[power] swsusp Cleanups

- do_magic()
  - Rename to swsusp_arch_suspend().
  - Move declaration to swsusp.c

- arch_prepare_suspend()
  - Return an int
  - Fix x86 version to return -EFAULT if cpu does not have pse, instead of 
    calling panic().
  - Call from swsusp_save().

- do_magic_suspend_1()
  - Move body to pm_suspend_disk()
  - Remove.

- do_magic_suspend_2()
  - Rename to swsusp_suspend()
  - Move IRQ fiddling to suspend_save_image(), since that's the only call 
    that needs it. 
  - Return an int.

- do_magic_resume_1()
  - Move body to pm_resume().
  - Remove

- do_magic_resume_2()
  - Rename to swsusp_resume(). 
  - Return an int. 

- swsusp general
  - Remove unnecessary includes.
  - Remove suspend_pagedir_lock, since it was only used to disable IRQs.
  - Change swsusp_{suspend,resume} return an int, so pm_suspend_disk() knows
    if anything failed. 

 

arch/i386/power/swsusp.S

@@ -8,11 +8,10 @@
 
 	.text
 
-ENTRY(do_magic)
+ENTRY(swsusp_arch_suspend)
 	pushl %ebx
 	cmpl $0,8(%esp)
 	jne .L1450
-	call do_magic_suspend_1
 	call save_processor_state
 
 	movl %esp, saved_context_esp
@@ -25,14 +24,13 @@ ENTRY(do_magic)
 	movl %edi, saved_context_edi
 	pushfl ; popl saved_context_eflags
 
-	call do_magic_suspend_2
+	call swsusp_suspend
 	jmp .L1449
 	.p2align 4,,7
 .L1450:
 	movl $swapper_pg_dir-__PAGE_OFFSET,%ecx
 	movl %ecx,%cr3
 
-	call do_magic_resume_1
 	movl $0,loop
 	cmpl $0,nr_copy_pages
 	je .L1453
@@ -80,7 +78,7 @@ ENTRY(do_magic)
 	movl saved_context_edi, %edi
 	call restore_processor_state
 	pushl saved_context_eflags ; popfl
-	call do_magic_resume_2
+	call swsusp_resume
 .L1449:
 	popl %ebx
 	ret
@@ -91,4 +89,4 @@ loop:
 loop2:
        .quad 0
        .previous
-	
+
\ No newline at end of file

include/asm-i386/suspend.h

@@ -6,11 +6,12 @@
 #include <asm/desc.h>
 #include <asm/i387.h>
 
-static inline void
+static inline int
 arch_prepare_suspend(void)
 {
 	if (!cpu_has_pse)
-		panic("pse required");
+		return -EPERM;
+	return 0;
 }
 
 /* image of the saved processor state */
@@ -38,8 +39,6 @@ struct saved_context {
 extern void save_processor_state(void);
 extern void restore_processor_state(void);
 
-extern int do_magic(int resume);
-
 #ifdef CONFIG_ACPI_SLEEP
 extern unsigned long saved_eip;
 extern unsigned long saved_esp;

kernel/power/main.c

@@ -8,10 +8,13 @@
  *
  */
 
+#define DEBUG
+
 #include <linux/suspend.h>
 #include <linux/kobject.h>
 #include <linux/reboot.h>
 #include <linux/string.h>
+#include <linux/delay.h>
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/pm.h>
@@ -182,11 +185,19 @@ static int pm_suspend_disk(void)
 
 	pr_debug("PM: snapshotting memory.\n");
 	in_suspend = 1;
+	local_irq_disable();
 	if ((error = swsusp_save()))
 		goto Done;
 
 	if (in_suspend) {
 		pr_debug("PM: writing image.\n");
+
+		/* 
+		 * FIXME: Leftover from swsusp. Are they necessary? 
+		 */
+		mb();
+		barrier();
+
 		error = swsusp_write();
 		if (!error)
 			error = power_down(pm_disk_mode);
@@ -195,6 +206,7 @@ static int pm_suspend_disk(void)
 		pr_debug("PM: Image restored successfully.\n");
 	swsusp_free();
  Done:
+	local_irq_enable();
 	return error;
 }
 
@@ -363,9 +375,23 @@ static int pm_resume(void)
 	if ((error = suspend_prepare(PM_SUSPEND_DISK)))
 		goto Free;
 
+	barrier();
+	mb();
+	local_irq_disable();
+
+	/* FIXME: The following (comment and mdelay()) are from swsusp. 
+	 * Are they really necessary? 
+	 *
+	 * We do not want some readahead with DMA to corrupt our memory, right?
+	 * Do it with disabled interrupts for best effect. That way, if some
+	 * driver scheduled DMA, we have good chance for DMA to finish ;-).
+	 */
+	pr_debug("PM: Waiting for DMAs to settle down.\n");
+	mdelay(1000);
+
 	pr_debug("PM: Restoring saved image.\n");
 	swsusp_restore();
-
+	local_irq_enable();
 	pr_debug("PM: Restore failed, recovering.n");
 	suspend_finish(PM_SUSPEND_DISK);
  Free:

kernel/power/swsusp.c

@@ -34,38 +34,21 @@
  * For TODOs,FIXMEs also look in Documentation/swsusp.txt
  */
 
-#include <linux/module.h>
 #include <linux/mm.h>
 #include <linux/suspend.h>
-#include <linux/smp_lock.h>
-#include <linux/file.h>
-#include <linux/utsname.h>
 #include <linux/version.h>
-#include <linux/delay.h>
 #include <linux/reboot.h>
-#include <linux/bitops.h>
-#include <linux/vt_kern.h>
-#include <linux/kbd_kern.h>
-#include <linux/keyboard.h>
-#include <linux/spinlock.h>
-#include <linux/genhd.h>
-#include <linux/kernel.h>
-#include <linux/major.h>
-#include <linux/swap.h>
-#include <linux/pm.h>
 #include <linux/device.h>
 #include <linux/buffer_head.h>
 #include <linux/swapops.h>
 #include <linux/bootmem.h>
 
-#include <asm/uaccess.h>
 #include <asm/mmu_context.h>
-#include <asm/pgtable.h>
-#include <asm/io.h>
 
 #include "power.h"
 
-unsigned char software_suspend_enabled = 1;
+
+extern int swsusp_arch_suspend(int resume);
 
 #define __ADDRESS(x)  ((unsigned long) phys_to_virt(x))
 #define ADDRESS(x) __ADDRESS((x) << PAGE_SHIFT)
@@ -76,9 +59,6 @@ extern char __nosave_begin, __nosave_end;
 
 extern int is_head_of_free_region(struct page *);
 
-/* Locks */
-spinlock_t suspend_pagedir_lock __nosavedata = SPIN_LOCK_UNLOCKED;
-
 /* Variables to be preserved over suspend */
 static int pagedir_order_check;
 static int nr_copy_pages_check;
@@ -488,21 +468,30 @@ static int suspend_prepare_image(void)
 	return 0;
 }
 
+
+/**
+ *	suspend_save_image - Prepare and write saved image to swap.
+ *
+ *	IRQs are re-enabled here so we can resume devices and safely write 
+ *	to the swap devices. We disable them again before we leave.
+ *
+ *	The second lock_swapdevices() will unlock ignored swap devices since
+ *	writing is finished.
+ *	It is important _NOT_ to umount filesystems at this point. We want
+ *	them synced (in case something goes wrong) but we DO not want to mark
+ *	filesystem clean: it is not. (And it does not matter, if we resume
+ *	correctly, we'll mark system clean, anyway.)
+ */
+
 static int suspend_save_image(void)
 {
 	int error;
-
+	local_irq_enable();
 	device_resume();
-
 	lock_swapdevices();
 	error = write_suspend_image();
-	lock_swapdevices();	/* This will unlock ignored swap devices since writing is finished */
-
-	/* It is important _NOT_ to umount filesystems at this point. We want
-	 * them synced (in case something goes wrong) but we DO not want to mark
-	 * filesystem clean: it is not. (And it does not matter, if we resume
-	 * correctly, we'll mark system clean, anyway.)
-	 */
+	lock_swapdevices();
+	local_irq_disable();
 	return error;
 }
 
@@ -510,66 +499,49 @@ static int suspend_save_image(void)
  * Magic happens here
  */
 
-void do_magic_resume_1(void)
-{
-	barrier();
-	mb();
-	spin_lock_irq(&suspend_pagedir_lock);	/* Done to disable interrupts */ 
-	PRINTK( "Waiting for DMAs to settle down...\n");
-	/* We do not want some readahead with DMA to corrupt our memory, right?
-	   Do it with disabled interrupts for best effect. That way, if some
-	   driver scheduled DMA, we have good chance for DMA to finish ;-). */
-	mdelay(1000);
-}
-
-void do_magic_resume_2(void)
+int swsusp_resume(void)
 {
 	BUG_ON (nr_copy_pages_check != nr_copy_pages);
 	BUG_ON (pagedir_order_check != pagedir_order);
 	
 	/* Even mappings of "global" things (vmalloc) need to be fixed */
 	__flush_tlb_global();
-	spin_unlock_irq(&suspend_pagedir_lock);
+	return 0;
 }
 
-/* do_magic() is implemented in arch/?/kernel/suspend_asm.S, and basically does:
+/* swsusp_arch_suspend() is implemented in arch/?/power/swsusp.S, 
+   and basically does:
 
 	if (!resume) {
-		do_magic_suspend_1();
 		save_processor_state();
 		SAVE_REGISTERS
-		do_magic_suspend_2();
+		swsusp_suspend();
 		return;
 	}
 	GO_TO_SWAPPER_PAGE_TABLES
-	do_magic_resume_1();
 	COPY_PAGES_BACK
 	RESTORE_REGISTERS
 	restore_processor_state();
-	do_magic_resume_2();
+	swsusp_resume();
 
  */
 
-void do_magic_suspend_1(void)
-{
-	mb();
-	barrier();
-	spin_lock_irq(&suspend_pagedir_lock);
-}
 
-int do_magic_suspend_2(void)
+int swsusp_suspend(void)
 {
-	int is_problem;
+	int error;
 	read_swapfiles();
-	is_problem = suspend_prepare_image();
-	spin_unlock_irq(&suspend_pagedir_lock);
-	if (!is_problem)
-		return suspend_save_image();
-	printk(KERN_EMERG "%sSuspend failed, trying to recover...\n", name_suspend);
-	barrier();
-	mb();
-	mdelay(1000);
-	return -EFAULT;
+	error = suspend_prepare_image();
+	if (!error)
+		error = suspend_save_image();
+	if (error) {
+		printk(KERN_EMERG "%sSuspend failed, trying to recover...\n", 
+		       name_suspend);
+		barrier();
+		mb();
+		mdelay(1000);
+	}
+	return error;
 }
 
 /* More restore stuff */
@@ -806,24 +778,23 @@ int swsusp_save(void)
 	printk("swsusp is not supported with high- or discontig-mem.\n");
 	return -EPERM;
 #endif
-	return 0;
+	return arch_prepare_suspend();
 }
 
 
 /**
  *	swsusp_write - Write saved memory image to swap.
  *
- *	do_magic(0) returns after system is resumed.
+ *	swsusp_arch_suspend(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
+ *	swsusp_arch_suspend() 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();
-	return do_magic(0);
+	return swsusp_arch_suspend(0);
 }
 
 
@@ -873,7 +844,7 @@ int __init swsusp_read(void)
 
 int __init swsusp_restore(void)
 {
-	return do_magic(1);
+	return swsusp_arch_suspend(1);
 }