DPDK  19.05.0
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
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 
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 
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 
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 
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 
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;
279  return (*slab2) & (1llu << offset2);
280 }
281 
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 
304  *slab2 |= 1llu << offset2;
305  *slab1 |= 1llu << offset1;
306 }
307 
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;
332  *slab1 |= 1llu << offset1;
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 
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 */
370  *slab2 &= ~(1llu << offset2);
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;
386  *slab1 &= ~(1llu << offset1);
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 
401  if (rte_bsf64_safe(value1, &bmp->offset1))
402  return 1;
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 
411  if (rte_bsf64_safe(value1, &bmp->offset1))
412  return 1;
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 
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__ */
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