summaryrefslogtreecommitdiffstats
path: root/arch/arm/kernel/sleep.S
blob: bfad698a02e75a3e4e34069a5b67e580e7edc3a4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
#include <linux/linkage.h>
#include <linux/threads.h>
#include <asm/asm-offsets.h>
#include <asm/assembler.h>
#include <asm/glue-cache.h>
#include <asm/glue-proc.h>
#include <asm/system.h>
	.text

/*
 * Save CPU state for a suspend
 *  r1 = v:p offset
 *  r3 = virtual return function
 * Note: sp is decremented to allocate space for CPU state on stack
 * r0-r3,r9,r10,lr corrupted
 */
ENTRY(cpu_suspend)
	mov	r9, lr
#ifdef MULTI_CPU
	ldr	r10, =processor
	mov	r2, sp			@ current virtual SP
	ldr	r0, [r10, #CPU_SLEEP_SIZE] @ size of CPU sleep state
	ldr	ip, [r10, #CPU_DO_RESUME] @ virtual resume function
	sub	sp, sp, r0		@ allocate CPU state on stack
	mov	r0, sp			@ save pointer
	add	ip, ip, r1		@ convert resume fn to phys
	stmfd	sp!, {r1, r2, r3, ip}	@ save v:p, virt SP, retfn, phys resume fn
	ldr	r3, =sleep_save_sp
	add	r2, sp, r1		@ convert SP to phys
#ifdef CONFIG_SMP
	ALT_SMP(mrc p15, 0, lr, c0, c0, 5)
	ALT_UP(mov lr, #0)
	and	lr, lr, #15
	str	r2, [r3, lr, lsl #2]	@ save phys SP
#else
	str	r2, [r3]		@ save phys SP
#endif
	mov	lr, pc
	ldr	pc, [r10, #CPU_DO_SUSPEND] @ save CPU state
#else
	mov	r2, sp			@ current virtual SP
	ldr	r0, =cpu_suspend_size
	sub	sp, sp, r0		@ allocate CPU state on stack
	mov	r0, sp			@ save pointer
	stmfd	sp!, {r1, r2, r3}	@ save v:p, virt SP, return fn
	ldr	r3, =sleep_save_sp
	add	r2, sp, r1		@ convert SP to phys
#ifdef CONFIG_SMP
	ALT_SMP(mrc p15, 0, lr, c0, c0, 5)
	ALT_UP(mov lr, #0)
	and	lr, lr, #15
	str	r2, [r3, lr, lsl #2]	@ save phys SP
#else
	str	r2, [r3]		@ save phys SP
#endif
	bl	cpu_do_suspend
#endif

	@ flush data cache
#ifdef MULTI_CACHE
	ldr	r10, =cpu_cache
	mov	lr, r9
	ldr	pc, [r10, #CACHE_FLUSH_KERN_ALL]
#else
	mov	lr, r9
	b	__cpuc_flush_kern_all
#endif
ENDPROC(cpu_suspend)
	.ltorg

/*
 * r0 = control register value
 * r1 = v:p offset (preserved by cpu_do_resume)
 * r2 = phys page table base
 * r3 = L1 section flags
 */
ENTRY(cpu_resume_mmu)
	adr	r4, cpu_resume_turn_mmu_on
	mov	r4, r4, lsr #20
	orr	r3, r3, r4, lsl #20
	ldr	r5, [r2, r4, lsl #2]	@ save old mapping
	str	r3, [r2, r4, lsl #2]	@ setup 1:1 mapping for mmu code
	sub	r2, r2, r1
	ldr	r3, =cpu_resume_after_mmu
	bic	r1, r0, #CR_C		@ ensure D-cache is disabled
	b	cpu_resume_turn_mmu_on
ENDPROC(cpu_resume_mmu)
	.ltorg
	.align	5
cpu_resume_turn_mmu_on:
	mcr	p15, 0, r1, c1, c0, 0	@ turn on MMU, I-cache, etc
	mrc	p15, 0, r1, c0, c0, 0	@ read id reg
	mov	r1, r1
	mov	r1, r1
	mov	pc, r3			@ jump to virtual address
ENDPROC(cpu_resume_turn_mmu_on)
cpu_resume_after_mmu:
	str	r5, [r2, r4, lsl #2]	@ restore old mapping
	mcr	p15, 0, r0, c1, c0, 0	@ turn on D-cache
	mov	pc, lr
ENDPROC(cpu_resume_after_mmu)

/*
 * Note: Yes, part of the following code is located into the .data section.
 *       This is to allow sleep_save_sp to be accessed with a relative load
 *       while we can't rely on any MMU translation.  We could have put
 *       sleep_save_sp in the .text section as well, but some setups might
 *       insist on it to be truly read-only.
 */
	.data
	.align
ENTRY(cpu_resume)
#ifdef CONFIG_SMP
	adr	r0, sleep_save_sp
	ALT_SMP(mrc p15, 0, r1, c0, c0, 5)
	ALT_UP(mov r1, #0)
	and	r1, r1, #15
	ldr	r0, [r0, r1, lsl #2]	@ stack phys addr
#else
	ldr	r0, sleep_save_sp	@ stack phys addr
#endif
	msr	cpsr_c, #PSR_I_BIT | PSR_F_BIT | SVC_MODE @ set SVC, irqs off
#ifdef MULTI_CPU
	ldmia	r0!, {r1, sp, lr, pc}	@ load v:p, stack, return fn, resume fn
#else
	ldmia	r0!, {r1, sp, lr}	@ load v:p, stack, return fn
	b	cpu_do_resume
#endif
ENDPROC(cpu_resume)

sleep_save_sp:
	.rept	CONFIG_NR_CPUS
	.long	0				@ preserve stack phys ptr here
	.endr
OpenPOWER on IntegriCloud