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authorMihai Caraman <mihai.caraman@freescale.com>2012-08-06 03:27:07 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-09-05 15:35:52 +1000
commit8b64a9dfb091f1eca8b7e58da82f1e7d1d5fe0ad (patch)
tree9d0bfd7ecd07c02fef68e7b198a0560340bf0846 /arch/powerpc/mm
parent79b5c8dbaa4528a6fd03a4d9d8a6d56a46293a3a (diff)
downloadlinux-8b64a9dfb091f1eca8b7e58da82f1e7d1d5fe0ad.tar.bz2
powerpc/booke64: Use SPRG0/3 scratch for bolted TLB miss & crit int
Embedded.Hypervisor category defines GSPRG0..3 physical registers for guests. Avoid SPRG4-7 usage as scratch in host exception handlers, otherwise guest SPRG4-7 registers will be clobbered. For bolted TLB miss exception handlers, which is the version currently supported by KVM, use SPRN_SPRG_GEN_SCRATCH aka SPRG0 instead of SPRN_SPRG_TLB_SCRATCH aka SPRG6. Keep using TLB PACA slots to fit in one 64-byte cache line. For critical exception handlers use SPRG3 instead of SPRG7. Provide a routine to store and restore user-visible SPRGs. This will be subsequently used to restore VDSO information in SPRG3. Add EX_R13 to paca slots to free up SPRG3 and change the critical exception epilog to use it. Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/mm')
-rw-r--r--arch/powerpc/mm/tlb_low_64e.S4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/powerpc/mm/tlb_low_64e.S b/arch/powerpc/mm/tlb_low_64e.S
index d884fa44d34f..b4113bf86353 100644
--- a/arch/powerpc/mm/tlb_low_64e.S
+++ b/arch/powerpc/mm/tlb_low_64e.S
@@ -40,7 +40,7 @@
**********************************************************************/
.macro tlb_prolog_bolted intnum addr
- mtspr SPRN_SPRG_TLB_SCRATCH,r13
+ mtspr SPRN_SPRG_GEN_SCRATCH,r13
mfspr r13,SPRN_SPRG_PACA
std r10,PACA_EXTLB+EX_TLB_R10(r13)
mfcr r10
@@ -69,7 +69,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)
ld r15,PACA_EXTLB+EX_TLB_R15(r13)
TLB_MISS_RESTORE_STATS_BOLTED
ld r16,PACA_EXTLB+EX_TLB_R16(r13)
- mfspr r13,SPRN_SPRG_TLB_SCRATCH
+ mfspr r13,SPRN_SPRG_GEN_SCRATCH
.endm
/* Data TLB miss */