linux/arch/arm/include/asm/dma-direct.h
Christoph Hellwig ea8c64ace8 dma-mapping: move swiotlb arch helpers to a new header
phys_to_dma, dma_to_phys and dma_capable are helpers published by
architecture code for use of swiotlb and xen-swiotlb only.  Drivers are
not supposed to use these directly, but use the DMA API instead.

Move these to a new asm/dma-direct.h helper, included by a
linux/dma-direct.h wrapper that provides the default linear mapping
unless the architecture wants to override it.

In the MIPS case the existing dma-coherent.h is reused for now as
untangling it will take a bit of work.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Robin Murphy <robin.murphy@arm.com>
2018-01-10 16:40:54 +01:00

37 lines
802 B
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef ASM_ARM_DMA_DIRECT_H
#define ASM_ARM_DMA_DIRECT_H 1
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)
return 0;
mask = *dev->dma_mask;
limit = (mask + 1) & ~mask;
if (limit && size > limit)
return 0;
if ((addr | (addr + size - 1)) & ~mask)
return 0;
return 1;
}
#endif /* ASM_ARM_DMA_DIRECT_H */