1/*
2 * Hibernation support for x86-64
3 *
4 * Distribute under GPLv2.
5 *
6 * Copyright 2007 Rafael J. Wysocki <rjw@sisk.pl>
7 * Copyright 2005 Andi Kleen <ak@suse.de>
8 * Copyright 2004 Pavel Machek <pavel@suse.cz>
9 *
10 * swsusp_arch_resume must not use any stack or any nonlocal variables while
11 * copying pages:
12 *
13 * Its rewriting one kernel image with another. What is stack in "old"
14 * image could very well be data page in "new" image, and overwriting
15 * your own stack under you is bad idea.
16 */
17
18	.text
19#include <linux/linkage.h>
20#include <asm/segment.h>
21#include <asm/page_types.h>
22#include <asm/asm-offsets.h>
23#include <asm/processor-flags.h>
24#include <asm/frame.h>
25
26ENTRY(swsusp_arch_suspend)
27	FRAME_BEGIN
28	movq	$saved_context, %rax
29	movq	%rsp, pt_regs_sp(%rax)
30	movq	%rbp, pt_regs_bp(%rax)
31	movq	%rsi, pt_regs_si(%rax)
32	movq	%rdi, pt_regs_di(%rax)
33	movq	%rbx, pt_regs_bx(%rax)
34	movq	%rcx, pt_regs_cx(%rax)
35	movq	%rdx, pt_regs_dx(%rax)
36	movq	%r8, pt_regs_r8(%rax)
37	movq	%r9, pt_regs_r9(%rax)
38	movq	%r10, pt_regs_r10(%rax)
39	movq	%r11, pt_regs_r11(%rax)
40	movq	%r12, pt_regs_r12(%rax)
41	movq	%r13, pt_regs_r13(%rax)
42	movq	%r14, pt_regs_r14(%rax)
43	movq	%r15, pt_regs_r15(%rax)
44	pushfq
45	popq	pt_regs_flags(%rax)
46
47	/* save the address of restore_registers */
48	movq	$restore_registers, %rax
49	movq	%rax, restore_jump_address(%rip)
50	/* save cr3 */
51	movq	%cr3, %rax
52	movq	%rax, restore_cr3(%rip)
53
54	call swsusp_save
55	FRAME_END
56	ret
57ENDPROC(swsusp_arch_suspend)
58
59ENTRY(restore_image)
60	/* switch to temporary page tables */
61	movq	$__PAGE_OFFSET, %rdx
62	movq	temp_level4_pgt(%rip), %rax
63	subq	%rdx, %rax
64	movq	%rax, %cr3
65	/* Flush TLB */
66	movq	mmu_cr4_features(%rip), %rax
67	movq	%rax, %rdx
68	andq	$~(X86_CR4_PGE), %rdx
69	movq	%rdx, %cr4;  # turn off PGE
70	movq	%cr3, %rcx;  # flush TLB
71	movq	%rcx, %cr3;
72	movq	%rax, %cr4;  # turn PGE back on
73
74	/* prepare to jump to the image kernel */
75	movq	restore_jump_address(%rip), %rax
76	movq	restore_cr3(%rip), %rbx
77
78	/* prepare to copy image data to their original locations */
79	movq	restore_pblist(%rip), %rdx
80	movq	relocated_restore_code(%rip), %rcx
81	jmpq	*%rcx
82
83	/* code below has been relocated to a safe page */
84ENTRY(core_restore_code)
85.Lloop:
86	testq	%rdx, %rdx
87	jz	.Ldone
88
89	/* get addresses from the pbe and copy the page */
90	movq	pbe_address(%rdx), %rsi
91	movq	pbe_orig_address(%rdx), %rdi
92	movq	$(PAGE_SIZE >> 3), %rcx
93	rep
94	movsq
95
96	/* progress to the next pbe */
97	movq	pbe_next(%rdx), %rdx
98	jmp	.Lloop
99.Ldone:
100	/* jump to the restore_registers address from the image header */
101	jmpq	*%rax
102	/*
103	 * NOTE: This assumes that the boot kernel's text mapping covers the
104	 * image kernel's page containing restore_registers and the address of
105	 * this page is the same as in the image kernel's text mapping (it
106	 * should always be true, because the text mapping is linear, starting
107	 * from 0, and is supposed to cover the entire kernel text for every
108	 * kernel).
109	 *
110	 * code below belongs to the image kernel
111	 */
112
113ENTRY(restore_registers)
114	FRAME_BEGIN
115	/* go back to the original page tables */
116	movq    %rbx, %cr3
117
118	/* Flush TLB, including "global" things (vmalloc) */
119	movq	mmu_cr4_features(%rip), %rax
120	movq	%rax, %rdx
121	andq	$~(X86_CR4_PGE), %rdx
122	movq	%rdx, %cr4;  # turn off PGE
123	movq	%cr3, %rcx;  # flush TLB
124	movq	%rcx, %cr3
125	movq	%rax, %cr4;  # turn PGE back on
126
127	/* We don't restore %rax, it must be 0 anyway */
128	movq	$saved_context, %rax
129	movq	pt_regs_sp(%rax), %rsp
130	movq	pt_regs_bp(%rax), %rbp
131	movq	pt_regs_si(%rax), %rsi
132	movq	pt_regs_di(%rax), %rdi
133	movq	pt_regs_bx(%rax), %rbx
134	movq	pt_regs_cx(%rax), %rcx
135	movq	pt_regs_dx(%rax), %rdx
136	movq	pt_regs_r8(%rax), %r8
137	movq	pt_regs_r9(%rax), %r9
138	movq	pt_regs_r10(%rax), %r10
139	movq	pt_regs_r11(%rax), %r11
140	movq	pt_regs_r12(%rax), %r12
141	movq	pt_regs_r13(%rax), %r13
142	movq	pt_regs_r14(%rax), %r14
143	movq	pt_regs_r15(%rax), %r15
144	pushq	pt_regs_flags(%rax)
145	popfq
146
147	/* Saved in save_processor_state. */
148	lgdt	saved_context_gdt_desc(%rax)
149
150	xorq	%rax, %rax
151
152	/* tell the hibernation core that we've just restored the memory */
153	movq	%rax, in_suspend(%rip)
154
155	FRAME_END
156	ret
157ENDPROC(restore_registers)
158