Re: Fix S3 resume when kernel is big

[Pavel Machek <pavel-+ZI9xUNit7I@public.gmane.org>]

Hi!

>  > -	acpi_create_identity_pmd();
>  > +	if (!cpu_has_pse) {
>  > +		printk(KERN_ERR "You have S3 capable machine without pse? Wow!");
>  > +		return 1;
>  > +	}
> 
> Mobile K6 family never had PSE iirc, and also VIA Cyrix 3's are being
> dropped into various laptops.

Okay, here is patch that should be ableto handle machines without
pse... I'd still like to see machine where ACPI S3 work and it does
not have pse, through.

								Pavel

--- clean/arch/i386/kernel/acpi.c	2002-09-22 23:46:52.000000000 +0200
+++ linux-swsusp/arch/i386/kernel/acpi.c	2002-11-24 20:29:33.000000000 +0100
@@ -446,72 +446,19 @@
 
 #ifdef CONFIG_ACPI_SLEEP
 
-#define DEBUG
-
-#ifdef DEBUG
-#include <linux/serial.h>
-#endif
-
 /* address in low memory of the wakeup routine. */
 unsigned long acpi_wakeup_address = 0;
 
-/* new page directory that we will be using */
-static pmd_t *pmd;
-
-/* saved page directory */
-static pmd_t saved_pmd;
-
-/* page which we'll use for the new page directory */
-static pte_t *ptep;
-
 extern unsigned long FASTCALL(acpi_copy_wakeup_routine(unsigned long));
 
-/*
- * acpi_create_identity_pmd
- *
- * Create a new, identity mapped pmd.
- *
- * Do this by creating new page directory, and marking all the pages as R/W
- * Then set it as the new Page Middle Directory.
- * And, of course, flush the TLB so it takes effect.
- *
- * We save the address of the old one, for later restoration.
- */
-static void acpi_create_identity_pmd (void)
+static void init_low_mapping(pgd_t *pgd, int pgd_ofs, int pgd_limit)
 {
-	pgd_t *pgd;
-	int i;
-
-	ptep = (pte_t*)__get_free_page(GFP_KERNEL);
+	int pgd_ofs = 0;
 
-	/* fill page with low mapping */
-	for (i = 0; i < PTRS_PER_PTE; i++)
-		set_pte(ptep + i, pfn_pte(i, PAGE_SHARED));
-
-	pgd = pgd_offset(current->active_mm, 0);
-	pmd = pmd_alloc(current->mm,pgd, 0);
-
-	/* save the old pmd */
-	saved_pmd = *pmd;
-
-	/* set the new one */
-	set_pmd(pmd, __pmd(_PAGE_TABLE + __pa(ptep)));
-
-	/* flush the TLB */
-	local_flush_tlb();
-}
-
-/*
- * acpi_restore_pmd
- *
- * Restore the old pmd saved by acpi_create_identity_pmd and
- * free the page that said function alloc'd
- */
-static void acpi_restore_pmd (void)
-{
-	set_pmd(pmd, saved_pmd);
-	local_flush_tlb();
-	free_page((unsigned long)ptep);
+	while ((pgd_ofs < pgd_limit) && (pgd_ofs + USER_PTRS_PER_PGD < PTRS_PER_PGD)) {
+		set_pgd(pgd, *(pgd+USER_PTRS_PER_PGD));
+		pgd_ofs++, pgd++;
+	}
 }
 
 /**
@@ -522,7 +469,11 @@
  */
 int acpi_save_state_mem (void)
 {
-	acpi_create_identity_pmd();
+#if CONFIG_X86_PAE
+	panic("S3 and PAE do not like each other for now.");
+	return 1;
+#endif
+	init_low_mapping(swapper_pg_dir, 0, USER_PTRS_PER_PGD);
 	acpi_copy_wakeup_routine(acpi_wakeup_address);
 
 	return 0;
@@ -542,7 +493,7 @@
  */
 void acpi_restore_state_mem (void)
 {
-	acpi_restore_pmd();
+	zap_low_mappings();
 }
 
 /**
@@ -555,7 +506,10 @@
  */
 void __init acpi_reserve_bootmem(void)
 {
+	extern char wakeup_start, wakeup_end;
 	acpi_wakeup_address = (unsigned long)alloc_bootmem_low(PAGE_SIZE);
+	if ((&wakeup_end - &wakeup_start) > PAGE_SIZE)
+		printk(KERN_CRIT "ACPI: Wakeup code way too big, will crash on attempt to suspend\n");
 	printk(KERN_DEBUG "ACPI: have wakeup address 0x%8.8lx\n", acpi_wakeup_address);
 }
 
--- clean/arch/i386/kernel/acpi_wakeup.S	2002-11-19 16:45:58.000000000 +0100
+++ linux-swsusp/arch/i386/kernel/acpi_wakeup.S	2002-11-23 20:44:44.000000000 +0100
@@ -1,12 +1,17 @@
-
 .text
 #include <linux/linkage.h>
 #include <asm/segment.h>
+#include <asm/page.h>
 
-# Do we need to deal with A20?
+#
+# wakeup_code runs in real mode, and at unknown address (determined at run-time).
+# Therefore it must only use relative jumps/calls. 
+#
+# Do we need to deal with A20? It seems okay
 
 ALIGN
-wakeup_start:
+	.align	4096
+ENTRY(wakeup_start)
 wakeup_code:
 	wakeup_code_start = .
 	.code16
@@ -14,49 +19,71 @@
  	movw	$0xb800, %ax
 	movw	%ax,%fs
 	movw	$0x0e00 + 'L', %fs:(0x10)
+	
 	cli
 	cld
-	  
-	# setup data segment
-	movw	%cs, %ax
 
-	addw	$(wakeup_data - wakeup_code) >> 4, %ax
-	movw	%ax, %ds
-	movw	%ax, %ss
-	mov	$(wakeup_stack - wakeup_data), %sp		# Private stack is needed for ASUS board
+# We are now probably running at something like 0x0000 : 0x1000
+	call here
+here:
+	pop	 %bx
+	subw	$(here-wakeup_start), %bx
+	shrw	$4, %bx
+	
+        # setup data segment
+        movw    %cs, %ax
+	addw    %bx, %ax
+	movw    %ax, %ds					# Make ds:0 point to wakeup_start
+	movw    %ax, %ss
+	mov	$(wakeup_stack-wakeup_code), %sp		# Private stack is needed for ASUS board
 	movw	$0x0e00 + 'S', %fs:(0x12)	
 
-	movl	real_magic - wakeup_data, %eax
+	pushl	$0						# Kill any dangerous flags
+	popfl
+	cli
+	cld
+	
+	movl	real_magic-wakeup_code, %eax
 	cmpl	$0x12345678, %eax
 	jne	bogus_real_magic
 
-	mov	video_mode - wakeup_data, %ax
+	mov	video_mode-wakeup_code, %ax
 	call	mode_set
 
 	# set up page table
-	movl	(real_save_cr3 - wakeup_data), %eax
+	movl	$swapper_pg_dir-__PAGE_OFFSET,%eax
 	movl	%eax, %cr3
 
 	# make sure %cr4 is set correctly (features, etc)
-	movl	(real_save_cr4 - wakeup_data), %eax
+	movl	real_save_cr4-wakeup_code, %eax
 	movl	%eax, %cr4
 	movw	$0xb800, %ax
 	movw	%ax,%fs
 	movw	$0x0e00 + 'i', %fs:(0x12)
-
+	
 	# need a gdt
-	lgdt	real_save_gdt - wakeup_data
+	lgdt	real_save_gdt-wakeup_code
 
-	movl	(real_save_cr0 - wakeup_data), %eax
+	movl	real_save_cr0-wakeup_code, %eax
 	movl	%eax, %cr0
+	jmp 1f
+1:
 	movw	$0x0e00 + 'n', %fs:(0x14)
 
-	movl	real_magic - wakeup_data, %eax
+	movl	real_magic-wakeup_code, %eax
 	cmpl	$0x12345678, %eax
 	jne	bogus_real_magic
 
 	ljmpl	$__KERNEL_CS,$wakeup_pmode_return
 
+real_save_gdt:	.word 0
+		.long 0
+real_save_cr0:	.long 0
+real_save_cr3:	.long 0
+real_save_cr4:	.long 0
+real_magic:	.long 0
+video_mode:	.long 0
+
 bogus_real_magic:
 	movw	$0x0e00 + 'B', %fs:(0x12)
 	jmp bogus_real_magic
@@ -129,20 +156,12 @@
 	.code32
 	ALIGN
 
-.org	0x300
-wakeup_data:
-		.word 0
-real_save_gdt:	.word 0
-		.long 0
-real_save_cr0:	.long 0
-real_save_cr3:	.long 0
-real_save_cr4:	.long 0
-real_magic:	.long 0
-video_mode:	.long 0
 
-.org	0x500
+.org	0x2000
 wakeup_stack:
-wakeup_end:
+.org	0x3000
+ENTRY(wakeup_end)
+.org	0x4000
 
 wakeup_pmode_return:
 	movl	$__KERNEL_DS, %eax
@@ -205,6 +224,9 @@
 	movw	$0x0e00 + '2', %ds:(0xb8018)
 	jmp bogus_magic2
 		
+.org 0x123456
+eat_some_memory:	
+		.long 0
 
 ##
 # acpi_copy_wakeup_routine
@@ -228,7 +250,7 @@
 
 	movl	%eax, %edi
 	leal	wakeup_start, %esi
-	movl	$(wakeup_end - wakeup_start) >> 2, %ecx
+	movl	$(wakeup_end - wakeup_start + 3) >> 2, %ecx
 
 	rep ;  movsl
 
@@ -290,8 +312,8 @@
 	ret
 	.p2align 4,,7
 .L1432:
-	movl $104,%eax
-	movw %eax, %ds
+	movl $__KERNEL_DS,%eax
+	movw %ax, %ds
 	movl saved_context_esp, %esp
 	movl saved_context_ebp, %ebp
 	movl saved_context_eax, %eax
@@ -310,5 +332,4 @@
 saved_idt:	.long	0,0
 saved_ldt:	.long	0
 saved_tss:	.long	0
-saved_cr0:	.long	0
 
--- clean/arch/i386/mm/init.c	2002-11-19 16:45:26.000000000 +0100
+++ linux-swsusp/arch/i386/mm/init.c	2002-11-24 20:18:22.000000000 +0100
@@ -299,7 +299,7 @@
 #endif
 }
 
-void __init zap_low_mappings (void)
+void zap_low_mappings (void)
 {
 	int i;
 	/*


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