From fe9e1d54e3ea2e5134d7aaa233441f9229326ef6 Mon Sep 17 00:00:00 2001 From: Ian Munsie Date: Wed, 14 Nov 2012 18:49:48 +0000 Subject: [PATCH] powerpc: Add code to handle soft-disabled doorbells on server This patch adds the logic to properly handle doorbells that come in when interrupts have been soft disabled and to replay them when interrupts are re-enabled: - masked_##_H##interrupt is modified to leave interrupts enabled when a doorbell has come in since doorbells are edge sensitive and as such won't be automatically re-raised. - __check_irq_replay now tests if a doorbell happened on book3s, and returns either 0xe80 or 0xa00 depending on whether we are the hypervisor or not. - restore_check_irq_replay now tests for the two possible server doorbell vector numbers to replay. - __replay_interrupt also adds tests for the two server doorbell vector numbers, and is modified to use a compare instruction rather than an andi. on the single bit difference between 0x500 and 0x900. The last two use a CPU feature section to avoid needlessly testing against the hypervisor vector if it is not the hypervisor, and vice versa. Signed-off-by: Ian Munsie Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/entry_64.S | 13 ++++++++-- arch/powerpc/kernel/exceptions-64s.S | 37 +++++++++++++++++++--------- arch/powerpc/kernel/irq.c | 11 +++++++-- 3 files changed, 45 insertions(+), 16 deletions(-) diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index b310a0573625..73c1f083ba21 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -836,13 +836,22 @@ restore_check_irq_replay: addi r3,r1,STACK_FRAME_OVERHEAD; bl .timer_interrupt b .ret_from_except +#ifdef CONFIG_PPC_DOORBELL +1: #ifdef CONFIG_PPC_BOOK3E -1: cmpwi cr0,r3,0x280 + cmpwi cr0,r3,0x280 +#else + BEGIN_FTR_SECTION + cmpwi cr0,r3,0xe80 + FTR_SECTION_ELSE + cmpwi cr0,r3,0xa00 + ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE) +#endif /* CONFIG_PPC_BOOK3E */ bne 1f addi r3,r1,STACK_FRAME_OVERHEAD; bl .doorbell_exception b .ret_from_except -#endif /* CONFIG_PPC_BOOK3E */ +#endif /* CONFIG_PPC_DOORBELL */ 1: b .ret_from_except /* What else to do here ? */ unrecov_restore: diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 176bf99e01c6..32fc04f78890 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -528,10 +528,12 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_206) KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0xf40) /* - * An interrupt came in while soft-disabled. We set paca->irq_happened, - * then, if it was a decrementer interrupt, we bump the dec to max and - * and return, else we hard disable and return. This is called with - * r10 containing the value to OR to the paca field. + * An interrupt came in while soft-disabled. We set paca->irq_happened, then: + * - If it was a decrementer interrupt, we bump the dec to max and and return. + * - If it was a doorbell we return immediately since doorbells are edge + * triggered and won't automatically refire. + * - else we hard disable and return. + * This is called with r10 containing the value to OR to the paca field. */ #define MASKED_INTERRUPT(_H) \ masked_##_H##interrupt: \ @@ -539,13 +541,15 @@ masked_##_H##interrupt: \ lbz r11,PACAIRQHAPPENED(r13); \ or r11,r11,r10; \ stb r11,PACAIRQHAPPENED(r13); \ - andi. r10,r10,PACA_IRQ_DEC; \ - beq 1f; \ + cmpwi r10,PACA_IRQ_DEC; \ + bne 1f; \ lis r10,0x7fff; \ ori r10,r10,0xffff; \ mtspr SPRN_DEC,r10; \ b 2f; \ -1: mfspr r10,SPRN_##_H##SRR1; \ +1: cmpwi r10,PACA_IRQ_DBELL; \ + beq 2f; \ + mfspr r10,SPRN_##_H##SRR1; \ rldicl r10,r10,48,1; /* clear MSR_EE */ \ rotldi r10,r10,16; \ mtspr SPRN_##_H##SRR1,r10; \ @@ -562,8 +566,8 @@ masked_##_H##interrupt: \ /* * Called from arch_local_irq_enable when an interrupt needs - * to be resent. r3 contains 0x500 or 0x900 to indicate which - * kind of interrupt. MSR:EE is already off. We generate a + * to be resent. r3 contains 0x500, 0x900, 0xa00 or 0xe80 to indicate + * which kind of interrupt. MSR:EE is already off. We generate a * stackframe like if a real interrupt had happened. * * Note: While MSR:EE is off, we need to make sure that _MSR @@ -579,9 +583,18 @@ _GLOBAL(__replay_interrupt) mflr r11 mfcr r9 ori r12,r12,MSR_EE - andi. r3,r3,0x0800 - bne decrementer_common - b hardware_interrupt_common + cmpwi r3,0x900 + beq decrementer_common + cmpwi r3,0x500 + beq hardware_interrupt_common +BEGIN_FTR_SECTION + cmpwi r3,0xe80 + beq h_doorbell_common +FTR_SECTION_ELSE + cmpwi r3,0xa00 + beq doorbell_super_common +ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE) + blr #ifdef CONFIG_PPC_PSERIES /* diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index 71413f41278f..4f97fe345526 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -122,8 +122,8 @@ static inline notrace int decrementer_check_overflow(void) } /* This is called whenever we are re-enabling interrupts - * and returns either 0 (nothing to do) or 500/900 if there's - * either an EE or a DEC to generate. + * and returns either 0 (nothing to do) or 500/900/280/a00/e80 if + * there's an EE, DEC or DBELL to generate. * * This is called in two contexts: From arch_local_irq_restore() * before soft-enabling interrupts, and from the exception exit @@ -182,6 +182,13 @@ notrace unsigned int __check_irq_replay(void) local_paca->irq_happened &= ~PACA_IRQ_DBELL; if (happened & PACA_IRQ_DBELL) return 0x280; +#else + local_paca->irq_happened &= ~PACA_IRQ_DBELL; + if (happened & PACA_IRQ_DBELL) { + if (cpu_has_feature(CPU_FTR_HVMODE)) + return 0xe80; + return 0xa00; + } #endif /* CONFIG_PPC_BOOK3E */ /* There should be nothing left ! */ -- 2.39.2