From 7c28f04828dc8321cb234b2ad57266b9f902add0 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Sun, 21 May 2017 23:15:43 +1000 Subject: [PATCH] powerpc/64s: Avoid saving faulting address into EX_DAR in SLB miss The EX_DAR save area is only used in exceptional cases. With r3 no longer clobbered by slb_allocate_realmode, saving faulting address to EX_DAR can be deferred to those cases. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/exceptions-64s.S | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 64365907cddc..fe3bc52aadf8 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -631,7 +631,6 @@ EXC_COMMON_BEGIN(slb_miss_realmode) stw r9,PACA_EXSLB+EX_CCR(r13) /* save CR in exc. frame */ std r10,PACA_EXSLB+EX_LR(r13) /* save LR */ - std r3,PACA_EXSLB+EX_DAR(r13) crset 4*cr0+eq #ifdef CONFIG_PPC_STD_MMU_64 @@ -641,11 +640,10 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX) #endif ld r10,PACA_EXSLB+EX_LR(r13) - ld r3,PACA_EXSLB+EX_R3(r13) lwz r9,PACA_EXSLB+EX_CCR(r13) /* get saved CR */ mtlr r10 - beq 8f /* if bad address, make full stack frame */ + beq- 8f /* if bad address, make full stack frame */ andi. r10,r12,MSR_RI /* check for unrecoverable exception */ beq- 2f @@ -660,6 +658,7 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX) .machine pop RESTORE_PPR_PACA(PACA_EXSLB, r9) + ld r3,PACA_EXSLB+EX_R3(r13) ld r9,PACA_EXSLB+EX_R9(r13) ld r10,PACA_EXSLB+EX_R10(r13) ld r11,PACA_EXSLB+EX_R11(r13) @@ -668,7 +667,9 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX) rfid b . /* prevent speculative execution */ -2: mfspr r11,SPRN_SRR0 +2: std r3,PACA_EXSLB+EX_DAR(r13) + ld r3,PACA_EXSLB+EX_R3(r13) + mfspr r11,SPRN_SRR0 LOAD_HANDLER(r10,unrecov_slb) mtspr SPRN_SRR0,r10 ld r10,PACAKMSR(r13) @@ -676,7 +677,9 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX) rfid b . -8: mfspr r11,SPRN_SRR0 +8: std r3,PACA_EXSLB+EX_DAR(r13) + ld r3,PACA_EXSLB+EX_R3(r13) + mfspr r11,SPRN_SRR0 LOAD_HANDLER(r10,bad_addr_slb) mtspr SPRN_SRR0,r10 ld r10,PACAKMSR(r13) -- 2.39.2