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authorFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>2008-03-04 14:29:27 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-03-04 16:35:17 -0800
commit3715863aa142c4f4c5208f5f3e5e9bac06006d2f (patch)
treecd93a86f90bfd8e9bef9cbcf40abde55acc26b80
parent7eb701dc7779794d46e02a7fa1380289cb730d46 (diff)
downloadkernel-3715863aa142c4f4c5208f5f3e5e9bac06006d2f.tar.gz
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>
-rw-r--r--include/linux/iommu-helper.h3
-rw-r--r--lib/iommu-helper.c10
2 files changed, 9 insertions, 4 deletions
diff --git a/include/linux/iommu-helper.h b/include/linux/iommu-helper.h
index 4dd4c04ff2f4..c975caf75385 100644
--- a/include/linux/iommu-helper.h
+++ b/include/linux/iommu-helper.h
@@ -1,3 +1,6 @@
+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,
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;