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authorJoerg Roedel <joerg.roedel@amd.com>2008-10-15 22:02:10 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-16 11:21:33 -0700
commit56d936607408d71c4141b2ed501410b072f1e211 (patch)
tree610b7e0d5a655c2bc69ea6179b6bd5be2f42dd8d /lib/iommu-helper.c
parent3400001c531d283068a60e9f884f7de6f22314be (diff)
downloadlinux-linaro-stable-56d936607408d71c4141b2ed501410b072f1e211.tar.gz
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.c9
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);