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Commit 3bc9f79e authored by Joerg Roedel's avatar Joerg Roedel Committed by Ingo Molnar
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iommu: add iommu_num_pages helper function 



Calculating the number of pages from given address and length numbers is a task
required in multiple IOMMU implementations. So implement this as a generic
function into the IOMMU helper code.

Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
Cc: iommu@lists.linux-foundation.org
Cc: bhavna.sarathy@amd.com
Cc: robert.richter@amd.com
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 024e8ac0

include/linux/iommu-helper.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -8,3 +8,4 @@ extern unsigned long iommu_area_alloc(unsigned long *map, unsigned long size, 
				      unsigned long align_mask);

				      unsigned long align_mask);

extern void iommu_area_free(unsigned long *map, unsigned long start,

extern void iommu_area_free(unsigned long *map, unsigned long start,

			    unsigned int nr);

			    unsigned int nr);

extern unsigned long iommu_num_pages(unsigned long addr, unsigned long len);

lib/iommu-helper.c

+8 −0
Original line number Original line Diff line number Diff line
@@ -80,3 +80,11 @@ void iommu_area_free(unsigned long *map, unsigned long start, unsigned int nr) 
	}

	}

}

}

EXPORT_SYMBOL(iommu_area_free);

EXPORT_SYMBOL(iommu_area_free);



unsigned long iommu_num_pages(unsigned long addr, unsigned long len)

{

	unsigned long size = roundup((addr & ~PAGE_MASK) + len, PAGE_SIZE);



	return size >> PAGE_SHIFT;

}

EXPORT_SYMBOL(iommu_num_pages);