[PATCH 4.4 058/266] powerpc/fsl: Add macro to flush the branch predictor

From: Greg Kroah-Hartman
Date: Wed May 15 2019 - 07:05:55 EST


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 | 11 +++++++++++
1 file changed, 11 insertions(+)

--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -821,4 +821,15 @@ END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,C
.long 0x2400004c /* rfid */
#endif /* !CONFIG_PPC_BOOK3E */
#endif /* __ASSEMBLY__ */
+
+#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 */