Commit 6cb42f91 authored by Yury Norov's avatar Yury Norov
Browse files

bitmap: move bitmap_*_region() functions to bitmap.h 



Now that bitmap_*_region() functions are implemented as thin wrappers
around others, it's worth to move them to the header, as it opens room
for compile-time optimizations.

CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
CC: Rasmus Villemoes <linux@rasmusvillemoes.dk>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarYury Norov <yury.norov@gmail.com>
parent 1d483652

include/linux/bitmap.h

+61 −3
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 


#include <linux/align.h>

#include <linux/bitops.h>

#include <linux/errno.h>

#include <linux/find.h>

#include <linux/limits.h>

#include <linux/string.h>
@@ -209,9 +210,6 @@ void bitmap_onto(unsigned long *dst, const unsigned long *orig, 
		const unsigned long *relmap, unsigned int bits);

void bitmap_fold(unsigned long *dst, const unsigned long *orig,

		unsigned int sz, unsigned int nbits);

int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);

void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);

int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);



#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))

#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
@@ -497,6 +495,66 @@ static inline void bitmap_next_set_region(unsigned long *bitmap, 
	*re = find_next_zero_bit(bitmap, end, *rs + 1);

}



/**

 * bitmap_release_region - release allocated bitmap region

 *	@bitmap: array of unsigned longs corresponding to the bitmap

 *	@pos: beginning of bit region to release

 *	@order: region size (log base 2 of number of bits) to release

 *

 * This is the complement to __bitmap_find_free_region() and releases

 * the found region (by clearing it in the bitmap).

 */

static inline void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)

{

	bitmap_clear(bitmap, pos, BIT(order));

}



/**

 * bitmap_allocate_region - allocate bitmap region

 *	@bitmap: array of unsigned longs corresponding to the bitmap

 *	@pos: beginning of bit region to allocate

 *	@order: region size (log base 2 of number of bits) to allocate

 *

 * Allocate (set bits in) a specified region of a bitmap.

 *

 * Returns: 0 on success, or %-EBUSY if specified region wasn't

 * free (not all bits were zero).

 */

static inline int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)

{

	unsigned int len = BIT(order);



	if (find_next_bit(bitmap, pos + len, pos) < pos + len)

		return -EBUSY;

	bitmap_set(bitmap, pos, len);

	return 0;

}



/**

 * bitmap_find_free_region - find a contiguous aligned mem region

 *	@bitmap: array of unsigned longs corresponding to the bitmap

 *	@bits: number of bits in the bitmap

 *	@order: region size (log base 2 of number of bits) to find

 *

 * Find a region of free (zero) bits in a @bitmap of @bits bits and

 * allocate them (set them to one).  Only consider regions of length

 * a power (@order) of two, aligned to that power of two, which

 * makes the search algorithm much faster.

 *

 * Returns: the bit offset in bitmap of the allocated region,

 * or -errno on failure.

 */

static inline int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)

{

	unsigned int pos, end;		/* scans bitmap by regions of size order */



	for (pos = 0; (end = pos + BIT(order)) <= bits; pos = end) {

		if (!bitmap_allocate_region(bitmap, pos, order))

			return pos;

	}

	return -ENOMEM;

}



/**

 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.

 * @n: u64 value

lib/bitmap.c

+0 −64
Original line number Diff line number Diff line
@@ -8,7 +8,6 @@ 
#include <linux/bitops.h>

#include <linux/ctype.h>

#include <linux/device.h>

#include <linux/errno.h>

#include <linux/export.h>

#include <linux/slab.h>
@@ -708,69 +707,6 @@ void bitmap_fold(unsigned long *dst, const unsigned long *orig, 
}

#endif /* CONFIG_NUMA */



/**

 * bitmap_find_free_region - find a contiguous aligned mem region

 *	@bitmap: array of unsigned longs corresponding to the bitmap

 *	@bits: number of bits in the bitmap

 *	@order: region size (log base 2 of number of bits) to find

 *

 * Find a region of free (zero) bits in a @bitmap of @bits bits and

 * allocate them (set them to one).  Only consider regions of length

 * a power (@order) of two, aligned to that power of two, which

 * makes the search algorithm much faster.

 *

 * Return: the bit offset in bitmap of the allocated region,

 * or -errno on failure.

 */

int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)

{

	unsigned int pos, end;		/* scans bitmap by regions of size order */



	for (pos = 0; (end = pos + BIT(order)) <= bits; pos = end) {

		if (!bitmap_allocate_region(bitmap, pos, order))

			return pos;

	}

	return -ENOMEM;

}

EXPORT_SYMBOL(bitmap_find_free_region);



/**

 * bitmap_release_region - release allocated bitmap region

 *	@bitmap: array of unsigned longs corresponding to the bitmap

 *	@pos: beginning of bit region to release

 *	@order: region size (log base 2 of number of bits) to release

 *

 * This is the complement to __bitmap_find_free_region() and releases

 * the found region (by clearing it in the bitmap).

 */

void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)

{

	bitmap_clear(bitmap, pos, BIT(order));

}

EXPORT_SYMBOL(bitmap_release_region);



/**

 * bitmap_allocate_region - allocate bitmap region

 *	@bitmap: array of unsigned longs corresponding to the bitmap

 *	@pos: beginning of bit region to allocate

 *	@order: region size (log base 2 of number of bits) to allocate

 *

 * Allocate (set bits in) a specified region of a bitmap.

 *

 * Return: 0 on success, or %-EBUSY if specified region wasn't

 * free (not all bits were zero).

 */

int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)

{

	unsigned int len = BIT(order);



	if (find_next_bit(bitmap, pos + len, pos) < pos + len)

		return -EBUSY;

	bitmap_set(bitmap, pos, len);

	return 0;

}

EXPORT_SYMBOL(bitmap_allocate_region);



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

{

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