[PATCH AUTOSEL 4.19 55/81] ARM: 8856/1: NOMMU: Fix CCR register faulty initialization when MPU is disabled

Sasha Levin
2019-05-07T05:37:47Z

From: Tigran Tadevosyan <tigran.tadevosyan@arm.com>

[ Upstream commit c3143967807adb1357c36b68a7563fc0c4e1f615 ]

When CONFIG_ARM_MPU is not defined, the base address of v7M SCB register
is not initialized with correct value. This prevents enabling I/D caches
when the L1 cache poilcy is applied in kernel.

Fixes: 3c24121039c9da14692eb48f6e39565b28c0f3cf ("ARM: 8756/1: NOMMU: Postpone MPU activation till __after_proc_init")
Signed-off-by: Tigran Tadevosyan <tigran.tadevosyan@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm/kernel/head-nommu.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S
index ec29de250076..cab89479d15e 100644
--- a/arch/arm/kernel/head-nommu.S
+++ b/arch/arm/kernel/head-nommu.S
@@ -133,9 +133,9 @@ __secondary_data:
*/
.text
__after_proc_init:
-#ifdef CONFIG_ARM_MPU
M_CLASS(movw r12, #:lower16:BASEADDR_V7M_SCB)
M_CLASS(movt r12, #:upper16:BASEADDR_V7M_SCB)
+#ifdef CONFIG_ARM_MPU
M_CLASS(ldr r3, [r12, 0x50])
AR_CLASS(mrc p15, 0, r3, c0, c1, 4) @ Read ID_MMFR0
and r3, r3, #(MMFR0_PMSA) @ PMSA field
--
2.20.1