Commit c42b65e3 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Dmitry Torokhov
Browse files

bitmap: Add bitmap_alloc(), bitmap_zalloc() and bitmap_free() 



A lot of code become ugly because of open coding allocations for bitmaps.

Introduce three helpers to allow users be more clear of intention
and keep their code neat.

Note, due to multiple circular dependencies we may not provide
the helpers as inliners. For now we keep them exported and, perhaps,
at some point in the future we will sort out header inclusion and
inheritance.

Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent e64e4018

include/linux/bitmap.h

+8 −0
Original line number Diff line number Diff line
@@ -104,6 +104,14 @@ 
 * contain all bit positions from 0 to 'bits' - 1.

 */



/*

 * Allocation and deallocation of bitmap.

 * Provided in lib/bitmap.c to avoid circular dependency.

 */

extern unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);

extern unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);

extern void bitmap_free(const unsigned long *bitmap);



/*

 * lib/bitmap.c provides these functions:

 */

lib/bitmap.c

+20 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/bitops.h>

#include <linux/bug.h>

#include <linux/kernel.h>

#include <linux/slab.h>

#include <linux/string.h>

#include <linux/uaccess.h>
@@ -1128,6 +1129,25 @@ void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int n 
EXPORT_SYMBOL(bitmap_copy_le);

#endif



unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags)

{

	return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long),

			     flags);

}

EXPORT_SYMBOL(bitmap_alloc);



unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags)

{

	return bitmap_alloc(nbits, flags | __GFP_ZERO);

}

EXPORT_SYMBOL(bitmap_zalloc);



void bitmap_free(const unsigned long *bitmap)

{

	kfree(bitmap);

}

EXPORT_SYMBOL(bitmap_free);



#if BITS_PER_LONG == 64

/**

 * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap

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