swiotlb: use iommu_is_span_boundary helper function

iommu_is_span_boundary in lib/iommu-helper.c was exported for PARISC IOMMUs
(commit 3715863aa142c4f4c5208f5f3e5e9bac06006d2f).  SWIOTLB can use it instead
of the homegrown function.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 11 deletions

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 256c8445e54d..3c95922e51e7 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -31,6 +31,7 @@
 
 #include <linux/init.h>
 #include <linux/bootmem.h>
+#include <linux/iommu-helper.h>
 
 #define OFFSET(val,align) ((unsigned long)      \
                            ( (val) & ( (align) - 1)))
@@ -282,15 +283,6 @@ address_needs_mapping(struct device *hwdev, dma_addr_t addr)
         return (addr & ~mask) != 0;
 }
 
-static inline unsigned int is_span_boundary(unsigned int index,
-                                            unsigned int nslots,
-                                            unsigned long offset_slots,
-                                            unsigned long max_slots)
-{
-        unsigned long offset = (offset_slots + index) & (max_slots - 1);
-        return offset + nslots > max_slots;
-}
-
 /*
  * Allocates bounce buffer and returns its kernel virtual address.
  */
@@ -337,8 +329,8 @@ map_single(struct device *hwdev, char *buffer, size_t size, int dir)
         wrap = index;
 
         do {
-                while (is_span_boundary(index, nslots, offset_slots,
-                                max_slots)) {
+                while (iommu_is_span_boundary(index, nslots, offset_slots,
+                                              max_slots)) {
                         index += stride;
                         if (index >= io_tlb_nslabs)
                                 index = 0;