X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=arch%2Fmips%2Finclude%2Fasm%2Fstackframe.h;h=c8419129e77085e7010bab42c4acef99e4aa99e9;hb=1f10cd34d9b347106cb34ef91c8ff76f12ee67a8;hp=3b6da3330e321772358c9791914e3d472290d2f9;hpb=795d580baec0d5386b83a8b557df47c20810e86b;p=pandora-kernel.git

diff --git a/arch/mips/include/asm/stackframe.h b/arch/mips/include/asm/stackframe.h
index 3b6da3330e32..c8419129e770 100644
--- a/arch/mips/include/asm/stackframe.h
+++ b/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