Commit abda1bd5 authored by Russell King's avatar Russell King
Browse files

ARM: pm: convert some assembly to C 



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: default avatarSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: default avatarShawn Guo <shawn.guo@linaro.org>
Tested-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 62b2d07c

arch/arm/include/asm/proc-fns.h

+8 −0
Original line number Diff line number Diff line
@@ -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);

arch/arm/kernel/sleep.S

+17 −36
Original line number Diff line number Diff line
@@ -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)

arch/arm/kernel/suspend.c

+21 −3
Original line number Diff line number Diff line
@@ -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();

CRA Git | Maintained and supported by SUSTech CRA and CCSE