Commit 6ce0d200 authored Apr 24, 2014 by Grygorii Strashko Committed by Santosh Shilimkar May 07, 2014

ARM: dma: Use dma_pfn_offset for dma address translation



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

Thanks to Russell King for suggesting the optimised macro's for
conversion.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <olof@lixom.net>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>

parent 591c1ee4

arch/arm/include/asm/dma-mapping.h

+17 −1

Original line number	Diff line number	Diff line
		@@ -58,21 +58,37 @@ static inline int dma_set_mask(struct device *dev, u64 mask)
		#ifndef __arch_pfn_to_dma
		static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
		{
		if (dev)
		pfn -= dev->dma_pfn_offset;
		return (dma_addr_t)__pfn_to_bus(pfn);
		}

		static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
		{
		return __bus_to_pfn(addr);
		unsigned long pfn = __bus_to_pfn(addr);

		if (dev)
		pfn += dev->dma_pfn_offset;

		return pfn;
		}

		static inline void dma_to_virt(struct device dev, dma_addr_t addr)
		{
		if (dev) {
		unsigned long pfn = dma_to_pfn(dev, addr);

		return phys_to_virt(__pfn_to_phys(pfn));
		}

		return (void *)__bus_to_virt((unsigned long)addr);
		}

		static inline dma_addr_t virt_to_dma(struct device dev, void addr)
		{
		if (dev)
		return pfn_to_dma(dev, virt_to_pfn(addr));

		return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
		}