参照元†
- struct device *dev
- dma_addr_t handle
- size_t size
- enum dma_data_direction dir
- struct dma_attrs *attrs
返り値†
/**
* arm_dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @handle: DMA address of buffer
* @size: size of buffer (same as passed to dma_map_page)
* @dir: DMA transfer direction (same as passed to dma_map_page)
*
* Unmap a page streaming mode DMA translation. The handle and size
* must match what was provided in the previous dma_map_page() call.
* All other usages are undefined.
*
* After this call, reads by the CPU to the buffer are guaranteed to see
* whatever the device wrote there.
*/
static void arm_dma_unmap_page(struct device *dev, dma_addr_t handle,
size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
__dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),
handle & ~PAGE_MASK, size, dir);
}
コメント†