Commit 7bfa5bd2 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

iommu/amd: Build io page-tables with cmpxchg64 



This allows to build up the page-tables without holding any
locks. As a consequence it removes the need to pre-populate
dma_ops page-tables.

Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 266a3bd2

drivers/iommu/amd_iommu.c

+13 −3
Original line number Diff line number Diff line
@@ -1206,11 +1206,21 @@ static u64 *alloc_pte(struct protection_domain *domain, 
	end_lvl = PAGE_SIZE_LEVEL(page_size);



	while (level > end_lvl) {

		if (!IOMMU_PTE_PRESENT(*pte)) {

		u64 __pte, __npte;



		__pte = *pte;



		if (!IOMMU_PTE_PRESENT(__pte)) {

			page = (u64 *)get_zeroed_page(gfp);

			if (!page)

				return NULL;

			*pte = PM_LEVEL_PDE(level, virt_to_phys(page));



			__npte = PM_LEVEL_PDE(level, virt_to_phys(page));



			if (cmpxchg64(pte, __pte, __npte)) {

				free_page((unsigned long)page);

				continue;

			}

		}



		/* No level skipping support yet */
@@ -1607,7 +1617,7 @@ static unsigned long dma_ops_alloc_addresses(struct device *dev, 
		address = dma_ops_area_alloc(dev, dom, pages,

					     align_mask, dma_mask);



		if (address == -1 && alloc_new_range(dom, true, GFP_ATOMIC))

		if (address == -1 && alloc_new_range(dom, false, GFP_ATOMIC))

			break;

	}