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-rw-r--r--arch/arm/kernel/traps.c26
1 files changed, 23 insertions, 3 deletions
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index a964c9f40f87..0c8b10801d36 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -25,6 +25,7 @@
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/sched.h>
+#include <linux/irq.h>
#include <linux/atomic.h>
#include <asm/cacheflush.h>
@@ -460,10 +461,29 @@ die_sig:
arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6);
}
-asmlinkage void do_unexp_fiq (struct pt_regs *regs)
+/*
+ * Handle FIQ similarly to NMI on x86 systems.
+ *
+ * The runtime environment for NMIs is extremely restrictive
+ * (NMIs can pre-empt critical sections meaning almost all locking is
+ * forbidden) meaning this default FIQ handling must only be used in
+ * circumstances where non-maskability improves robustness, such as
+ * watchdog or debug logic.
+ *
+ * This handler is not appropriate for general purpose use in drivers
+ * platform code and can be overrideen using set_fiq_handler.
+ */
+asmlinkage void __exception_irq_entry handle_fiq_as_nmi(struct pt_regs *regs)
{
- printk("Hmm. Unexpected FIQ received, but trying to continue\n");
- printk("You may have a hardware problem...\n");
+ struct pt_regs *old_regs = set_irq_regs(regs);
+
+ nmi_enter();
+
+ /* nop. FIQ handlers for special arch/arm features can be added here. */
+
+ nmi_exit();
+
+ set_irq_regs(old_regs);
}
/*