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Commit 5cf0a76f authored by David Woodhouse's avatar David Woodhouse
Browse files

iommu/vt-d: Clean up size handling for intel_iommu_unmap() 



We have this horrid API where iommu_unmap() can unmap more than it's asked
to, if the IOVA in question happens to be mapped with a large page.

Instead of propagating this nonsense to the point where we end up returning
the page order from dma_pte_clear_range(), let's just do it once and adjust
the 'size' parameter accordingly.

Augment pfn_to_dma_pte() to return the level at which the PTE was found,
which will also be useful later if we end up changing the API for
iommu_iova_to_phys() to behave the same way as is being discussed upstream.

Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 75f05569

drivers/iommu/intel-iommu.c

+25 −12
Original line number Diff line number Diff line
@@ -784,7 +784,7 @@ static void free_context_table(struct intel_iommu *iommu) 
}



static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,

				      unsigned long pfn, int target_level)

				      unsigned long pfn, int *target_level)

{

	int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;

	struct dma_pte *parent, *pte = NULL;
@@ -799,14 +799,14 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain, 


	parent = domain->pgd;



	while (level > 0) {

	while (1) {

		void *tmp_page;



		offset = pfn_level_offset(pfn, level);

		pte = &parent[offset];

		if (!target_level && (dma_pte_superpage(pte) || !dma_pte_present(pte)))

		if (!*target_level && (dma_pte_superpage(pte) || !dma_pte_present(pte)))

			break;

		if (level == target_level)

		if (level == *target_level)

			break;



		if (!dma_pte_present(pte)) {
@@ -827,10 +827,16 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain, 
				domain_flush_cache(domain, pte, sizeof(*pte));

			}

		}

		if (level == 1)

			break;



		parent = phys_to_virt(dma_pte_addr(pte));

		level--;

	}



	if (!*target_level)

		*target_level = level;



	return pte;

}
@@ -868,7 +874,7 @@ static struct dma_pte *dma_pfn_level_pte(struct dmar_domain *domain, 
}



/* clear last level pte, a tlb flush should be followed */

static int dma_pte_clear_range(struct dmar_domain *domain,

static void dma_pte_clear_range(struct dmar_domain *domain,

				unsigned long start_pfn,

				unsigned long last_pfn)

{
@@ -898,8 +904,6 @@ static int dma_pte_clear_range(struct dmar_domain *domain, 
				   (void *)pte - (void *)first_pte);



	} while (start_pfn && start_pfn <= last_pfn);



	return min_t(int, (large_page - 1) * 9, MAX_AGAW_PFN_WIDTH);

}



static void dma_pte_free_level(struct dmar_domain *domain, int level,
@@ -1832,7 +1836,7 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn, 
		if (!pte) {

			largepage_lvl = hardware_largepage_caps(domain, iov_pfn, phys_pfn, sg_res);



			first_pte = pte = pfn_to_dma_pte(domain, iov_pfn, largepage_lvl);

			first_pte = pte = pfn_to_dma_pte(domain, iov_pfn, &largepage_lvl);

			if (!pte)

				return -ENOMEM;

			/* It is large page*/
@@ -4099,15 +4103,23 @@ static size_t intel_iommu_unmap(struct iommu_domain *domain, 
			     unsigned long iova, size_t size)

{

	struct dmar_domain *dmar_domain = domain->priv;

	int order;

	int level = 0;



	/* Cope with horrid API which requires us to unmap more than the

	   size argument if it happens to be a large-page mapping. */

	if (!pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level))

		BUG();



	if (size < VTD_PAGE_SIZE << level_to_offset_bits(level))

		size = VTD_PAGE_SIZE << level_to_offset_bits(level);



	order = dma_pte_clear_range(dmar_domain, iova >> VTD_PAGE_SHIFT,

	dma_pte_clear_range(dmar_domain, iova >> VTD_PAGE_SHIFT,

			    (iova + size - 1) >> VTD_PAGE_SHIFT);



	if (dmar_domain->max_addr == iova + size)

		dmar_domain->max_addr = iova;



	return PAGE_SIZE << order;

	return size;

}



static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
@@ -4115,9 +4127,10 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain, 
{

	struct dmar_domain *dmar_domain = domain->priv;

	struct dma_pte *pte;

	int level = 0;

	u64 phys = 0;



	pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, 0);

	pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level);

	if (pte)

		phys = dma_pte_addr(pte);