From 3715863aa142c4f4c5208f5f3e5e9bac06006d2f Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Tue, 4 Mar 2008 14:29:27 -0800 Subject: 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 Cc: Kyle McMartin Cc: Matthew Wilcox Cc: Grant Grundler Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 4dd4c04ff2f..c975caf7538 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 495575a59ca..a3b8d4c3f77 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; -- cgit v1.2.3