From 9a8b4584065dd241d6c2bf818e349986bd900b8e Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Thu, 17 Nov 2005 16:24:52 -0500 Subject: [PATCH] [PARISC] Make sure timer and IPI execute with interrupts disabled Fix a longstanding smp bug The problem is that both the timer and ipi interrupts are being called with interrupts enabled, which isn't what anyone is expecting. The IPI issue has just started to show up by causing a BUG_ON in the slab debugging code. The timer issue never shows up because there's an eiem work around in our irq.c The fix is to label both these as SA_INTERRUPT which causes the generic irq code not to enable interrupts. I also suspect the smp_call_function timeouts we're seeing might be connected with the fact that we disable IPIs when handling any other type of interrupt. I've put a WARN_ON in the code for executing smp_call_function() with IPIs disabled. Signed-off-by: James Bottomley Signed-off-by: Kyle McMartin --- arch/parisc/kernel/irq.c | 2 ++ arch/parisc/kernel/smp.c | 4 ++++ 2 files changed, 6 insertions(+) diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c index 006385dbee66..f7ae2bcd49a5 100644 --- a/arch/parisc/kernel/irq.c +++ b/arch/parisc/kernel/irq.c @@ -291,12 +291,14 @@ void do_cpu_irq_mask(struct pt_regs *regs) static struct irqaction timer_action = { .handler = timer_interrupt, .name = "timer", + .flags = SA_INTERRUPT, }; #ifdef CONFIG_SMP static struct irqaction ipi_action = { .handler = ipi_interrupt, .name = "IPI", + .flags = SA_INTERRUPT, }; #endif diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c index a9ecf6465784..268b0f2a328e 100644 --- a/arch/parisc/kernel/smp.c +++ b/arch/parisc/kernel/smp.c @@ -338,6 +338,10 @@ smp_call_function (void (*func) (void *info), void *info, int retry, int wait) /* Can deadlock when called with interrupts disabled */ WARN_ON(irqs_disabled()); + + /* can also deadlock if IPIs are disabled */ + WARN_ON((get_eiem() & (1UL<<(CPU_IRQ_MAX - IPI_IRQ))) == 0); + data.func = func; data.info = info; -- 2.20.1