Messages in this thread Patch in this message | | | From | Joerg Roedel <> | Subject | [PATCH] add iommu_num_pages helper function | Date | Fri, 25 Jul 2008 14:57:58 +0200 |
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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.
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> --- include/linux/iommu-helper.h | 1 + lib/iommu-helper.c | 8 ++++++++ 2 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/include/linux/iommu-helper.h b/include/linux/iommu-helper.h index c975caf..f8598f5 100644 --- a/include/linux/iommu-helper.h +++ b/include/linux/iommu-helper.h @@ -8,3 +8,4 @@ extern unsigned long iommu_area_alloc(unsigned long *map, unsigned long size, unsigned long align_mask); extern void iommu_area_free(unsigned long *map, unsigned long start, unsigned int nr); +extern unsigned long iommu_num_pages(unsigned long addr, unsigned long len); diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c index a3b8d4c..889ddce 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); -- 1.5.3.7
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