From 0fc12c022ad25532b66bf6f6c818ee1c1d63e702 Mon Sep 17 00:00:00 2001
From: Michael Ellerman <mpe@ellerman.id.au>
Date: Mon, 8 Jul 2019 16:02:19 +1000
Subject: [PATCH] powerpc/irq: Don't WARN continuously in
 arch_local_irq_restore()

References: bsc#1065729
Patch-mainline: v5.3-rc1
Git-commit: 0fc12c022ad25532b66bf6f6c818ee1c1d63e702

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: e2b36d591720 ("powerpc/64: Don't trace code that runs with the soft irq mask unreconciled")
Fixes: 9b81c0211c24 ("powerpc/64s: make PACA_IRQ_HARD_DIS track MSR[EE] closely")
Fixes: 7c0482e3d055 ("powerpc/irq: Fix another case of lazy IRQ state getting out of sync")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190708061046.7075-1-mpe@ellerman.id.au
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 arch/powerpc/kernel/irq.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -265,7 +265,7 @@ notrace void arch_local_irq_restore(unsi
 		 * 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 /* CONFIG_TRACE_IRQFLAGS */