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

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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: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Andy Shevchenko 2018-08-01 15:42:56 -07:00 committed by Dmitry Torokhov
parent e64e4018d5
commit c42b65e363
2 changed files with 28 additions and 0 deletions
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8
include/linux/bitmap.h
View File

@ -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:
*/

20
lib/bitmap.c
View File

@ -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