Commit e8856a87 authored by Russell King's avatar Russell King
Browse files

ARM: pm: convert cpu_suspend() to a normal function 



cpu_suspend() has a weird calling method which makes it only possible to
call from assembly code: it returns with a modified stack pointer to
finish the suspend, but on resume, it 'returns' via a provided pointer.

We can make cpu_suspend() appear to be a normal function merely by
swapping the resume pointer argument and the link register.

Do so, and update all callers to take account of this more traditional
behaviour.

Acked-by: default avatarFrank Hofmann <frank.hofmann@tomtom.com>
Tested-by: default avatarKevin Hilman <khilman@ti.com>
Acked-by: default avatarJean Pihet <j-pihet@ti.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent dbc12516

arch/arm/include/asm/system.h

+2 −0
Original line number Diff line number Diff line
@@ -106,6 +106,8 @@ extern void __show_regs(struct pt_regs *); 


extern int cpu_architecture(void);

extern void cpu_init(void);

extern void cpu_suspend(int, long, unsigned long, void (*)(unsigned long));

extern void cpu_resume(void);



void arm_machine_restart(char mode, const char *cmd);

extern void (*arm_pm_restart)(char str, const char *cmd);

arch/arm/kernel/sleep.S

+4 −6
Original line number Diff line number Diff line
@@ -11,13 +11,11 @@ 
 * Save CPU state for a suspend

 *  r1 = v:p offset

 *  r2 = suspend function arg0

 *  r3 = virtual return function

 * Note: sp is decremented to allocate space for CPU state on stack

 * r0-r3,ip,lr corrupted

 *  r3 = suspend function

 * Note: does not return until system resumes

 */

ENTRY(cpu_suspend)

	stmfd	sp!, {r3}

	stmfd	sp!, {r4 - r11}

	stmfd	sp!, {r4 - r11, lr}

#ifdef MULTI_CPU

	ldr	r10, =processor

	ldr	r5, [r10, #CPU_SLEEP_SIZE] @ size of CPU sleep state
@@ -33,7 +31,7 @@ ENTRY(cpu_suspend) 
	stmfd	sp!, {r1, r6, ip}	@ save v:p, virt SP, phys resume fn

	ldr	r5, =sleep_save_sp

	add	r6, sp, r1		@ convert SP to phys

	stmfd	sp!, {r2, lr}		@ save suspend func arg and pointer

	stmfd	sp!, {r2, r3}		@ save suspend func arg and pointer

#ifdef CONFIG_SMP

	ALT_SMP(mrc p15, 0, lr, c0, c0, 5)

	ALT_UP(mov lr, #0)

arch/arm/mach-exynos4/sleep.S

+3 −4
Original line number Diff line number Diff line
@@ -42,16 +42,15 @@ 
ENTRY(s3c_cpu_save)



	stmfd	sp!, { r3 - r12, lr }

	ldr	r3, =resume_with_mmu

	adr	r3, BSYM(exynos4_finish_suspend)

	bl	cpu_suspend

	ldmfd	sp!, { r3 - r12, pc }



exynos4_finish_suspend:

	ldr	r0, =pm_cpu_sleep

	ldr	r0, [ r0 ]

	mov	pc, r0



resume_with_mmu:

	ldmfd	sp!, { r3 - r12, pc }



	.ltorg



	/*

arch/arm/mach-pxa/sleep.S

+10 −3
Original line number Diff line number Diff line
@@ -35,9 +35,11 @@ ENTRY(pxa3xx_cpu_suspend) 
#endif

	stmfd	sp!, {r2 - r12, lr}	@ save registers on stack

	mov	r1, r0

	ldr	r3, =pxa_cpu_resume	@ resume function

	adr	r3, BSYM(pxa3xx_finish_suspend)

	bl	cpu_suspend

	b	pxa_cpu_resume



pxa3xx_finish_suspend:

	mov	r0, #0x06		@ S2D3C4 mode

	mcr	p14, 0, r0, c7, c0, 0	@ enter sleep
@@ -60,9 +62,11 @@ ENTRY(pxa27x_cpu_suspend) 
#endif

	stmfd	sp!, {r2 - r12, lr}		@ save registers on stack

	mov	r2, r0				@ save sleep mode

	ldr	r3, =pxa_cpu_resume		@ resume function

	adr	r3, BSYM(pxa27x_finish_suspend)

	bl	cpu_suspend

	b	pxa_cpu_resume



pxa27x_finish_suspend:

	@ Put the processor to sleep

	@ (also workaround for sighting 28071)
@@ -110,8 +114,11 @@ ENTRY(pxa27x_cpu_suspend) 
ENTRY(pxa25x_cpu_suspend)

	stmfd	sp!, {r2 - r12, lr}		@ save registers on stack

	mov	r2, r0				@ save sleep mode

	ldr	r3, =pxa_cpu_resume		@ resume function

	adr	r3, BSYM(pxa25x_finish_suspend)

	bl	cpu_suspend

	b	pxa_cpu_resume



pxa25x_finish_suspend:

	@ prepare value for sleep mode

	mov	r1, r0				@ sleep mode

arch/arm/mach-s3c64xx/sleep.S

+3 −6
Original line number Diff line number Diff line
@@ -36,18 +36,15 @@ 


ENTRY(s3c_cpu_save)

	stmfd	sp!, { r4 - r12, lr }

	ldr	r3, =resume_with_mmu

	adr	r3, BSYM(s3c64xx_finish_suspend)

	bl	cpu_suspend

	ldmfd	sp!, { r4 - r12, pc }



s3c64xx_finish_suspend:

	@@ call final suspend code

	ldr	r0, =pm_cpu_sleep

	ldr	pc, [r0]

	

	@@ return to the caller, after the MMU is turned on.

	@@ restore the last bits of the stack and return.

resume_with_mmu:

	ldmfd	sp!, { r4 - r12, pc }	@ return, from sp from s3c_cpu_save



	/* Sleep magic, the word before the resume entry point so that the

	 * bootloader can check for a resumeable image. */

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