LXR dpdk/lib/ring/rte

   1/* SPDX-License-Identifier: BSD-3-Clause
   2 *
   3 * Copyright (c) 2010-2015 Intel Corporation
   4 * Copyright (c) 2007,2008 Kip Macy kmacy@freebsd.org
   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
  38TAILQ_HEAD(rte_ring_list, rte_tailq_entry);
  39
  40static struct rte_tailq_elem rte_ring_tailq = {
  41        .name = RTE_TAILQ_RING_NAME,
  42};
  43EAL_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 */
  57ssize_t
  58rte_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 */
  84ssize_t
  85rte_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 */
  93static void
  94reset_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
 123void
 124rte_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 */
 135static int
 136get_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
 181int
 182rte_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 */
 248struct rte_ring *
 249rte_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 */
 316struct rte_ring *
 317rte_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 */
 325void
 326rte_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 */
 371void
 372rte_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 */
 387void
 388rte_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 */
 405struct rte_ring *
 406rte_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