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authorKumar Gala <galak@kernel.crashing.org>2009-03-19 03:55:40 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-03-24 13:47:31 +1100
commiteb3436a0139a651a39dbb37a75b10a2cccd00ad5 (patch)
treeb3925f180d0a7e80b76476694db42bb338db4d6c /arch/powerpc/kernel/head_32.S
parent00fcb14703d8322a9c66cb3f48b5c49ac7d43f0a (diff)
downloadop-kernel-dev-eb3436a0139a651a39dbb37a75b10a2cccd00ad5.zip
op-kernel-dev-eb3436a0139a651a39dbb37a75b10a2cccd00ad5.tar.gz
powerpc/mm: Used free register to save a few cycles in SW TLB miss handling
Now that r0 is free we can keep the value of I/DMISS in r3 and not reload it before doing the tlbli/d. This saves us a few cycles 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.S51
1 files changed, 24 insertions, 27 deletions
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index f37df0c..58dcc7c 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -498,28 +498,27 @@ InstructionTLBMiss:
rlwinm. r2,r2,0,0,19 /* extract address of pte page */
beq- InstructionAddressInvalid /* return if no mapping */
rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
- lwz r3,0(r2) /* get linux-style pte */
- andc. r1,r1,r3 /* check access & ~permission */
+ lwz r0,0(r2) /* get linux-style pte */
+ andc. r1,r1,r0 /* check access & ~permission */
bne- InstructionAddressInvalid /* return if access not permitted */
- ori r3,r3,_PAGE_ACCESSED /* set _PAGE_ACCESSED in pte */
+ ori r0,r0,_PAGE_ACCESSED /* set _PAGE_ACCESSED in pte */
/*
* NOTE! We are assuming this is not an SMP system, otherwise
* we would need to update the pte atomically with lwarx/stwcx.
*/
- stw r3,0(r2) /* update PTE (accessed bit) */
+ stw r0,0(r2) /* update PTE (accessed bit) */
/* Convert linux-style PTE to low word of PPC-style PTE */
- rlwinm r1,r3,32-10,31,31 /* _PAGE_RW -> PP lsb */
- rlwinm r2,r3,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
+ rlwinm r1,r0,32-10,31,31 /* _PAGE_RW -> PP lsb */
+ rlwinm r2,r0,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
and r1,r1,r2 /* writable if _RW and _DIRTY */
- rlwimi r3,r3,32-1,30,30 /* _PAGE_USER -> PP msb */
- rlwimi r3,r3,32-1,31,31 /* _PAGE_USER -> PP lsb */
+ rlwimi r0,r0,32-1,30,30 /* _PAGE_USER -> PP msb */
+ rlwimi r0,r0,32-1,31,31 /* _PAGE_USER -> PP lsb */
ori r1,r1,0xe04 /* clear out reserved bits */
- andc r1,r3,r1 /* PP = user? (rw&dirty? 2: 3): 0 */
+ andc r1,r0,r1 /* PP = user? (rw&dirty? 2: 3): 0 */
BEGIN_FTR_SECTION
rlwinm r1,r1,0,~_PAGE_COHERENT /* clear M (coherence not required) */
END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
mtspr SPRN_RPA,r1
- mfspr r3,SPRN_IMISS
tlbli r3
mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
mtcrf 0x80,r3
@@ -573,28 +572,27 @@ DataLoadTLBMiss:
rlwinm. r2,r2,0,0,19 /* extract address of pte page */
beq- DataAddressInvalid /* return if no mapping */
rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
- lwz r3,0(r2) /* get linux-style pte */
- andc. r1,r1,r3 /* check access & ~permission */
+ lwz r0,0(r2) /* get linux-style pte */
+ andc. r1,r1,r0 /* check access & ~permission */
bne- DataAddressInvalid /* return if access not permitted */
- ori r3,r3,_PAGE_ACCESSED /* set _PAGE_ACCESSED in pte */
+ ori r0,r0,_PAGE_ACCESSED /* set _PAGE_ACCESSED in pte */
/*
* NOTE! We are assuming this is not an SMP system, otherwise
* we would need to update the pte atomically with lwarx/stwcx.
*/
- stw r3,0(r2) /* update PTE (accessed bit) */
+ stw r0,0(r2) /* update PTE (accessed bit) */
/* Convert linux-style PTE to low word of PPC-style PTE */
- rlwinm r1,r3,32-10,31,31 /* _PAGE_RW -> PP lsb */
- rlwinm r2,r3,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
+ rlwinm r1,r0,32-10,31,31 /* _PAGE_RW -> PP lsb */
+ rlwinm r2,r0,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
and r1,r1,r2 /* writable if _RW and _DIRTY */
- rlwimi r3,r3,32-1,30,30 /* _PAGE_USER -> PP msb */
- rlwimi r3,r3,32-1,31,31 /* _PAGE_USER -> PP lsb */
+ rlwimi r0,r0,32-1,30,30 /* _PAGE_USER -> PP msb */
+ rlwimi r0,r0,32-1,31,31 /* _PAGE_USER -> PP lsb */
ori r1,r1,0xe04 /* clear out reserved bits */
- andc r1,r3,r1 /* PP = user? (rw&dirty? 2: 3): 0 */
+ andc r1,r0,r1 /* PP = user? (rw&dirty? 2: 3): 0 */
BEGIN_FTR_SECTION
rlwinm r1,r1,0,~_PAGE_COHERENT /* clear M (coherence not required) */
END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
mtspr SPRN_RPA,r1
- mfspr r3,SPRN_DMISS
tlbld r3
mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
mtcrf 0x80,r3
@@ -646,24 +644,23 @@ DataStoreTLBMiss:
rlwinm. r2,r2,0,0,19 /* extract address of pte page */
beq- DataAddressInvalid /* return if no mapping */
rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
- lwz r3,0(r2) /* get linux-style pte */
- andc. r1,r1,r3 /* check access & ~permission */
+ lwz r0,0(r2) /* get linux-style pte */
+ andc. r1,r1,r0 /* check access & ~permission */
bne- DataAddressInvalid /* return if access not permitted */
- ori r3,r3,_PAGE_ACCESSED|_PAGE_DIRTY
+ ori r0,r0,_PAGE_ACCESSED|_PAGE_DIRTY
/*
* NOTE! We are assuming this is not an SMP system, otherwise
* we would need to update the pte atomically with lwarx/stwcx.
*/
- stw r3,0(r2) /* update PTE (accessed/dirty bits) */
+ stw r0,0(r2) /* update PTE (accessed/dirty bits) */
/* Convert linux-style PTE to low word of PPC-style PTE */
- rlwimi r3,r3,32-1,30,30 /* _PAGE_USER -> PP msb */
+ rlwimi r0,r0,32-1,30,30 /* _PAGE_USER -> PP msb */
li r1,0xe05 /* clear out reserved bits & PP lsb */
- andc r1,r3,r1 /* PP = user? 2: 0 */
+ andc r1,r0,r1 /* PP = user? 2: 0 */
BEGIN_FTR_SECTION
rlwinm r1,r1,0,~_PAGE_COHERENT /* clear M (coherence not required) */
END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
mtspr SPRN_RPA,r1
- mfspr r3,SPRN_DMISS
tlbld r3
mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
mtcrf 0x80,r3
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