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Commit 56d93660 authored by Joerg Roedel's avatar Joerg Roedel Committed by Linus Torvalds
Browse files

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: default avatarJoerg 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3400001c

include/linux/iommu-helper.h

+3 −0
Original line number Diff line number Diff line
@@ -23,4 +23,7 @@ extern unsigned long iommu_area_alloc(unsigned long *map, unsigned long size, 
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,

				     unsigned long io_page_size);



#endif

lib/iommu-helper.c

+9 −0
Original line number Diff line number Diff line
@@ -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);