Re: [PATCH v2 1/7] ARM: mm: Introduce archdata.dma_pfn_offset

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On Fri, Feb 28, 2014 at 5:17 AM, Santosh Shilimkar
<santosh.shilimkar@xxxxxx> wrote:

> From: Grygorii Strashko <grygorii.strashko@xxxxxx>
>
> In most of cases DMA addresses can be performed using offset value of
>  Bus address space relatively to physical address space as following:
>
> PFN->DMA:
>  __pfn_to_phys(pfn + [-]dma_pfn_offset)
>
> DMA->PFN:
>  __phys_to_pfn(dma_addr) + [-]dma_pfn_offset
>
> This patch introduces new field dma_pfn_offset in ARM dev_archdata
> structure which has to be filed per-device at arch init time
> (simplest way is to use Platform bus notifier to handle
> BUS_NOTIFY_ADD_DEVICE event) and updates DMA address translation
> routines in order to accommodate bus offset value by default.
>
> Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Olof Johansson <olof@xxxxxxxxx>
> Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>

This looks like exactly what I need to proceed to multiplatform on
Integrator.
Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

Yours,
Linus Walleij
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