1/*
2 * This may not use any stack, nor any variable that is not "NoSave":
3 *
4 * Its rewriting one kernel image with another. What is stack in "old"
5 * image could very well be data page in "new" image, and overwriting
6 * your own stack under you is bad idea.
7 */
8
9#include <linux/linkage.h>
10#include <asm/segment.h>
11#include <asm/page_types.h>
12#include <asm/asm-offsets.h>
13#include <asm/processor-flags.h>
14
15.text
16
17ENTRY(swsusp_arch_suspend)
18	movl %esp, saved_context_esp
19	movl %ebx, saved_context_ebx
20	movl %ebp, saved_context_ebp
21	movl %esi, saved_context_esi
22	movl %edi, saved_context_edi
23	pushfl
24	popl saved_context_eflags
25
26	call swsusp_save
27	ret
28
29ENTRY(restore_image)
30	movl	mmu_cr4_features, %ecx
31	movl	resume_pg_dir, %eax
32	subl	$__PAGE_OFFSET, %eax
33	movl	%eax, %cr3
34
35	jecxz	1f	# cr4 Pentium and higher, skip if zero
36	andl	$~(X86_CR4_PGE), %ecx
37	movl	%ecx, %cr4;  # turn off PGE
38	movl	%cr3, %eax;  # flush TLB
39	movl	%eax, %cr3
401:
41	movl	restore_pblist, %edx
42	.p2align 4,,7
43
44copy_loop:
45	testl	%edx, %edx
46	jz	done
47
48	movl	pbe_address(%edx), %esi
49	movl	pbe_orig_address(%edx), %edi
50
51	movl	$1024, %ecx
52	rep
53	movsl
54
55	movl	pbe_next(%edx), %edx
56	jmp	copy_loop
57	.p2align 4,,7
58
59done:
60	/* go back to the original page tables */
61	movl	$swapper_pg_dir, %eax
62	subl	$__PAGE_OFFSET, %eax
63	movl	%eax, %cr3
64	movl	mmu_cr4_features, %ecx
65	jecxz	1f	# cr4 Pentium and higher, skip if zero
66	movl	%ecx, %cr4;  # turn PGE back on
671:
68
69	movl saved_context_esp, %esp
70	movl saved_context_ebp, %ebp
71	movl saved_context_ebx, %ebx
72	movl saved_context_esi, %esi
73	movl saved_context_edi, %edi
74
75	pushl saved_context_eflags
76	popfl
77
78	/* Saved in save_processor_state. */
79	movl $saved_context, %eax
80	lgdt saved_context_gdt_desc(%eax)
81
82	xorl	%eax, %eax
83
84	ret
85