/*
 * Copyright (c) 2015, Xilinx Inc. and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

/*
 * @file	utilities.h
 * @brief	Utility routines for libmetal.
 */

#ifndef __METAL_UTILITIES__H__
#define __METAL_UTILITIES__H__

#include <stdint.h>
#include <limits.h>
#include <metal/assert.h>

#ifdef __cplusplus
extern "C" {
#endif

/** \defgroup utilities Simple Utilities
 *  @{
 */

/** Marker for unused function arguments/variables. */
#define metal_unused(x)	do { (x) = (x); } while (0)

/** Figure out number of elements in an array. */
#define metal_dim(x)	(sizeof(x) / sizeof(x[0]))

/** Minimum of two numbers (warning: multiple evaluation!).  */
#define metal_min(x, y)	((x) < (y) ? (x) : (y))

/** Maximum of two numbers (warning: multiple evaluation!).  */
#define metal_max(x, y)	((x) > (y) ? (x) : (y))

/** Sign of a number [-1, 0, or 1] (warning: multiple evaluation!).  */
#define metal_sign(x)	((x) < 0 ? -1 : ((x) > 0 ? 1 : 0))

/** Align 'size' down to a multiple of 'align' (must be a power of two). */
#define metal_align_down(size, align)			\
	((size) & ~((align) - 1))

/** Align 'size' up to a multiple of 'align' (must be a power of two). */
#define metal_align_up(size, align)			\
	metal_align_down((size) + (align) - 1, align)

/** Divide (and round down). */
#define metal_div_round_down(num, den)			\
	((num) / (den))

/** Divide (and round up). */
#define metal_div_round_up(num, den)			\
	metal_div_round_down((num) + (den) - 1, (den))

/** Align 'ptr' down to a multiple of 'align' (must be a power of two). */
#define metal_ptr_align_down(ptr, align)		\
	(void *)(metal_align_down((uintptr_t)(ptr), (uintptr_t)(align)))

/** Align 'ptr' up to a multiple of 'align' (must be a power of two). */
#define metal_ptr_align_up(ptr, align)			\
	(void *)(metal_align_up((uintptr_t)(ptr), (uintptr_t)(align)))

/** Compute offset of a field within a structure. */
#define metal_offset_of(structure, member)		\
	((uintptr_t)&(((structure *)0)->member))

/** Compute pointer to a structure given a pointer to one of its fields. */
#define metal_container_of(ptr, structure, member)	\
	(void *)((uintptr_t)(ptr) - metal_offset_of(structure, member))

#define METAL_BITS_PER_ULONG	(CHAR_BIT * sizeof(unsigned long))

#define metal_bit(bit)		(1UL << (bit))

#define metal_bitmap_longs(x)	metal_div_round_up((x), METAL_BITS_PER_ULONG)

static inline void metal_bitmap_set_bit(unsigned long *bitmap, int bit)
{
	bitmap[bit / METAL_BITS_PER_ULONG] |=
		metal_bit(bit & (METAL_BITS_PER_ULONG - 1));
}

static inline int metal_bitmap_is_bit_set(unsigned long *bitmap, int bit)
{
	return ((bitmap[bit / METAL_BITS_PER_ULONG] &
		metal_bit(bit & (METAL_BITS_PER_ULONG - 1))) == 0) ? 0 : 1;
}

static inline void metal_bitmap_clear_bit(unsigned long *bitmap, int bit)
{
	bitmap[bit / METAL_BITS_PER_ULONG] &=
		~metal_bit(bit & (METAL_BITS_PER_ULONG - 1));
}

static inline int metal_bitmap_is_bit_clear(unsigned long *bitmap, int bit)
{
	return !metal_bitmap_is_bit_set(bitmap, bit);
}

static inline unsigned int
metal_bitmap_next_set_bit(unsigned long *bitmap, unsigned int start,
			  unsigned int max)
{
	unsigned int bit;

	for (bit = start;
	     bit < max && !metal_bitmap_is_bit_set(bitmap, bit);
	     bit++)
		;
	return bit;
}

#define metal_bitmap_for_each_set_bit(bitmap, bit, max)			\
	for ((bit) = metal_bitmap_next_set_bit((bitmap), 0, (max));	\
	     (bit) < (max);						\
	     (bit) = metal_bitmap_next_set_bit((bitmap), (bit + 1), (max)))

static inline unsigned int
metal_bitmap_next_clear_bit(unsigned long *bitmap, unsigned int start,
			    unsigned int max)
{
	unsigned int bit;

	for (bit = start;
	     bit < max && !metal_bitmap_is_bit_clear(bitmap, bit);
	     bit++)
		;
	return bit;
}

#define metal_bitmap_for_each_clear_bit(bitmap, bit, max)		\
	for ((bit) = metal_bitmap_next_clear_bit((bitmap), 0, (max));	\
	     (bit) < (max);						\
	     (bit) = metal_bitmap_next_clear_bit((bitmap), (bit + 1), (max)))

static inline unsigned long metal_log2(unsigned long in)
{
	unsigned long result;

	metal_assert((in & (in - 1)) == 0);

	for (result = 0; (1UL << result) < in; result++)
		;
	return result;
}

/** @} */

#ifdef __cplusplus
}
#endif

#endif /* __METAL_UTILITIES__H__ */