[PATCH 4.14 044/107] powerpc/fsl: Add macro to flush the branch predictor

From: Greg Kroah-Hartman
Date: Mon Apr 01 2019 - 13:24:25 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Diana Craciun <diana.craciun@xxxxxxx>

commit 1cbf8990d79ff69da8ad09e8a3df014e1494462b upstream.

The BUCSR register can be used to invalidate the entries in the
branch prediction mechanisms.

Signed-off-by: Diana Craciun <diana.craciun@xxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/ppc_asm.h | 10 ++++++++++
1 file changed, 10 insertions(+)

--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -802,4 +802,14 @@ END_FTR_SECTION_IFCLR(CPU_FTR_601)
stringify_in_c(.long (_target) - . ;) \
stringify_in_c(.previous)

+#ifdef CONFIG_PPC_FSL_BOOK3E
+#define BTB_FLUSH(reg) \
+ lis reg,BUCSR_INIT@h; \
+ ori reg,reg,BUCSR_INIT@l; \
+ mtspr SPRN_BUCSR,reg; \
+ isync;
+#else
+#define BTB_FLUSH(reg)
+#endif /* CONFIG_PPC_FSL_BOOK3E */
+
#endif /* _ASM_POWERPC_PPC_ASM_H */