Commit 06e6295b authored by Stefano Stabellini's avatar Stefano Stabellini
Browse files

arm: make SWIOTLB available 



IOMMU_HELPER is needed because SWIOTLB calls iommu_is_span_boundary,
provided by lib/iommu_helper.c.

Signed-off-by: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: will.deacon@arm.com
CC: linux@arm.linux.org.uk


Changes in v8:
- use __phys_to_pfn and __pfn_to_phys.

Changes in v7:
- dma_mark_clean: empty implementation;
- in dma_capable use coherent_dma_mask if dma_mask hasn't been
  allocated.

Changes in v6:
- check for dev->dma_mask being NULL in dma_capable.

Changes in v5:
- implement dma_mark_clean using dmac_flush_range.

Changes in v3:
- dma_capable: do not treat dma_mask as a limit;
- remove SWIOTLB dependency on NEED_SG_DMA_LENGTH.
parent 61e6cfa8

arch/arm/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -1872,6 +1872,12 @@ config CC_STACKPROTECTOR 
	  neutralized via a kernel panic.

	  This feature requires gcc version 4.2 or above.



config SWIOTLB

	def_bool y



config IOMMU_HELPER

	def_bool SWIOTLB



config XEN_DOM0

	def_bool y

	depends on XEN

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

+37 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 


#include <asm-generic/dma-coherent.h>

#include <asm/memory.h>

#include <asm/cacheflush.h>



#define DMA_ERROR_CODE	(~0)

extern struct dma_map_ops arm_dma_ops;
@@ -86,6 +87,42 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr) 
}

#endif



static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)

{

	unsigned int offset = paddr & ~PAGE_MASK;

	return pfn_to_dma(dev, __phys_to_pfn(paddr)) + offset;

}



static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)

{

	unsigned int offset = dev_addr & ~PAGE_MASK;

	return __pfn_to_phys(dma_to_pfn(dev, dev_addr)) + offset;

}



static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)

{

	u64 limit, mask;

	

	if (dev->dma_mask)

		mask = *dev->dma_mask;

	else 

		mask = dev->coherent_dma_mask;



	if (mask == 0)

		return 0;



	limit = (mask + 1) & ~mask;

	if (limit && size > limit)

		return 0;



	if ((addr | (addr + size - 1)) & ~mask)

		return 0;



	return 1;

}



static inline void dma_mark_clean(void *addr, size_t size) { }



/*

 * DMA errors are defined by all-bits-set in the DMA address.

 */

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