/**
* dma_map_sg - map a set of SG buffers for streaming mode DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map
* @dir: DMA transfer direction
*
* Map a set of buffers described by scatterlist in streaming mode for DMA.
* This is the scatter-gather version of the dma_map_single interface.
* Here the scatter gather list elements are each tagged with the
* appropriate dma address and length. They are obtained via
* sg_dma_{address,length}.
*
* Device ownership issues as mentioned for dma_map_single are the same
* here.
*/
int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
struct scatterlist *s;
int i, j;
BUG_ON(!valid_dma_direction(dir));
for_each_sg(sg, s, nents, i) {
s->dma_address = __dma_map_page(dev, sg_page(s), s->offset,
s->length, dir);
if (dma_mapping_error(dev, s->dma_address))
goto bad_mapping;
}
/**
* dma_map_sg - map a set of SG buffers for streaming mode DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map
* @dir: DMA transfer direction
*
* Map a set of buffers described by scatterlist in streaming mode for DMA.
* This is the scatter-gather version of the dma_map_single interface.
* Here the scatter gather list elements are each tagged with the
* appropriate dma address and length. They are obtained via
* sg_dma_{address,length}.
*
* Device ownership issues as mentioned for dma_map_single are the same
* here.
*/
int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
dma_addr_t dma_address;
struct scatterlist *s;
int i, j;
BUG_ON(!valid_dma_direction(dir));
for_each_sg(sg, s, nents, i) {
dma_address = __dma_map_page(dev, sg_page(s), s->offset,
s->length, dir);
/* When the page doesn't have a valid PFN, we assume that
* dma_address is already present. */
if (pfn_valid(page_to_pfn(sg_page(s))))
s->dma_address = dma_address;
#ifdef CONFIG_NEED_SG_DMA_LENGTH
s->dma_length = s->length;
#endif
if (dma_mapping_error(dev, s->dma_address))
goto bad_mapping;
}
