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Commit 3715863a authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by Linus Torvalds
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iommu: export iommu_is_span_boundary helper function 



iommu_is_span_boundary is used internally in the IOMMU helper
(lib/iommu-helper.c), a primitive function that judges whether a memory area
spans LLD's segment boundary or not.

It's difficult to convert some IOMMUs to use the IOMMU helper but
iommu_is_span_boundary is still useful for them.  So this patch exports it.

This is needed for the parisc iommu fixes.

Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7eb701dc

include/linux/iommu-helper.h

+3 −0
Original line number Diff line number Diff line 
extern int iommu_is_span_boundary(unsigned int index, unsigned int nr,

				  unsigned long shift,

				  unsigned long boundary_size);

extern unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,

				      unsigned long start, unsigned int nr,

				      unsigned long shift,

lib/iommu-helper.c

+6 −4
Original line number Diff line number Diff line
@@ -40,10 +40,12 @@ static inline void set_bit_area(unsigned long *map, unsigned long i, 
	}

}



static inline int is_span_boundary(unsigned int index, unsigned int nr,

int iommu_is_span_boundary(unsigned int index, unsigned int nr,

			   unsigned long shift,

			   unsigned long boundary_size)

{

	BUG_ON(!is_power_of_2(boundary_size));



	shift = (shift + index) & (boundary_size - 1);

	return shift + nr > boundary_size;

}
@@ -57,7 +59,7 @@ unsigned long iommu_area_alloc(unsigned long *map, unsigned long size, 
again:

	index = find_next_zero_area(map, size, start, nr, align_mask);

	if (index != -1) {

		if (is_span_boundary(index, nr, shift, boundary_size)) {

		if (iommu_is_span_boundary(index, nr, shift, boundary_size)) {

			/* we could do more effectively */

			start = index + 1;

			goto again;