[PATCH v2 2/6] ARM: mm: Introduce virt_to_idmap() with an arch hook

Santosh Shilimkar santosh.shilimkar at ti.com
Sat Aug 3 15:03:02 EDT 2013


On Friday 02 August 2013 09:53 PM, Nicolas Pitre wrote:
> On Wed, 31 Jul 2013, Santosh Shilimkar wrote:
> 
>> On some PAE systems (e.g. TI Keystone), memory is above the
>> 32-bit addressable limit, and the interconnect provides an
>> aliased view of parts of physical memory in the 32-bit addressable
>> space.  This alias is strictly for boot time usage, and is not
>> otherwise usable because of coherency limitations. On such systems,
>> the idmap mechanism needs to take this aliased mapping into account.
>>
>> This patch introduces virt_to_idmap() and a arch function pointer which
>> can be populated by platform which needs it. Also populate necessary
>> idmap spots with now available virt_to_idmap(). Avoided #ifdef approach
>> to be compatible with multi-platform builds.
>>
>> Most architecture won't touch it and in that case virt_to_idmap()
>> fall-back to existing virt_to_phys() macro.
>>
>> Cc: Nicolas Pitre <nico at linaro.org>
>> Cc: Russell King <linux at arm.linux.org.uk>
>>
>> Signed-off-by: Santosh Shilimkar <santosh.shilimkar at ti.com>
> 
> Acked-by: Nicolas Pitre <nico at linaro.org>
> 
Thanks !!




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