1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * This may not use any stack, nor any variable that is not "NoSave":
4 *
5 * Its rewriting one kernel image with another. What is stack in "old"
6 * image could very well be data page in "new" image, and overwriting
7 * your own stack under you is bad idea.
8 */
9
10#include <linux/linkage.h>
11#include <asm/segment.h>
12#include <asm/page_types.h>
13#include <asm/asm-offsets.h>
14#include <asm/processor-flags.h>
15
16.text
17
18ENTRY(swsusp_arch_suspend)
19	movl %esp, saved_context_esp
20	movl %ebx, saved_context_ebx
21	movl %ebp, saved_context_ebp
22	movl %esi, saved_context_esi
23	movl %edi, saved_context_edi
24	pushfl
25	popl saved_context_eflags
26
27	call swsusp_save
28	ret
29
30ENTRY(restore_image)
31	movl	mmu_cr4_features, %ecx
32	movl	resume_pg_dir, %eax
33	subl	$__PAGE_OFFSET, %eax
34	movl	%eax, %cr3
35
36	jecxz	1f	# cr4 Pentium and higher, skip if zero
37	andl	$~(X86_CR4_PGE), %ecx
38	movl	%ecx, %cr4;  # turn off PGE
39	movl	%cr3, %eax;  # flush TLB
40	movl	%eax, %cr3
411:
42	movl	restore_pblist, %edx
43	.p2align 4,,7
44
45copy_loop:
46	testl	%edx, %edx
47	jz	done
48
49	movl	pbe_address(%edx), %esi
50	movl	pbe_orig_address(%edx), %edi
51
52	movl	$1024, %ecx
53	rep
54	movsl
55
56	movl	pbe_next(%edx), %edx
57	jmp	copy_loop
58	.p2align 4,,7
59
60done:
61	/* go back to the original page tables */
62	movl	$swapper_pg_dir, %eax
63	subl	$__PAGE_OFFSET, %eax
64	movl	%eax, %cr3
65	movl	mmu_cr4_features, %ecx
66	jecxz	1f	# cr4 Pentium and higher, skip if zero
67	movl	%ecx, %cr4;  # turn PGE back on
681:
69
70	movl saved_context_esp, %esp
71	movl saved_context_ebp, %ebp
72	movl saved_context_ebx, %ebx
73	movl saved_context_esi, %esi
74	movl saved_context_edi, %edi
75
76	pushl saved_context_eflags
77	popfl
78
79	/* Saved in save_processor_state. */
80	movl $saved_context, %eax
81	lgdt saved_context_gdt_desc(%eax)
82
83	xorl	%eax, %eax
84
85	ret
86