On Thursday 27 February 2014 16:17:46 Santosh Shilimkar 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 was my suggestion, and the implementation is trivial, so Acked-by: Arnd Bergmann <arnd@xxxxxxxx> This should be most of what LinusW needs to generalize the mach-integrator PCI DMA mapping. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
