ARM: LPAE: add ISBs around MMU enabling code

Before we enable the MMU, we must ensure that the TTBR registers contain
sane values. After the MMU has been enabled, we jump to the *virtual*
address of the following function, so we also need to ensure that the
SCTLR write has taken effect.

This patch adds ISB instructions around the SCTLR write to ensure the
visibility of the above.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 29035e86a59d..b6e65dedfd71 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -187,6 +187,17 @@
 #endif
 
 /*
+ * Instruction barrier
+ */
+        .macro  instr_sync
+#if __LINUX_ARM_ARCH__ >= 7
+        isb
+#elif __LINUX_ARM_ARCH__ == 6
+        mcr     p15, 0, r0, c7, c5, 4
+#endif
+        .endm
+
+/*
  * SMP data memory barrier
  */
         .macro  smp_dmb mode