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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2012-05-08 13:31:59 +1000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2012-05-09 09:42:21 +1000 |
| commit | 56dfa7fa19e36db352a94be022243ed461710119 (patch) | |
| tree | 37ea957522aa18a2d3f4fb62629e9e4ca0e7f38c | |
| parent | 810b4de25e53459323ff48957b0162b48d6cbd57 (diff) | |
| download | lwn-56dfa7fa19e36db352a94be022243ed461710119.tar.gz lwn-56dfa7fa19e36db352a94be022243ed461710119.zip | |
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 <benh@kernel.crashing.org>
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 18 | ||||
| -rw-r--r-- | 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 f8a7a1a1a9f4..fc6015027a86 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 43eb74fcedde..c6c6f3b7f8cd 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 */ |