* [PATCH 1/3] powerpc/mm: Respect _PAGE_COHERENT on classic ppc32 SW TLB load machines @ 2009-03-16 11:53 Kumar Gala 2009-03-16 11:53 ` [PATCH 2/3] powerpc/mm: Remove unused register usage in SW TLB miss handling Kumar Gala 0 siblings, 1 reply; 3+ messages in thread From: Kumar Gala @ 2009-03-16 11:53 UTC (permalink / raw) Cc: linuxppc-dev Since we now set _PAGE_COHERENT in the Linux PTE we shouldn't be clearing it out before we setup the SW TLB. Today all the SW TLB machines (603/e300) that we support are non-SMP, however there are some errata on some devices that cause us to set _PAGE_COHERENT via CPU_FTR_NEED_COHERENT. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> --- Note: I've only compiled tested this and not booted on real HW. - k arch/powerpc/kernel/head_32.S | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S index f8c2e6b..6da5505 100644 --- a/arch/powerpc/kernel/head_32.S +++ b/arch/powerpc/kernel/head_32.S @@ -514,7 +514,7 @@ InstructionTLBMiss: 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 */ - ori r1,r1,0xe14 /* clear out reserved bits and M */ + ori r1,r1,0xe04 /* clear out reserved bits */ andc r1,r3,r1 /* PP = user? (rw&dirty? 2: 3): 0 */ mtspr SPRN_RPA,r1 mfspr r3,SPRN_IMISS @@ -588,7 +588,7 @@ DataLoadTLBMiss: 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 */ - ori r1,r1,0xe14 /* clear out reserved bits and M */ + ori r1,r1,0xe04 /* clear out reserved bits */ andc r1,r3,r1 /* PP = user? (rw&dirty? 2: 3): 0 */ mtspr SPRN_RPA,r1 mfspr r3,SPRN_DMISS @@ -656,7 +656,7 @@ DataStoreTLBMiss: stw r3,0(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 */ - li r1,0xe15 /* clear out reserved bits and M */ + li r1,0xe05 /* clear out reserved bits & PP lsb */ andc r1,r3,r1 /* PP = user? 2: 0 */ mtspr SPRN_RPA,r1 mfspr r3,SPRN_DMISS -- 1.5.6.6 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 2/3] powerpc/mm: Remove unused register usage in SW TLB miss handling 2009-03-16 11:53 [PATCH 1/3] powerpc/mm: Respect _PAGE_COHERENT on classic ppc32 SW TLB load machines Kumar Gala @ 2009-03-16 11:53 ` Kumar Gala 2009-03-16 11:53 ` [RFC][PATCH 3/3] powerpc/mm: Used free register to save a few cycles " Kumar Gala 0 siblings, 1 reply; 3+ messages in thread From: Kumar Gala @ 2009-03-16 11:53 UTC (permalink / raw) Cc: linuxppc-dev 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> --- Note: I've only compiled tested this and not booted on real HW. - k arch/powerpc/kernel/head_32.S | 11 +++-------- 1 files changed, 3 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S index 6da5505..aafb469 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 */ @@ -528,7 +527,6 @@ 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 @@ -549,12 +547,11 @@ 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 */ @@ -601,7 +598,6 @@ 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 */ @@ -621,12 +617,11 @@ 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 */ -- 1.5.6.6 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* [RFC][PATCH 3/3] powerpc/mm: Used free register to save a few cycles in SW TLB miss handling 2009-03-16 11:53 ` [PATCH 2/3] powerpc/mm: Remove unused register usage in SW TLB miss handling Kumar Gala @ 2009-03-16 11:53 ` Kumar Gala 0 siblings, 0 replies; 3+ messages in thread From: Kumar Gala @ 2009-03-16 11:53 UTC (permalink / raw) Cc: linuxppc-dev 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> --- There might be better uses of the free r0 to save more cycles in these code paths. If anyone has suggestions I'm willing to look at them. - k arch/powerpc/kernel/head_32.S | 51 +++++++++++++++++++--------------------- 1 files changed, 24 insertions(+), 27 deletions(-) diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S index aafb469..b6c5955 100644 --- a/arch/powerpc/kernel/head_32.S +++ b/arch/powerpc/kernel/head_32.S @@ -498,25 +498,24 @@ 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 */ mtspr SPRN_RPA,r1 - mfspr r3,SPRN_IMISS tlbli r3 mfspr r3,SPRN_SRR1 /* Need to restore CR0 */ mtcrf 0x80,r3 @@ -570,25 +569,24 @@ 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 */ mtspr SPRN_RPA,r1 - mfspr r3,SPRN_DMISS tlbld r3 mfspr r3,SPRN_SRR1 /* Need to restore CR0 */ mtcrf 0x80,r3 @@ -640,21 +638,20 @@ 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 */ mtspr SPRN_RPA,r1 - mfspr r3,SPRN_DMISS tlbld r3 mfspr r3,SPRN_SRR1 /* Need to restore CR0 */ mtcrf 0x80,r3 -- 1.5.6.6 ^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2009-03-16 11:54 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2009-03-16 11:53 [PATCH 1/3] powerpc/mm: Respect _PAGE_COHERENT on classic ppc32 SW TLB load machines Kumar Gala 2009-03-16 11:53 ` [PATCH 2/3] powerpc/mm: Remove unused register usage in SW TLB miss handling Kumar Gala 2009-03-16 11:53 ` [RFC][PATCH 3/3] powerpc/mm: Used free register to save a few cycles " Kumar Gala
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