/usr/share/dpdk/x86_64-default-linuxapp-gcc/include/rte_bitmap.h is in dpdk-dev 17.11.1-6.
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* BSD LICENSE
*
* Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#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>
#ifndef RTE_BITMAP_OPTIMIZATIONS
#define RTE_BITMAP_OPTIMIZATIONS 1
#endif
/* 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 (~1lu) << 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);
}
#if RTE_BITMAP_OPTIMIZATIONS
static inline int
rte_bsf64(uint64_t slab, uint32_t *pos)
{
if (likely(slab == 0)) {
return 0;
}
*pos = __builtin_ctzll(slab);
return 1;
}
#else
static inline int
rte_bsf64(uint64_t slab, uint32_t *pos)
{
uint64_t mask;
uint32_t i;
if (likely(slab == 0)) {
return 0;
}
for (i = 0, mask = 1; i < RTE_BITMAP_SLAB_BIT_SIZE; i ++, mask <<= 1) {
if (unlikely(slab & mask)) {
*pos = i;
return 1;
}
}
return 0;
}
#endif
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 mem_size
* Minimum expected size of bitmap.
* @param mem
* Base address of array1 and array2.
* @param n_bits
* Number of pre-allocated bits in array2. Must be non-zero and multiple of 512.
* @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) & (1lu << 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 |= 1lu << offset2;
*slab1 |= 1lu << 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 |= 1lu << 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 &= ~(1lu << 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 &= ~(1lu << 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(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(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__ */
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