From 6bd7d693d6070bbf039835943ecbe5fb18113bb7 Mon Sep 17 00:00:00 2001
From: Wu Zhangjin <wuzhangjin@gmail.com>
Date: Sat, 13 Mar 2010 12:34:15 +0800
Subject: [PATCH] --- yaml --- r: 189778 b: refs/heads/master c:
 f1df323924e2fde14cbcd51209a8cbfc33e0c232 h: refs/heads/master v: v3

---
 [refs]                                   |  2 +-
 trunk/arch/mips/include/asm/stackframe.h | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index b8be41fe79e1..cea74aed437f 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d814c28ceca8f659c0012eaec8e21eee43710716
+refs/heads/master: f1df323924e2fde14cbcd51209a8cbfc33e0c232
diff --git a/trunk/arch/mips/include/asm/stackframe.h b/trunk/arch/mips/include/asm/stackframe.h
index 3b6da3330e32..c8419129e770 100644
--- a/trunk/arch/mips/include/asm/stackframe.h
+++ b/trunk/arch/mips/include/asm/stackframe.h
@@ -121,6 +121,25 @@
 		.endm
 #else
 		.macro	get_saved_sp	/* Uniprocessor variation */
+#ifdef CONFIG_CPU_LOONGSON2F
+		/*
+		 * Clear BTB (branch target buffer), forbid RAS (return address
+		 * stack) to workaround the Out-of-order Issue in Loongson2F
+		 * via its diagnostic register.
+		 */
+		move	k0, ra
+		jal	1f
+		 nop
+1:		jal	1f
+		 nop
+1:		jal	1f
+		 nop
+1:		jal	1f
+		 nop
+1:		move	ra, k0
+		li	k0, 3
+		mtc0	k0, $22
+#endif /* CONFIG_CPU_LOONGSON2F */
 #if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
 		lui	k1, %hi(kernelsp)
 #else