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authorJoerg Roedel <joerg.roedel@amd.com>2008-07-25 14:57:58 +0200
committerIngo Molnar <mingo@elte.hu>2008-07-26 15:43:05 +0200
commit3bc9f79ee1ddc913be0a6d3592036683ef8a3148 (patch)
tree21f0dc5f5feb140d8566e22fa3c7ecac009e27f3 /lib
parent024e8ac04453b3525448c31ef39848cf675ba6db (diff)
downloadconfigs-3bc9f79ee1ddc913be0a6d3592036683ef8a3148.tar.gz
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 <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: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'lib')
-rw-r--r--lib/iommu-helper.c8
1 files changed, 8 insertions, 0 deletions
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);