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authorJim Quinlan <james.quinlan@broadcom.com>2020-09-17 18:43:40 +0200
committerChristoph Hellwig <hch@lst.de>2020-09-17 18:43:56 +0200
commite0d072782c734d27f5af062c62266f2598f68542 (patch)
treef259e9eaab55ae8ffedaea07a19e8f147dcceb9a /include/linux/device.h
parent6eb0233ec2d0df288fe8515d5b0b2b15562e05bb (diff)
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>
Diffstat (limited to 'include/linux/device.h')
-rw-r--r--include/linux/device.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/device.h b/include/linux/device.h
index ca18da4768e3..1c78621fc3c0 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -466,7 +466,7 @@ struct dev_links_info {
* such descriptors.
* @bus_dma_limit: Limit of an upstream bridge or bus which imposes a smaller
* DMA limit than the device itself supports.
- * @dma_pfn_offset: offset of DMA memory range relatively of RAM
+ * @dma_range_map: map for DMA memory ranges relative to that of RAM
* @dma_parms: A low level driver may set these to teach IOMMU code about
* segment limitations.
* @dma_pools: Dma pools (if dma'ble device).
@@ -561,7 +561,7 @@ struct device {
64 bit addresses for consistent
allocations such descriptors. */
u64 bus_dma_limit; /* upstream dma constraint */
- unsigned long dma_pfn_offset;
+ const struct bus_dma_region *dma_range_map;
struct device_dma_parameters *dma_parms;