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dma-mapping: introduce DMA range map, supplanting dma_pfn_offset

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The new field 'dma_range_map' in struct device is used to facilitate the
use of single or multiple offsets between mapping regions of cpu addrs and
dma addrs.  It subsumes the role of "dev->dma_pfn_offset" which was only
capable of holding a single uniform offset and had no region bounds
checking.

The function of_dma_get_range() has been modified so that it takes a single
argument -- the device node -- and returns a map, NULL, or an error code.
The map is an array that holds the information regarding the DMA regions.
Each range entry contains the address offset, the cpu_start address, the
dma_start address, and the size of the region.

of_dma_configure() is the typical manner to set range offsets but there are
a number of ad hoc assignments to "dev->dma_pfn_offset" in the kernel
driver code.  These cases now invoke the function
dma_direct_set_offset(dev, cpu_addr, dma_addr, size).

Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
[hch: various interface cleanups]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
This commit is contained in:
Jim Quinlan
2020-09-17 18:43:40 +02:00
committed by Christoph Hellwig
parent 6eb0233ec2
commit e0d072782c
22 changed files with 285 additions and 118 deletions
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9
include/linux/dma-mapping.h
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@@ -730,4 +730,11 @@ static inline int dma_mmap_wc(struct device *dev,
#define dma_unmap_len_set(PTR, LEN_NAME, VAL) do { } while (0)
#endif
#endif
/*
* Legacy interface to set up the dma offset map. Drivers really should not
* actually use it, but we have a few legacy cases left.
*/
int dma_direct_set_offset(struct device *dev, phys_addr_t cpu_start,
dma_addr_t dma_start, u64 size);
#endif /* _LINUX_DMA_MAPPING_H */