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| -rw-r--r-- | Documentation/DMA-API.txt | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index bb0e75e368b..c8db3d0dba5 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -364,6 +364,48 @@ API. Note: <nents> must be the number you passed in, *not* the number of physical entries returned. +void +dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size, + enum dma_data_direction direction) +void +pci_dma_sync_single_for_cpu(struct pci_dev *hwdev, dma_addr_t dma_handle, + size_t size, int direction) +void +dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, size_t size, + enum dma_data_direction direction) +void +pci_dma_sync_single_for_device(struct pci_dev *hwdev, dma_addr_t dma_handle, + size_t size, int direction) +void +dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems, + enum dma_data_direction direction) +void +pci_dma_sync_sg_for_cpu(struct pci_dev *hwdev, struct scatterlist *sg, + int nelems, int direction) +void +dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems, + enum dma_data_direction direction) +void +pci_dma_sync_sg_for_device(struct pci_dev *hwdev, struct scatterlist *sg, + int nelems, int direction) + +Synchronise a single contiguous or scatter/gather mapping for the cpu +and device. With the sync_sg API, all the parameters must be the same +as those passed into the single mapping API. With the sync_single API, +you can use dma_handle and size parameters that aren't identical to +those passed into the single mapping API to do a partial sync. + +Notes: You must do this: + +- Before reading values that have been written by DMA from the device + (use the DMA_FROM_DEVICE direction) +- After writing values that will be written to the device using DMA + (use the DMA_TO_DEVICE) direction +- before *and* after handing memory to the device if the memory is + DMA_BIDIRECTIONAL + +See also dma_map_single(). + dma_addr_t dma_map_single_attrs(struct device *dev, void *cpu_addr, size_t size, enum dma_data_direction dir, |