ceph/src/seastar/dpdk/lib/librte_ring/rte_ring.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2015 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * Derived from FreeBSD's bufring.c
  36  *
  37  **************************************************************************
  38  *
  39  * Copyright (c) 2007,2008 Kip Macy kmacy@freebsd.org
  40  * All rights reserved.
  41  *
  42  * Redistribution and use in source and binary forms, with or without
  43  * modification, are permitted provided that the following conditions are met:
  44  *
  45  * 1. Redistributions of source code must retain the above copyright notice,
  46  *    this list of conditions and the following disclaimer.
  47  *
  48  * 2. The name of Kip Macy nor the names of other
  49  *    contributors may be used to endorse or promote products derived from
  50  *    this software without specific prior written permission.
  51  *
  52  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  53  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  55  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  56  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  57  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  58  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  59  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  60  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  61  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  62  * POSSIBILITY OF SUCH DAMAGE.
  63  *
  64  ***************************************************************************/
  65
  66 #include <stdio.h>
  67 #include <stdarg.h>
  68 #include <string.h>
  69 #include <stdint.h>
  70 #include <inttypes.h>
  71 #include <errno.h>
  72 #include <sys/queue.h>
  73
  74 #include <rte_common.h>
  75 #include <rte_log.h>
  76 #include <rte_memory.h>
  77 #include <rte_memzone.h>
  78 #include <rte_malloc.h>
  79 #include <rte_launch.h>
  80 #include <rte_eal.h>
  81 #include <rte_eal_memconfig.h>
  82 #include <rte_atomic.h>
  83 #include <rte_per_lcore.h>
  84 #include <rte_lcore.h>
  85 #include <rte_branch_prediction.h>
  86 #include <rte_errno.h>
  87 #include <rte_string_fns.h>
  88 #include <rte_spinlock.h>
  89
  90 #include "rte_ring.h"
  91
  92 TAILQ_HEAD(rte_ring_list, rte_tailq_entry);
  93
  94 static struct rte_tailq_elem rte_ring_tailq = {
  95         .name = RTE_TAILQ_RING_NAME,
  96 };
  97 EAL_REGISTER_TAILQ(rte_ring_tailq)
  98
  99 /* true if x is a power of 2 */
 100 #define POWEROF2(x) ((((x)-1) & (x)) == 0)
 101
 102 /* return the size of memory occupied by a ring */
 103 ssize_t
 104 rte_ring_get_memsize(unsigned count)
 105 {
 106         ssize_t sz;
 107
 108         /* count must be a power of 2 */
 109         if ((!POWEROF2(count)) || (count > RTE_RING_SZ_MASK )) {
 110                 RTE_LOG(ERR, RING,
 111                         "Requested size is invalid, must be power of 2, and "
 112                         "do not exceed the size limit %u\n", RTE_RING_SZ_MASK);
 113                 return -EINVAL;
 114         }
 115
 116         sz = sizeof(struct rte_ring) + count * sizeof(void *);
 117         sz = RTE_ALIGN(sz, RTE_CACHE_LINE_SIZE);
 118         return sz;
 119 }
 120
 121 int
 122 rte_ring_init(struct rte_ring *r, const char *name, unsigned count,
 123         unsigned flags)
 124 {
 125         int ret;
 126
 127         /* compilation-time checks */
 128         RTE_BUILD_BUG_ON((sizeof(struct rte_ring) &
 129                           RTE_CACHE_LINE_MASK) != 0);
 130         RTE_BUILD_BUG_ON((offsetof(struct rte_ring, cons) &
 131                           RTE_CACHE_LINE_MASK) != 0);
 132         RTE_BUILD_BUG_ON((offsetof(struct rte_ring, prod) &
 133                           RTE_CACHE_LINE_MASK) != 0);
 134
 135         /* init the ring structure */
 136         memset(r, 0, sizeof(*r));
 137         ret = snprintf(r->name, sizeof(r->name), "%s", name);
 138         if (ret < 0 || ret >= (int)sizeof(r->name))
 139                 return -ENAMETOOLONG;
 140         r->flags = flags;
 141         r->prod.single = (flags & RING_F_SP_ENQ) ? __IS_SP : __IS_MP;
 142         r->cons.single = (flags & RING_F_SC_DEQ) ? __IS_SC : __IS_MC;
 143         r->size = count;
 144         r->mask = count - 1;
 145         r->prod.head = r->cons.head = 0;
 146         r->prod.tail = r->cons.tail = 0;
 147
 148         return 0;
 149 }
 150
 151 /* create the ring */
 152 struct rte_ring *
 153 rte_ring_create(const char *name, unsigned count, int socket_id,
 154                 unsigned flags)
 155 {
 156         char mz_name[RTE_MEMZONE_NAMESIZE];
 157         struct rte_ring *r;
 158         struct rte_tailq_entry *te;
 159         const struct rte_memzone *mz;
 160         ssize_t ring_size;
 161         int mz_flags = 0;
 162         struct rte_ring_list* ring_list = NULL;
 163         int ret;
 164
 165         ring_list = RTE_TAILQ_CAST(rte_ring_tailq.head, rte_ring_list);
 166
 167         ring_size = rte_ring_get_memsize(count);
 168         if (ring_size < 0) {
 169                 rte_errno = ring_size;
 170                 return NULL;
 171         }
 172
 173         ret = snprintf(mz_name, sizeof(mz_name), "%s%s",
 174                 RTE_RING_MZ_PREFIX, name);
 175         if (ret < 0 || ret >= (int)sizeof(mz_name)) {
 176                 rte_errno = ENAMETOOLONG;
 177                 return NULL;
 178         }
 179
 180         te = rte_zmalloc("RING_TAILQ_ENTRY", sizeof(*te), 0);
 181         if (te == NULL) {
 182                 RTE_LOG(ERR, RING, "Cannot reserve memory for tailq\n");
 183                 rte_errno = ENOMEM;
 184                 return NULL;
 185         }
 186
 187         rte_rwlock_write_lock(RTE_EAL_TAILQ_RWLOCK);
 188
 189         /* reserve a memory zone for this ring. If we can't get rte_config or
 190          * we are secondary process, the memzone_reserve function will set
 191          * rte_errno for us appropriately - hence no check in this this function */
 192         mz = rte_memzone_reserve(mz_name, ring_size, socket_id, mz_flags);
 193         if (mz != NULL) {
 194                 r = mz->addr;
 195                 /* no need to check return value here, we already checked the
 196                  * arguments above */
 197                 rte_ring_init(r, name, count, flags);
 198
 199                 te->data = (void *) r;
 200                 r->memzone = mz;
 201
 202                 TAILQ_INSERT_TAIL(ring_list, te, next);
 203         } else {
 204                 r = NULL;
 205                 RTE_LOG(ERR, RING, "Cannot reserve memory\n");
 206                 rte_free(te);
 207         }
 208         rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);
 209
 210         return r;
 211 }
 212
 213 /* free the ring */
 214 void
 215 rte_ring_free(struct rte_ring *r)
 216 {
 217         struct rte_ring_list *ring_list = NULL;
 218         struct rte_tailq_entry *te;
 219
 220         if (r == NULL)
 221                 return;
 222
 223         /*
 224          * Ring was not created with rte_ring_create,
 225          * therefore, there is no memzone to free.
 226          */
 227         if (r->memzone == NULL) {
 228                 RTE_LOG(ERR, RING, "Cannot free ring (not created with rte_ring_create()");
 229                 return;
 230         }
 231
 232         if (rte_memzone_free(r->memzone) != 0) {
 233                 RTE_LOG(ERR, RING, "Cannot free memory\n");
 234                 return;
 235         }
 236
 237         ring_list = RTE_TAILQ_CAST(rte_ring_tailq.head, rte_ring_list);
 238         rte_rwlock_write_lock(RTE_EAL_TAILQ_RWLOCK);
 239
 240         /* find out tailq entry */
 241         TAILQ_FOREACH(te, ring_list, next) {
 242                 if (te->data == (void *) r)
 243                         break;
 244         }
 245
 246         if (te == NULL) {
 247                 rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);
 248                 return;
 249         }
 250
 251         TAILQ_REMOVE(ring_list, te, next);
 252
 253         rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);
 254
 255         rte_free(te);
 256 }
 257
 258 /* dump the status of the ring on the console */
 259 void
 260 rte_ring_dump(FILE *f, const struct rte_ring *r)
 261 {
 262         fprintf(f, "ring <%s>@%p\n", r->name, r);
 263         fprintf(f, "  flags=%x\n", r->flags);
 264         fprintf(f, "  size=%"PRIu32"\n", r->size);
 265         fprintf(f, "  ct=%"PRIu32"\n", r->cons.tail);
 266         fprintf(f, "  ch=%"PRIu32"\n", r->cons.head);
 267         fprintf(f, "  pt=%"PRIu32"\n", r->prod.tail);
 268         fprintf(f, "  ph=%"PRIu32"\n", r->prod.head);
 269         fprintf(f, "  used=%u\n", rte_ring_count(r));
 270         fprintf(f, "  avail=%u\n", rte_ring_free_count(r));
 271 }
 272
 273 /* dump the status of all rings on the console */
 274 void
 275 rte_ring_list_dump(FILE *f)
 276 {
 277         const struct rte_tailq_entry *te;
 278         struct rte_ring_list *ring_list;
 279
 280         ring_list = RTE_TAILQ_CAST(rte_ring_tailq.head, rte_ring_list);
 281
 282         rte_rwlock_read_lock(RTE_EAL_TAILQ_RWLOCK);
 283
 284         TAILQ_FOREACH(te, ring_list, next) {
 285                 rte_ring_dump(f, (struct rte_ring *) te->data);
 286         }
 287
 288         rte_rwlock_read_unlock(RTE_EAL_TAILQ_RWLOCK);
 289 }
 290
 291 /* search a ring from its name */
 292 struct rte_ring *
 293 rte_ring_lookup(const char *name)
 294 {
 295         struct rte_tailq_entry *te;
 296         struct rte_ring *r = NULL;
 297         struct rte_ring_list *ring_list;
 298
 299         ring_list = RTE_TAILQ_CAST(rte_ring_tailq.head, rte_ring_list);
 300
 301         rte_rwlock_read_lock(RTE_EAL_TAILQ_RWLOCK);
 302
 303         TAILQ_FOREACH(te, ring_list, next) {
 304                 r = (struct rte_ring *) te->data;
 305                 if (strncmp(name, r->name, RTE_RING_NAMESIZE) == 0)
 306                         break;
 307         }
 308
 309         rte_rwlock_read_unlock(RTE_EAL_TAILQ_RWLOCK);
 310
 311         if (te == NULL) {
 312                 rte_errno = ENOENT;
 313                 return NULL;
 314         }
 315
 316         return r;
 317 }