diff mbox

powerpc: Use 32 bit loads and stores when operating on condition register values

Message ID 20131015143631.1879607c@kryten (mailing list archive)
State Accepted, archived
Headers show

Commit Message

Anton Blanchard Oct. 15, 2013, 3:36 a.m. UTC 
The condition register (CR) is a 32 bit quantity so we should use
32 bit loads and stores.

Signed-off-by: Anton Blanchard <anton@samba.org>
---

Comments

Paul Mackerras Oct. 15, 2013, 3:42 a.m. UTC | #1 
On Tue, Oct 15, 2013 at 02:36:31PM +1100, Anton Blanchard wrote:
> 
> The condition register (CR) is a 32 bit quantity so we should use
> 32 bit loads and stores.

Does this make any practical difference or fix any bugs, or is this
just for aesthetics?

Paul.
Anton Blanchard Oct. 15, 2013, 3:55 a.m. UTC | #2 
Hi Paul,

> Does this make any practical difference or fix any bugs, or is this
> just for aesthetics?

There is talk of the other 32 bits of that word being used for a
stack canary in a future ABI revision. So right now it is just
cosmetic, but it could be important in the future.

I guess it could be an issue for kgdb since the CR will be in
the wrong spot on BE.

Anton
diff mbox

Patch

diff --git a/arch/powerpc/kernel/tm.S b/arch/powerpc/kernel/tm.S
index cd809ea..432cf54 100644
--- a/arch/powerpc/kernel/tm.S
+++ b/arch/powerpc/kernel/tm.S
@@ -107,7 +107,7 @@  DSCR_DEFAULT:
 _GLOBAL(tm_reclaim)
 	mfcr	r6
 	mflr	r0
-	std	r6, 8(r1)
+	stw	r6, 8(r1)
 	std	r0, 16(r1)
 	std	r2, 40(r1)
 	stdu	r1, -TM_FRAME_SIZE(r1)
@@ -284,7 +284,7 @@  dont_backup_fp:
 	REST_NVGPRS(r1)
 
 	addi    r1, r1, TM_FRAME_SIZE
-	ld	r4, 8(r1)
+	lwz	r4, 8(r1)
 	ld	r0, 16(r1)
 	mtcr	r4
 	mtlr	r0
@@ -309,7 +309,7 @@  dont_backup_fp:
 _GLOBAL(tm_recheckpoint)
 	mfcr	r5
 	mflr	r0
-	std	r5, 8(r1)
+	stw	r5, 8(r1)
 	std	r0, 16(r1)
 	std	r2, 40(r1)
 	stdu	r1, -TM_FRAME_SIZE(r1)
@@ -441,7 +441,7 @@  restore_gprs:
 	REST_NVGPRS(r1)
 
 	addi    r1, r1, TM_FRAME_SIZE
-	ld	r4, 8(r1)
+	lwz	r4, 8(r1)
 	ld	r0, 16(r1)
 	mtcr	r4
 	mtlr	r0
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
index 8f38445..2acc226 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -24,7 +24,7 @@ 
 	mflr	r0;			\
 	mfcr	r12;			\
 	std	r0,16(r1);		\
-	std	r12,8(r1);		\
+	stw	r12,8(r1);		\
 	std	r1,PACAR1(r13);		\
 	li	r0,0;			\
 	mfmsr	r12;			\
@@ -46,7 +46,7 @@ 
 
 _STATIC(opal_return)
 	ld	r2,PACATOC(r13);
-	ld	r4,8(r1);
+	lwz	r4,8(r1);
 	ld	r5,16(r1);
 	ld	r6,PACASAVEDMSR(r13);
 	mtspr	SPRN_SRR0,r5;