diff options
| author | Will Deacon <will.deacon@arm.com> | 2012-08-24 15:20:59 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-08-25 09:15:56 +0100 |
| commit | dbece45894d3ab1baac15a96dc4e1e8e23f64a93 (patch) | |
| tree | a1454fd7596c527fdcedde312b89679941b7061c | |
| parent | d968d2b801d877601d54e35e6dd0f52d9c797c99 (diff) | |
ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores
When enabling the MMU for ARMv7 CPUs, the decompressor does not touch
the ttbcr register, assuming that it will be zeroed (N == 0, EAE == 0).
Given that only EAE is defined as 0 for non-secure copies of the
register (and a bootloader such as kexec may leave it set to 1 anyway),
we should ensure that we reset the register ourselves before turning on
the MMU.
This patch zeroes TTBCR.EAE and TTBCR.N prior to enabling the MMU for
ARMv7 cores in the decompressor, configuring us exclusively for 32-bit
translation tables via TTBR0.
Cc: <stable@vger.kernel.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Matthew Leach <matthew.leach@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/boot/compressed/head.S | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index b8c64b80bafc..81769c1341fa 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -659,10 +659,14 @@ __armv7_mmu_cache_on: #ifdef CONFIG_CPU_ENDIAN_BE8 orr r0, r0, #1 << 25 @ big-endian page tables #endif + mrcne p15, 0, r6, c2, c0, 2 @ read ttb control reg orrne r0, r0, #1 @ MMU enabled movne r1, #0xfffffffd @ domain 0 = client + bic r6, r6, #1 << 31 @ 32-bit translation system + bic r6, r6, #3 << 0 @ use only ttbr0 mcrne p15, 0, r3, c2, c0, 0 @ load page table pointer mcrne p15, 0, r1, c3, c0, 0 @ load domain access control + mcrne p15, 0, r6, c2, c0, 2 @ load ttb control #endif mcr p15, 0, r0, c7, c5, 4 @ ISB mcr p15, 0, r0, c1, c0, 0 @ load control register |