[power] Adapt swsusp to new PM core. Clean up heavily.

- Split suspend/resume code into the four functions called from the PM core.
- Remove now-duplicated code. 
- Make sure PM core frees memory and sync's disks before we shut down devices.
- Remove software_suspend(), in favor of pm_suspend(). 
- Remove unused definitions from suspend.h

include/linux/suspend.h

@@ -8,8 +8,7 @@
 #include <linux/notifier.h>
 #include <linux/config.h>
 #include <linux/init.h>
-
-extern unsigned char software_suspend_enabled;
+#include <linux/pm.h>
 
 #ifdef CONFIG_SOFTWARE_SUSPEND
 /* page backup entry */
@@ -46,12 +45,6 @@ extern int shrink_mem(void);
 /* mm/page_alloc.c */
 extern void drain_local_pages(void);
 
-/* kernel/suspend.c */
-extern int software_suspend(void);
-
-extern int register_suspend_notifier(struct notifier_block *);
-extern int unregister_suspend_notifier(struct notifier_block *);
-
 extern unsigned int nr_copy_pages __nosavedata;
 extern suspend_pagedir_t *pagedir_nosave __nosavedata;
 
@@ -72,31 +65,16 @@ static inline int software_suspend(void)
 {
 	return -EPERM;
 }
-#define register_suspend_notifier(a)	do { } while(0)
-#define unregister_suspend_notifier(a)	do { } while(0)
 #endif	/* CONFIG_SOFTWARE_SUSPEND */
 
 
 #ifdef CONFIG_PM
 extern void refrigerator(unsigned long);
-extern int freeze_processes(void);
-extern void thaw_processes(void);
-
-extern int pm_prepare_console(void);
-extern void pm_restore_console(void);
 
 #else
 static inline void refrigerator(unsigned long flag)
 {
 
-}
-static inline int freeze_processes(void)
-{
-	return 0;
-}
-static inline void thaw_processes(void)
-{
-
 }
 #endif	/* CONFIG_PM */
 

kernel/power/main.c

@@ -15,6 +15,8 @@
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/pm.h>
+#include <linux/fs.h>
+
 
 #include "power.h"
 
@@ -30,6 +32,8 @@ static int have_swsusp = 1;
 static int have_swsusp = 0;
 #endif
 
+extern long sys_sync(void);
+
 
 /**
  *	pm_set_ops - Set the global power method table. 
@@ -128,6 +132,25 @@ static int power_down(u32 mode)
 static int in_suspend __nosavedata = 0;
 
 
+/**
+ *	free_some_memory -  Try to free as much memory as possible
+ *
+ *	... but do not OOM-kill anyone
+ *
+ *	Notice: all userland should be stopped at this point, or 
+ *	livelock is possible.
+ */
+
+static void free_some_memory(void)
+{
+	printk("Freeing memory: ");
+	while (shrink_all_memory(10000))
+		printk(".");
+	printk("|\n");
+	blk_run_queues();
+}
+
+
 /**
  *	pm_suspend_disk - The granpappy of power management.
  *	
@@ -197,6 +220,7 @@ static int suspend_prepare(u32 state)
 
 	pm_prepare_console();
 
+	sys_sync();
 	if (freeze_processes()) {
 		error = -EAGAIN;
 		goto Thaw;
@@ -207,6 +231,10 @@ static int suspend_prepare(u32 state)
 			goto Thaw;
 	}
 
+	/* Free memory before shutting down devices. */
+	if (state == PM_SUSPEND_DISK)
+		free_some_memory();
+
 	if ((error = device_pm_suspend(state)))
 		goto Finish;
 

kernel/power/power.h

@@ -37,3 +37,10 @@ static inline int swsusp_free(void)
 	return 0;
 }
 #endif
+
+
+extern int freeze_processes(void);
+extern void thaw_processes(void);
+
+extern int pm_prepare_console(void);
+extern void pm_restore_console(void);

kernel/power/swsusp.c

@@ -65,8 +65,6 @@
 
 #include "power.h"
 
-extern long sys_sync(void);
-
 unsigned char software_suspend_enabled = 1;
 
 #define __ADDRESS(x)  ((unsigned long) phys_to_virt(x))
@@ -439,29 +437,6 @@ static suspend_pagedir_t *create_suspend_pagedir(int nr_copy_pages)
 	return pagedir;
 }
 
-static int prepare_suspend_processes(void)
-{
-	sys_sync();	/* Syncing needs pdflushd, so do it before stopping processes */
-	if (freeze_processes()) {
-		printk( KERN_ERR "Suspend failed: Not all processes stopped!\n" );
-		thaw_processes();
-		return 1;
-	}
-	return 0;
-}
-
-/*
- * Try to free as much memory as possible, but do not OOM-kill anyone
- *
- * Notice: all userland should be stopped at this point, or livelock is possible.
- */
-static void free_some_memory(void)
-{
-	printk("Freeing memory: ");
-	while (shrink_all_memory(10000))
-		printk(".");
-	printk("|\n");
-}
 
 /* Make disk drivers accept operations, again */
 static void drivers_unsuspend(void)
@@ -470,28 +445,6 @@ static void drivers_unsuspend(void)
 	device_resume(RESUME_ENABLE);
 }
 
-/* Called from process context */
-static int drivers_suspend(void)
-{
-	if (device_suspend(4, SUSPEND_NOTIFY))
-		return -EIO;
-	if (device_suspend(4, SUSPEND_SAVE_STATE)) {
-		device_resume(RESUME_RESTORE_STATE);
-		return -EIO;
-	}
-	if (!pm_suspend_state) {
-		if(pm_send_all(PM_SUSPEND,(void *)3)) {
-			printk(KERN_WARNING "Problem while sending suspend event\n");
-			return -EIO;
-		}
-		pm_suspend_state=1;
-	} else
-		printk(KERN_WARNING "PM suspend state already raised\n");
-	device_suspend(4, SUSPEND_DISABLE);
-	  
-	return 0;
-}
-
 #define RESUME_PHASE1 1 /* Called from interrupts disabled */
 #define RESUME_PHASE2 2 /* Called with interrupts enabled */
 #define RESUME_ALL_PHASES (RESUME_PHASE1 | RESUME_PHASE2)
@@ -694,72 +647,6 @@ void do_magic_suspend_2(void)
 	mark_swapfiles(((swp_entry_t) {0}), MARK_SWAP_RESUME);
 }
 
-static int do_software_suspend(void)
-{
-	arch_prepare_suspend();
-	if (pm_prepare_console())
-		printk( "%sCan't allocate a console... proceeding\n", name_suspend);
-	if (!prepare_suspend_processes()) {
-
-		/* At this point, all user processes and "dangerous"
-                   kernel threads are stopped. Free some memory, as we
-                   need half of memory free. */
-
-		free_some_memory();
-		
-		/* No need to invalidate any vfsmnt list -- 
-		 * they will be valid after resume, anyway.
-		 */
-		blk_run_queues();
-
-		/* Save state of all device drivers, and stop them. */		   
-		if (drivers_suspend()==0)
-			/* If stopping device drivers worked, we proceed basically into
-			 * suspend_save_image.
-			 *
-			 * do_magic(0) returns after system is resumed.
-			 *
-			 * do_magic() copies all "used" memory to "free" memory, then
-			 * unsuspends all device drivers, and writes memory to disk
-			 * using normal kernel mechanism.
-			 */
-			do_magic(0);
-		thaw_processes();
-	}
-	software_suspend_enabled = 1;
-	MDELAY(1000);
-	pm_restore_console();
-	return 0;
-}
-
-
-/**
- *	software_suspend - initiate suspend-to-swap transition.
- *
- *	This is main interface to the outside world. It needs to be
- *	called from process context.
- */
-
-int software_suspend(void)
-{
-	if(!software_suspend_enabled)
-		return -EINVAL;
-
-	if (num_online_cpus() > 1) {
-		printk(KERN_WARNING "swsusp does not support SMP.\n");	
-		return -EPERM;
-	}
-
-#if defined (CONFIG_HIGHMEM) || defined (COFNIG_DISCONTIGMEM)
-	printk("swsusp is not supported with high- or discontig-mem.\n");
-	return -EPERM;
-#endif
-
-	software_suspend_enabled = 0;
-	might_sleep();
-	return do_software_suspend();
-}
-
 /* More restore stuff */
 
 /* FIXME: Why not memcpy(to, from, 1<<pagedir_order*PAGE_SIZE)? */
@@ -1030,55 +917,35 @@ static int read_suspend_image(const char * specialfile)
 	return error;
 }
 
-/**
- *	software_resume - Check and load saved image from swap.
- *
- *	Defined as a late_initcall, so it gets called after all devices
- *	have been probed and initialized, but before we've mounted anything.
- */
-
-static int software_resume(void)
-{
-	if (!strlen(resume_file))
-		return 0;
-
-	if (pm_prepare_console())
-		printk("swsusp: Can't allocate a console... proceeding\n");
-
-	printk("swsusp: %s\n", name_resume );
-
-	MDELAY(1000);
-
-	printk("swsusp: resuming from %s\n", resume_file);
-	if (read_suspend_image(resume_file))
-		goto read_failure;
-	do_magic(1);
-	printk("swsusp: Resume failed. Continuing.\n");
-
-read_failure:
-	pm_restore_console();
-	return -EFAULT;
-}
-
-late_initcall(software_resume);
-
-
 /**
  *	swsusp_save - Snapshot memory
  */
 
 int swsusp_save(void) 
 {
+#if defined (CONFIG_HIGHMEM) || defined (COFNIG_DISCONTIGMEM)
+	printk("swsusp is not supported with high- or discontig-mem.\n");
 	return -EPERM;
+#endif
+	return 0;
 }
 
 
 /**
  *	swsusp_write - Write saved memory image to swap.
+ *
+ *	do_magic(0) returns after system is resumed.
+ *
+ *	do_magic() copies all "used" memory to "free" memory, then
+ *	unsuspends all device drivers, and writes memory to disk
+ *	using normal kernel mechanism.
  */
 
 int swsusp_write(void)
 {
+	arch_prepare_suspend();
+	do_magic(0);
+	MDELAY(1000);
 	return 0;
 }
 
@@ -1089,7 +956,11 @@ int swsusp_write(void)
 
 int swsusp_read(void)
 {
-	return -ENOENT;
+	if (!strlen(resume_file))
+		return -ENOENT;
+	printk("swsusp: %s\n", name_resume );
+	MDELAY(1000);
+	return read_suspend_image(resume_file);
 }
 
 
@@ -1099,6 +970,7 @@ int swsusp_read(void)
 
 int swsusp_restore(void)
 {
+	do_magic(1);
 	return 0;
 }
 
@@ -1114,7 +986,8 @@ int swsusp_free(void)
 
 static int __init resume_setup(char *str)
 {
-	strncpy( resume_file, str, 255 );
+	if (strlen(str))
+		strncpy(resume_file, str, 255);
 	return 1;
 }
 
@@ -1127,5 +1000,3 @@ static int __init noresume_setup(char *str)
 __setup("noresume", noresume_setup);
 __setup("resume=", resume_setup);
 
-EXPORT_SYMBOL(software_suspend);
-EXPORT_SYMBOL(software_suspend_enabled);

kernel/sys.c

@@ -456,11 +456,8 @@ asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user
 
 #ifdef CONFIG_SOFTWARE_SUSPEND
 	case LINUX_REBOOT_CMD_SW_SUSPEND:
-		if (!software_suspend_enabled) {
-			unlock_kernel();
-			return -EAGAIN;
-		}		
-		software_suspend();
+		if (!pm_suspend(PM_SUSPEND_DISK))
+			break;
 		do_exit(0);
 		break;
 #endif