From b0a779debd56514b2b5de7617a1643e5dac2d4dd Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Wed, 18 Oct 2006 10:11:22 +1000 Subject: [PATCH] [POWERPC] Make sure interrupt enable gets restored properly The lazy IRQ disable patch missed a couple of places where the interrupt enable flags need to be restored correctly. First, we weren't restoring the paca->hard_enabled flag on interrupt exit. Instead of saving it on entry, we compute it from the MSR_EE bit in the MSR we are restoring at exit. Secondly, the MMU hash miss code was clearing both paca->soft_enabled and paca->hard_enabled but not restoring them in the case where hash_page was able to resolve the miss from the Linux page tables. Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/entry_64.S | 4 ++++ arch/powerpc/kernel/head_64.S | 28 +++++++++++++++++++--------- 2 files changed, 23 insertions(+), 9 deletions(-) diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index efda48741b29..86e2bdd5afd6 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -489,6 +489,10 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES) andi. r0,r3,MSR_RI beq- unrecov_restore + /* extract EE bit and use it to restore paca->hard_enabled */ + rldicl r4,r3,49,63 /* r0 = (r3 >> 15) & 1 */ + stb r4,PACAHARDIRQEN(r13) + andi. r0,r3,MSR_PR /* diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S index c93d9f35a121..d2890050b7e0 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -961,10 +961,18 @@ bad_stack: * any task or sent any task a signal, you should use * ret_from_except or ret_from_except_lite instead of this. */ +fast_exc_return_irq: /* restores irq state too */ + ld r3,SOFTE(r1) + ld r12,_MSR(r1) + stb r3,PACASOFTIRQEN(r13) /* restore paca->soft_enabled */ + rldicl r4,r12,49,63 /* get MSR_EE to LSB */ + stb r4,PACAHARDIRQEN(r13) /* restore paca->hard_enabled */ + b 1f + .globl fast_exception_return fast_exception_return: ld r12,_MSR(r1) - ld r11,_NIP(r1) +1: ld r11,_NIP(r1) andi. r3,r12,MSR_RI /* check if RI is set */ beq- unrecov_fer @@ -1361,6 +1369,16 @@ BEGIN_FW_FTR_SECTION * interrupts if necessary. */ beq .ret_from_except_lite +END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES) +#endif +BEGIN_FW_FTR_SECTION + /* + * Here we have interrupts hard-disabled, so it is sufficient + * to restore paca->{soft,hard}_enable and get out. + */ + beq fast_exc_return_irq /* Return from exception on success */ +END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES) + /* For a hash failure, we don't bother re-enabling interrupts */ ble- 12f @@ -1372,14 +1390,6 @@ BEGIN_FW_FTR_SECTION ld r3,SOFTE(r1) bl .local_irq_restore b 11f -END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES) -#endif -BEGIN_FW_FTR_SECTION - beq fast_exception_return /* Return from exception on success */ - ble- 12f /* Failure return from hash_page */ - - /* fall through */ -END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES) /* Here we have a page fault that hash_page can't handle. */ _GLOBAL(handle_page_fault) -- 2.20.1