ARM: mm: update __v7_setup() to the new LoUIS cache maintenance API

The ARMv7 processor setup function __v7_setup() cleans and invalidates the
CPU cache before enabling MMU to start the CPU with a clean CPU local cache.

But on ARMv7 architectures like Cortex-[A15/A8], this code will end
up flushing the L2 caches(up to level of Coherency) which is undesirable
and expensive. The setup functions are used in the CPU hotplug scenario too
and hence flushing all cache levels should be avoided.

This patch replaces the cache flushing call with the newly introduced
v7 dcache LoUIS API where only cache levels up to LoUIS are cleaned and
invalidated when a processors executes __v7_setup which is the expected
behavior.

For processors like A9 and A5 where the L2 cache is an outer one the
behavior should be unchanged.

Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>

diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index c2e2b66f72b5cd08648085c28ffc5d8c2ee8359a..846d279f31764d7803fc6144df9517087286c768 100644 (file)
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -172,7 +172,7 @@ __v7_ca15mp_setup:
 __v7_setup:
        adr     r12, __v7_setup_stack           @ the local stack
        stmia   r12, {r0-r5, r7, r9, r11, lr}
-       bl      v7_flush_dcache_all
+       bl      v7_flush_dcache_louis
        ldmia   r12, {r0-r5, r7, r9, r11, lr}
 
        mrc     p15, 0, r0, c0, c0, 0           @ read main ID register