1 files changed, 17 insertions, 16 deletions

diff --git a/drivers/vfio/iova_bitmap.c b/drivers/vfio/iova_bitmap.c
index 6631e8befe1b..0848f920efb7 100644
--- a/drivers/vfio/iova_bitmap.c
+++ b/drivers/vfio/iova_bitmap.c
@@ -5,6 +5,7 @@
  */
 #include <linux/iova_bitmap.h>
 #include <linux/mm.h>
+#include <linux/slab.h>
 #include <linux/highmem.h>
 
 #define BITS_PER_PAGE (PAGE_SIZE * BITS_PER_BYTE)
@@ -295,11 +296,13 @@ void iova_bitmap_free(struct iova_bitmap *bitmap)
  */
 static unsigned long iova_bitmap_mapped_remaining(struct iova_bitmap *bitmap)
 {
-	unsigned long remaining;
+	unsigned long remaining, bytes;
+
+	bytes = (bitmap->mapped.npages << PAGE_SHIFT) - bitmap->mapped.pgoff;
 
 	remaining = bitmap->mapped_total_index - bitmap->mapped_base_index;
 	remaining = min_t(unsigned long, remaining,
-	      (bitmap->mapped.npages << PAGE_SHIFT) / sizeof(*bitmap->bitmap));
+			  bytes / sizeof(*bitmap->bitmap));
 
 	return remaining;
 }
@@ -394,29 +397,27 @@ int iova_bitmap_for_each(struct iova_bitmap *bitmap, void *opaque,
  * Set the bits corresponding to the range [iova .. iova+length-1] in
  * the user bitmap.
  *
- * Return: The number of bits set.
  */
 void iova_bitmap_set(struct iova_bitmap *bitmap,
 		     unsigned long iova, size_t length)
 {
 	struct iova_bitmap_map *mapped = &bitmap->mapped;
-	unsigned long offset = (iova - mapped->iova) >> mapped->pgshift;
-	unsigned long nbits = max_t(unsigned long, 1, length >> mapped->pgshift);
-	unsigned long page_idx = offset / BITS_PER_PAGE;
-	unsigned long page_offset = mapped->pgoff;
-	void *kaddr;
-
-	offset = offset % BITS_PER_PAGE;
+	unsigned long cur_bit = ((iova - mapped->iova) >>
+			mapped->pgshift) + mapped->pgoff * BITS_PER_BYTE;
+	unsigned long last_bit = (((iova + length - 1) - mapped->iova) >>
+			mapped->pgshift) + mapped->pgoff * BITS_PER_BYTE;
 
 	do {
-		unsigned long size = min(BITS_PER_PAGE - offset, nbits);
+		unsigned int page_idx = cur_bit / BITS_PER_PAGE;
+		unsigned int offset = cur_bit % BITS_PER_PAGE;
+		unsigned int nbits = min(BITS_PER_PAGE - offset,
+					 last_bit - cur_bit + 1);
+		void *kaddr;
 
 		kaddr = kmap_local_page(mapped->pages[page_idx]);
-		bitmap_set(kaddr + page_offset, offset, size);
+		bitmap_set(kaddr, offset, nbits);
 		kunmap_local(kaddr);
-		page_offset = offset = 0;
-		nbits -= size;
-		page_idx++;
-	} while (nbits > 0);
+		cur_bit += nbits;
+	} while (cur_bit <= last_bit);
 }
 EXPORT_SYMBOL_GPL(iova_bitmap_set);