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| author | FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> | 2008-03-04 14:29:27 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-03-04 16:35:17 -0800 |
| commit | 3715863aa142c4f4c5208f5f3e5e9bac06006d2f (patch) | |
| tree | cd93a86f90bfd8e9bef9cbcf40abde55acc26b80 /lib/iommu-helper.c | |
| parent | 7eb701dc7779794d46e02a7fa1380289cb730d46 (diff) | |
| download | lwn-3715863aa142c4f4c5208f5f3e5e9bac06006d2f.tar.gz lwn-3715863aa142c4f4c5208f5f3e5e9bac06006d2f.zip | |
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: FUJITA 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: 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 | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c index 495575a59ca6..a3b8d4c3f77a 100644 --- a/lib/iommu-helper.c +++ b/lib/iommu-helper.c @@ -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, - unsigned long shift, - unsigned long boundary_size) +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; |