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authorMagnus Damm <damm@igel.co.jp>2009-08-17 09:27:29 +0000
committerPaul Mundt <lethal@linux-sh.org>2009-08-18 10:17:29 +0900
commit309214af53f030e0664aea011a9f628c5eb9cc2d (patch)
tree9a84da7f3d9f017850afbf4b51d4d247edf26534 /arch/sh/kernel/cpu
parentcd7246f0e2747bd2b43d25d0f63f05db182a62c0 (diff)
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: Magnus Damm <damm@igel.co.jp> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/kernel/cpu')
-rw-r--r--arch/sh/kernel/cpu/shmobile/pm.c16
-rw-r--r--arch/sh/kernel/cpu/shmobile/sleep.S155
2 files changed, 107 insertions, 64 deletions
diff --git a/arch/sh/kernel/cpu/shmobile/pm.c b/arch/sh/kernel/cpu/shmobile/pm.c
index de078d24ce5..ee3c2aaf66f 100644
--- a/arch/sh/kernel/cpu/shmobile/pm.c
+++ b/arch/sh/kernel/cpu/shmobile/pm.c
@@ -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)
diff --git a/arch/sh/kernel/cpu/shmobile/sleep.S b/arch/sh/kernel/cpu/shmobile/sleep.S
index baf2d7d46b0..a439e6c7824 100644
--- a/arch/sh/kernel/cpu/shmobile/sleep.S
+++ b/arch/sh/kernel/cpu/shmobile/sleep.S
@@ -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" */
- mov #0x10, r1
+ 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: