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| author | Joerg Roedel <joerg.roedel@amd.com> | 2008-10-15 22:02:10 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-10-16 11:21:33 -0700 |
| commit | 56d936607408d71c4141b2ed501410b072f1e211 (patch) | |
| tree | 610b7e0d5a655c2bc69ea6179b6bd5be2f42dd8d /lib/iommu-helper.c | |
| parent | 3400001c531d283068a60e9f884f7de6f22314be (diff) | |
| download | lwn-56d936607408d71c4141b2ed501410b072f1e211.tar.gz lwn-56d936607408d71c4141b2ed501410b072f1e211.zip | |
introduce generic iommu_num_pages function
This patch introduces the generic iommu_num_pages function. It can be used by
a given memory area.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/iommu-helper.c')
| -rw-r--r-- | lib/iommu-helper.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c index 5d90074dca75..75dbda03f4fb 100644 --- a/lib/iommu-helper.c +++ b/lib/iommu-helper.c @@ -79,3 +79,12 @@ 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 io_page_size) +{ + unsigned long size = (addr & (io_page_size - 1)) + len; + + return DIV_ROUND_UP(size, io_page_size); +} +EXPORT_SYMBOL(iommu_num_pages); |