tools/include/linux/bitmap.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _TOOLS_LINUX_BITMAP_H
#define _TOOLS_LINUX_BITMAP_H

#include <string.h>
#include <asm-generic/bitsperlong.h>
#include <linux/align.h>
#include <linux/bitops.h>
#include <linux/find.h>
#include <stdlib.h>
#include <linux/kernel.h>

#define DECLARE_BITMAP(name,bits) \
	unsigned long name[BITS_TO_LONGS(bits)]

unsigned int __bitmap_weight(const unsigned long *bitmap, int bits);
void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
		 const unsigned long *bitmap2, int bits);
bool __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
		 const unsigned long *bitmap2, unsigned int bits);
bool __bitmap_equal(const unsigned long *bitmap1,
		    const unsigned long *bitmap2, unsigned int bits);
void __bitmap_clear(unsigned long *map, unsigned int start, int len);
bool __bitmap_intersects(const unsigned long *bitmap1,
			 const unsigned long *bitmap2, unsigned int bits);

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

#define bitmap_size(nbits)	(ALIGN(nbits, BITS_PER_LONG) / BITS_PER_BYTE)

static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		*dst = 0UL;
	else {
		memset(dst, 0, bitmap_size(nbits));
	}
}

static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
{
	unsigned int nlongs = BITS_TO_LONGS(nbits);
	if (!small_const_nbits(nbits)) {
		unsigned int len = (nlongs - 1) * sizeof(unsigned long);
		memset(dst, 0xff,  len);
	}
	dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
}

static inline bool bitmap_empty(const unsigned long *src, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		return ! (*src & BITMAP_LAST_WORD_MASK(nbits));

	return find_first_bit(src, nbits) == nbits;
}

static inline bool bitmap_full(const unsigned long *src, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));

	return find_first_zero_bit(src, nbits) == nbits;
}

static inline unsigned int bitmap_weight(const unsigned long *src, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
	return __bitmap_weight(src, nbits);
}

static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
			     const unsigned long *src2, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		*dst = *src1 | *src2;
	else
		__bitmap_or(dst, src1, src2, nbits);
}

/**
 * bitmap_zalloc - Allocate bitmap
 * @nbits: Number of bits
 */
static inline unsigned long *bitmap_zalloc(int nbits)
{
	return calloc(1, bitmap_size(nbits));
}

/*
 * bitmap_free - Free bitmap
 * @bitmap: pointer to bitmap
 */
static inline void bitmap_free(unsigned long *bitmap)
{
	free(bitmap);
}

/*
 * bitmap_scnprintf - print bitmap list into buffer
 * @bitmap: bitmap
 * @nbits: size of bitmap
 * @buf: buffer to store output
 * @size: size of @buf
 */
size_t bitmap_scnprintf(unsigned long *bitmap, unsigned int nbits,
			char *buf, size_t size);

/**
 * bitmap_and - Do logical and on bitmaps
 * @dst: resulting bitmap
 * @src1: operand 1
 * @src2: operand 2
 * @nbits: size of bitmap
 */
static inline bool bitmap_and(unsigned long *dst, const unsigned long *src1,
			     const unsigned long *src2, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
	return __bitmap_and(dst, src1, src2, nbits);
}

#ifdef __LITTLE_ENDIAN
#define BITMAP_MEM_ALIGNMENT 8
#else
#define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
#endif
#define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)

static inline bool bitmap_equal(const unsigned long *src1,
				const unsigned long *src2, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
	if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
	    IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
		return !memcmp(src1, src2, nbits / 8);
	return __bitmap_equal(src1, src2, nbits);
}

static inline bool bitmap_intersects(const unsigned long *src1,
				     const unsigned long *src2,
				     unsigned int nbits)
{
	if (small_const_nbits(nbits))
		return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
	else
		return __bitmap_intersects(src1, src2, nbits);
}

static inline void bitmap_clear(unsigned long *map, unsigned int start,
			       unsigned int nbits)
{
	if (__builtin_constant_p(nbits) && nbits == 1)
		__clear_bit(start, map);
	else if (small_const_nbits(start + nbits))
		*map &= ~GENMASK(start + nbits - 1, start);
	else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
		 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
		 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
		 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
		memset((char *)map + start / 8, 0, nbits / 8);
	else
		__bitmap_clear(map, start, nbits);
}
#endif /* _TOOLS_LINUX_BITMAP_H */