[PATCH v2] powerpc: Fix determining TI_CPU in power_save_ppc32_restore()

[PATCH v2] powerpc: Fix determining TI_CPU in power_save_ppc32_restore()

[Kumar Gala]

The calculation to get TI_CPU based off of SPRG3 was just plain wrong.
Just offset off the stack pointer (to get to thread_info) like all the
other references to TI_CPU do.

This was pointed out by Chen Gong <G.Chen@freescale.com>

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---

The first version was just brain damaged.  This version should be cleaner and
doesn't assume anything about the call site having r9 setup already.

(updated for-2.6.27 w/this and rebased to top of linus).

- k

 arch/powerpc/kernel/idle_6xx.S  |    3 ++-
 arch/powerpc/kernel/idle_e500.S |    3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/idle_6xx.S b/arch/powerpc/kernel/idle_6xx.S
index 019b02d..6dfcdb6 100644
--- a/arch/powerpc/kernel/idle_6xx.S
+++ b/arch/powerpc/kernel/idle_6xx.S
@@ -158,7 +158,8 @@ _GLOBAL(power_save_ppc32_restore)
 	stw	r9,_NIP(r11)		/* make it do a blr */
 
 #ifdef CONFIG_SMP
-	mfspr	r12,SPRN_SPRG3
+	rlwinm	r12,r1,0,0,31-THREAD_SHIFT
+	tophys(r12,r12)			/* check local flags */
 	lwz	r11,TI_CPU(r12)		/* get cpu number * 4 */
 	slwi	r11,r11,2
 #else
diff --git a/arch/powerpc/kernel/idle_e500.S b/arch/powerpc/kernel/idle_e500.S
index 0630403..47a1a98 100644
--- a/arch/powerpc/kernel/idle_e500.S
+++ b/arch/powerpc/kernel/idle_e500.S
@@ -84,10 +84,11 @@ _GLOBAL(power_save_ppc32_restore)
 	stw	r9,_NIP(r11)		/* make it do a blr */
 
 #ifdef CONFIG_SMP
-	mfspr	r12,SPRN_SPRG3
+	rlwinm	r12,r1,0,0,31-THREAD_SHIFT
 	lwz	r11,TI_CPU(r12)		/* get cpu number * 4 */
 	slwi	r11,r11,2
 #else
 	li	r11,0
 #endif
+
 	b	transfer_to_handler_cont
-- 
1.5.5.1

Re: [PATCH v2] powerpc: Fix determining TI_CPU in power_save_ppc32_restore()

[Benjamin Herrenschmidt]

On Mon, 2008-08-25 at 21:08 -0500, Kumar Gala wrote:
> The calculation to get TI_CPU based off of SPRG3 was just plain wrong.
> Just offset off the stack pointer (to get to thread_info) like all the
> other references to TI_CPU do.
> 
> This was pointed out by Chen Gong <G.Chen@freescale.com>
> 
> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Re: [PATCH v2] powerpc: Fix determining TI_CPU in power_save_ppc32_restore()

[Kumar Gala]

On Aug 25, 2008, at 11:39 PM, Benjamin Herrenschmidt wrote:

> On Mon, 2008-08-25 at 21:08 -0500, Kumar Gala wrote:
>> The calculation to get TI_CPU based off of SPRG3 was just plain  
>> wrong.
>> Just offset off the stack pointer (to get to thread_info) like all  
>> the
>> other references to TI_CPU do.
>>
>> This was pointed out by Chen Gong <G.Chen@freescale.com>
>>
>> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
>
> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Paul, you picking this up for 2.6.27?

- k