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
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 the address of restore_registers */
46	movq	$restore_registers, %rax
47	movq	%rax, restore_jump_address(%rip)
48	/* save cr3 */
49	movq	%cr3, %rax
50	movq	%rax, restore_cr3(%rip)
51
52	call swsusp_save
53	ret
54
55ENTRY(restore_image)
56	/* switch to temporary page tables */
57	movq	$__PAGE_OFFSET, %rdx
58	movq	temp_level4_pgt(%rip), %rax
59	subq	%rdx, %rax
60	movq	%rax, %cr3
61	/* Flush TLB */
62	movq	mmu_cr4_features(%rip), %rax
63	movq	%rax, %rdx
64	andq	$~(X86_CR4_PGE), %rdx
65	movq	%rdx, %cr4;  # turn off PGE
66	movq	%cr3, %rcx;  # flush TLB
67	movq	%rcx, %cr3;
68	movq	%rax, %cr4;  # turn PGE back on
69
70	/* prepare to jump to the image kernel */
71	movq	restore_jump_address(%rip), %rax
72	movq	restore_cr3(%rip), %rbx
73
74	/* prepare to copy image data to their original locations */
75	movq	restore_pblist(%rip), %rdx
76	movq	relocated_restore_code(%rip), %rcx
77	jmpq	*%rcx
78
79	/* code below has been relocated to a safe page */
80ENTRY(core_restore_code)
81loop:
82	testq	%rdx, %rdx
83	jz	done
84
85	/* get addresses from the pbe and copy the page */
86	movq	pbe_address(%rdx), %rsi
87	movq	pbe_orig_address(%rdx), %rdi
88	movq	$(PAGE_SIZE >> 3), %rcx
89	rep
90	movsq
91
92	/* progress to the next pbe */
93	movq	pbe_next(%rdx), %rdx
94	jmp	loop
95done:
96	/* jump to the restore_registers address from the image header */
97	jmpq	*%rax
98	/*
99	 * NOTE: This assumes that the boot kernel's text mapping covers the
100	 * image kernel's page containing restore_registers and the address of
101	 * this page is the same as in the image kernel's text mapping (it
102	 * should always be true, because the text mapping is linear, starting
103	 * from 0, and is supposed to cover the entire kernel text for every
104	 * kernel).
105	 *
106	 * code below belongs to the image kernel
107	 */
108
109ENTRY(restore_registers)
110	/* go back to the original page tables */
111	movq    %rbx, %cr3
112
113	/* Flush TLB, including "global" things (vmalloc) */
114	movq	mmu_cr4_features(%rip), %rax
115	movq	%rax, %rdx
116	andq	$~(X86_CR4_PGE), %rdx
117	movq	%rdx, %cr4;  # turn off PGE
118	movq	%cr3, %rcx;  # flush TLB
119	movq	%rcx, %cr3
120	movq	%rax, %cr4;  # turn PGE back on
121
122	/* We don't restore %rax, it must be 0 anyway */
123	movq	$saved_context, %rax
124	movq	pt_regs_sp(%rax), %rsp
125	movq	pt_regs_bp(%rax), %rbp
126	movq	pt_regs_si(%rax), %rsi
127	movq	pt_regs_di(%rax), %rdi
128	movq	pt_regs_bx(%rax), %rbx
129	movq	pt_regs_cx(%rax), %rcx
130	movq	pt_regs_dx(%rax), %rdx
131	movq	pt_regs_r8(%rax), %r8
132	movq	pt_regs_r9(%rax), %r9
133	movq	pt_regs_r10(%rax), %r10
134	movq	pt_regs_r11(%rax), %r11
135	movq	pt_regs_r12(%rax), %r12
136	movq	pt_regs_r13(%rax), %r13
137	movq	pt_regs_r14(%rax), %r14
138	movq	pt_regs_r15(%rax), %r15
139	pushq	pt_regs_flags(%rax)
140	popfq
141
142	/* Saved in save_processor_state. */
143	lgdt	saved_context_gdt_desc(%rax)
144
145	xorq	%rax, %rax
146
147	/* tell the hibernation core that we've just restored the memory */
148	movq	%rax, in_suspend(%rip)
149
150	ret
151