[patch] bitmap: add bitmap_copy_le()

[David Vrabel <david.vrabel@xxxxxxx>]

-- 
David Vrabel, Senior Software Engineer, Drivers
CSR, Churchill House, Cambridge Business Park,  Tel: +44 (0)1223 692562
Cowley Road, Cambridge, CB4 0WZ                 http://www.csr.com/

bitmap: add bitmap_copy_le()

From: David Vrabel <david.vrabel@xxxxxxx>

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@xxxxxxx>
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
 include/linux/bitmap.h |    1 +
 lib/bitmap.c           |   22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)

Index: linux-git/include/linux/bitmap.h
===================================================================
--- linux-git.orig/include/linux/bitmap.h	2008-08-12 14:51:02.000000000 +0100
+++ linux-git/include/linux/bitmap.h	2008-08-12 14:51:07.000000000 +0100
@@ -129,6 +129,7 @@
 extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
 extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
 extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
+extern void bitmap_copy_le(void *dst, const unsigned long *src, int nbits);
 
 #define BITMAP_LAST_WORD_MASK(nbits)					\
 (									\
Index: linux-git/lib/bitmap.c
===================================================================
--- linux-git.orig/lib/bitmap.c	2008-08-12 14:51:02.000000000 +0100
+++ linux-git/lib/bitmap.c	2008-08-12 14:51:07.000000000 +0100
@@ -996,3 +996,25 @@
 	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);