DPDK  20.11.3
rte_bitmap.h
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1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2014 Intel Corporation
3  */
4 
5 #ifndef __INCLUDE_RTE_BITMAP_H__
6 #define __INCLUDE_RTE_BITMAP_H__
7 
8 #ifdef __cplusplus
9 extern "C" {
10 #endif
11 
38 #include <string.h>
39 #include <rte_common.h>
40 #include <rte_config.h>
41 #include <rte_debug.h>
42 #include <rte_memory.h>
43 #include <rte_branch_prediction.h>
44 #include <rte_prefetch.h>
45 
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 
61 struct rte_bitmap {
62  /* Context for array1 and array2 */
63  uint64_t *array1;
64  uint64_t *array2;
65  uint32_t array1_size;
66  uint32_t array2_size;
68  /* Context for the "scan next" operation */
69  uint32_t index1;
70  uint32_t offset1;
71  uint32_t index2;
72  uint32_t go2;
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 {
87  return (~1llu) << bmp->offset1;
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 
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 
147 static inline uint32_t
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 
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  /* Setup bitmap */
192  memset(mem, 0, size);
193  bmp = (struct rte_bitmap *) mem;
194 
195  bmp->array1 = (uint64_t *) &mem[array1_byte_offset];
196  bmp->array1_size = array1_slabs;
197  bmp->array2 = (uint64_t *) &mem[array2_byte_offset];
198  bmp->array2_size = array2_slabs;
199 
200  __rte_bitmap_scan_init(bmp);
201 
202  return bmp;
203 }
204 
218 __rte_experimental
219 static inline void
220 __rte_bitmap_clear_slab_overhead_bits(uint64_t *slabs, uint32_t slab_size,
221  uint32_t pos)
222 {
223  uint32_t i;
224  uint32_t index = pos / RTE_BITMAP_SLAB_BIT_SIZE;
225  uint32_t offset = pos & RTE_BITMAP_SLAB_BIT_MASK;
226 
227  if (offset) {
228  for (i = offset; i < RTE_BITMAP_SLAB_BIT_SIZE; i++)
229  slabs[index] &= ~(1llu << i);
230  index++;
231  }
232  if (index < slab_size)
233  memset(&slabs[index], 0, sizeof(slabs[0]) *
234  (slab_size - index));
235 }
236 
252 __rte_experimental
253 static inline struct rte_bitmap *
254 rte_bitmap_init_with_all_set(uint32_t n_bits, uint8_t *mem, uint32_t mem_size)
255 {
256  struct rte_bitmap *bmp;
257  uint32_t array1_byte_offset, array1_slabs;
258  uint32_t array2_byte_offset, array2_slabs;
259  uint32_t size;
260 
261  /* Check input arguments */
262  if (!n_bits || !mem || (((uintptr_t) mem) & RTE_CACHE_LINE_MASK))
263  return NULL;
264 
265  size = __rte_bitmap_get_memory_footprint(n_bits,
266  &array1_byte_offset, &array1_slabs,
267  &array2_byte_offset, &array2_slabs);
268  if (size < mem_size)
269  return NULL;
270 
271  /* Setup bitmap */
272  bmp = (struct rte_bitmap *) mem;
273  bmp->array1 = (uint64_t *) &mem[array1_byte_offset];
274  bmp->array1_size = array1_slabs;
275  bmp->array2 = (uint64_t *) &mem[array2_byte_offset];
276  bmp->array2_size = array2_slabs;
277 
278  __rte_bitmap_scan_init(bmp);
279 
280  memset(bmp->array1, 0xff, bmp->array1_size * sizeof(bmp->array1[0]));
281  memset(bmp->array2, 0xff, bmp->array2_size * sizeof(bmp->array2[0]));
282  /* Clear overhead bits. */
284  bmp->array2_size >> RTE_BITMAP_CL_SLAB_SIZE_LOG2);
286  n_bits);
287  return bmp;
288 }
289 
298 static inline int
300 {
301  /* Check input arguments */
302  if (bmp == NULL) {
303  return -1;
304  }
305 
306  return 0;
307 }
308 
315 static inline void
317 {
318  memset(bmp->array1, 0, bmp->array1_size * sizeof(uint64_t));
319  memset(bmp->array2, 0, bmp->array2_size * sizeof(uint64_t));
320  __rte_bitmap_scan_init(bmp);
321 }
322 
333 static inline void
334 rte_bitmap_prefetch0(struct rte_bitmap *bmp, uint32_t pos)
335 {
336  uint64_t *slab2;
337  uint32_t index2;
338 
339  index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
340  slab2 = bmp->array2 + index2;
341  rte_prefetch0((void *) slab2);
342 }
343 
354 static inline uint64_t
355 rte_bitmap_get(struct rte_bitmap *bmp, uint32_t pos)
356 {
357  uint64_t *slab2;
358  uint32_t index2, offset2;
359 
360  index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
361  offset2 = pos & RTE_BITMAP_SLAB_BIT_MASK;
362  slab2 = bmp->array2 + index2;
363  return (*slab2) & (1llu << offset2);
364 }
365 
374 static inline void
375 rte_bitmap_set(struct rte_bitmap *bmp, uint32_t pos)
376 {
377  uint64_t *slab1, *slab2;
378  uint32_t index1, index2, offset1, offset2;
379 
380  /* Set bit in array2 slab and set bit in array1 slab */
381  index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
382  offset2 = pos & RTE_BITMAP_SLAB_BIT_MASK;
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  slab2 = bmp->array2 + index2;
386  slab1 = bmp->array1 + index1;
387 
388  *slab2 |= 1llu << offset2;
389  *slab1 |= 1llu << offset1;
390 }
391 
402 static inline void
403 rte_bitmap_set_slab(struct rte_bitmap *bmp, uint32_t pos, uint64_t slab)
404 {
405  uint64_t *slab1, *slab2;
406  uint32_t index1, index2, offset1;
407 
408  /* Set bits in array2 slab and set bit in array1 slab */
409  index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
410  index1 = pos >> (RTE_BITMAP_SLAB_BIT_SIZE_LOG2 + RTE_BITMAP_CL_BIT_SIZE_LOG2);
411  offset1 = (pos >> RTE_BITMAP_CL_BIT_SIZE_LOG2) & RTE_BITMAP_SLAB_BIT_MASK;
412  slab2 = bmp->array2 + index2;
413  slab1 = bmp->array1 + index1;
414 
415  *slab2 |= slab;
416  *slab1 |= 1llu << offset1;
417 }
418 
419 static inline uint64_t
420 __rte_bitmap_line_not_empty(uint64_t *slab2)
421 {
422  uint64_t v1, v2, v3, v4;
423 
424  v1 = slab2[0] | slab2[1];
425  v2 = slab2[2] | slab2[3];
426  v3 = slab2[4] | slab2[5];
427  v4 = slab2[6] | slab2[7];
428  v1 |= v2;
429  v3 |= v4;
430 
431  return v1 | v3;
432 }
433 
442 static inline void
443 rte_bitmap_clear(struct rte_bitmap *bmp, uint32_t pos)
444 {
445  uint64_t *slab1, *slab2;
446  uint32_t index1, index2, offset1, offset2;
447 
448  /* Clear bit in array2 slab */
449  index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
450  offset2 = pos & RTE_BITMAP_SLAB_BIT_MASK;
451  slab2 = bmp->array2 + index2;
452 
453  /* Return if array2 slab is not all-zeros */
454  *slab2 &= ~(1llu << offset2);
455  if (*slab2){
456  return;
457  }
458 
459  /* Check the entire cache line of array2 for all-zeros */
460  index2 &= ~ RTE_BITMAP_CL_SLAB_MASK;
461  slab2 = bmp->array2 + index2;
462  if (__rte_bitmap_line_not_empty(slab2)) {
463  return;
464  }
465 
466  /* The array2 cache line is all-zeros, so clear bit in array1 slab */
467  index1 = pos >> (RTE_BITMAP_SLAB_BIT_SIZE_LOG2 + RTE_BITMAP_CL_BIT_SIZE_LOG2);
468  offset1 = (pos >> RTE_BITMAP_CL_BIT_SIZE_LOG2) & RTE_BITMAP_SLAB_BIT_MASK;
469  slab1 = bmp->array1 + index1;
470  *slab1 &= ~(1llu << offset1);
471 
472  return;
473 }
474 
475 static inline int
476 __rte_bitmap_scan_search(struct rte_bitmap *bmp)
477 {
478  uint64_t value1;
479  uint32_t i;
480 
481  /* Check current array1 slab */
482  value1 = bmp->array1[bmp->index1];
483  value1 &= __rte_bitmap_mask1_get(bmp);
484 
485  if (rte_bsf64_safe(value1, &bmp->offset1))
486  return 1;
487 
488  __rte_bitmap_index1_inc(bmp);
489  bmp->offset1 = 0;
490 
491  /* Look for another array1 slab */
492  for (i = 0; i < bmp->array1_size; i ++, __rte_bitmap_index1_inc(bmp)) {
493  value1 = bmp->array1[bmp->index1];
494 
495  if (rte_bsf64_safe(value1, &bmp->offset1))
496  return 1;
497  }
498 
499  return 0;
500 }
501 
502 static inline void
503 __rte_bitmap_scan_read_init(struct rte_bitmap *bmp)
504 {
505  __rte_bitmap_index2_set(bmp);
506  bmp->go2 = 1;
507  rte_prefetch1((void *)(bmp->array2 + bmp->index2 + 8));
508 }
509 
510 static inline int
511 __rte_bitmap_scan_read(struct rte_bitmap *bmp, uint32_t *pos, uint64_t *slab)
512 {
513  uint64_t *slab2;
514 
515  slab2 = bmp->array2 + bmp->index2;
516  for ( ; bmp->go2 ; bmp->index2 ++, slab2 ++, bmp->go2 = bmp->index2 & RTE_BITMAP_CL_SLAB_MASK) {
517  if (*slab2) {
518  *pos = bmp->index2 << RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
519  *slab = *slab2;
520 
521  bmp->index2 ++;
522  slab2 ++;
523  bmp->go2 = bmp->index2 & RTE_BITMAP_CL_SLAB_MASK;
524  return 1;
525  }
526  }
527 
528  return 0;
529 }
530 
551 static inline int
552 rte_bitmap_scan(struct rte_bitmap *bmp, uint32_t *pos, uint64_t *slab)
553 {
554  /* Return data from current array2 line if available */
555  if (__rte_bitmap_scan_read(bmp, pos, slab)) {
556  return 1;
557  }
558 
559  /* Look for non-empty array2 line */
560  if (__rte_bitmap_scan_search(bmp)) {
561  __rte_bitmap_scan_read_init(bmp);
562  __rte_bitmap_scan_read(bmp, pos, slab);
563  return 1;
564  }
565 
566  /* Empty bitmap */
567  return 0;
568 }
569 
570 #ifdef __cplusplus
571 }
572 #endif
573 
574 #endif /* __INCLUDE_RTE_BITMAP_H__ */
static int rte_bitmap_free(struct rte_bitmap *bmp)
Definition: rte_bitmap.h:299
static void rte_bitmap_set_slab(struct rte_bitmap *bmp, uint32_t pos, uint64_t slab)
Definition: rte_bitmap.h:403
static void rte_bitmap_set(struct rte_bitmap *bmp, uint32_t pos)
Definition: rte_bitmap.h:375
static void rte_bitmap_reset(struct rte_bitmap *bmp)
Definition: rte_bitmap.h:316
static void rte_bitmap_clear(struct rte_bitmap *bmp, uint32_t pos)
Definition: rte_bitmap.h:443
static struct rte_bitmap * rte_bitmap_init(uint32_t n_bits, uint8_t *mem, uint32_t mem_size)
Definition: rte_bitmap.h:170
uint32_t array1_size
Definition: rte_bitmap.h:65
uint64_t * array1
Definition: rte_bitmap.h:63
static uint32_t rte_bitmap_get_memory_footprint(uint32_t n_bits)
Definition: rte_bitmap.h:148
uint64_t * array2
Definition: rte_bitmap.h:64
static uint32_t rte_align32pow2(uint32_t x)
Definition: rte_common.h:508
static int rte_bsf64_safe(uint64_t v, uint32_t *pos)
Definition: rte_common.h:703
static uint64_t rte_bitmap_get(struct rte_bitmap *bmp, uint32_t pos)
Definition: rte_bitmap.h:355
static __rte_experimental void __rte_bitmap_clear_slab_overhead_bits(uint64_t *slabs, uint32_t slab_size, uint32_t pos)
Definition: rte_bitmap.h:220
uint32_t index2
Definition: rte_bitmap.h:71
static void rte_bitmap_prefetch0(struct rte_bitmap *bmp, uint32_t pos)
Definition: rte_bitmap.h:334
uint32_t index1
Definition: rte_bitmap.h:69
static void rte_prefetch1(const volatile void *p)
#define RTE_CACHE_LINE_MASK
Definition: rte_common.h:380
static int rte_bitmap_scan(struct rte_bitmap *bmp, uint32_t *pos, uint64_t *slab)
Definition: rte_bitmap.h:552
uint32_t go2
Definition: rte_bitmap.h:72
static __rte_experimental struct rte_bitmap * rte_bitmap_init_with_all_set(uint32_t n_bits, uint8_t *mem, uint32_t mem_size)
Definition: rte_bitmap.h:254
uint32_t array2_size
Definition: rte_bitmap.h:66
uint32_t offset1
Definition: rte_bitmap.h:70
static void rte_prefetch0(const volatile void *p)