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ARM: pm: convert some assembly to C

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Convert some of the sleep.S guts to C code, which makes it easier to
use our macros and to add L2 cache handling.  We provide a helper
function, __cpu_suspend_save(), which deals with saving the common
state, setting up for resume, and flushing caches.

The remainder left as assembly code is the saving of the CPU general
purpose registers, and allocating space on the stack to save the CPU
specific registers and resume state.

Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2011-09-01 11:52:33 +01:00
parent 62b2d07c0e
commit abda1bd5f4
3 changed files with 46 additions and 39 deletions
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8
arch/arm/include/asm/proc-fns.h
View File

@ -81,6 +81,10 @@ extern void cpu_dcache_clean_area(void *, int);
extern void cpu_do_switch_mm(unsigned long pgd_phys, struct mm_struct *mm);
extern void cpu_set_pte_ext(pte_t *ptep, pte_t pte, unsigned int ext);
extern void cpu_reset(unsigned long addr) __attribute__((noreturn));
/* These three are private to arch/arm/kernel/suspend.c */
extern void cpu_do_suspend(void *);
extern void cpu_do_resume(void *);
#else
#define cpu_proc_init processor._proc_init
#define cpu_proc_fin processor._proc_fin
@ -89,6 +93,10 @@ extern void cpu_reset(unsigned long addr) __attribute__((noreturn));
#define cpu_dcache_clean_area processor.dcache_clean_area
#define cpu_set_pte_ext processor.set_pte_ext
#define cpu_do_switch_mm processor.switch_mm
/* These three are private to arch/arm/kernel/suspend.c */
#define cpu_do_suspend processor.do_suspend
#define cpu_do_resume processor.do_resume
#endif
extern void cpu_resume(void);

53
arch/arm/kernel/sleep.S
View File

@ -8,54 +8,35 @@
.text
/*
* Save CPU state for a suspend
* r0 = phys addr of temporary page tables
* r1 = v:p offset
* r2 = suspend function arg0
* r3 = suspend function
* Save CPU state for a suspend. This saves the CPU general purpose
* registers, and allocates space on the kernel stack to save the CPU
* specific registers and some other data for resume.
* r0 = suspend function arg0
* r1 = suspend function
*/
ENTRY(__cpu_suspend)
stmfd sp!, {r4 - r11, lr}
mov r4, r0
#ifdef MULTI_CPU
ldr r10, =processor
ldr r5, [r10, #CPU_SLEEP_SIZE] @ size of CPU sleep state
ldr ip, [r10, #CPU_DO_RESUME] @ virtual resume function
ldr r4, [r10, #CPU_SLEEP_SIZE] @ size of CPU sleep state
#else
ldr r5, =cpu_suspend_size
ldr ip, =cpu_do_resume
ldr r4, =cpu_suspend_size
#endif
mov r6, sp @ current virtual SP
sub sp, sp, r5 @ allocate CPU state on stack
mov r0, sp @ save pointer to CPU save block
add ip, ip, r1 @ convert resume fn to phys
stmfd sp!, {r4, r6, ip} @ save phys pgd, virt SP, phys resume fn
ldr r5, =sleep_save_sp
add r6, sp, r1 @ convert SP to phys
stmfd sp!, {r2, r3} @ save suspend func arg and pointer
mov r5, sp @ current virtual SP
add r4, r4, #12 @ Space for pgd, virt sp, phys resume fn
sub sp, sp, r4 @ allocate CPU state on stack
stmfd sp!, {r0, r1} @ save suspend func arg and pointer
add r0, sp, #8 @ save pointer to save block
mov r1, r4 @ size of save block
mov r2, r5 @ virtual SP
ldr r3, =sleep_save_sp
#ifdef CONFIG_SMP
ALT_SMP(mrc p15, 0, lr, c0, c0, 5)
ALT_UP(mov lr, #0)
and lr, lr, #15
str r6, [r5, lr, lsl #2] @ save phys SP
#else
str r6, [r5] @ save phys SP
#endif
#ifdef MULTI_CPU
mov lr, pc
ldr pc, [r10, #CPU_DO_SUSPEND] @ save CPU state
#else
bl cpu_do_suspend
#endif
@ flush data cache
#ifdef MULTI_CACHE
ldr r10, =cpu_cache
mov lr, pc
ldr pc, [r10, #CACHE_FLUSH_KERN_ALL]
#else
bl __cpuc_flush_kern_all
add r3, r3, lr, lsl #2
#endif
bl __cpu_suspend_save
adr lr, BSYM(cpu_suspend_abort)
ldmfd sp!, {r0, pc} @ call suspend fn
ENDPROC(__cpu_suspend)

24
arch/arm/kernel/suspend.c
View File

@ -8,9 +8,28 @@
static pgd_t *suspend_pgd;
extern int __cpu_suspend(int, long, unsigned long, int (*)(unsigned long));
extern int __cpu_suspend(unsigned long, int (*)(unsigned long));
extern void cpu_resume_mmu(void);
/*
* This is called by __cpu_suspend() to save the state, and do whatever
* flushing is required to ensure that when the CPU goes to sleep we have
* the necessary data available when the caches are not searched.
*/
void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr)
{
*save_ptr = virt_to_phys(ptr);
/* This must correspond to the LDM in cpu_resume() assembly */
*ptr++ = virt_to_phys(suspend_pgd);
*ptr++ = sp;
*ptr++ = virt_to_phys(cpu_do_resume);
cpu_do_suspend(ptr);
flush_cache_all();
}
/*
* Hide the first two arguments to __cpu_suspend - these are an implementation
* detail which platform code shouldn't have to know about.
@ -29,8 +48,7 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
* resume (indicated by a zero return code), we need to switch
* back to the correct page tables.
*/
ret = __cpu_suspend(virt_to_phys(suspend_pgd),
PHYS_OFFSET - PAGE_OFFSET, arg, fn);
ret = __cpu_suspend(arg, fn);
if (ret == 0) {
cpu_switch_mm(mm->pgd, mm);
local_flush_tlb_all();