DPDK  20.05.0
rte_bitmap.h
Go to the documentation of this file.
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 
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 
219 __rte_experimental
220 static inline void
221 __rte_bitmap_clear_slab_overhead_bits(uint64_t *slabs, uint32_t slab_size,
222  uint32_t pos)
223 {
224  uint32_t i;
225  uint32_t index = pos / RTE_BITMAP_SLAB_BIT_SIZE;
226  uint32_t offset = pos & RTE_BITMAP_SLAB_BIT_MASK;
227 
228  if (offset) {
229  for (i = offset; i < RTE_BITMAP_SLAB_BIT_SIZE; i++)
230  slabs[index] &= ~(1llu << i);
231  index++;
232  }
233  if (index < slab_size)
234  memset(&slabs[index], 0, sizeof(slabs[0]) *
235  (slab_size - index));
236 }
237 
253 __rte_experimental
254 static inline struct rte_bitmap *
255 rte_bitmap_init_with_all_set(uint32_t n_bits, uint8_t *mem, uint32_t mem_size)
256 {
257  struct rte_bitmap *bmp;
258  uint32_t array1_byte_offset, array1_slabs;
259  uint32_t array2_byte_offset, array2_slabs;
260  uint32_t size;
261 
262  /* Check input arguments */
263  if (!n_bits || !mem || (((uintptr_t) mem) & RTE_CACHE_LINE_MASK))
264  return NULL;
265 
266  size = __rte_bitmap_get_memory_footprint(n_bits,
267  &array1_byte_offset, &array1_slabs,
268  &array2_byte_offset, &array2_slabs);
269  if (size < mem_size)
270  return NULL;
271 
272  /* Setup bitmap */
273  bmp = (struct rte_bitmap *) mem;
274  bmp->array1 = (uint64_t *) &mem[array1_byte_offset];
275  bmp->array1_size = array1_slabs;
276  bmp->array2 = (uint64_t *) &mem[array2_byte_offset];
277  bmp->array2_size = array2_slabs;
278 
279  __rte_bitmap_scan_init(bmp);
280 
281  memset(bmp->array1, 0xff, bmp->array1_size * sizeof(bmp->array1[0]));
282  memset(bmp->array2, 0xff, bmp->array2_size * sizeof(bmp->array2[0]));
283  /* Clear overhead bits. */
285  bmp->array2_size >> RTE_BITMAP_CL_SLAB_SIZE_LOG2);
287  n_bits);
288  return bmp;
289 }
290 
299 static inline int
301 {
302  /* Check input arguments */
303  if (bmp == NULL) {
304  return -1;
305  }
306 
307  return 0;
308 }
309 
316 static inline void
318 {
319  memset(bmp->array1, 0, bmp->array1_size * sizeof(uint64_t));
320  memset(bmp->array2, 0, bmp->array2_size * sizeof(uint64_t));
321  __rte_bitmap_scan_init(bmp);
322 }
323 
334 static inline void
335 rte_bitmap_prefetch0(struct rte_bitmap *bmp, uint32_t pos)
336 {
337  uint64_t *slab2;
338  uint32_t index2;
339 
340  index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
341  slab2 = bmp->array2 + index2;
342  rte_prefetch0((void *) slab2);
343 }
344 
355 static inline uint64_t
356 rte_bitmap_get(struct rte_bitmap *bmp, uint32_t pos)
357 {
358  uint64_t *slab2;
359  uint32_t index2, offset2;
360 
361  index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
362  offset2 = pos & RTE_BITMAP_SLAB_BIT_MASK;
363  slab2 = bmp->array2 + index2;
364  return (*slab2) & (1llu << offset2);
365 }
366 
375 static inline void
376 rte_bitmap_set(struct rte_bitmap *bmp, uint32_t pos)
377 {
378  uint64_t *slab1, *slab2;
379  uint32_t index1, index2, offset1, offset2;
380 
381  /* Set bit in array2 slab and set bit in array1 slab */
382  index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
383  offset2 = pos & RTE_BITMAP_SLAB_BIT_MASK;
384  index1 = pos >> (RTE_BITMAP_SLAB_BIT_SIZE_LOG2 + RTE_BITMAP_CL_BIT_SIZE_LOG2);
385  offset1 = (pos >> RTE_BITMAP_CL_BIT_SIZE_LOG2) & RTE_BITMAP_SLAB_BIT_MASK;
386  slab2 = bmp->array2 + index2;
387  slab1 = bmp->array1 + index1;
388 
389  *slab2 |= 1llu << offset2;
390  *slab1 |= 1llu << offset1;
391 }
392 
403 static inline void
404 rte_bitmap_set_slab(struct rte_bitmap *bmp, uint32_t pos, uint64_t slab)
405 {
406  uint64_t *slab1, *slab2;
407  uint32_t index1, index2, offset1;
408 
409  /* Set bits in array2 slab and set bit in array1 slab */
410  index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
411  index1 = pos >> (RTE_BITMAP_SLAB_BIT_SIZE_LOG2 + RTE_BITMAP_CL_BIT_SIZE_LOG2);
412  offset1 = (pos >> RTE_BITMAP_CL_BIT_SIZE_LOG2) & RTE_BITMAP_SLAB_BIT_MASK;
413  slab2 = bmp->array2 + index2;
414  slab1 = bmp->array1 + index1;
415 
416  *slab2 |= slab;
417  *slab1 |= 1llu << offset1;
418 }
419 
420 static inline uint64_t
421 __rte_bitmap_line_not_empty(uint64_t *slab2)
422 {
423  uint64_t v1, v2, v3, v4;
424 
425  v1 = slab2[0] | slab2[1];
426  v2 = slab2[2] | slab2[3];
427  v3 = slab2[4] | slab2[5];
428  v4 = slab2[6] | slab2[7];
429  v1 |= v2;
430  v3 |= v4;
431 
432  return v1 | v3;
433 }
434 
443 static inline void
444 rte_bitmap_clear(struct rte_bitmap *bmp, uint32_t pos)
445 {
446  uint64_t *slab1, *slab2;
447  uint32_t index1, index2, offset1, offset2;
448 
449  /* Clear bit in array2 slab */
450  index2 = pos >> RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
451  offset2 = pos & RTE_BITMAP_SLAB_BIT_MASK;
452  slab2 = bmp->array2 + index2;
453 
454  /* Return if array2 slab is not all-zeros */
455  *slab2 &= ~(1llu << offset2);
456  if (*slab2){
457  return;
458  }
459 
460  /* Check the entire cache line of array2 for all-zeros */
461  index2 &= ~ RTE_BITMAP_CL_SLAB_MASK;
462  slab2 = bmp->array2 + index2;
463  if (__rte_bitmap_line_not_empty(slab2)) {
464  return;
465  }
466 
467  /* The array2 cache line is all-zeros, so clear bit in array1 slab */
468  index1 = pos >> (RTE_BITMAP_SLAB_BIT_SIZE_LOG2 + RTE_BITMAP_CL_BIT_SIZE_LOG2);
469  offset1 = (pos >> RTE_BITMAP_CL_BIT_SIZE_LOG2) & RTE_BITMAP_SLAB_BIT_MASK;
470  slab1 = bmp->array1 + index1;
471  *slab1 &= ~(1llu << offset1);
472 
473  return;
474 }
475 
476 static inline int
477 __rte_bitmap_scan_search(struct rte_bitmap *bmp)
478 {
479  uint64_t value1;
480  uint32_t i;
481 
482  /* Check current array1 slab */
483  value1 = bmp->array1[bmp->index1];
484  value1 &= __rte_bitmap_mask1_get(bmp);
485 
486  if (rte_bsf64_safe(value1, &bmp->offset1))
487  return 1;
488 
489  __rte_bitmap_index1_inc(bmp);
490  bmp->offset1 = 0;
491 
492  /* Look for another array1 slab */
493  for (i = 0; i < bmp->array1_size; i ++, __rte_bitmap_index1_inc(bmp)) {
494  value1 = bmp->array1[bmp->index1];
495 
496  if (rte_bsf64_safe(value1, &bmp->offset1))
497  return 1;
498  }
499 
500  return 0;
501 }
502 
503 static inline void
504 __rte_bitmap_scan_read_init(struct rte_bitmap *bmp)
505 {
506  __rte_bitmap_index2_set(bmp);
507  bmp->go2 = 1;
508  rte_prefetch1((void *)(bmp->array2 + bmp->index2 + 8));
509 }
510 
511 static inline int
512 __rte_bitmap_scan_read(struct rte_bitmap *bmp, uint32_t *pos, uint64_t *slab)
513 {
514  uint64_t *slab2;
515 
516  slab2 = bmp->array2 + bmp->index2;
517  for ( ; bmp->go2 ; bmp->index2 ++, slab2 ++, bmp->go2 = bmp->index2 & RTE_BITMAP_CL_SLAB_MASK) {
518  if (*slab2) {
519  *pos = bmp->index2 << RTE_BITMAP_SLAB_BIT_SIZE_LOG2;
520  *slab = *slab2;
521 
522  bmp->index2 ++;
523  slab2 ++;
524  bmp->go2 = bmp->index2 & RTE_BITMAP_CL_SLAB_MASK;
525  return 1;
526  }
527  }
528 
529  return 0;
530 }
531 
552 static inline int
553 rte_bitmap_scan(struct rte_bitmap *bmp, uint32_t *pos, uint64_t *slab)
554 {
555  /* Return data from current array2 line if available */
556  if (__rte_bitmap_scan_read(bmp, pos, slab)) {
557  return 1;
558  }
559 
560  /* Look for non-empty array2 line */
561  if (__rte_bitmap_scan_search(bmp)) {
562  __rte_bitmap_scan_read_init(bmp);
563  __rte_bitmap_scan_read(bmp, pos, slab);
564  return 1;
565  }
566 
567  /* Empty bitmap */
568  return 0;
569 }
570 
571 #ifdef __cplusplus
572 }
573 #endif
574 
575 #endif /* __INCLUDE_RTE_BITMAP_H__ */
static int rte_bitmap_free(struct rte_bitmap *bmp)
Definition: rte_bitmap.h:300
static void rte_bitmap_set_slab(struct rte_bitmap *bmp, uint32_t pos, uint64_t slab)
Definition: rte_bitmap.h:404
static void rte_bitmap_set(struct rte_bitmap *bmp, uint32_t pos)
Definition: rte_bitmap.h:376
static void rte_bitmap_reset(struct rte_bitmap *bmp)
Definition: rte_bitmap.h:317
static void rte_bitmap_clear(struct rte_bitmap *bmp, uint32_t pos)
Definition: rte_bitmap.h:444
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:475
static int rte_bsf64_safe(uint64_t v, uint32_t *pos)
Definition: rte_common.h:670
static uint64_t rte_bitmap_get(struct rte_bitmap *bmp, uint32_t pos)
Definition: rte_bitmap.h:356
static __rte_experimental void __rte_bitmap_clear_slab_overhead_bits(uint64_t *slabs, uint32_t slab_size, uint32_t pos)
Definition: rte_bitmap.h:221
uint32_t index2
Definition: rte_bitmap.h:71
static void rte_bitmap_prefetch0(struct rte_bitmap *bmp, uint32_t pos)
Definition: rte_bitmap.h:335
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:347
static int rte_bitmap_scan(struct rte_bitmap *bmp, uint32_t *pos, uint64_t *slab)
Definition: rte_bitmap.h:553
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:255
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)