From 8b64a9dfb091f1eca8b7e58da82f1e7d1d5fe0ad Mon Sep 17 00:00:00 2001 From: Mihai Caraman Date: Mon, 6 Aug 2012 03:27:07 +0000 Subject: 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 Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/mm/tlb_low_64e.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/powerpc/mm') diff --git a/arch/powerpc/mm/tlb_low_64e.S b/arch/powerpc/mm/tlb_low_64e.S index d884fa44d34..b4113bf8635 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 */ -- cgit v1.2.3-18-g5258