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* [PATCH] powerpc: Fix determining TI_CPU in power_save_ppc32_restore()
@ 2008-08-26  1:59 Kumar Gala
  2008-08-26  2:10 ` Kumar Gala
  2008-08-26  4:37 ` Benjamin Herrenschmidt
  0 siblings, 2 replies; 3+ messages in thread
From: Kumar Gala @ 2008-08-26  1:59 UTC (permalink / raw)
  To: Paul Mackerras; +Cc: linuxppc-dev, G.Chen

The calculation to get TI_CPU based off of SPRG3 was just plain wrong.
Since we already have thread_info in r9 there is no reason to bother
to figure it out again.

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

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

Paul, this is in for-2.6.27 branch.

- k

 arch/powerpc/kernel/idle_6xx.S  |   13 +++++++------
 arch/powerpc/kernel/idle_e500.S |   11 ++++++-----
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/kernel/idle_6xx.S b/arch/powerpc/kernel/idle_6xx.S
index 019b02d..0138d88 100644
--- a/arch/powerpc/kernel/idle_6xx.S
+++ b/arch/powerpc/kernel/idle_6xx.S
@@ -151,19 +151,20 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
  * Return from NAP/DOZE mode, restore some CPU specific registers,
  * we are called with DR/IR still off and r2 containing physical
  * address of current.  R11 points to the exception frame (physical
- * address).  We have to preserve r10.
+ * address).  We have to preserve r10.  R9 contains the physical
+ * address of thread_info.
  */
 _GLOBAL(power_save_ppc32_restore)
-	lwz	r9,_LINK(r11)		/* interrupted in ppc6xx_idle: */
-	stw	r9,_NIP(r11)		/* make it do a blr */
-
 #ifdef CONFIG_SMP
-	mfspr	r12,SPRN_SPRG3
-	lwz	r11,TI_CPU(r12)		/* get cpu number * 4 */
+	lwz	r11,TI_CPU(r9)		/* get cpu number * 4 */
 	slwi	r11,r11,2
 #else
 	li	r11,0
 #endif
+
+	lwz	r9,_LINK(r11)		/* interrupted in ppc6xx_idle: */
+	stw	r9,_NIP(r11)		/* make it do a blr */
+
 	/* Todo make sure all these are in the same page
 	 * and load r11 (@ha part + CPU offset) only once
 	 */
diff --git a/arch/powerpc/kernel/idle_e500.S b/arch/powerpc/kernel/idle_e500.S
index 0630403..c9d7234 100644
--- a/arch/powerpc/kernel/idle_e500.S
+++ b/arch/powerpc/kernel/idle_e500.S
@@ -76,18 +76,19 @@ END_FTR_SECTION_IFSET(CPU_FTR_L2CSR|CPU_FTR_CAN_NAP)
 /*
  * Return from NAP/DOZE mode, restore some CPU specific registers,
  * r2 containing physical address of current.
+ * r9 points to thread_info
  * r11 points to the exception frame (physical address).
  * We have to preserve r10.
  */
 _GLOBAL(power_save_ppc32_restore)
-	lwz	r9,_LINK(r11)		/* interrupted in e500_idle */
-	stw	r9,_NIP(r11)		/* make it do a blr */
-
 #ifdef CONFIG_SMP
-	mfspr	r12,SPRN_SPRG3
-	lwz	r11,TI_CPU(r12)		/* get cpu number * 4 */
+	lwz	r11,TI_CPU(r9)		/* get cpu number * 4 */
 	slwi	r11,r11,2
 #else
 	li	r11,0
 #endif
+
+	lwz	r9,_LINK(r11)		/* interrupted in e500_idle */
+	stw	r9,_NIP(r11)		/* make it do a blr */
+
 	b	transfer_to_handler_cont
-- 
1.5.5.1

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] powerpc: Fix determining TI_CPU in power_save_ppc32_restore()
  2008-08-26  1:59 [PATCH] powerpc: Fix determining TI_CPU in power_save_ppc32_restore() Kumar Gala
@ 2008-08-26  2:10 ` Kumar Gala
  2008-08-26  4:37 ` Benjamin Herrenschmidt
  1 sibling, 0 replies; 3+ messages in thread
From: Kumar Gala @ 2008-08-26  2:10 UTC (permalink / raw)
  To: Kumar Gala; +Cc: linuxppc-dev, G.Chen, Paul Mackerras

> diff --git a/arch/powerpc/kernel/idle_6xx.S b/arch/powerpc/kernel/ 
> idle_6xx.S
> index 019b02d..0138d88 100644
> --- a/arch/powerpc/kernel/idle_6xx.S
> +++ b/arch/powerpc/kernel/idle_6xx.S
> @@ -151,19 +151,20 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
>  * Return from NAP/DOZE mode, restore some CPU specific registers,
>  * we are called with DR/IR still off and r2 containing physical
>  * address of current.  R11 points to the exception frame (physical
> - * address).  We have to preserve r10.
> + * address).  We have to preserve r10.  R9 contains the physical
> + * address of thread_info.
>  */
> _GLOBAL(power_save_ppc32_restore)
> -	lwz	r9,_LINK(r11)		/* interrupted in ppc6xx_idle: */
> -	stw	r9,_NIP(r11)		/* make it do a blr */
> -
> #ifdef CONFIG_SMP
> -	mfspr	r12,SPRN_SPRG3
> -	lwz	r11,TI_CPU(r12)		/* get cpu number * 4 */
> +	lwz	r11,TI_CPU(r9)		/* get cpu number * 4 */
> 	slwi	r11,r11,2
> #else
> 	li	r11,0
> #endif
> +
> +	lwz	r9,_LINK(r11)		/* interrupted in ppc6xx_idle: */
> +	stw	r9,_NIP(r11)		/* make it do a blr */
> +

this is just brain damaged as I'm clobber r11 before setting up r9  
with LR.  V2 of the patch does things right.

- k

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] powerpc: Fix determining TI_CPU in power_save_ppc32_restore()
  2008-08-26  1:59 [PATCH] powerpc: Fix determining TI_CPU in power_save_ppc32_restore() Kumar Gala
  2008-08-26  2:10 ` Kumar Gala
@ 2008-08-26  4:37 ` Benjamin Herrenschmidt
  1 sibling, 0 replies; 3+ messages in thread
From: Benjamin Herrenschmidt @ 2008-08-26  4:37 UTC (permalink / raw)
  To: Kumar Gala; +Cc: linuxppc-dev, G.Chen, Paul Mackerras


>  #ifdef CONFIG_SMP
> -	mfspr	r12,SPRN_SPRG3
> -	lwz	r11,TI_CPU(r12)		/* get cpu number * 4 */
> +	lwz	r11,TI_CPU(r9)		/* get cpu number * 4 */
>  	slwi	r11,r11,2
>  #else
>  	li	r11,0
>  #endif
> +
> +	lwz	r9,_LINK(r11)		/* interrupted in ppc6xx_idle: */
> +	stw	r9,_NIP(r11)		/* make it do a blr */
> +

hrm... you just clobbered r11, won't work very well :-)

Ben.

>  	/* Todo make sure all these are in the same page
>  	 * and load r11 (@ha part + CPU offset) only once
>  	 */
> diff --git a/arch/powerpc/kernel/idle_e500.S b/arch/powerpc/kernel/idle_e500.S
> index 0630403..c9d7234 100644
> --- a/arch/powerpc/kernel/idle_e500.S
> +++ b/arch/powerpc/kernel/idle_e500.S
> @@ -76,18 +76,19 @@ END_FTR_SECTION_IFSET(CPU_FTR_L2CSR|CPU_FTR_CAN_NAP)
>  /*
>   * Return from NAP/DOZE mode, restore some CPU specific registers,
>   * r2 containing physical address of current.
> + * r9 points to thread_info
>   * r11 points to the exception frame (physical address).
>   * We have to preserve r10.
>   */
>  _GLOBAL(power_save_ppc32_restore)
> -	lwz	r9,_LINK(r11)		/* interrupted in e500_idle */
> -	stw	r9,_NIP(r11)		/* make it do a blr */
> -
>  #ifdef CONFIG_SMP
> -	mfspr	r12,SPRN_SPRG3
> -	lwz	r11,TI_CPU(r12)		/* get cpu number * 4 */
> +	lwz	r11,TI_CPU(r9)		/* get cpu number * 4 */
>  	slwi	r11,r11,2
>  #else
>  	li	r11,0
>  #endif
> +
> +	lwz	r9,_LINK(r11)		/* interrupted in e500_idle */
> +	stw	r9,_NIP(r11)		/* make it do a blr */
> +
>  	b	transfer_to_handler_cont

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2008-08-26  4:37 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2008-08-26  1:59 [PATCH] powerpc: Fix determining TI_CPU in power_save_ppc32_restore() Kumar Gala
2008-08-26  2:10 ` Kumar Gala
2008-08-26  4:37 ` Benjamin Herrenschmidt

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