From 3bc9f79ee1ddc913be0a6d3592036683ef8a3148 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 25 Jul 2008 14:57:58 +0200 Subject: 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: Joerg Roedel Cc: iommu@lists.linux-foundation.org Cc: bhavna.sarathy@amd.com Cc: robert.richter@amd.com Cc: FUJITA Tomonori Signed-off-by: Ingo Molnar --- lib/iommu-helper.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'lib') diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c index a3b8d4c3f77..889ddce2021 100644 --- a/lib/iommu-helper.c +++ b/lib/iommu-helper.c @@ -80,3 +80,11 @@ void iommu_area_free(unsigned long *map, unsigned long start, unsigned int nr) } } 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); -- cgit v1.2.3