * very tight, so we have to free it as soon as we can to avoid
+ * subsequent failures
+ */
+ swsusp_free();
+ restore_processor_state();
+ touch_softlockup_watchdog();
+ device_power_up();
+ Enable_irqs:
+ local_irq_enable();
+ return error;
+}
+
+/**
* hibernation_restore - quiesce devices and restore the hibernation
* snapshot image. If successful, control returns in hibernation_snaphot()
* @platform_mode - if set, use the platform driver, if available, to
@@ -297,7 +344,7 @@ int hibernation_restore(int platform_mod
if (!error) {
error = disable_nonboot_cpus();
if (!error)
- error = swsusp_resume();
+ error = resume_target_kernel();
enable_nonboot_cpus();
}
platform_restore_cleanup(platform_mode);
Index: linux-2.6/kernel/power/swsusp.c
===================================================================
--- linux-2.6.orig/kernel/power/swsusp.c
+++ linux-2.6/kernel/power/swsusp.c
@@ -261,38 +261,3 @@ int swsusp_shrink_memory(void)

return 0;
}
-
-int swsusp_resume(void)
-{
- int error;
-
- local_irq_disable();
- /* NOTE: device_power_down() is just a suspend() with irqs off;
- * it has no special "power things down" semantics
- */
- if (device_power_down(PMSG_PRETHAW))
- printk(KERN_ERR "Some devices failed to power down, very bad\n");
- /* We'll ignore saved state, but this gets preempt count (etc) right */
- save_processor_state();
- error = restore_highmem();
- if (!error) {
- error = swsusp_arch_resume();
- /* The code below is only ever reached in case of a failure.
- * Otherwise execution continues at place where
- * swsusp_arch_suspend() was called
- */
- BUG_ON(!error);
- /* This call to restore_highmem() undos the previous one */
- restore_highmem();
- }
- /* The only reason why swsusp_arch_resume() can fail is memory being
- * very tight, so we have to free it as soon as we can to avoid
- * subsequent failures
- */
- swsusp_free();
- restore_processor_state();
- touch_softlockup_watchdog();
- device_power_up();
- local_irq_enable();
- return error;
-}
Index: linux-2.6/kernel/power/power.h
===================================================================
--- linux-2.6.orig/kernel/power/power.h
+++ linux-2.6/kernel/power/power.h
@@ -154,7 +154,6 @@ extern int swsusp_swap_in_use(void);
extern int swsusp_check(void);
extern int swsusp_shrink_memory(void);
extern void swsusp_free(void);
-extern int swsusp_resume(void);
extern int swsusp_read(unsigned int *flags_p);
extern int swsusp_write(unsigned int flags);
extern void swsusp_close(void);

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