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From: dave.martin@linaro.org (Dave Martin)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: Correct WFE() in asm/spinlock.h for Thumb-2
Date: Tue,  8 Feb 2011 15:20:14 +0000	[thread overview]
Message-ID: <1297178414-20983-1-git-send-email-dave.martin@linaro.org> (raw)

The content for ALT_SMP() in the definition of WFE() expands to 6
bytes (IT cc ; WFEcc.W), which breaks the assumptions of the fixup
code, leading to lockups when the affected code gets run.

This patch works around the problem by explicitly using an
IT + WFEcc.N pair.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
---
 arch/arm/include/asm/spinlock.h |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/arch/arm/include/asm/spinlock.h b/arch/arm/include/asm/spinlock.h
index da1af52..7cba79c 100644
--- a/arch/arm/include/asm/spinlock.h
+++ b/arch/arm/include/asm/spinlock.h
@@ -18,7 +18,12 @@
 
 #ifdef CONFIG_THUMB2_KERNEL
 #define SEV		ALT_SMP("sev.w", "nop.w")
-#define WFE(cond)	ALT_SMP("wfe" cond ".w", "nop.w")
+#define WFE(cond)	ALT_SMP(		\
+	"it " cond "\n\t"			\
+	"wfe" cond ".n",			\
+						\
+	"nop.w"					\
+)
 #else
 #define SEV		ALT_SMP("sev", "nop")
 #define WFE(cond)	ALT_SMP("wfe" cond, "nop")
-- 
1.7.1

             reply	other threads:[~2011-02-08 15:20 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-08 15:20 Dave Martin [this message]
2011-02-08 16:40 ` [PATCH] ARM: Correct WFE() in asm/spinlock.h for Thumb-2 Russell King - ARM Linux
2011-02-08 16:56   ` Dave Martin
2011-02-09 10:20     ` Will Deacon
2011-02-09 13:04       ` Russell King - ARM Linux
2011-02-09 16:38 ` Nicolas Pitre
2011-02-09 17:00   ` Dave Martin

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