linux/arch/arm/kernel/sleep.S

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ArmAsm
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#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
setmode PSR_I_BIT | PSR_F_BIT | SVC_MODE, r1 @ set SVC, irqs off
#ifdef MULTI_CPU
@ load v:p, stack, return fn, resume fn
ARM( ldmia r0!, {r1, sp, lr, pc} )
THUMB( ldmia r0!, {r1, r2, r3, r4} )
THUMB( mov sp, r2 )
THUMB( mov lr, r3 )
THUMB( bx r4 )
#else
@ load v:p, stack, return fn
ARM( ldmia r0!, {r1, sp, lr} )
THUMB( ldmia r0!, {r1, r2, lr} )
THUMB( mov sp, r2 )
b cpu_do_resume
#endif
ENDPROC(cpu_resume)
sleep_save_sp:
.rept CONFIG_NR_CPUS
.long 0 @ preserve stack phys ptr here
.endr