Commit 309214af authored by Magnus Damm's avatar Magnus Damm Committed by Paul Mundt
Browse files

sh: rework SuperH Mobile sleep code exception handling 



This patch updates the exception handling in the sleep code
for SuperH Mobile. With the patch applied the sleep code
always rewrites the VBR and resumes from the exception vector,
re-initializes hardware and jumps straight to the original
interrupt vector.

Tested on sh7722 and sh7724 with "Sleep Mode", "Sleep Mode + SF"
and "Software Standby Mode + SF" with CONFIG_SUSPEND.

Signed-off-by: default avatarMagnus Damm <damm@igel.co.jp>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent cd7246f0

arch/sh/kernel/cpu/shmobile/pm.c

+2 −14
Original line number Diff line number Diff line
@@ -41,23 +41,11 @@ extern const unsigned int sh_mobile_standby_size; 


void sh_mobile_call_standby(unsigned long mode)

{

	extern void *vbr_base;

	void *onchip_mem = (void *)ILRAM_BASE;

	void (*standby_onchip_mem)(unsigned long) = onchip_mem;



	/* Note: Wake up from sleep may generate exceptions!

	 * Setup VBR to point to on-chip ram if self-refresh is

	 * going to be used.

	 */

	if (mode & SUSP_SH_SF)

		asm volatile("ldc %0, vbr" : : "r" (onchip_mem) : "memory");

	void (*standby_onchip_mem)(unsigned long, unsigned long) = onchip_mem;



	/* Let assembly snippet in on-chip memory handle the rest */

	standby_onchip_mem(mode);



	/* Put VBR back in System RAM again */

	if (mode & SUSP_SH_SF)

		asm volatile("ldc %0, vbr" : : "r" (&vbr_base) : "memory");

	standby_onchip_mem(mode, ILRAM_BASE);

}



static int sh_pm_enter(suspend_state_t state)

arch/sh/kernel/cpu/shmobile/sleep.S

+105 −50
Original line number Diff line number Diff line
@@ -16,19 +16,52 @@ 
#include <asm/asm-offsets.h>

#include <asm/suspend.h>



/*

 * Kernel mode register usage, see entry.S:

 *	k0	scratch

 *	k1	scratch

 *	k4	scratch

 */

#define k0	r0

#define k1	r1

#define k4	r4



/* manage self-refresh and enter standby mode.

 * this code will be copied to on-chip memory and executed from there.

 */



	.balign 	4096,0,4096

ENTRY(sh_mobile_standby)



	/* save original vbr */

	stc	vbr, r1

	mova	saved_vbr, r0

	mov.l	r1, @r0



	/* point vbr to our on-chip memory page */

	ldc	r5, vbr



	/* save return address */

	mova	saved_spc, r0

	sts	pr, r5

	mov.l	r5, @r0



	/* save sr */

	mova	saved_sr, r0

	stc	sr, r5

	mov.l	r5, @r0



	/* save mode flags */

	mova	saved_mode, r0

	mov.l	r4, @r0



	/* put mode flags in r0 */

	mov	r4, r0



	tst	#SUSP_SH_SF, r0

	bt	skip_set_sf

#ifdef CONFIG_CPU_SUBTYPE_SH7724

	/* DBSC: put memory in self-refresh mode */



	mov.l	dben_reg, r4

	mov.l	dben_data0, r1

	mov.l	r1, @r4
@@ -60,14 +93,6 @@ ENTRY(sh_mobile_standby) 
#endif



skip_set_sf:

	tst	#SUSP_SH_SLEEP, r0

	bt	test_standby



	/* set mode to "sleep mode" */

	bra	do_sleep

	 mov	#0x00, r1



test_standby:

	tst	#SUSP_SH_STANDBY, r0

	bt	test_rstandby
@@ -85,77 +110,107 @@ test_rstandby: 


test_ustandby:

	tst	#SUSP_SH_USTANDBY, r0

	bt	done_sleep

	bt	force_sleep



	/* set mode to "u-standby mode" */

	bra	do_sleep

	 mov	#0x10, r1



	/* fall-through */

force_sleep:



	/* set mode to "sleep mode" */

	mov	#0x00, r1



do_sleep:

	/* setup and enter selected standby mode */

	mov.l	5f, r4

	mov.l	r1, @r4

again:

	sleep

	bra	again

	 nop



restore_jump_vbr:

	/* setup spc with return address to c code */

	mov.l	saved_spc, k0

	ldc	k0, spc



	/* restore vbr */

	mov.l	saved_vbr, k0

	ldc	k0, vbr



	/* setup ssr with saved sr */

	mov.l	saved_sr, k0

	ldc	k0, ssr



	/* get mode flags */

	mov.l	saved_mode, k0



done_sleep:

	/* reset standby mode to sleep mode */

	mov.l	5f, r4

	mov	#0x00, r1

	mov.l	r1, @r4

	mov.l	5f, k4

	mov	#0x00, k1

	mov.l	k1, @k4



	tst	#SUSP_SH_SF, r0

	tst	#SUSP_SH_SF, k0

	bt	skip_restore_sf



#ifdef CONFIG_CPU_SUBTYPE_SH7724

	/* DBSC: put memory in auto-refresh mode */

	mov.l	dbrfpdn0_reg, k4

	mov.l	dbrfpdn0_data0, k1

	mov.l	k1, @k4



	mov.l	dbrfpdn0_reg, r4

	mov.l	dbrfpdn0_data0, r1

	mov.l	r1, @r4



	/* sleep 140 ns */

	nop

	nop /* sleep 140 ns */

	nop

	nop

	nop



	mov.l	dbcmdcnt_reg, r4

	mov.l	dbcmdcnt_data0, r1

	mov.l	r1, @r4

	mov.l	dbcmdcnt_reg, k4

	mov.l	dbcmdcnt_data0, k1

	mov.l	k1, @k4



	mov.l	dbcmdcnt_reg, r4

	mov.l	dbcmdcnt_data1, r1

	mov.l	r1, @r4

	mov.l	dbcmdcnt_reg, k4

	mov.l	dbcmdcnt_data1, k1

	mov.l	k1, @k4



	mov.l	dben_reg, r4

	mov.l	dben_data1, r1

	mov.l	r1, @r4

	mov.l	dben_reg, k4

	mov.l	dben_data1, k1

	mov.l	k1, @k4



	mov.l	dbrfpdn0_reg, r4

	mov.l	dbrfpdn0_data2, r1

	mov.l	r1, @r4

	mov.l	dbrfpdn0_reg, k4

	mov.l	dbrfpdn0_data2, k1

	mov.l	k1, @k4

#else

	/* SBSC: set auto-refresh mode */

	mov.l	1f, r4

	mov.l	@r4, r2

	mov.l   4f, r3

	and	r3, r2

	mov.l	r2, @r4

	mov.l	6f, r4

	mov.l	7f, r1

	mov.l	8f, r2

	mov.l	@r4, r3

	mov	#-1, r4

	add	r4, r3

	or	r2, r3

	mov.l	r3, @r1

	mov.l	1f, k4

	mov.l	@k4, k0

	mov.l   4f, k1

	and	k1, k0

	mov.l	k0, @k4

	mov.l	6f, k4

	mov.l	8f, k0

	mov.l	@k4, k1

	mov	#-1, k4

	add	k4, k1

	or	k1, k0

	mov.l	7f, k1

	mov.l	k0, @k1

#endif

skip_restore_sf:

	rts

	/* jump to vbr vector */

	mov.l	saved_vbr, k0

	mov.l	offset_vbr, k4

	add	k4, k0

	jmp	@k0

	 nop



	.balign 4

saved_mode:	.long	0

saved_spc:	.long	0

saved_sr:	.long	0

saved_vbr:	.long	0

offset_vbr:	.long	0x600

#ifdef CONFIG_CPU_SUBTYPE_SH7724

dben_reg:	.long	0xfd000010 /* DBEN */

dben_data0:	.long	0
@@ -178,12 +233,12 @@ dbcmdcnt_data1: .long 4 
7:	.long   0xfe400018 /* RTCNT */

8:	.long   0xa55a0000





/* interrupt vector @ 0x600 */

	.balign 	0x400,0,0x400

	.long	0xdeadbeef

	.balign 	0x200,0,0x200

	/* sh7722 will end up here in sleep mode */

	rte

	bra	restore_jump_vbr

	 nop

sh_mobile_standby_end:

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