From mboxrd@z Thu Jan 1 00:00:00 1970 From: ohaugan@codeaurora.org (Olav Haugan) Date: Tue, 12 Aug 2014 09:56:11 -0700 Subject: [PATCH v5 1/1] iommu-api: Add map_sg/unmap_sg functions In-Reply-To: References: <1407797150-515-1-git-send-email-ohaugan@codeaurora.org> <1407797150-515-2-git-send-email-ohaugan@codeaurora.org> <871tsm5vcn.fsf@nvidia.com> Message-ID: <53EA472B.3020900@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 8/12/2014 3:48 AM, Rob Clark wrote: > On Mon, Aug 11, 2014 at 9:51 PM, Hiroshi Doyu wrote: >> Hi Olav, >> >> Olav Haugan writes: >> >>> @@ -93,6 +94,10 @@ enum iommu_attr { >>> * @detach_dev: detach device from an iommu domain >>> * @map: map a physically contiguous memory region to an iommu domain >>> * @unmap: unmap a physically contiguous memory region from an iommu domain >>> + * @map_sg: map a scatter-gather list of physically contiguous memory chunks >>> + * to an iommu domain >>> + * @unmap_sg: unmap a scatter-gather list of physically contiguous memory >>> + * chunks from an iommu domain >>> * @iova_to_phys: translate iova to physical address >>> * @domain_has_cap: domain capabilities query >>> * @add_device: add device to iommu grouping >>> @@ -110,6 +115,11 @@ struct iommu_ops { >>> phys_addr_t paddr, size_t size, int prot); >>> size_t (*unmap)(struct iommu_domain *domain, unsigned long iova, >>> size_t size); >>> + int (*map_sg)(struct iommu_domain *domain, unsigned long iova, >>> + struct scatterlist *sg, unsigned int nents, int prot, >>> + unsigned long flags); >>> + int (*unmap_sg)(struct iommu_domain *domain, unsigned long iova, >>> + size_t size, unsigned long flags); >> >> Do you have any exmaple/explanation for the above "flags"? >> >> Is this going to be used for iommu global/standard attribute or SoC >> spcific one? > > iirc, one plan for 'flags' was some sort of DONT_FLUSH_TLB flag for > drivers which wanted to map/unmap N buffers with a single flush at the > end. There might have been some other usages envisioned. > Yes, that was the original intent of the flags for now. I am sure we can find other uses for this in the future. Thanks, Olav -- The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation