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authorWill Deacon <will.deacon@arm.com>2011-11-22 17:30:28 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2011-12-08 10:30:38 +0000
commitd675d0bc47f28c5414fbbe17fcc801f69c45b960 (patch)
tree78d7b2c43650d6af96caac9e631409cf15c8f25a
parent8d2cd3a38fd663bd341507f5ac29002ffd81d986 (diff)
downloadlinux-d675d0bc47f28c5414fbbe17fcc801f69c45b960.tar.bz2
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>
-rw-r--r--arch/arm/boot/compressed/head.S1
-rw-r--r--arch/arm/include/asm/assembler.h11
-rw-r--r--arch/arm/kernel/head.S2
-rw-r--r--arch/arm/kernel/sleep.S2
4 files changed, 16 insertions, 0 deletions
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index c2effc917254..c5d60250d43d 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -659,6 +659,7 @@ __armv7_mmu_cache_on:
mcrne p15, 0, r3, c2, c0, 0 @ load page table pointer
mcrne p15, 0, r1, c3, c0, 0 @ load domain access control
#endif
+ mcr p15, 0, r0, c7, c5, 4 @ ISB
mcr p15, 0, r0, c1, c0, 0 @ load control register
mrc p15, 0, r0, c1, c0, 0 @ and read it back
mov r0, #0
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
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 64e9943ea4f0..54eb94aff6cd 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -401,8 +401,10 @@ ENDPROC(__enable_mmu)
.pushsection .idmap.text, "ax"
ENTRY(__turn_mmu_on)
mov r0, r0
+ instr_sync
mcr p15, 0, r0, c1, c0, 0 @ write control reg
mrc p15, 0, r3, c0, c0, 0 @ read id reg
+ instr_sync
mov r3, r3
mov r3, r13
mov pc, r3
diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S
index 9e64231c8cfe..1f268bda4552 100644
--- a/arch/arm/kernel/sleep.S
+++ b/arch/arm/kernel/sleep.S
@@ -57,8 +57,10 @@ ENDPROC(cpu_suspend_abort)
.pushsection .idmap.text,"ax"
ENTRY(cpu_resume_mmu)
ldr r3, =cpu_resume_after_mmu
+ instr_sync
mcr p15, 0, r0, c1, c0, 0 @ turn on MMU, I-cache, etc
mrc p15, 0, r0, c0, c0, 0 @ read id reg
+ instr_sync
mov r0, r0
mov r0, r0
mov pc, r3 @ jump to virtual address