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ARM: dma: Use dma_pfn_offset for dma address translation

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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>
This commit is contained in:
Grygorii Strashko 2014-04-24 11:30:05 -04:00 committed by Santosh Shilimkar
parent 591c1ee465
commit 6ce0d20016
1 changed files with 17 additions and 1 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

18
arch/arm/include/asm/dma-mapping.h
View file

@ -58,21 +58,37 @@ static inline int dma_set_mask(struct device *dev, u64 mask)
#ifndef __arch_pfn_to_dma #ifndef __arch_pfn_to_dma
static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn) 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); return (dma_addr_t)__pfn_to_bus(pfn);
} }
static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr) 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) 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); return (void *)__bus_to_virt((unsigned long)addr);
} }
static inline dma_addr_t virt_to_dma(struct device *dev, void *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)); return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
} }