[PATCH stable v4.4 46/52] powerpc/fsl: Add macro to flush the branch predictor

[Michael Ellerman]

From: Diana Craciun <diana.craciun at nxp.com>

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 at nxp.com>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
---
 arch/powerpc/include/asm/ppc_asm.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index 160bb2311bbb..d219816b3e19 100644
--- 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,CPU_FTR_HAS_PPR,945)
 	.long 0x2400004c  /* rfid				*/
 #endif /* !CONFIG_PPC_BOOK3E */
 #endif /*  __ASSEMBLY__ */
+
+#ifdef CONFIG_PPC_FSL_BOOK3E
+#define BTB_FLUSH(reg)			\
+	lis reg,BUCSR_INIT at h;		\
+	ori reg,reg,BUCSR_INIT at l;	\
+	mtspr SPRN_BUCSR,reg;		\
+	isync;
+#else
+#define BTB_FLUSH(reg)
+#endif /* CONFIG_PPC_FSL_BOOK3E */
+
 #endif /* _ASM_POWERPC_PPC_ASM_H */
-- 
2.20.1