1 files changed, 19 insertions, 0 deletions

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