1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Hibernation support for x86-64
4 *
5 * Copyright 2007 Rafael J. Wysocki <rjw@sisk.pl>
6 * Copyright 2005 Andi Kleen <ak@suse.de>
7 * Copyright 2004 Pavel Machek <pavel@suse.cz>
8 *
9 * swsusp_arch_resume must not use any stack or any nonlocal variables while
10 * copying pages:
11 *
12 * Its rewriting one kernel image with another. What is stack in "old"
13 * image could very well be data page in "new" image, and overwriting
14 * your own stack under you is bad idea.
15 */
16
17	.text
18#include <linux/linkage.h>
19#include <asm/segment.h>
20#include <asm/page_types.h>
21#include <asm/asm-offsets.h>
22#include <asm/processor-flags.h>
23#include <asm/frame.h>
24
25ENTRY(swsusp_arch_suspend)
26	movq	$saved_context, %rax
27	movq	%rsp, pt_regs_sp(%rax)
28	movq	%rbp, pt_regs_bp(%rax)
29	movq	%rsi, pt_regs_si(%rax)
30	movq	%rdi, pt_regs_di(%rax)
31	movq	%rbx, pt_regs_bx(%rax)
32	movq	%rcx, pt_regs_cx(%rax)
33	movq	%rdx, pt_regs_dx(%rax)
34	movq	%r8, pt_regs_r8(%rax)
35	movq	%r9, pt_regs_r9(%rax)
36	movq	%r10, pt_regs_r10(%rax)
37	movq	%r11, pt_regs_r11(%rax)
38	movq	%r12, pt_regs_r12(%rax)
39	movq	%r13, pt_regs_r13(%rax)
40	movq	%r14, pt_regs_r14(%rax)
41	movq	%r15, pt_regs_r15(%rax)
42	pushfq
43	popq	pt_regs_flags(%rax)
44
45	/* save cr3 */
46	movq	%cr3, %rax
47	movq	%rax, restore_cr3(%rip)
48
49	FRAME_BEGIN
50	call swsusp_save
51	FRAME_END
52	ret
53ENDPROC(swsusp_arch_suspend)
54
55ENTRY(restore_image)
56	/* prepare to jump to the image kernel */
57	movq	restore_jump_address(%rip), %r8
58	movq	restore_cr3(%rip), %r9
59
60	/* prepare to switch to temporary page tables */
61	movq	temp_pgt(%rip), %rax
62	movq	mmu_cr4_features(%rip), %rbx
63
64	/* prepare to copy image data to their original locations */
65	movq	restore_pblist(%rip), %rdx
66
67	/* jump to relocated restore code */
68	movq	relocated_restore_code(%rip), %rcx
69	jmpq	*%rcx
70
71	/* code below has been relocated to a safe page */
72ENTRY(core_restore_code)
73	/* switch to temporary page tables */
74	movq	%rax, %cr3
75	/* flush TLB */
76	movq	%rbx, %rcx
77	andq	$~(X86_CR4_PGE), %rcx
78	movq	%rcx, %cr4;  # turn off PGE
79	movq	%cr3, %rcx;  # flush TLB
80	movq	%rcx, %cr3;
81	movq	%rbx, %cr4;  # turn PGE back on
82.Lloop:
83	testq	%rdx, %rdx
84	jz	.Ldone
85
86	/* get addresses from the pbe and copy the page */
87	movq	pbe_address(%rdx), %rsi
88	movq	pbe_orig_address(%rdx), %rdi
89	movq	$(PAGE_SIZE >> 3), %rcx
90	rep
91	movsq
92
93	/* progress to the next pbe */
94	movq	pbe_next(%rdx), %rdx
95	jmp	.Lloop
96
97.Ldone:
98	/* jump to the restore_registers address from the image header */
99	jmpq	*%r8
100
101	 /* code below belongs to the image kernel */
102	.align PAGE_SIZE
103ENTRY(restore_registers)
104	/* go back to the original page tables */
105	movq    %r9, %cr3
106
107	/* Flush TLB, including "global" things (vmalloc) */
108	movq	mmu_cr4_features(%rip), %rax
109	movq	%rax, %rdx
110	andq	$~(X86_CR4_PGE), %rdx
111	movq	%rdx, %cr4;  # turn off PGE
112	movq	%cr3, %rcx;  # flush TLB
113	movq	%rcx, %cr3
114	movq	%rax, %cr4;  # turn PGE back on
115
116	/* We don't restore %rax, it must be 0 anyway */
117	movq	$saved_context, %rax
118	movq	pt_regs_sp(%rax), %rsp
119	movq	pt_regs_bp(%rax), %rbp
120	movq	pt_regs_si(%rax), %rsi
121	movq	pt_regs_di(%rax), %rdi
122	movq	pt_regs_bx(%rax), %rbx
123	movq	pt_regs_cx(%rax), %rcx
124	movq	pt_regs_dx(%rax), %rdx
125	movq	pt_regs_r8(%rax), %r8
126	movq	pt_regs_r9(%rax), %r9
127	movq	pt_regs_r10(%rax), %r10
128	movq	pt_regs_r11(%rax), %r11
129	movq	pt_regs_r12(%rax), %r12
130	movq	pt_regs_r13(%rax), %r13
131	movq	pt_regs_r14(%rax), %r14
132	movq	pt_regs_r15(%rax), %r15
133	pushq	pt_regs_flags(%rax)
134	popfq
135
136	/* Saved in save_processor_state. */
137	lgdt	saved_context_gdt_desc(%rax)
138
139	xorl	%eax, %eax
140
141	/* tell the hibernation core that we've just restored the memory */
142	movq	%rax, in_suspend(%rip)
143
144	ret
145ENDPROC(restore_registers)
146