linux/include/asm-generic/dma-mapping.h
Christoph Hellwig 782e6769c0 dma-mapping: provide a generic dma-noncoherent implementation
Add a new dma_map_ops implementation that uses dma-direct for the
address mapping of streaming mappings, and which requires arch-specific
implemenations of coherent allocate/free.

Architectures have to provide flushing helpers to ownership trasnfers
to the device and/or CPU, and can provide optional implementations of
the coherent mmap functionality, and the cache_flush routines for
non-coherent long term allocations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Alexey Brodkin <abrodkin@synopsys.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
2018-05-19 08:46:12 +02:00

20 lines
547 B
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_GENERIC_DMA_MAPPING_H
#define _ASM_GENERIC_DMA_MAPPING_H
static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
{
/*
* Use the non-coherent ops if available. If an architecture wants a
* more fine-grained selection of operations it will have to implement
* get_arch_dma_ops itself or use the per-device dma_ops.
*/
#ifdef CONFIG_DMA_NONCOHERENT_OPS
return &dma_noncoherent_ops;
#else
return &dma_direct_ops;
#endif
}
#endif /* _ASM_GENERIC_DMA_MAPPING_H */