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