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authorKumar Gala <galak@kernel.crashing.org>2009-03-19 03:55:39 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-03-24 13:47:31 +1100
commit00fcb14703d8322a9c66cb3f48b5c49ac7d43f0a (patch)
treee23dd5504897c5dc75d2dc839ef84dfd56c6ff6b /arch/powerpc/kernel/head_32.S
parent4ae0ff606e848fa4957ebf8f97e5db5fdeec27be (diff)
powerpc/mm: Remove unused register usage in SW TLB miss handling
Long ago we had some code that actually used the CTR in the SW TLB miss handlers (603/e300). Since we don't use it no reason to waste cycles saving it off and restoring it (we actually didn't restore it in the fast path case). Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/head_32.S')
-rw-r--r--arch/powerpc/kernel/head_32.S11
1 files changed, 3 insertions, 8 deletions
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index d0bad4b93a9..f37df0c3afb 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -475,12 +475,11 @@ SystemCall:
. = 0x1000
InstructionTLBMiss:
/*
- * r0: stored ctr
+ * r0: scratch
* r1: linux style pte ( later becomes ppc hardware pte )
* r2: ptr to linux-style pte
* r3: scratch
*/
- mfctr r0
/* Get PTE (linux-style) and check access */
mfspr r3,SPRN_IMISS
lis r1,PAGE_OFFSET@h /* check if kernel address */
@@ -531,7 +530,6 @@ InstructionAddressInvalid:
addis r1,r1,0x2000
mtspr SPRN_DSISR,r1 /* (shouldn't be needed) */
- mtctr r0 /* Restore CTR */
andi. r2,r3,0xFFFF /* Clear upper bits of SRR1 */
or r2,r2,r1
mtspr SPRN_SRR1,r2
@@ -552,12 +550,11 @@ InstructionAddressInvalid:
. = 0x1100
DataLoadTLBMiss:
/*
- * r0: stored ctr
+ * r0: scratch
* r1: linux style pte ( later becomes ppc hardware pte )
* r2: ptr to linux-style pte
* r3: scratch
*/
- mfctr r0
/* Get PTE (linux-style) and check access */
mfspr r3,SPRN_DMISS
lis r1,PAGE_OFFSET@h /* check if kernel address */
@@ -607,7 +604,6 @@ DataAddressInvalid:
rlwinm r1,r3,9,6,6 /* Get load/store bit */
addis r1,r1,0x2000
mtspr SPRN_DSISR,r1
- mtctr r0 /* Restore CTR */
andi. r2,r3,0xFFFF /* Clear upper bits of SRR1 */
mtspr SPRN_SRR1,r2
mfspr r1,SPRN_DMISS /* Get failing address */
@@ -627,12 +623,11 @@ DataAddressInvalid:
. = 0x1200
DataStoreTLBMiss:
/*
- * r0: stored ctr
+ * r0: scratch
* r1: linux style pte ( later becomes ppc hardware pte )
* r2: ptr to linux-style pte
* r3: scratch
*/
- mfctr r0
/* Get PTE (linux-style) and check access */
mfspr r3,SPRN_DMISS
lis r1,PAGE_OFFSET@h /* check if kernel address */