[ceph.git] / ceph / src / spdk / dpdk / lib / librte_eal / common / include / rte_bitmap.h

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2014 Intel Corporation
 */

#ifndef __INCLUDE_RTE_BITMAP_H__
#define __INCLUDE_RTE_BITMAP_H__

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @file
 * RTE Bitmap
 *
 * The bitmap component provides a mechanism to manage large arrays of bits
 * through bit get/set/clear and bit array scan operations.
 *
 * The bitmap scan operation is optimized for 64-bit CPUs using 64/128 byte cache
 * lines. The bitmap is hierarchically organized using two arrays (array1 and
 * array2), with each bit in array1 being associated with a full cache line
 * (512/1024 bits) of bitmap bits, which are stored in array2: the bit in array1
 * is set only when there is at least one bit set within its associated array2
 * bits, otherwise the bit in array1 is cleared. The read and write operations
 * for array1 and array2 are always done in slabs of 64 bits.
 *
 * This bitmap is not thread safe. For lock free operation on a specific bitmap
 * instance, a single writer thread performing bit set/clear operations is
 * allowed, only the writer thread can do bitmap scan operations, while there
 * can be several reader threads performing bit get operations in parallel with
 * the writer thread. When the use of locking primitives is acceptable, the
 * serialization of the bit set/clear and bitmap scan operations needs to be
 * enforced by the caller, while the bit get operation does not require locking
 * the bitmap.
 *
 ***/

#include <string.h>
#include <rte_common.h>
#include <rte_config.h>
#include <rte_debug.h>
#include <rte_memory.h>
#include <rte_branch_prediction.h>
#include <rte_prefetch.h>

/* Slab */
#define RTE_BITMAP_SLAB_BIT_SIZE                 64
#define RTE_BITMAP_SLAB_BIT_SIZE_LOG2            6
#define RTE_BITMAP_SLAB_BIT_MASK                 (RTE_BITMAP_SLAB_BIT_SIZE - 1)

/* Cache line (CL) */
#define RTE_BITMAP_CL_BIT_SIZE                   (RTE_CACHE_LINE_SIZE * 8)
#define RTE_BITMAP_CL_BIT_SIZE_LOG2              (RTE_CACHE_LINE_SIZE_LOG2 + 3)
#define RTE_BITMAP_CL_BIT_MASK                   (RTE_BITMAP_CL_BIT_SIZE - 1)

#define RTE_BITMAP_CL_SLAB_SIZE                  (RTE_BITMAP_CL_BIT_SIZE / RTE_BITMAP_SLAB_BIT_SIZE)
#define RTE_BITMAP_CL_SLAB_SIZE_LOG2             (RTE_BITMAP_CL_BIT_SIZE_LOG2 - RTE_BITMAP_SLAB_BIT_SIZE_LOG2)
#define RTE_BITMAP_CL_SLAB_MASK                  (RTE_BITMAP_CL_SLAB_SIZE - 1)

/** Bitmap data structure */
struct rte_bitmap {
	/* Context for array1 and array2 */
	uint64_t *array1;                        /**< Bitmap array1 */
	uint64_t *array2;                        /**< Bitmap array2 */
	uint32_t array1_size;                    /**< Number of 64-bit slabs in array1 that are actually used */
	uint32_t array2_size;                    /**< Number of 64-bit slabs in array2 */

	/* Context for the "scan next" operation */
	uint32_t index1;  /**< Bitmap scan: Index of current array1 slab */
	uint32_t offset1; /**< Bitmap scan: Offset of current bit within current array1 slab */
	uint32_t index2;  /**< Bitmap scan: Index of current array2 slab */
	uint32_t go2;     /**< Bitmap scan: Go/stop condition for current array2 cache line */

	/* Storage space for array1 and array2 */
	uint8_t memory[];
};

static inline void
__rte_bitmap_index1_inc(struct rte_bitmap *bmp)
{
	bmp->index1 = (bmp->index1 + 1) & (bmp->array1_size - 1);
}

static inline uint64_t
__rte_bitmap_mask1_get(struct rte_bitmap *bmp)
{
	return (~1llu) << bmp->offset1;
}

static inline void
__rte_bitmap_index2_set(struct rte_bitmap *bmp)
{
	bmp->index2 = (((bmp->index1 << RTE_BITMAP_SLAB_BIT_SIZE_LOG2) + bmp->offset1) << RTE_BITMAP_CL_SLAB_SIZE_LOG2);
}

static inline uint32_t
__rte_bitmap_get_memory_footprint(uint32_t n_bits,
	uint32_t *array1_byte_offset, uint32_t *array1_slabs,
	uint32_t *array2_byte_offset, uint32_t *array2_slabs)
{
	uint32_t n_slabs_context, n_slabs_array1, n_cache_lines_context_and_array1;
	uint32_t n_cache_lines_array2;
	uint32_t n_bytes_total;

	n_cache_lines_array2 = (n_bits + RTE_BITMAP_CL_BIT_SIZE - 1) / RTE_BITMAP_CL_BIT_SIZE;
	n_slabs_array1 = (n_cache_lines_array2 + RTE_BITMAP_SLAB_BIT_SIZE - 1) / RTE_BITMAP_SLAB_BIT_SIZE;
	n_slabs_array1 = rte_align32pow2(n_slabs_array1);
	n_slabs_context = (sizeof(struct rte_bitmap) + (RTE_BITMAP_SLAB_BIT_SIZE / 8) - 1) / (RTE_BITMAP_SLAB_BIT_SIZE / 8);
	n_cache_lines_context_and_array1 = (n_slabs_context + n_slabs_array1 + RTE_BITMAP_CL_SLAB_SIZE - 1) / RTE_BITMAP_CL_SLAB_SIZE;
	n_bytes_total = (n_cache_lines_context_and_array1 + n_cache_lines_array2) * RTE_CACHE_LINE_SIZE;

	if (array1_byte_offset) {
		*array1_byte_offset = n_slabs_context * (RTE_BITMAP_SLAB_BIT_SIZE / 8);
	}
	if (array1_slabs) {
		*array1_slabs = n_slabs_array1;
	}
	if (array2_byte_offset) {
		*array2_byte_offset = n_cache_lines_context_and_array1 * RTE_CACHE_LINE_SIZE;
	}
	if (array2_slabs) {
		*array2_slabs = n_cache_lines_array2 * RTE_BITMAP_CL_SLAB_SIZE;
	}

	return n_bytes_total;
}

static inline void
__rte_bitmap_scan_init(struct rte_bitmap *bmp)
{
	bmp->index1 = bmp->array1_size - 1;
	bmp->offset1 = RTE_BITMAP_SLAB_BIT_SIZE - 1;
	__rte_bitmap_index2_set(bmp);
	bmp->index2 += RTE_BITMAP_CL_SLAB_SIZE;

	bmp->go2 = 0;
}

/**
 * Bitmap memory footprint calculation
 *
 * @param n_bits
 *   Number of bits in the bitmap
 * @return
 *   Bitmap memory footprint measured in bytes on success, 0 on error
 */
static inline uint32_t
rte_bitmap_get_memory_footprint(uint32_t n_bits) {
	/* Check input arguments */
	if (n_bits == 0) {
		return 0;
	}

	return __rte_bitmap_get_memory_footprint(n_bits, NULL, NULL, NULL, NULL);
}

/**
 * Bitmap initialization
 *
 * @param n_bits
 *   Number of pre-allocated bits in array2.
 * @param mem
 *   Base address of array1 and array2.
 * @param mem_size
 *   Minimum expected size of bitmap.
 * @return
 *   Handle to bitmap instance.
 */
static inline struct rte_bitmap *
rte_bitmap_init(uint32_t n_bits, uint8_t *mem, uint32_t mem_size)
{
	struct rte_bitmap *bmp;
	uint32_t array1_byte_offset, array1_slabs, array2_byte_offset, array2_slabs;
	uint32_t size;

	/* Check input arguments */
	if (n_bits == 0) {
		return NULL;
	}

	if ((mem == NULL) || (((uintptr_t) mem) & RTE_CACHE_LINE_MASK)) {
		return NULL;
	}

	size = __rte_bitmap_get_memory_footprint(n_bits,
		&array1_byte_offset, &array1_slabs,
		&array2_byte_offset, &array2_slabs);
	if (size < mem_size) {
		return NULL;
	}

	/* Setup bitmap */
	memset(mem, 0, size);
	bmp = (struct rte_bitmap *) mem;

	bmp->array1 = (uint64_t *) &mem[array1_byte_offset];
	bmp->array1_size = array1_slabs;
	bmp->array2 = (uint64_t *) &mem[array2_byte_offset];
	bmp->array2_size = array2_slabs;

	__rte_bitmap_scan_init(bmp);

	return bmp;
}

/**
 * Bitmap free
 *
 * @param bmp
 *   Handle to bitmap instance
 * @return
 *   0 upon success, error code otherwise
 */
static inline int
rte_bitmap_free(struct rte_bitmap *bmp)
{
	/* Check input arguments */
	if (bmp == NULL) {
		return -1;
	}

	return 0;
}

/**
 * Bitmap reset
 *
 * @param bmp
 *   Handle to bitmap instance
 */
static inline void
rte_bitmap_reset(struct rte_bitmap *bmp)
{
	memset(bmp->array1, 0, bmp->array1_size * sizeof(uint64_t));
	memset(bmp->array2, 0, bmp->array2_size * sizeof(uint64_t));
	__rte_bitmap_scan_init(bmp);
}

/**
 * Bitmap location prefetch into CPU L1 cache
 *
 * @param bmp
 *   Handle to bitmap instance
 * @param pos
 *   Bit position
 * @return
 *   0 upon success, error code otherwise
 */
static inline void
rte_bitmap_prefetch0(struct rte_bitmap *bmp, uint32_t pos)
{
	uint64_t *slab2;
	uint32_t index2;

	index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
	slab2 = bmp->array2 + index2;
	rte_prefetch0((void *) slab2);
}

/**
 * Bitmap bit get
 *
 * @param bmp
 *   Handle to bitmap instance
 * @param pos
 *   Bit position
 * @return
 *   0 when bit is cleared, non-zero when bit is set
 */
static inline uint64_t
rte_bitmap_get(struct rte_bitmap *bmp, uint32_t pos)
{
	uint64_t *slab2;
	uint32_t index2, offset2;

	index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
	offset2 = pos & RTE_BITMAP_SLAB_BIT_MASK;
	slab2 = bmp->array2 + index2;
	return (*slab2) & (1llu << offset2);
}

/**
 * Bitmap bit set
 *
 * @param bmp
 *   Handle to bitmap instance
 * @param pos
 *   Bit position
 */
static inline void
rte_bitmap_set(struct rte_bitmap *bmp, uint32_t pos)
{
	uint64_t *slab1, *slab2;
	uint32_t index1, index2, offset1, offset2;

	/* Set bit in array2 slab and set bit in array1 slab */
	index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
	offset2 = pos & RTE_BITMAP_SLAB_BIT_MASK;
	index1 = pos >> (RTE_BITMAP_SLAB_BIT_SIZE_LOG2 + RTE_BITMAP_CL_BIT_SIZE_LOG2);
	offset1 = (pos >> RTE_BITMAP_CL_BIT_SIZE_LOG2) & RTE_BITMAP_SLAB_BIT_MASK;
	slab2 = bmp->array2 + index2;
	slab1 = bmp->array1 + index1;

	*slab2 |= 1llu << offset2;
	*slab1 |= 1llu << offset1;
}

/**
 * Bitmap slab set
 *
 * @param bmp
 *   Handle to bitmap instance
 * @param pos
 *   Bit position identifying the array2 slab
 * @param slab
 *   Value to be assigned to the 64-bit slab in array2
 */
static inline void
rte_bitmap_set_slab(struct rte_bitmap *bmp, uint32_t pos, uint64_t slab)
{
	uint64_t *slab1, *slab2;
	uint32_t index1, index2, offset1;

	/* Set bits in array2 slab and set bit in array1 slab */
	index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
	index1 = pos >> (RTE_BITMAP_SLAB_BIT_SIZE_LOG2 + RTE_BITMAP_CL_BIT_SIZE_LOG2);
	offset1 = (pos >> RTE_BITMAP_CL_BIT_SIZE_LOG2) & RTE_BITMAP_SLAB_BIT_MASK;
	slab2 = bmp->array2 + index2;
	slab1 = bmp->array1 + index1;

	*slab2 |= slab;
	*slab1 |= 1llu << offset1;
}

static inline uint64_t
__rte_bitmap_line_not_empty(uint64_t *slab2)
{
	uint64_t v1, v2, v3, v4;

	v1 = slab2[0] | slab2[1];
	v2 = slab2[2] | slab2[3];
	v3 = slab2[4] | slab2[5];
	v4 = slab2[6] | slab2[7];
	v1 |= v2;
	v3 |= v4;

	return v1 | v3;
}

/**
 * Bitmap bit clear
 *
 * @param bmp
 *   Handle to bitmap instance
 * @param pos
 *   Bit position
 */
static inline void
rte_bitmap_clear(struct rte_bitmap *bmp, uint32_t pos)
{
	uint64_t *slab1, *slab2;
	uint32_t index1, index2, offset1, offset2;

	/* Clear bit in array2 slab */
	index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
	offset2 = pos & RTE_BITMAP_SLAB_BIT_MASK;
	slab2 = bmp->array2 + index2;

	/* Return if array2 slab is not all-zeros */
	*slab2 &= ~(1llu << offset2);
	if (*slab2){
		return;
	}

	/* Check the entire cache line of array2 for all-zeros */
	index2 &= ~ RTE_BITMAP_CL_SLAB_MASK;
	slab2 = bmp->array2 + index2;
	if (__rte_bitmap_line_not_empty(slab2)) {
		return;
	}

	/* The array2 cache line is all-zeros, so clear bit in array1 slab */
	index1 = pos >> (RTE_BITMAP_SLAB_BIT_SIZE_LOG2 + RTE_BITMAP_CL_BIT_SIZE_LOG2);
	offset1 = (pos >> RTE_BITMAP_CL_BIT_SIZE_LOG2) & RTE_BITMAP_SLAB_BIT_MASK;
	slab1 = bmp->array1 + index1;
	*slab1 &= ~(1llu << offset1);

	return;
}

static inline int
__rte_bitmap_scan_search(struct rte_bitmap *bmp)
{
	uint64_t value1;
	uint32_t i;

	/* Check current array1 slab */
	value1 = bmp->array1[bmp->index1];
	value1 &= __rte_bitmap_mask1_get(bmp);

	if (rte_bsf64_safe(value1, &bmp->offset1))
		return 1;

	__rte_bitmap_index1_inc(bmp);
	bmp->offset1 = 0;

	/* Look for another array1 slab */
	for (i = 0; i < bmp->array1_size; i ++, __rte_bitmap_index1_inc(bmp)) {
		value1 = bmp->array1[bmp->index1];

		if (rte_bsf64_safe(value1, &bmp->offset1))
			return 1;
	}

	return 0;
}

static inline void
__rte_bitmap_scan_read_init(struct rte_bitmap *bmp)
{
	__rte_bitmap_index2_set(bmp);
	bmp->go2 = 1;
	rte_prefetch1((void *)(bmp->array2 + bmp->index2 + 8));
}

static inline int
__rte_bitmap_scan_read(struct rte_bitmap *bmp, uint32_t *pos, uint64_t *slab)
{
	uint64_t *slab2;

	slab2 = bmp->array2 + bmp->index2;
	for ( ; bmp->go2 ; bmp->index2 ++, slab2 ++, bmp->go2 = bmp->index2 & RTE_BITMAP_CL_SLAB_MASK) {
		if (*slab2) {
			*pos = bmp->index2 << RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
			*slab = *slab2;

			bmp->index2 ++;
			slab2 ++;
			bmp->go2 = bmp->index2 & RTE_BITMAP_CL_SLAB_MASK;
			return 1;
		}
	}

	return 0;
}

/**
 * Bitmap scan (with automatic wrap-around)
 *
 * @param bmp
 *   Handle to bitmap instance
 * @param pos
 *   When function call returns 1, pos contains the position of the next set
 *   bit, otherwise not modified
 * @param slab
 *   When function call returns 1, slab contains the value of the entire 64-bit
 *   slab where the bit indicated by pos is located. Slabs are always 64-bit
 *   aligned, so the position of the first bit of the slab (this bit is not
 *   necessarily set) is pos / 64. Once a slab has been returned by the bitmap
 *   scan operation, the internal pointers of the bitmap are updated to point
 *   after this slab, so the same slab will not be returned again if it
 *   contains more than one bit which is set. When function call returns 0,
 *   slab is not modified.
 * @return
 *   0 if there is no bit set in the bitmap, 1 otherwise
 */
static inline int
rte_bitmap_scan(struct rte_bitmap *bmp, uint32_t *pos, uint64_t *slab)
{
	/* Return data from current array2 line if available */
	if (__rte_bitmap_scan_read(bmp, pos, slab)) {
		return 1;
	}

	/* Look for non-empty array2 line */
	if (__rte_bitmap_scan_search(bmp)) {
		__rte_bitmap_scan_read_init(bmp);
		__rte_bitmap_scan_read(bmp, pos, slab);
		return 1;
	}

	/* Empty bitmap */
	return 0;
}

#ifdef __cplusplus
}
#endif

#endif /* __INCLUDE_RTE_BITMAP_H__ */
Commit	Line	Data
11fdf7f2 TL	1	/* SPDX-License-Identifier: BSD-3-Clause
11fdf7f2 TL	2	* Copyright(c) 2010-2014 Intel Corporation
7c673cae FG	3	*/
	4
	5	#ifndef __INCLUDE_RTE_BITMAP_H__
	6	#define __INCLUDE_RTE_BITMAP_H__
	7
	8	#ifdef __cplusplus
	9	extern "C" {
	10	#endif
	11
	12	/**
	13	* @file
	14	* RTE Bitmap
	15	*
	16	* The bitmap component provides a mechanism to manage large arrays of bits
	17	* through bit get/set/clear and bit array scan operations.
	18	*
	19	* The bitmap scan operation is optimized for 64-bit CPUs using 64/128 byte cache
	20	* lines. The bitmap is hierarchically organized using two arrays (array1 and
	21	* array2), with each bit in array1 being associated with a full cache line
	22	* (512/1024 bits) of bitmap bits, which are stored in array2: the bit in array1
	23	* is set only when there is at least one bit set within its associated array2
	24	* bits, otherwise the bit in array1 is cleared. The read and write operations
	25	* for array1 and array2 are always done in slabs of 64 bits.
	26	*
	27	* This bitmap is not thread safe. For lock free operation on a specific bitmap
	28	* instance, a single writer thread performing bit set/clear operations is
	29	* allowed, only the writer thread can do bitmap scan operations, while there
	30	* can be several reader threads performing bit get operations in parallel with
	31	* the writer thread. When the use of locking primitives is acceptable, the
	32	* serialization of the bit set/clear and bitmap scan operations needs to be
	33	* enforced by the caller, while the bit get operation does not require locking
	34	* the bitmap.
	35	*
	36	***/
	37
	38	#include <string.h>
	39	#include <rte_common.h>
11fdf7f2	40	#include <rte_config.h>
7c673cae FG	41	#include <rte_debug.h>
	42	#include <rte_memory.h>
	43	#include <rte_branch_prediction.h>
	44	#include <rte_prefetch.h>
	45
7c673cae FG	46	/* Slab */
	47	#define RTE_BITMAP_SLAB_BIT_SIZE 64
	48	#define RTE_BITMAP_SLAB_BIT_SIZE_LOG2 6
	49	#define RTE_BITMAP_SLAB_BIT_MASK (RTE_BITMAP_SLAB_BIT_SIZE - 1)
	50
	51	/* Cache line (CL) */
	52	#define RTE_BITMAP_CL_BIT_SIZE (RTE_CACHE_LINE_SIZE * 8)
	53	#define RTE_BITMAP_CL_BIT_SIZE_LOG2 (RTE_CACHE_LINE_SIZE_LOG2 + 3)
	54	#define RTE_BITMAP_CL_BIT_MASK (RTE_BITMAP_CL_BIT_SIZE - 1)
	55
	56	#define RTE_BITMAP_CL_SLAB_SIZE (RTE_BITMAP_CL_BIT_SIZE / RTE_BITMAP_SLAB_BIT_SIZE)
	57	#define RTE_BITMAP_CL_SLAB_SIZE_LOG2 (RTE_BITMAP_CL_BIT_SIZE_LOG2 - RTE_BITMAP_SLAB_BIT_SIZE_LOG2)
	58	#define RTE_BITMAP_CL_SLAB_MASK (RTE_BITMAP_CL_SLAB_SIZE - 1)
	59
	60	/** Bitmap data structure */
	61	struct rte_bitmap {
	62	/* Context for array1 and array2 */
	63	uint64_t array1; /< Bitmap array1 /
	64	uint64_t array2; /< Bitmap array2 /
	65	uint32_t array1_size; /*< Number of 64-bit slabs in array1 that are actually used /
	66	uint32_t array2_size; /*< Number of 64-bit slabs in array2 /
	67
	68	/* Context for the "scan next" operation */
	69	uint32_t index1; /*< Bitmap scan: Index of current array1 slab /
	70	uint32_t offset1; /*< Bitmap scan: Offset of current bit within current array1 slab /
	71	uint32_t index2; /*< Bitmap scan: Index of current array2 slab /
	72	uint32_t go2; /*< Bitmap scan: Go/stop condition for current array2 cache line /
	73
	74	/* Storage space for array1 and array2 */
	75	uint8_t memory[];
	76	};
	77
	78	static inline void
	79	__rte_bitmap_index1_inc(struct rte_bitmap *bmp)
	80	{
	81	bmp->index1 = (bmp->index1 + 1) & (bmp->array1_size - 1);
	82	}
	83
	84	static inline uint64_t
	85	__rte_bitmap_mask1_get(struct rte_bitmap *bmp)
	86	{
9f95a23c	87	return (~1llu) << bmp->offset1;
7c673cae FG	88	}
	89
	90	static inline void
	91	__rte_bitmap_index2_set(struct rte_bitmap *bmp)
	92	{
	93	bmp->index2 = (((bmp->index1 << RTE_BITMAP_SLAB_BIT_SIZE_LOG2) + bmp->offset1) << RTE_BITMAP_CL_SLAB_SIZE_LOG2);
	94	}
	95
7c673cae FG	96	static inline uint32_t
	97	__rte_bitmap_get_memory_footprint(uint32_t n_bits,
	98	uint32_t array1_byte_offset, uint32_t array1_slabs,
	99	uint32_t array2_byte_offset, uint32_t array2_slabs)
	100	{
	101	uint32_t n_slabs_context, n_slabs_array1, n_cache_lines_context_and_array1;
	102	uint32_t n_cache_lines_array2;
	103	uint32_t n_bytes_total;
	104
	105	n_cache_lines_array2 = (n_bits + RTE_BITMAP_CL_BIT_SIZE - 1) / RTE_BITMAP_CL_BIT_SIZE;
	106	n_slabs_array1 = (n_cache_lines_array2 + RTE_BITMAP_SLAB_BIT_SIZE - 1) / RTE_BITMAP_SLAB_BIT_SIZE;
	107	n_slabs_array1 = rte_align32pow2(n_slabs_array1);
	108	n_slabs_context = (sizeof(struct rte_bitmap) + (RTE_BITMAP_SLAB_BIT_SIZE / 8) - 1) / (RTE_BITMAP_SLAB_BIT_SIZE / 8);
	109	n_cache_lines_context_and_array1 = (n_slabs_context + n_slabs_array1 + RTE_BITMAP_CL_SLAB_SIZE - 1) / RTE_BITMAP_CL_SLAB_SIZE;
	110	n_bytes_total = (n_cache_lines_context_and_array1 + n_cache_lines_array2) * RTE_CACHE_LINE_SIZE;
	111
	112	if (array1_byte_offset) {
	113	array1_byte_offset = n_slabs_context (RTE_BITMAP_SLAB_BIT_SIZE / 8);
	114	}
	115	if (array1_slabs) {
	116	*array1_slabs = n_slabs_array1;
	117	}
	118	if (array2_byte_offset) {
	119	array2_byte_offset = n_cache_lines_context_and_array1 RTE_CACHE_LINE_SIZE;
	120	}
	121	if (array2_slabs) {
	122	array2_slabs = n_cache_lines_array2 RTE_BITMAP_CL_SLAB_SIZE;
	123	}
	124
	125	return n_bytes_total;
	126	}
	127
	128	static inline void
	129	__rte_bitmap_scan_init(struct rte_bitmap *bmp)
	130	{
	131	bmp->index1 = bmp->array1_size - 1;
	132	bmp->offset1 = RTE_BITMAP_SLAB_BIT_SIZE - 1;
	133	__rte_bitmap_index2_set(bmp);
	134	bmp->index2 += RTE_BITMAP_CL_SLAB_SIZE;
	135
	136	bmp->go2 = 0;
	137	}
	138
	139	/**
	140	* Bitmap memory footprint calculation
	141	*
	142	* @param n_bits
	143	* Number of bits in the bitmap
	144	* @return
	145	* Bitmap memory footprint measured in bytes on success, 0 on error
	146	*/
	147	static inline uint32_t
	148	rte_bitmap_get_memory_footprint(uint32_t n_bits) {
	149	/* Check input arguments */
	150	if (n_bits == 0) {
	151	return 0;
	152	}
	153
	154	return __rte_bitmap_get_memory_footprint(n_bits, NULL, NULL, NULL, NULL);
	155	}
	156
	157	/**
	158	* Bitmap initialization
	159	*
11fdf7f2 TL	160	* @param n_bits
11fdf7f2 TL	161	* Number of pre-allocated bits in array2.
7c673cae FG	162	* @param mem
7c673cae FG	163	* Base address of array1 and array2.
11fdf7f2 TL	164	* @param mem_size
11fdf7f2 TL	165	* Minimum expected size of bitmap.
7c673cae FG	166	* @return
	167	* Handle to bitmap instance.
	168	*/
	169	static inline struct rte_bitmap *
	170	rte_bitmap_init(uint32_t n_bits, uint8_t *mem, uint32_t mem_size)
	171	{
	172	struct rte_bitmap *bmp;
	173	uint32_t array1_byte_offset, array1_slabs, array2_byte_offset, array2_slabs;
	174	uint32_t size;
	175
	176	/* Check input arguments */
	177	if (n_bits == 0) {
	178	return NULL;
	179	}
	180
	181	if ((mem == NULL) \|\| (((uintptr_t) mem) & RTE_CACHE_LINE_MASK)) {
	182	return NULL;
	183	}
	184
	185	size = __rte_bitmap_get_memory_footprint(n_bits,
	186	&array1_byte_offset, &array1_slabs,
	187	&array2_byte_offset, &array2_slabs);
	188	if (size < mem_size) {
	189	return NULL;
	190	}
	191
	192	/* Setup bitmap */
	193	memset(mem, 0, size);
	194	bmp = (struct rte_bitmap *) mem;
	195
	196	bmp->array1 = (uint64_t *) &mem[array1_byte_offset];
	197	bmp->array1_size = array1_slabs;
	198	bmp->array2 = (uint64_t *) &mem[array2_byte_offset];
	199	bmp->array2_size = array2_slabs;
	200
	201	__rte_bitmap_scan_init(bmp);
	202
	203	return bmp;
	204	}
	205
	206	/**
	207	* Bitmap free
	208	*
	209	* @param bmp
	210	* Handle to bitmap instance
	211	* @return
	212	* 0 upon success, error code otherwise
	213	*/
	214	static inline int
	215	rte_bitmap_free(struct rte_bitmap *bmp)
	216	{
	217	/* Check input arguments */
	218	if (bmp == NULL) {
	219	return -1;
	220	}
	221
	222	return 0;
	223	}
	224
	225	/**
	226	* Bitmap reset
	227	*
	228	* @param bmp
	229	* Handle to bitmap instance
230	*/
231	static inline void
232	rte_bitmap_reset(struct rte_bitmap *bmp)
233	{
234	memset(bmp->array1, 0, bmp->array1_size * sizeof(uint64_t));
235	memset(bmp->array2, 0, bmp->array2_size * sizeof(uint64_t));
236	__rte_bitmap_scan_init(bmp);
237	}
238
239	/**
240	* Bitmap location prefetch into CPU L1 cache
241	*
242	* @param bmp
243	* Handle to bitmap instance
244	* @param pos
245	* Bit position
246	* @return
247	* 0 upon success, error code otherwise
248	*/
249	static inline void
250	rte_bitmap_prefetch0(struct rte_bitmap *bmp, uint32_t pos)
251	{
252	uint64_t *slab2;
253	uint32_t index2;
254
255	index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
256	slab2 = bmp->array2 + index2;
257	rte_prefetch0((void *) slab2);
258	}
259
260	/**
261	* Bitmap bit get
262	*
263	* @param bmp
264	* Handle to bitmap instance
265	* @param pos
266	* Bit position
267	* @return
268	* 0 when bit is cleared, non-zero when bit is set
269	*/
270	static inline uint64_t
271	rte_bitmap_get(struct rte_bitmap *bmp, uint32_t pos)
272	{
273	uint64_t *slab2;
274	uint32_t index2, offset2;
275
276	index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
277	offset2 = pos & RTE_BITMAP_SLAB_BIT_MASK;
278	slab2 = bmp->array2 + index2;
9f95a23c	279	return (*slab2) & (1llu << offset2);
7c673cae FG	280	}
	281
	282	/**
	283	* Bitmap bit set
	284	*
	285	* @param bmp
	286	* Handle to bitmap instance
	287	* @param pos
	288	* Bit position
	289	*/
	290	static inline void
	291	rte_bitmap_set(struct rte_bitmap *bmp, uint32_t pos)
	292	{
	293	uint64_t slab1, slab2;
	294	uint32_t index1, index2, offset1, offset2;
	295
	296	/* Set bit in array2 slab and set bit in array1 slab */
	297	index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
	298	offset2 = pos & RTE_BITMAP_SLAB_BIT_MASK;
	299	index1 = pos >> (RTE_BITMAP_SLAB_BIT_SIZE_LOG2 + RTE_BITMAP_CL_BIT_SIZE_LOG2);
	300	offset1 = (pos >> RTE_BITMAP_CL_BIT_SIZE_LOG2) & RTE_BITMAP_SLAB_BIT_MASK;
	301	slab2 = bmp->array2 + index2;
	302	slab1 = bmp->array1 + index1;
	303
9f95a23c TL	304	*slab2 \|= 1llu << offset2;
9f95a23c TL	305	*slab1 \|= 1llu << offset1;
7c673cae FG	306	}
	307
	308	/**
	309	* Bitmap slab set
	310	*
	311	* @param bmp
	312	* Handle to bitmap instance
	313	* @param pos
	314	* Bit position identifying the array2 slab
	315	* @param slab
	316	* Value to be assigned to the 64-bit slab in array2
	317	*/
	318	static inline void
	319	rte_bitmap_set_slab(struct rte_bitmap *bmp, uint32_t pos, uint64_t slab)
	320	{
	321	uint64_t slab1, slab2;
	322	uint32_t index1, index2, offset1;
	323
	324	/* Set bits in array2 slab and set bit in array1 slab */
	325	index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
	326	index1 = pos >> (RTE_BITMAP_SLAB_BIT_SIZE_LOG2 + RTE_BITMAP_CL_BIT_SIZE_LOG2);
	327	offset1 = (pos >> RTE_BITMAP_CL_BIT_SIZE_LOG2) & RTE_BITMAP_SLAB_BIT_MASK;
	328	slab2 = bmp->array2 + index2;
	329	slab1 = bmp->array1 + index1;
	330
	331	*slab2 \|= slab;
9f95a23c	332	*slab1 \|= 1llu << offset1;
7c673cae FG	333	}
	334
	335	static inline uint64_t
	336	__rte_bitmap_line_not_empty(uint64_t *slab2)
	337	{
	338	uint64_t v1, v2, v3, v4;
	339
	340	v1 = slab2[0] \| slab2[1];
	341	v2 = slab2[2] \| slab2[3];
	342	v3 = slab2[4] \| slab2[5];
	343	v4 = slab2[6] \| slab2[7];
	344	v1 \|= v2;
	345	v3 \|= v4;
	346
	347	return v1 \| v3;
	348	}
	349
	350	/**
	351	* Bitmap bit clear
	352	*
	353	* @param bmp
	354	* Handle to bitmap instance
	355	* @param pos
	356	* Bit position
	357	*/
	358	static inline void
	359	rte_bitmap_clear(struct rte_bitmap *bmp, uint32_t pos)
	360	{
	361	uint64_t slab1, slab2;
	362	uint32_t index1, index2, offset1, offset2;
	363
	364	/* Clear bit in array2 slab */
	365	index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
	366	offset2 = pos & RTE_BITMAP_SLAB_BIT_MASK;
	367	slab2 = bmp->array2 + index2;
	368
	369	/* Return if array2 slab is not all-zeros */
9f95a23c	370	*slab2 &= ~(1llu << offset2);
7c673cae FG	371	if (*slab2){
	372	return;
	373	}
	374
	375	/* Check the entire cache line of array2 for all-zeros */
	376	index2 &= ~ RTE_BITMAP_CL_SLAB_MASK;
	377	slab2 = bmp->array2 + index2;
	378	if (__rte_bitmap_line_not_empty(slab2)) {
	379	return;
	380	}
	381
	382	/* The array2 cache line is all-zeros, so clear bit in array1 slab */
	383	index1 = pos >> (RTE_BITMAP_SLAB_BIT_SIZE_LOG2 + RTE_BITMAP_CL_BIT_SIZE_LOG2);
	384	offset1 = (pos >> RTE_BITMAP_CL_BIT_SIZE_LOG2) & RTE_BITMAP_SLAB_BIT_MASK;
	385	slab1 = bmp->array1 + index1;
9f95a23c	386	*slab1 &= ~(1llu << offset1);
7c673cae FG	387
	388	return;
	389	}
	390
	391	static inline int
	392	__rte_bitmap_scan_search(struct rte_bitmap *bmp)
	393	{
	394	uint64_t value1;
	395	uint32_t i;
	396
	397	/* Check current array1 slab */
	398	value1 = bmp->array1[bmp->index1];
	399	value1 &= __rte_bitmap_mask1_get(bmp);
	400
9f95a23c	401	if (rte_bsf64_safe(value1, &bmp->offset1))
7c673cae	402	return 1;
7c673cae FG	403
	404	__rte_bitmap_index1_inc(bmp);
	405	bmp->offset1 = 0;
	406
	407	/* Look for another array1 slab */
	408	for (i = 0; i < bmp->array1_size; i ++, __rte_bitmap_index1_inc(bmp)) {
	409	value1 = bmp->array1[bmp->index1];
	410
9f95a23c	411	if (rte_bsf64_safe(value1, &bmp->offset1))
7c673cae	412	return 1;
7c673cae FG	413	}
	414
	415	return 0;
	416	}
	417
	418	static inline void
	419	__rte_bitmap_scan_read_init(struct rte_bitmap *bmp)
	420	{
	421	__rte_bitmap_index2_set(bmp);
	422	bmp->go2 = 1;
	423	rte_prefetch1((void *)(bmp->array2 + bmp->index2 + 8));
	424	}
	425
	426	static inline int
	427	__rte_bitmap_scan_read(struct rte_bitmap bmp, uint32_t pos, uint64_t *slab)
	428	{
	429	uint64_t *slab2;
	430
	431	slab2 = bmp->array2 + bmp->index2;
	432	for ( ; bmp->go2 ; bmp->index2 ++, slab2 ++, bmp->go2 = bmp->index2 & RTE_BITMAP_CL_SLAB_MASK) {
	433	if (*slab2) {
	434	*pos = bmp->index2 << RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
	435	slab = slab2;
	436
	437	bmp->index2 ++;
	438	slab2 ++;
	439	bmp->go2 = bmp->index2 & RTE_BITMAP_CL_SLAB_MASK;
	440	return 1;
	441	}
	442	}
	443
	444	return 0;
	445	}
	446
	447	/**
	448	* Bitmap scan (with automatic wrap-around)
	449	*
	450	* @param bmp
	451	* Handle to bitmap instance
	452	* @param pos
	453	* When function call returns 1, pos contains the position of the next set
	454	* bit, otherwise not modified
	455	* @param slab
	456	* When function call returns 1, slab contains the value of the entire 64-bit
	457	* slab where the bit indicated by pos is located. Slabs are always 64-bit
	458	* aligned, so the position of the first bit of the slab (this bit is not
	459	* necessarily set) is pos / 64. Once a slab has been returned by the bitmap
	460	* scan operation, the internal pointers of the bitmap are updated to point
	461	* after this slab, so the same slab will not be returned again if it
	462	* contains more than one bit which is set. When function call returns 0,
	463	* slab is not modified.
	464	* @return
	465	* 0 if there is no bit set in the bitmap, 1 otherwise
	466	*/
	467	static inline int
	468	rte_bitmap_scan(struct rte_bitmap bmp, uint32_t pos, uint64_t *slab)
	469	{
	470	/* Return data from current array2 line if available */
	471	if (__rte_bitmap_scan_read(bmp, pos, slab)) {
	472	return 1;
	473	}
	474
	475	/* Look for non-empty array2 line */
	476	if (__rte_bitmap_scan_search(bmp)) {
477	__rte_bitmap_scan_read_init(bmp);
478	__rte_bitmap_scan_read(bmp, pos, slab);
479	return 1;
480	}
481
482	/* Empty bitmap */
483	return 0;
484	}
485
486	#ifdef __cplusplus
487	}
488	#endif
489
490	#endif /* __INCLUDE_RTE_BITMAP_H__ */