Messages in this thread Patch in this message | | | Date | Thu, 21 Aug 2008 14:19:06 +0100 | From | David Vrabel <> | Subject | [patch] bitmap: add bitmap_copy_le() |
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-- 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@csr.com>
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> Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- 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); | |