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Commit d3086444 authored by Joerg Roedel's avatar Joerg Roedel Committed by Ingo Molnar
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x86, AMD IOMMU: add address allocation and deallocation functions 



This patch adds the address allocator to the AMD IOMMU code.

Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
Cc: iommu@lists.linux-foundation.org
Cc: bhavna.sarathy@amd.com
Cc: Sebastian.Biemueller@amd.com
Cc: robert.richter@amd.com
Cc: joro@8bytes.org
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent bd0e5211

arch/x86/kernel/amd_iommu.c

+48 −0
Original line number Diff line number Diff line
@@ -266,3 +266,51 @@ static int init_unity_mappings_for_device(struct dma_ops_domain *dma_dom, 
	return 0;

}



static unsigned long dma_mask_to_pages(unsigned long mask)

{

	return (mask >> PAGE_SHIFT) +

		(PAGE_ALIGN(mask & ~PAGE_MASK) >> PAGE_SHIFT);

}



static unsigned long dma_ops_alloc_addresses(struct device *dev,

					     struct dma_ops_domain *dom,

					     unsigned int pages)

{

	unsigned long limit = dma_mask_to_pages(*dev->dma_mask);

	unsigned long address;

	unsigned long size = dom->aperture_size >> PAGE_SHIFT;

	unsigned long boundary_size;



	boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,

			PAGE_SIZE) >> PAGE_SHIFT;

	limit = limit < size ? limit : size;



	if (dom->next_bit >= limit)

		dom->next_bit = 0;



	address = iommu_area_alloc(dom->bitmap, limit, dom->next_bit, pages,

			0 , boundary_size, 0);

	if (address == -1)

		address = iommu_area_alloc(dom->bitmap, limit, 0, pages,

				0, boundary_size, 0);



	if (likely(address != -1)) {

		set_bit_string(dom->bitmap, address, pages);

		dom->next_bit = address + pages;

		address <<= PAGE_SHIFT;

	} else

		address = bad_dma_address;



	WARN_ON((address + (PAGE_SIZE*pages)) > dom->aperture_size);



	return address;

}



static void dma_ops_free_addresses(struct dma_ops_domain *dom,

				   unsigned long address,

				   unsigned int pages)

{

	address >>= PAGE_SHIFT;

	iommu_area_free(dom->bitmap, address, pages);

}