From 293c2e27b999e431ad5f9df3386bea37b18fce53 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Fri, 28 Jun 2019 16:33:22 +1000 Subject: [PATCH] powerpc/64s/exception: simplify hmi control flow Branch to the relocated 0xc000 address early (still in real mode), to simplify subsequent branches. Have the virt mode handler avoid just 'windup' and redo the exception from scratch, rather than branching back to the trampoline. Rearrange the stack setup instruction location to match the system reset handler (e.g., right before EXCEPTION_PROLOG_COMMON). Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/exceptions-64s.S | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index c6e1d1a88701..eee5bef736c8 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -260,17 +260,6 @@ END_FTR_SECTION_NESTED(ftr,ftr,943) mtctr reg; \ bctr -#ifdef CONFIG_RELOCATABLE -#define BRANCH_LINK_TO_FAR(label) \ - __LOAD_FAR_HANDLER(r12, label); \ - mtctr r12; \ - bctrl - -#else -#define BRANCH_LINK_TO_FAR(label) \ - bl label -#endif - #ifdef CONFIG_KVM_BOOK3S_64_HANDLER #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE /* @@ -1713,22 +1702,26 @@ EXC_REAL_BEGIN(hmi_exception, 0xe60, 0x20) EXCEPTION_PROLOG_0 PACA_EXGEN b hmi_exception_early EXC_REAL_END(hmi_exception, 0xe60, 0x20) -__TRAMP_REAL_OOL_MASKABLE_HV(hmi_exception, 0xe60, IRQS_DISABLED) EXC_VIRT_NONE(0x4e60, 0x20) TRAMP_KVM_HV(PACA_EXGEN, 0xe60) TRAMP_REAL_BEGIN(hmi_exception_early) EXCEPTION_PROLOG_1 EXC_HV, PACA_EXGEN, 1, 0xe60, 0, 0, 0 + mfctr r10 /* save ctr, even for !RELOCATABLE */ + BRANCH_TO_C000(r11, hmi_exception_early_common) + +EXC_COMMON_BEGIN(hmi_exception_early_common) + mtctr r10 /* Restore ctr */ + mfspr r11,SPRN_HSRR0 /* Save HSRR0 */ + mfspr r12,SPRN_HSRR1 /* Save HSRR1 */ mr r10,r1 /* Save r1 */ ld r1,PACAEMERGSP(r13) /* Use emergency stack for realmode */ subi r1,r1,INT_FRAME_SIZE /* alloc stack frame */ - mfspr r11,SPRN_HSRR0 /* Save HSRR0 */ - mfspr r12,SPRN_HSRR1 /* Save HSRR1 */ EXCEPTION_PROLOG_COMMON_1() /* We don't touch AMR here, we never go to virtual mode */ EXCEPTION_PROLOG_COMMON_2(PACA_EXGEN) EXCEPTION_PROLOG_COMMON_3(0xe60) addi r3,r1,STACK_FRAME_OVERHEAD - BRANCH_LINK_TO_FAR(DOTSYM(hmi_exception_realmode)) /* Function call ABI */ + bl hmi_exception_realmode cmpdi cr0,r3,0 bne 1f @@ -1742,7 +1735,8 @@ TRAMP_REAL_BEGIN(hmi_exception_early) */ EXCEPTION_RESTORE_REGS EXC_HV EXCEPTION_PROLOG_0 PACA_EXGEN - b tramp_real_hmi_exception + EXCEPTION_PROLOG_1 EXC_HV, PACA_EXGEN, 1, 0xe60, 0, 0, IRQS_DISABLED + EXCEPTION_PROLOG_2_REAL hmi_exception_common, EXC_HV, 1 EXC_COMMON_BEGIN(hmi_exception_common) EXCEPTION_COMMON(PACA_EXGEN, 0xe60)