summary refs log tree commit diff
path: root/arch/arm/include/asm/percpu.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/include/asm/percpu.h')
-rw-r--r--arch/arm/include/asm/percpu.h11
1 files changed, 9 insertions, 2 deletions
diff --git a/arch/arm/include/asm/percpu.h b/arch/arm/include/asm/percpu.h
index 968c0a14e0a3..209e6504922e 100644
--- a/arch/arm/include/asm/percpu.h
+++ b/arch/arm/include/asm/percpu.h
@@ -30,8 +30,15 @@ static inline void set_my_cpu_offset(unsigned long off)
 static inline unsigned long __my_cpu_offset(void)
 {
 	unsigned long off;
-	/* Read TPIDRPRW */
-	asm("mrc p15, 0, %0, c13, c0, 4" : "=r" (off) : : "memory");
+	register unsigned long *sp asm ("sp");
+
+	/*
+	 * Read TPIDRPRW.
+	 * We want to allow caching the value, so avoid using volatile and
+	 * instead use a fake stack read to hazard against barrier().
+	 */
+	asm("mrc p15, 0, %0, c13, c0, 4" : "=r" (off) : "Q" (*sp));
+
 	return off;
 }
 #define __my_cpu_offset __my_cpu_offset()