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#include <asm/frame.h>
16
17.text
18
19SYM_FUNC_START(swsusp_arch_suspend)
20 movl %esp, saved_context_esp
21 movl %ebx, saved_context_ebx
22 movl %ebp, saved_context_ebp
23 movl %esi, saved_context_esi
24 movl %edi, saved_context_edi
25 pushfl
26 popl saved_context_eflags
27
28 /* save cr3 */
29 movl %cr3, %eax
30 movl %eax, restore_cr3
31
32 FRAME_BEGIN
33 call swsusp_save
34 FRAME_END
35 RET
36SYM_FUNC_END(swsusp_arch_suspend)
37
38SYM_CODE_START(restore_image)
39 /* prepare to jump to the image kernel */
40 movl restore_jump_address, %ebx
41 movl restore_cr3, %ebp
42
43 movl mmu_cr4_features, %ecx
44
45 /* jump to relocated restore code */
46 movl relocated_restore_code, %eax
47 jmpl *%eax
48SYM_CODE_END(restore_image)
49
50/* code below has been relocated to a safe page */
51SYM_CODE_START(core_restore_code)
52 movl temp_pgt, %eax
53 movl %eax, %cr3
54
55 jecxz 1f # cr4 Pentium and higher, skip if zero
56 andl $~(X86_CR4_PGE), %ecx
57 movl %ecx, %cr4; # turn off PGE
58 movl %cr3, %eax; # flush TLB
59 movl %eax, %cr3
601:
61 movl restore_pblist, %edx
62 .p2align 4,,7
63
64copy_loop:
65 testl %edx, %edx
66 jz done
67
68 movl pbe_address(%edx), %esi
69 movl pbe_orig_address(%edx), %edi
70
71 movl $(PAGE_SIZE >> 2), %ecx
72 rep
73 movsl
74
75 movl pbe_next(%edx), %edx
76 jmp copy_loop
77 .p2align 4,,7
78
79done:
80 jmpl *%ebx
81SYM_CODE_END(core_restore_code)
82
83 /* code below belongs to the image kernel */
84 .align PAGE_SIZE
85SYM_FUNC_START(restore_registers)
86 /* go back to the original page tables */
87 movl %ebp, %cr3
88 movl mmu_cr4_features, %ecx
89 jecxz 1f # cr4 Pentium and higher, skip if zero
90 movl %ecx, %cr4; # turn PGE back on
911:
92
93 movl saved_context_esp, %esp
94 movl saved_context_ebp, %ebp
95 movl saved_context_ebx, %ebx
96 movl saved_context_esi, %esi
97 movl saved_context_edi, %edi
98
99 pushl saved_context_eflags
100 popfl
101
102 /* Saved in save_processor_state. */
103 movl $saved_context, %eax
104 lgdt saved_context_gdt_desc(%eax)
105
106 xorl %eax, %eax
107
108 /* tell the hibernation core that we've just restored the memory */
109 movl %eax, in_suspend
110
111 RET
112SYM_FUNC_END(restore_registers)
113

source code of linux/arch/x86/power/hibernate_asm_32.S