[PATCH] ARM: setup_mm_for_reboot(): use flush_cache_louis()

[Santosh Shilimkar]

On Wednesday 07 November 2012 03:47 AM, Lorenzo Pieralisi wrote:
> On Tue, Nov 06, 2012 at 09:57:17PM +0000, Santosh Shilimkar wrote:
>> On Tuesday 06 November 2012 03:12 PM, Nicolas Pitre wrote:
>>>
>>> ... instead of flush_cache_all().  The later unconditionally flushes
>>> the L2 cache on ARMv7 architectures such as Cortex A15 and A7 which
>>> is costly and unnecessary in some scenarios where setup_mm_for_reboot()
>>> is used.  If L2 has to be flushed as well, it should already be done
>>> separately on other architectures anyway.
>>>
>>> Signed-off-by: Nicolas Pitre <nico at linaro.org>
>>>
>>> diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c
>>> index ab88ed4f8e..2c61085a10 100644
>>> --- a/arch/arm/mm/idmap.c
>>> +++ b/arch/arm/mm/idmap.c
>>> @@ -104,7 +104,7 @@ early_initcall(init_static_idmap);
>>>    void setup_mm_for_reboot(void)
>>>    {
>>>    	/* Clean and invalidate L1. */
>>> -	flush_cache_all();
>>> +	flush_cache_louis();
>>>
>>>    	/* Switch to the identity mapping. */
>>>    	cpu_switch_mm(idmap_pgd, &init_mm);
>>>
>> Nice. Just one difference is that the I-cache invalidation won't
>> happen with this change. Not that it is needed here but capturing
>> that in change-log would be good.
>
> Yes, it does happen. The LoUIS API mirrors the flush_cache_all() API in
> this respect, and it has to. The only change is the data cache level at
> which it operates.
>
Indeed. I remember our discussion on this part now. Thanks Lorenzo
for clarification.

Regards
Santosh