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.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/iommu-helper.h | 3 +++
lib/iommu-helper.c | 10 ++++++----
2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/include/linux/iommu-helper.h b/include/linux/iommu-helper.h
index 4dd4c04..c975caf 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 495575a..a3b8d4c 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, ...
