1 /* SPDX-License-Identifier: BSD-3-Clause
2 *
3 * Copyright (c) 2010-2015 Intel Corporation
4 * Copyright (c) 2007,2008 Kip Macy [email protected]
5 * All rights reserved.
6 * Derived from FreeBSD's bufring.h
7 * Used as BSD-3 Licensed with permission from Kip Macy.
8 */
9
10 #include <stdio.h>
11 #include <stdarg.h>
12 #include <string.h>
13 #include <stdint.h>
14 #include <inttypes.h>
15 #include <errno.h>
16 #include <sys/queue.h>
17
18 #include <rte_common.h>
19 #include <rte_log.h>
20 #include <rte_memory.h>
21 #include <rte_memzone.h>
22 #include <rte_malloc.h>
23 #include <rte_launch.h>
24 #include <rte_eal.h>
25 #include <rte_eal_memconfig.h>
26 #include <rte_atomic.h>
27 #include <rte_per_lcore.h>
28 #include <rte_lcore.h>
29 #include <rte_branch_prediction.h>
30 #include <rte_errno.h>
31 #include <rte_string_fns.h>
32 #include <rte_spinlock.h>
33 #include <rte_tailq.h>
34
35 #include "rte_ring.h"
36 #include "rte_ring_elem.h"
37
38 TAILQ_HEAD(rte_ring_list, rte_tailq_entry);
39
40 static struct rte_tailq_elem rte_ring_tailq = {
41 .name = RTE_TAILQ_RING_NAME,
42 };
EAL_REGISTER_TAILQ(rte_ring_tailq)43 EAL_REGISTER_TAILQ(rte_ring_tailq)
44
45 /* mask of all valid flag values to ring_create() */
46 #define RING_F_MASK (RING_F_SP_ENQ | RING_F_SC_DEQ | RING_F_EXACT_SZ | \
47 RING_F_MP_RTS_ENQ | RING_F_MC_RTS_DEQ | \
48 RING_F_MP_HTS_ENQ | RING_F_MC_HTS_DEQ)
49
50 /* true if x is a power of 2 */
51 #define POWEROF2(x) ((((x)-1) & (x)) == 0)
52
53 /* by default set head/tail distance as 1/8 of ring capacity */
54 #define HTD_MAX_DEF 8
55
56 /* return the size of memory occupied by a ring */
57 ssize_t
58 rte_ring_get_memsize_elem(unsigned int esize, unsigned int count)
59 {
60 ssize_t sz;
61
62 /* Check if element size is a multiple of 4B */
63 if (esize % 4 != 0) {
64 RTE_LOG(ERR, RING, "element size is not a multiple of 4\n");
65
66 return -EINVAL;
67 }
68
69 /* count must be a power of 2 */
70 if ((!POWEROF2(count)) || (count > RTE_RING_SZ_MASK )) {
71 RTE_LOG(ERR, RING,
72 "Requested number of elements is invalid, must be power of 2, and not exceed %u\n",
73 RTE_RING_SZ_MASK);
74
75 return -EINVAL;
76 }
77
78 sz = sizeof(struct rte_ring) + count * esize;
79 sz = RTE_ALIGN(sz, RTE_CACHE_LINE_SIZE);
80 return sz;
81 }
82
83 /* return the size of memory occupied by a ring */
84 ssize_t
rte_ring_get_memsize(unsigned int count)85 rte_ring_get_memsize(unsigned int count)
86 {
87 return rte_ring_get_memsize_elem(sizeof(void *), count);
88 }
89
90 /*
91 * internal helper function to reset prod/cons head-tail values.
92 */
93 static void
reset_headtail(void * p)94 reset_headtail(void *p)
95 {
96 struct rte_ring_headtail *ht;
97 struct rte_ring_hts_headtail *ht_hts;
98 struct rte_ring_rts_headtail *ht_rts;
99
100 ht = p;
101 ht_hts = p;
102 ht_rts = p;
103
104 switch (ht->sync_type) {
105 case RTE_RING_SYNC_MT:
106 case RTE_RING_SYNC_ST:
107 ht->head = 0;
108 ht->tail = 0;
109 break;
110 case RTE_RING_SYNC_MT_RTS:
111 ht_rts->head.raw = 0;
112 ht_rts->tail.raw = 0;
113 break;
114 case RTE_RING_SYNC_MT_HTS:
115 ht_hts->ht.raw = 0;
116 break;
117 default:
118 /* unknown sync mode */
119 RTE_ASSERT(0);
120 }
121 }
122
123 void
rte_ring_reset(struct rte_ring * r)124 rte_ring_reset(struct rte_ring *r)
125 {
126 reset_headtail(&r->prod);
127 reset_headtail(&r->cons);
128 }
129
130 /*
131 * helper function, calculates sync_type values for prod and cons
132 * based on input flags. Returns zero at success or negative
133 * errno value otherwise.
134 */
135 static int
get_sync_type(uint32_t flags,enum rte_ring_sync_type * prod_st,enum rte_ring_sync_type * cons_st)136 get_sync_type(uint32_t flags, enum rte_ring_sync_type *prod_st,
137 enum rte_ring_sync_type *cons_st)
138 {
139 static const uint32_t prod_st_flags =
140 (RING_F_SP_ENQ | RING_F_MP_RTS_ENQ | RING_F_MP_HTS_ENQ);
141 static const uint32_t cons_st_flags =
142 (RING_F_SC_DEQ | RING_F_MC_RTS_DEQ | RING_F_MC_HTS_DEQ);
143
144 switch (flags & prod_st_flags) {
145 case 0:
146 *prod_st = RTE_RING_SYNC_MT;
147 break;
148 case RING_F_SP_ENQ:
149 *prod_st = RTE_RING_SYNC_ST;
150 break;
151 case RING_F_MP_RTS_ENQ:
152 *prod_st = RTE_RING_SYNC_MT_RTS;
153 break;
154 case RING_F_MP_HTS_ENQ:
155 *prod_st = RTE_RING_SYNC_MT_HTS;
156 break;
157 default:
158 return -EINVAL;
159 }
160
161 switch (flags & cons_st_flags) {
162 case 0:
163 *cons_st = RTE_RING_SYNC_MT;
164 break;
165 case RING_F_SC_DEQ:
166 *cons_st = RTE_RING_SYNC_ST;
167 break;
168 case RING_F_MC_RTS_DEQ:
169 *cons_st = RTE_RING_SYNC_MT_RTS;
170 break;
171 case RING_F_MC_HTS_DEQ:
172 *cons_st = RTE_RING_SYNC_MT_HTS;
173 break;
174 default:
175 return -EINVAL;
176 }
177
178 return 0;
179 }
180
181 int
rte_ring_init(struct rte_ring * r,const char * name,unsigned int count,unsigned int flags)182 rte_ring_init(struct rte_ring *r, const char *name, unsigned int count,
183 unsigned int flags)
184 {
185 int ret;
186
187 /* compilation-time checks */
188 RTE_BUILD_BUG_ON((sizeof(struct rte_ring) &
189 RTE_CACHE_LINE_MASK) != 0);
190 RTE_BUILD_BUG_ON((offsetof(struct rte_ring, cons) &
191 RTE_CACHE_LINE_MASK) != 0);
192 RTE_BUILD_BUG_ON((offsetof(struct rte_ring, prod) &
193 RTE_CACHE_LINE_MASK) != 0);
194
195 RTE_BUILD_BUG_ON(offsetof(struct rte_ring_headtail, sync_type) !=
196 offsetof(struct rte_ring_hts_headtail, sync_type));
197 RTE_BUILD_BUG_ON(offsetof(struct rte_ring_headtail, tail) !=
198 offsetof(struct rte_ring_hts_headtail, ht.pos.tail));
199
200 RTE_BUILD_BUG_ON(offsetof(struct rte_ring_headtail, sync_type) !=
201 offsetof(struct rte_ring_rts_headtail, sync_type));
202 RTE_BUILD_BUG_ON(offsetof(struct rte_ring_headtail, tail) !=
203 offsetof(struct rte_ring_rts_headtail, tail.val.pos));
204
205 /* future proof flags, only allow supported values */
206 if (flags & ~RING_F_MASK) {
207 RTE_LOG(ERR, RING,
208 "Unsupported flags requested %#x\n", flags);
209 return -EINVAL;
210 }
211
212 /* init the ring structure */
213 memset(r, 0, sizeof(*r));
214 ret = strlcpy(r->name, name, sizeof(r->name));
215 if (ret < 0 || ret >= (int)sizeof(r->name))
216 return -ENAMETOOLONG;
217 r->flags = flags;
218 ret = get_sync_type(flags, &r->prod.sync_type, &r->cons.sync_type);
219 if (ret != 0)
220 return ret;
221
222 if (flags & RING_F_EXACT_SZ) {
223 r->size = rte_align32pow2(count + 1);
224 r->mask = r->size - 1;
225 r->capacity = count;
226 } else {
227 if ((!POWEROF2(count)) || (count > RTE_RING_SZ_MASK)) {
228 RTE_LOG(ERR, RING,
229 "Requested size is invalid, must be power of 2, and not exceed the size limit %u\n",
230 RTE_RING_SZ_MASK);
231 return -EINVAL;
232 }
233 r->size = count;
234 r->mask = count - 1;
235 r->capacity = r->mask;
236 }
237
238 /* set default values for head-tail distance */
239 if (flags & RING_F_MP_RTS_ENQ)
240 rte_ring_set_prod_htd_max(r, r->capacity / HTD_MAX_DEF);
241 if (flags & RING_F_MC_RTS_DEQ)
242 rte_ring_set_cons_htd_max(r, r->capacity / HTD_MAX_DEF);
243
244 return 0;
245 }
246
247 /* create the ring for a given element size */
248 struct rte_ring *
rte_ring_create_elem(const char * name,unsigned int esize,unsigned int count,int socket_id,unsigned int flags)249 rte_ring_create_elem(const char *name, unsigned int esize, unsigned int count,
250 int socket_id, unsigned int flags)
251 {
252 char mz_name[RTE_MEMZONE_NAMESIZE];
253 struct rte_ring *r;
254 struct rte_tailq_entry *te;
255 const struct rte_memzone *mz;
256 ssize_t ring_size;
257 int mz_flags = 0;
258 struct rte_ring_list* ring_list = NULL;
259 const unsigned int requested_count = count;
260 int ret;
261
262 ring_list = RTE_TAILQ_CAST(rte_ring_tailq.head, rte_ring_list);
263
264 /* for an exact size ring, round up from count to a power of two */
265 if (flags & RING_F_EXACT_SZ)
266 count = rte_align32pow2(count + 1);
267
268 ring_size = rte_ring_get_memsize_elem(esize, count);
269 if (ring_size < 0) {
270 rte_errno = ring_size;
271 return NULL;
272 }
273
274 ret = snprintf(mz_name, sizeof(mz_name), "%s%s",
275 RTE_RING_MZ_PREFIX, name);
276 if (ret < 0 || ret >= (int)sizeof(mz_name)) {
277 rte_errno = ENAMETOOLONG;
278 return NULL;
279 }
280
281 te = rte_zmalloc("RING_TAILQ_ENTRY", sizeof(*te), 0);
282 if (te == NULL) {
283 RTE_LOG(ERR, RING, "Cannot reserve memory for tailq\n");
284 rte_errno = ENOMEM;
285 return NULL;
286 }
287
288 rte_mcfg_tailq_write_lock();
289
290 /* reserve a memory zone for this ring. If we can't get rte_config or
291 * we are secondary process, the memzone_reserve function will set
292 * rte_errno for us appropriately - hence no check in this this function */
293 mz = rte_memzone_reserve_aligned(mz_name, ring_size, socket_id,
294 mz_flags, __alignof__(*r));
295 if (mz != NULL) {
296 r = mz->addr;
297 /* no need to check return value here, we already checked the
298 * arguments above */
299 rte_ring_init(r, name, requested_count, flags);
300
301 te->data = (void *) r;
302 r->memzone = mz;
303
304 TAILQ_INSERT_TAIL(ring_list, te, next);
305 } else {
306 r = NULL;
307 RTE_LOG(ERR, RING, "Cannot reserve memory\n");
308 rte_free(te);
309 }
310 rte_mcfg_tailq_write_unlock();
311
312 return r;
313 }
314
315 /* create the ring */
316 struct rte_ring *
rte_ring_create(const char * name,unsigned int count,int socket_id,unsigned int flags)317 rte_ring_create(const char *name, unsigned int count, int socket_id,
318 unsigned int flags)
319 {
320 return rte_ring_create_elem(name, sizeof(void *), count, socket_id,
321 flags);
322 }
323
324 /* free the ring */
325 void
rte_ring_free(struct rte_ring * r)326 rte_ring_free(struct rte_ring *r)
327 {
328 struct rte_ring_list *ring_list = NULL;
329 struct rte_tailq_entry *te;
330
331 if (r == NULL)
332 return;
333
334 /*
335 * Ring was not created with rte_ring_create,
336 * therefore, there is no memzone to free.
337 */
338 if (r->memzone == NULL) {
339 RTE_LOG(ERR, RING,
340 "Cannot free ring, not created with rte_ring_create()\n");
341 return;
342 }
343
344 if (rte_memzone_free(r->memzone) != 0) {
345 RTE_LOG(ERR, RING, "Cannot free memory\n");
346 return;
347 }
348
349 ring_list = RTE_TAILQ_CAST(rte_ring_tailq.head, rte_ring_list);
350 rte_mcfg_tailq_write_lock();
351
352 /* find out tailq entry */
353 TAILQ_FOREACH(te, ring_list, next) {
354 if (te->data == (void *) r)
355 break;
356 }
357
358 if (te == NULL) {
359 rte_mcfg_tailq_write_unlock();
360 return;
361 }
362
363 TAILQ_REMOVE(ring_list, te, next);
364
365 rte_mcfg_tailq_write_unlock();
366
367 rte_free(te);
368 }
369
370 /* dump the status of the ring on the console */
371 void
rte_ring_dump(FILE * f,const struct rte_ring * r)372 rte_ring_dump(FILE *f, const struct rte_ring *r)
373 {
374 fprintf(f, "ring <%s>@%p\n", r->name, r);
375 fprintf(f, " flags=%x\n", r->flags);
376 fprintf(f, " size=%"PRIu32"\n", r->size);
377 fprintf(f, " capacity=%"PRIu32"\n", r->capacity);
378 fprintf(f, " ct=%"PRIu32"\n", r->cons.tail);
379 fprintf(f, " ch=%"PRIu32"\n", r->cons.head);
380 fprintf(f, " pt=%"PRIu32"\n", r->prod.tail);
381 fprintf(f, " ph=%"PRIu32"\n", r->prod.head);
382 fprintf(f, " used=%u\n", rte_ring_count(r));
383 fprintf(f, " avail=%u\n", rte_ring_free_count(r));
384 }
385
386 /* dump the status of all rings on the console */
387 void
rte_ring_list_dump(FILE * f)388 rte_ring_list_dump(FILE *f)
389 {
390 const struct rte_tailq_entry *te;
391 struct rte_ring_list *ring_list;
392
393 ring_list = RTE_TAILQ_CAST(rte_ring_tailq.head, rte_ring_list);
394
395 rte_mcfg_tailq_read_lock();
396
397 TAILQ_FOREACH(te, ring_list, next) {
398 rte_ring_dump(f, (struct rte_ring *) te->data);
399 }
400
401 rte_mcfg_tailq_read_unlock();
402 }
403
404 /* search a ring from its name */
405 struct rte_ring *
rte_ring_lookup(const char * name)406 rte_ring_lookup(const char *name)
407 {
408 struct rte_tailq_entry *te;
409 struct rte_ring *r = NULL;
410 struct rte_ring_list *ring_list;
411
412 ring_list = RTE_TAILQ_CAST(rte_ring_tailq.head, rte_ring_list);
413
414 rte_mcfg_tailq_read_lock();
415
416 TAILQ_FOREACH(te, ring_list, next) {
417 r = (struct rte_ring *) te->data;
418 if (strncmp(name, r->name, RTE_RING_NAMESIZE) == 0)
419 break;
420 }
421
422 rte_mcfg_tailq_read_unlock();
423
424 if (te == NULL) {
425 rte_errno = ENOENT;
426 return NULL;
427 }
428
429 return r;
430 }
431