Adding APIs in arm dma mapping code to map a scatterlist in iommu domain and get dma address. Allocators outside dma-mapping code like ION could allocate pages and devices would need to map them for iommu and obtain a linear dma address. Intention is to re-use the IOVA managment code and "mapping" across allocators.
Can the above requirement be done without adding new APIs? APIs available to map an sglist (arm_dma_map_sg) does not provide a linear dma address.
Signed-off-by: Nishanth Peethambaran nishanth@broadcom.com --- arch/arm/include/asm/dma-mapping.h | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index 5b579b9..f9e2f6c 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -268,6 +268,16 @@ extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, in extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt, void *cpu_addr, dma_addr_t dma_addr, size_t size, struct dma_attrs *attrs); +/* + * Map scatterlist pages for the device and return a dma address + */ +extern dma_addr_t arm_dma_map_sgtable(struct device *dev, struct sgtable *sgt, + enum dma_data_direction dir, struct dma_attrs *attrs); +/* + * Unmap the dma address + */ +extern void arm_dma_unmap(struct device *, dma_addr_t iova, int size, + enum dma_data_direction dir, struct dma_attrs *attrs);
#endif /* __KERNEL__ */ #endif