From 56dfa7fa19e36db352a94be022243ed461710119 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 8 May 2012 13:31:59 +1000 Subject: [PATCH] powerpc/irq: Fix bug with new lazy IRQ handling code We had a case where we could turn on hard interrupts while leaving the PACA_IRQ_HARD_DIS bit set in the PACA. This can in turn cause a BUG_ON() to hit in __check_irq_replay() due to interrupt state getting out of sync. The assembly code was also way too convoluted. Instead, we now leave it to the C code to do the right thing which ends up being smaller and more readable. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/entry_64.S | 18 ------------------ arch/powerpc/kernel/irq.c | 8 +++++++- 2 files changed, 7 insertions(+), 19 deletions(-) diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index f8a7a1a..fc60150 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -767,16 +767,6 @@ do_work: SOFT_DISABLE_INTS(r3,r4) 1: bl .preempt_schedule_irq - /* Hard-disable interrupts again (and update PACA) */ -#ifdef CONFIG_PPC_BOOK3E - wrteei 0 -#else - ld r10,PACAKMSR(r13) /* Get kernel MSR without EE */ - mtmsrd r10,1 -#endif /* CONFIG_PPC_BOOK3E */ - li r0,PACA_IRQ_HARD_DIS - stb r0,PACAIRQHAPPENED(r13) - /* Re-test flags and eventually loop */ clrrdi r9,r1,THREAD_SHIFT ld r4,TI_FLAGS(r9) @@ -787,14 +777,6 @@ do_work: user_work: #endif /* CONFIG_PREEMPT */ - /* Enable interrupts */ -#ifdef CONFIG_PPC_BOOK3E - wrteei 1 -#else - ori r10,r10,MSR_EE - mtmsrd r10,1 -#endif /* CONFIG_PPC_BOOK3E */ - andi. r0,r4,_TIF_NEED_RESCHED beq 1f bl .restore_interrupts diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index 43eb74f..c6c6f3b 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -260,11 +260,17 @@ EXPORT_SYMBOL(arch_local_irq_restore); * if they are currently disabled. This is typically called before * schedule() or do_signal() when returning to userspace. We do it * in C to avoid the burden of dealing with lockdep etc... + * + * NOTE: This is called with interrupts hard disabled but not marked + * as such in paca->irq_happened, so we need to resync this. */ void restore_interrupts(void) { - if (irqs_disabled()) + if (irqs_disabled()) { + local_paca->irq_happened |= PACA_IRQ_HARD_DIS; local_irq_enable(); + } else + __hard_irq_enable(); } #endif /* CONFIG_PPC64 */ -- 2.7.4