bitmap: add bitmap_copy_le()

bitmap_copy_le() copies a bitmap, putting the bits into little-endian
order (i.e., each unsigned long word in the bitmap is put into
little-endian order).

The UWB stack used bitmaps to manage Medium Access Slot availability,
and these bitmaps need to be written to the hardware in LE order.

Signed-off-by: David Vrabel <david.vrabel@csr.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/lib/bitmap.c b/lib/bitmap.c
index 06fb57c86de0..c2006bfeea41 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -1007,3 +1007,25 @@ int bitmap_allocate_region(unsigned long *bitmap, int pos, int order)
         return 0;
 }
 EXPORT_SYMBOL(bitmap_allocate_region);
+
+/**
+ * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order.
+ * @dst:   destination buffer
+ * @src:   bitmap to copy
+ * @nbits: number of bits in the bitmap
+ *
+ * Require nbits % BITS_PER_LONG == 0.
+ */
+void bitmap_copy_le(void *dst, const unsigned long *src, int nbits)
+{
+        unsigned long *d = dst;
+        int i;
+
+        for (i = 0; i < nbits/BITS_PER_LONG; i++) {
+                if (BITS_PER_LONG == 64)
+                        d[i] = cpu_to_le64(src[i]);
+                else
+                        d[i] = cpu_to_le32(src[i]);
+        }
+}
+EXPORT_SYMBOL(bitmap_copy_le);