Commit 816c698c authored by Chunyan Zhang's avatar Chunyan Zhang Committed by Joerg Roedel
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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: default avatarChunyan Zhang <chunyan.zhang@unisoc.com>
Link: https://lore.kernel.org/r/20230331033124.864691-3-zhang.lyra@gmail.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 9afea573

drivers/iommu/sprd-iommu.c

+19 −6
Original line number Diff line number Diff line
@@ -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;



	/* 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;

	}



	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);