From: Chunyan Zhang Date: Fri, 31 Mar 2023 03:31:24 +0000 (+0800) Subject: iommu/sprd: Add support for reattaching an existing domain X-Git-Tag: v6.6-pxa1908~1313^2^10 X-Git-Url: https://git.dujemihanovic.xyz/?a=commitdiff_plain;h=816c698c052471f525bea92ff0aeeda8a5844a85;p=linux.git iommu/sprd: Add support for reattaching an existing domain This IOMMU driver should allow a domain to be attached more than once. If IOMMU is reattaching to the same domain which is attached, there's nothing to be done. If reattching to a previously-used domain, do not alloc DMA buffer again which stores address mapping table to avoid memory leak. Signed-off-by: Chunyan Zhang Link: https://lore.kernel.org/r/20230331033124.864691-3-zhang.lyra@gmail.com Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/sprd-iommu.c b/drivers/iommu/sprd-iommu.c index 7df1f730c778..3513b2b108bf 100644 --- a/drivers/iommu/sprd-iommu.c +++ b/drivers/iommu/sprd-iommu.c @@ -62,6 +62,7 @@ enum sprd_iommu_version { * @eb: gate clock which controls IOMMU access */ struct sprd_iommu_device { + struct sprd_iommu_domain *dom; enum sprd_iommu_version ver; u32 *prot_page_va; dma_addr_t prot_page_pa; @@ -252,15 +253,27 @@ static int sprd_iommu_attach_device(struct iommu_domain *domain, struct sprd_iommu_domain *dom = to_sprd_domain(domain); size_t pgt_size = sprd_iommu_pgt_size(domain); - if (dom->sdev) - return -EINVAL; + /* The device is attached to this domain */ + if (sdev->dom == dom) + return 0; - dom->pgt_va = dma_alloc_coherent(sdev->dev, pgt_size, &dom->pgt_pa, GFP_KERNEL); - if (!dom->pgt_va) - return -ENOMEM; + /* The first time that domain is attaching to a device */ + if (!dom->pgt_va) { + dom->pgt_va = dma_alloc_coherent(sdev->dev, pgt_size, &dom->pgt_pa, GFP_KERNEL); + if (!dom->pgt_va) + return -ENOMEM; + + dom->sdev = sdev; + } - dom->sdev = sdev; + sdev->dom = dom; + /* + * One sprd IOMMU serves one client device only, disabled it before + * configure mapping table to avoid access conflict in case other + * mapping table is stored in. + */ + sprd_iommu_hw_en(sdev, false); sprd_iommu_first_ppn(dom); sprd_iommu_first_vpn(dom); sprd_iommu_vpn_range(dom);