From: Russell King <rmk@dyn-67.arm.linux.org.uk>
Date: Wed, 10 Aug 2005 13:52:52 +0000 (+0100)
Subject: [ARM SMP] Clear the exclusive monitor on ARMv6 CPUs on context switch
X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=b876386ee47e3ac9375a36e9107b8bd32e0599fc;p=openwrt%2Fstaging%2Fblogic.git

[ARM SMP] Clear the exclusive monitor on ARMv6 CPUs on context switch

Ensure that the exclusive monitor is cleared on context switch with
ARMv6 CPUs.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 39a6c1b0b9a3..7152bfbee581 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -533,6 +533,13 @@ ENTRY(__switch_to)
 	ldr	r3, [r2, #TI_TP_VALUE]
 	stmia	ip!, {r4 - sl, fp, sp, lr}	@ Store most regs on stack
 	ldr	r6, [r2, #TI_CPU_DOMAIN]!
+#if __LINUX_ARM_ARCH__ >= 6
+#ifdef CONFIG_CPU_MPCORE
+	clrex
+#else
+	strex	r3, r4, [ip]			@ Clear exclusive monitor
+#endif
+#endif
 #if defined(CONFIG_CPU_XSCALE) && !defined(CONFIG_IWMMXT)
 	mra	r4, r5, acc0
 	stmia   ip, {r4, r5}