Re: [PATCH 4/4] mips: dma: Add cma support

[Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>]

On 16/07/14 17:39, Michal Nazarewicz wrote:
> On Wed, Jul 16 2014, Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com> wrote:
>> Adds cma support to the mips architecture.
>>
>> cma uses memblock. However, mips uses bootmem.
> 
> Does cma_early_percent_memory work correctly then?
> 

Yes it does. All memblock functions work. And this is before bootmem
is informed.

>> bootmem is informed about any regions reserved by memblock
> 
> Alternatively maybe it would make sense to create a new definition of
> dma_contiguous_reserve_area that uses bootmem and choose it based on
> some CONFIG_CMA_USE_BOOTMEM which would be selected by MIPS.
> 

Telling bootmem takes only 3 lines.

Adding CONFIG_CMA_USE_BOOTMEM would add more functions and maintenance overhead.
And it will basically do the same thing.
Reserve memory. And tell the bootmem allocator.

>> dma api is modified to use cma reserved memory regions when available
>>
>> Tested using cma_test. cma_test is a simple driver that assigns blocks
>> of memory from cma reserved sections.
>>
>> Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
> 
> Acked-by: Michal Nazarewicz <mina86@mina86.com>

Thank-you

ZubairLK