dma-mapping: introduce DMA range map, supplanting dma_pfn_offset
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>
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