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Commit 0fc12c02 authored by Michael Ellerman's avatar Michael Ellerman
Browse files

powerpc/irq: Don't WARN continuously in arch_local_irq_restore() 



When CONFIG_PPC_IRQ_SOFT_MASK_DEBUG is enabled (uncommon), we have a
series of WARN_ON's in arch_local_irq_restore().

These are "should never happen" conditions, but if they do happen they
can flood the console and render the system unusable. So switch them
to WARN_ON_ONCE().

Fixes: e2b36d59 ("powerpc/64: Don't trace code that runs with the soft irq mask unreconciled")
Fixes: 9b81c021 ("powerpc/64s: make PACA_IRQ_HARD_DIS track MSR[EE] closely")
Fixes: 7c0482e3 ("powerpc/irq: Fix another case of lazy IRQ state getting out of sync")
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190708061046.7075-1-mpe@ellerman.id.au
parent a2b6f26c

arch/powerpc/kernel/irq.c

+3 −3
Original line number Diff line number Diff line
@@ -259,7 +259,7 @@ notrace void arch_local_irq_restore(unsigned long mask) 
	irq_happened = get_irq_happened();

	if (!irq_happened) {

#ifdef CONFIG_PPC_IRQ_SOFT_MASK_DEBUG

		WARN_ON(!(mfmsr() & MSR_EE));

		WARN_ON_ONCE(!(mfmsr() & MSR_EE));

#endif

		return;

	}
@@ -272,7 +272,7 @@ notrace void arch_local_irq_restore(unsigned long mask) 
	 */

	if (!(irq_happened & PACA_IRQ_HARD_DIS)) {

#ifdef CONFIG_PPC_IRQ_SOFT_MASK_DEBUG

		WARN_ON(!(mfmsr() & MSR_EE));

		WARN_ON_ONCE(!(mfmsr() & MSR_EE));

#endif

		__hard_irq_disable();

#ifdef CONFIG_PPC_IRQ_SOFT_MASK_DEBUG
@@ -283,7 +283,7 @@ notrace void arch_local_irq_restore(unsigned long mask) 
		 * warn if we are wrong. Only do that when IRQ tracing

		 * is enabled as mfmsr() can be costly.

		 */

		if (WARN_ON(mfmsr() & MSR_EE))

		if (WARN_ON_ONCE(mfmsr() & MSR_EE))

			__hard_irq_disable();

#endif

	}