From 9141a003a491c7230d17b9c29677ce2be437b95c Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 3 Feb 2012 14:48:01 +0100 Subject: [PATCH] ARM: 7316/1: kexec: EOI active and mask all interrupts in kexec crash path The kexec machine crash code can be called in interrupt context via a sysrq trigger made using the magic key combination. If the irq chip dealing with the serial interrupt is using the fasteoi flow handler, then we will never EOI the interrupt because the interrupt handler will be fatal. In the case of a GIC, this results in the crash kernel not receiving interrupts on that CPU interface. This patch adds code (based on the PowerPC implementation) to EOI any pending interrupts on the crash CPU before masking and disabling all interrupts. Secondary cores are not a problem since they are placed into a cpu_relax() loop via an IPI. Reported-by: Lei Wen Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/kernel/machine_kexec.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c index 764bd456d84f..a30004476e70 100644 --- a/arch/arm/kernel/machine_kexec.c +++ b/arch/arm/kernel/machine_kexec.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #include #include @@ -53,6 +54,29 @@ void machine_crash_nonpanic_core(void *unused) cpu_relax(); } +static void machine_kexec_mask_interrupts(void) +{ + unsigned int i; + struct irq_desc *desc; + + for_each_irq_desc(i, desc) { + struct irq_chip *chip; + + chip = irq_desc_get_chip(desc); + if (!chip) + continue; + + if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data)) + chip->irq_eoi(&desc->irq_data); + + if (chip->irq_mask) + chip->irq_mask(&desc->irq_data); + + if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) + chip->irq_disable(&desc->irq_data); + } +} + void machine_crash_shutdown(struct pt_regs *regs) { unsigned long msecs; @@ -70,6 +94,7 @@ void machine_crash_shutdown(struct pt_regs *regs) printk(KERN_WARNING "Non-crashing CPUs did not react to IPI\n"); crash_save_cpu(regs, smp_processor_id()); + machine_kexec_mask_interrupts(); printk(KERN_INFO "Loading crashdump kernel...\n"); } -- 2.30.2