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Commit 5a5e02a6 authored by David Woodhouse's avatar David Woodhouse
Browse files

intel-iommu: Fix dma vs. mm page confusion with aligned_nrpages() 



The aligned_nrpages() function rounds up to the next VM page, but
returns its result as a number of DMA pages.

Purely theoretical except on IA64, which doesn't boot with VT-d right
now anyway.

Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 405d7ca5

drivers/pci/intel-iommu.c

+7 −5
Original line number Diff line number Diff line
@@ -2368,15 +2368,15 @@ int __init init_dmars(void) 
	return ret;

}



/* Returns a number of VTD pages, but aligned to MM page size */

static inline unsigned long aligned_nrpages(unsigned long host_addr,

					    size_t size)

{

	host_addr &= ~PAGE_MASK;

	host_addr += size + PAGE_SIZE - 1;



	return host_addr >> VTD_PAGE_SHIFT;

	return PAGE_ALIGN(host_addr + size) >> VTD_PAGE_SHIFT;

}



/* This takes a number of _MM_ pages, not VTD pages */

static struct iova *intel_alloc_iova(struct device *dev,

				     struct dmar_domain *domain,

				     unsigned long nrpages, uint64_t dma_mask)
@@ -2506,7 +2506,8 @@ static dma_addr_t __intel_map_single(struct device *hwdev, phys_addr_t paddr, 
	iommu = domain_get_iommu(domain);

	size = aligned_nrpages(paddr, size);



	iova = intel_alloc_iova(hwdev, domain, size, pdev->dma_mask);

	iova = intel_alloc_iova(hwdev, domain, dma_to_mm_pfn(size),

				pdev->dma_mask);

	if (!iova)

		goto error;
@@ -2797,7 +2798,8 @@ static int intel_map_sg(struct device *hwdev, struct scatterlist *sglist, int ne 
	for_each_sg(sglist, sg, nelems, i)

		size += aligned_nrpages(sg->offset, sg->length);



	iova = intel_alloc_iova(hwdev, domain, size, pdev->dma_mask);

	iova = intel_alloc_iova(hwdev, domain, dma_to_mm_pfn(size),

				pdev->dma_mask);

	if (!iova) {

		sglist->dma_length = 0;

		return 0;