diff options
| -rw-r--r-- | include/linux/dma-mapping.h | 80 | ||||
| -rw-r--r-- | include/linux/iommu.h | 16 | ||||
| -rw-r--r-- | include/linux/scatterlist.h | 50 |
3 files changed, 143 insertions, 3 deletions
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index b43116a6405d..78f677cf45ab 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -609,6 +609,86 @@ static inline void dma_sync_single_range_for_device(struct device *dev, return dma_sync_single_for_device(dev, addr + offset, size, dir); } +/** + * dma_map_sgtable - Map the given buffer for DMA + * @dev: The device for which to perform the DMA operation + * @sgt: The sg_table object describing the buffer + * @dir: DMA direction + * @attrs: Optional DMA attributes for the map operation + * + * Maps a buffer described by a scatterlist stored in the given sg_table + * object for the @dir DMA operation by the @dev device. After success the + * ownership for the buffer is transferred to the DMA domain. One has to + * call dma_sync_sgtable_for_cpu() or dma_unmap_sgtable() to move the + * ownership of the buffer back to the CPU domain before touching the + * buffer by the CPU. + * + * Returns 0 on success or -EINVAL on error during mapping the buffer. + */ +static inline int dma_map_sgtable(struct device *dev, struct sg_table *sgt, + enum dma_data_direction dir, unsigned long attrs) +{ + int nents; + + nents = dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs); + if (nents <= 0) + return -EINVAL; + sgt->nents = nents; + return 0; +} + +/** + * dma_unmap_sgtable - Unmap the given buffer for DMA + * @dev: The device for which to perform the DMA operation + * @sgt: The sg_table object describing the buffer + * @dir: DMA direction + * @attrs: Optional DMA attributes for the unmap operation + * + * Unmaps a buffer described by a scatterlist stored in the given sg_table + * object for the @dir DMA operation by the @dev device. After this function + * the ownership of the buffer is transferred back to the CPU domain. + */ +static inline void dma_unmap_sgtable(struct device *dev, struct sg_table *sgt, + enum dma_data_direction dir, unsigned long attrs) +{ + dma_unmap_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs); +} + +/** + * dma_sync_sgtable_for_cpu - Synchronize the given buffer for CPU access + * @dev: The device for which to perform the DMA operation + * @sgt: The sg_table object describing the buffer + * @dir: DMA direction + * + * Performs the needed cache synchronization and moves the ownership of the + * buffer back to the CPU domain, so it is safe to perform any access to it + * by the CPU. Before doing any further DMA operations, one has to transfer + * the ownership of the buffer back to the DMA domain by calling the + * dma_sync_sgtable_for_device(). + */ +static inline void dma_sync_sgtable_for_cpu(struct device *dev, + struct sg_table *sgt, enum dma_data_direction dir) +{ + dma_sync_sg_for_cpu(dev, sgt->sgl, sgt->orig_nents, dir); +} + +/** + * dma_sync_sgtable_for_device - Synchronize the given buffer for DMA + * @dev: The device for which to perform the DMA operation + * @sgt: The sg_table object describing the buffer + * @dir: DMA direction + * + * Performs the needed cache synchronization and moves the ownership of the + * buffer back to the DMA domain, so it is safe to perform the DMA operation. + * Once finished, one has to call dma_sync_sgtable_for_cpu() or + * dma_unmap_sgtable(). + */ +static inline void dma_sync_sgtable_for_device(struct device *dev, + struct sg_table *sgt, enum dma_data_direction dir) +{ + dma_sync_sg_for_device(dev, sgt->sgl, sgt->orig_nents, dir); +} + #define dma_map_single(d, a, s, r) dma_map_single_attrs(d, a, s, r, 0) #define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, 0) #define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, 0) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 7ef8b0bda695..b1bfbe6dff42 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -466,6 +466,22 @@ extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t io extern void iommu_set_fault_handler(struct iommu_domain *domain, iommu_fault_handler_t handler, void *token); +/** + * iommu_map_sgtable - Map the given buffer to the IOMMU domain + * @domain: The IOMMU domain to perform the mapping + * @iova: The start address to map the buffer + * @sgt: The sg_table object describing the buffer + * @prot: IOMMU protection bits + * + * Creates a mapping at @iova for the buffer described by a scatterlist + * stored in the given sg_table object in the provided IOMMU domain. + */ +static inline size_t iommu_map_sgtable(struct iommu_domain *domain, + unsigned long iova, struct sg_table *sgt, int prot) +{ + return iommu_map_sg(domain, iova, sgt->sgl, sgt->orig_nents, prot); +} + extern void iommu_get_resv_regions(struct device *dev, struct list_head *list); extern void iommu_put_resv_regions(struct device *dev, struct list_head *list); extern void generic_iommu_put_resv_regions(struct device *dev, diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index 6eec50fb36c8..4f922afb607a 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -151,6 +151,20 @@ static inline void sg_set_buf(struct scatterlist *sg, const void *buf, #define for_each_sg(sglist, sg, nr, __i) \ for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg)) +/* + * Loop over each sg element in the given sg_table object. + */ +#define for_each_sgtable_sg(sgt, sg, i) \ + for_each_sg(sgt->sgl, sg, sgt->orig_nents, i) + +/* + * Loop over each sg element in the given *DMA mapped* sg_table object. + * Please use sg_dma_address(sg) and sg_dma_len(sg) to extract DMA addresses + * of the each element. + */ +#define for_each_sgtable_dma_sg(sgt, sg, i) \ + for_each_sg(sgt->sgl, sg, sgt->nents, i) + /** * sg_chain - Chain two sglists together * @prv: First scatterlist @@ -401,9 +415,10 @@ sg_page_iter_dma_address(struct sg_dma_page_iter *dma_iter) * @sglist: sglist to iterate over * @piter: page iterator to hold current page, sg, sg_pgoffset * @nents: maximum number of sg entries to iterate over - * @pgoffset: starting page offset + * @pgoffset: starting page offset (in pages) * * Callers may use sg_page_iter_page() to get each page pointer. + * In each loop it operates on PAGE_SIZE unit. */ #define for_each_sg_page(sglist, piter, nents, pgoffset) \ for (__sg_page_iter_start((piter), (sglist), (nents), (pgoffset)); \ @@ -412,18 +427,47 @@ sg_page_iter_dma_address(struct sg_dma_page_iter *dma_iter) /** * for_each_sg_dma_page - iterate over the pages of the given sg list * @sglist: sglist to iterate over - * @dma_iter: page iterator to hold current page + * @dma_iter: DMA page iterator to hold current page * @dma_nents: maximum number of sg entries to iterate over, this is the value * returned from dma_map_sg - * @pgoffset: starting page offset + * @pgoffset: starting page offset (in pages) * * Callers may use sg_page_iter_dma_address() to get each page's DMA address. + * In each loop it operates on PAGE_SIZE unit. */ #define for_each_sg_dma_page(sglist, dma_iter, dma_nents, pgoffset) \ for (__sg_page_iter_start(&(dma_iter)->base, sglist, dma_nents, \ pgoffset); \ __sg_page_iter_dma_next(dma_iter);) +/** + * for_each_sgtable_page - iterate over all pages in the sg_table object + * @sgt: sg_table object to iterate over + * @piter: page iterator to hold current page + * @pgoffset: starting page offset (in pages) + * + * Iterates over the all memory pages in the buffer described by + * a scatterlist stored in the given sg_table object. + * See also for_each_sg_page(). In each loop it operates on PAGE_SIZE unit. + */ +#define for_each_sgtable_page(sgt, piter, pgoffset) \ + for_each_sg_page(sgt->sgl, piter, sgt->orig_nents, pgoffset) + +/** + * for_each_sgtable_dma_page - iterate over the DMA mapped sg_table object + * @sgt: sg_table object to iterate over + * @dma_iter: DMA page iterator to hold current page + * @pgoffset: starting page offset (in pages) + * + * Iterates over the all DMA mapped pages in the buffer described by + * a scatterlist stored in the given sg_table object. + * See also for_each_sg_dma_page(). In each loop it operates on PAGE_SIZE + * unit. + */ +#define for_each_sgtable_dma_page(sgt, dma_iter, pgoffset) \ + for_each_sg_dma_page(sgt->sgl, dma_iter, sgt->nents, pgoffset) + + /* * Mapping sg iterator * |