Messages in this thread | | | Date | Thu, 11 Feb 2010 13:36:27 -0800 | From | Abhijeet Dharmapurikar <> | Subject | Re: [RFC 0/2] fix dma_map_sg not to do barriers for each buffer |
| |
> } > @@ -363,7 +366,7 @@ static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr, > * The device owns this memory once this call has completed. The CPU > * can regain ownership by calling dma_unmap_page(). > */ > -static inline dma_addr_t dma_map_page(struct device *dev, struct page *page, > +static inline dma_addr_t __dma_map_page(struct device *dev, struct page *page, > unsigned long offset, size_t size, enum dma_data_direction dir) > { > BUG_ON(!valid_dma_direction(dir)); > @@ -373,6 +376,14 @@ static inline dma_addr_t dma_map_page(struct device *dev, struct page *page, > return page_to_dma(dev, page) + offset; > } > > +static inline dma_addr_t dma_map_page(struct device *dev, struct page *page, > + unsigned long offset, size_t size, enum dma_data_direction dir) > +{ > + dma_addr_t addr = __dma_map_page(page, offset, size, dir); > + __dma_barrier(dir); > + return addr; > +} > + > /** . . . . > /** > * 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 > @@ -532,11 +539,14 @@ int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, > int i, j; > > for_each_sg(sg, s, nents, i) { > - s->dma_address = dma_map_page(dev, sg_page(s), s->offset, > + 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_barrier(dir); > + > return nents; > > bad_mapping: > @@ -564,6 +574,8 @@ void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, > > for_each_sg(sg, s, nents, i) > dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir); > + > + __dma_barrier(dir); > } > EXPORT_SYMBOL(dma_unmap_sg);
dma_unmap_sg too could use indirection like dma_map_sg.
Thanks for the patch. Abhijeet
| |