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

On Fri, Feb 28, 2014 at 5:17 AM, Santosh Shilimkar
[off-list ref] wrote:

From: Grygorii Strashko <grygorii.strashko@ti.com>

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 <redacted>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <redacted>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Santosh Shilimkar <redacted>

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

Yours,
Linus Walleij