参照元†
- struct device *dev
- struct page *page
- unsigned long offset
- size_t size
- enum dma_data_direction dir
- struct dma_attrs *attrs
返り値†
/**
* arm_dma_map_page - map a portion of a page for streaming DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @page: page that buffer resides in
* @offset: offset into page for start of buffer
* @size: size of buffer to map
* @dir: DMA transfer direction
*
* Ensure that any data held in the cache is appropriately discarded
* or written back.
*
* The device owns this memory once this call has completed. The CPU
* can regain ownership by calling dma_unmap_page().
*/
static dma_addr_t arm_dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
__dma_page_cpu_to_dev(page, offset, size, dir);
return pfn_to_dma(dev, page_to_pfn(page)) + offset;
}
コメント†