diff options
| author |   Marek Szyprowski <m.szyprowski@samsung.com> | 2020-05-13 15:32:10 +0200 |
|---|---|---|
| committer |   Christoph Hellwig <hch@lst.de> | 2020-05-13 15:48:20 +0200 |
| commit | 48530d9fab0d3bf08827f9167be54acf66d4d457 (patch) | |
| tree | e33ceb3a5ed8858d292e8856ea2029a13b04e7b3 | |
| parent | scatterlist: add generic wrappers for iterating over sgtable objects (diff) | |
| download | wireguard-linux-48530d9fab0d3bf08827f9167be54acf66d4d457.tar.xz wireguard-linux-48530d9fab0d3bf08827f9167be54acf66d4d457.zip | |
iommu: add generic helper for mapping sgtable objects
struct sg_table is a common structure used for describing a memory
buffer. It consists of a scatterlist with memory pages and DMA addresses
(sgl entry), as well as the number of scatterlist entries: CPU pages
(orig_nents entry) and DMA mapped pages (nents entry).
It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling mapping functions with a wrong number of entries.
To avoid such issues, lets introduce a common wrapper operating directly
on the struct sg_table objects, which take care of the proper use of
the nents and orig_nents entries.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
| -rw-r--r-- | include/linux/iommu.h | 16 |
1 files changed, 16 insertions, 0 deletions
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, |