Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt...

[pandora-kernel.git] / arch / mips / include / asm / stackframe.h

diff --git a/arch/mips/include/asm/stackframe.h b/arch/mips/include/asm/stackframe.h
index 3b6da33..c841912 100644 (file)
--- 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