lib/librte_mbuf/rte_mbuf_dyn.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright 2019 6WIND S.A.
   3  */
   4
   5 #include <sys/queue.h>
   6 #include <stdint.h>
   7 #include <limits.h>
   8
   9 #include <rte_common.h>
  10 #include <rte_eal.h>
  11 #include <rte_eal_memconfig.h>
  12 #include <rte_tailq.h>
  13 #include <rte_errno.h>
  14 #include <rte_malloc.h>
  15 #include <rte_string_fns.h>
  16 #include <rte_bitops.h>
  17 #include <rte_mbuf.h>
  18 #include <rte_mbuf_dyn.h>
  19
  20 #define RTE_MBUF_DYN_MZNAME "rte_mbuf_dyn"
  21
  22 struct mbuf_dynfield_elt {
  23         struct rte_mbuf_dynfield params;
  24         size_t offset;
  25 };
  26 TAILQ_HEAD(mbuf_dynfield_list, rte_tailq_entry);
  27
  28 static struct rte_tailq_elem mbuf_dynfield_tailq = {
  29         .name = "RTE_MBUF_DYNFIELD",
  30 };
  31 EAL_REGISTER_TAILQ(mbuf_dynfield_tailq);
  32
  33 struct mbuf_dynflag_elt {
  34         struct rte_mbuf_dynflag params;
  35         unsigned int bitnum;
  36 };
  37 TAILQ_HEAD(mbuf_dynflag_list, rte_tailq_entry);
  38
  39 static struct rte_tailq_elem mbuf_dynflag_tailq = {
  40         .name = "RTE_MBUF_DYNFLAG",
  41 };
  42 EAL_REGISTER_TAILQ(mbuf_dynflag_tailq);
  43
  44 struct mbuf_dyn_shm {
  45         /**
  46          * For each mbuf byte, free_space[i] != 0 if space is free.
  47          * The value is the size of the biggest aligned element that
  48          * can fit in the zone.
  49          */
  50         uint8_t free_space[sizeof(struct rte_mbuf)];
  51         /** Bitfield of available flags. */
  52         uint64_t free_flags;
  53 };
  54 static struct mbuf_dyn_shm *shm;
  55
  56 /* Set the value of free_space[] according to the size and alignment of
  57  * the free areas. This helps to select the best place when reserving a
  58  * dynamic field. Assume tailq is locked.
  59  */
  60 static void
  61 process_score(void)
  62 {
  63         size_t off, align, size, i;
  64
  65         /* first, erase previous info */
  66         for (i = 0; i < sizeof(struct rte_mbuf); i++) {
  67                 if (shm->free_space[i])
  68                         shm->free_space[i] = 1;
  69         }
  70
  71         off = 0;
  72         while (off < sizeof(struct rte_mbuf)) {
  73                 /* get the size of the free zone */
  74                 for (size = 0; (off + size) < sizeof(struct rte_mbuf) &&
  75                              shm->free_space[off + size]; size++)
  76                         ;
  77                 if (size == 0) {
  78                         off++;
  79                         continue;
  80                 }
  81
  82                 /* get the alignment of biggest object that can fit in
  83                  * the zone at this offset.
  84                  */
  85                 for (align = 1;
  86                      (off % (align << 1)) == 0 && (align << 1) <= size;
  87                      align <<= 1)
  88                         ;
  89
  90                 /* save it in free_space[] */
  91                 for (i = off; i < off + align; i++)
  92                         shm->free_space[i] = RTE_MAX(align, shm->free_space[i]);
  93
  94                 off += align;
  95         }
  96 }
  97
  98 /* Mark the area occupied by a mbuf field as available in the shm. */
  99 #define mark_free(field)                                                \
 100         memset(&shm->free_space[offsetof(struct rte_mbuf, field)],      \
 101                 1, sizeof(((struct rte_mbuf *)0)->field))
 102
 103 /* Allocate and initialize the shared memory. Assume tailq is locked */
 104 static int
 105 init_shared_mem(void)
 106 {
 107         const struct rte_memzone *mz;
 108         uint64_t mask;
 109
 110         if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
 111                 mz = rte_memzone_reserve_aligned(RTE_MBUF_DYN_MZNAME,
 112                                                 sizeof(struct mbuf_dyn_shm),
 113                                                 SOCKET_ID_ANY, 0,
 114                                                 RTE_CACHE_LINE_SIZE);
 115         } else {
 116                 mz = rte_memzone_lookup(RTE_MBUF_DYN_MZNAME);
 117         }
 118         if (mz == NULL)
 119                 return -1;
 120
 121         shm = mz->addr;
 122
 123         if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
 124                 /* init free_space, keep it sync'd with
 125                  * rte_mbuf_dynfield_copy().
 126                  */
 127                 memset(shm, 0, sizeof(*shm));
 128                 mark_free(dynfield0);
 129                 mark_free(dynfield1);
 130
 131                 /* init free_flags */
 132                 for (mask = PKT_FIRST_FREE; mask <= PKT_LAST_FREE; mask <<= 1)
 133                         shm->free_flags |= mask;
 134
 135                 process_score();
 136         }
 137
 138         return 0;
 139 }
 140
 141 /* check if this offset can be used */
 142 static int
 143 check_offset(size_t offset, size_t size, size_t align)
 144 {
 145         size_t i;
 146
 147         if ((offset & (align - 1)) != 0)
 148                 return -1;
 149         if (offset + size > sizeof(struct rte_mbuf))
 150                 return -1;
 151
 152         for (i = 0; i < size; i++) {
 153                 if (!shm->free_space[i + offset])
 154                         return -1;
 155         }
 156
 157         return 0;
 158 }
 159
 160 /* assume tailq is locked */
 161 static struct mbuf_dynfield_elt *
 162 __mbuf_dynfield_lookup(const char *name)
 163 {
 164         struct mbuf_dynfield_list *mbuf_dynfield_list;
 165         struct mbuf_dynfield_elt *mbuf_dynfield;
 166         struct rte_tailq_entry *te;
 167
 168         mbuf_dynfield_list = RTE_TAILQ_CAST(
 169                 mbuf_dynfield_tailq.head, mbuf_dynfield_list);
 170
 171         TAILQ_FOREACH(te, mbuf_dynfield_list, next) {
 172                 mbuf_dynfield = (struct mbuf_dynfield_elt *)te->data;
 173                 if (strcmp(name, mbuf_dynfield->params.name) == 0)
 174                         break;
 175         }
 176
 177         if (te == NULL || mbuf_dynfield == NULL) {
 178                 rte_errno = ENOENT;
 179                 return NULL;
 180         }
 181
 182         return mbuf_dynfield;
 183 }
 184
 185 int
 186 rte_mbuf_dynfield_lookup(const char *name, struct rte_mbuf_dynfield *params)
 187 {
 188         struct mbuf_dynfield_elt *mbuf_dynfield;
 189
 190         rte_mcfg_tailq_read_lock();
 191         if (shm == NULL && init_shared_mem() < 0)
 192                 mbuf_dynfield = NULL;
 193         else
 194                 mbuf_dynfield = __mbuf_dynfield_lookup(name);
 195         rte_mcfg_tailq_read_unlock();
 196
 197         if (mbuf_dynfield == NULL)
 198                 return -1;
 199
 200         if (params != NULL)
 201                 memcpy(params, &mbuf_dynfield->params, sizeof(*params));
 202
 203         return mbuf_dynfield->offset;
 204 }
 205
 206 static int mbuf_dynfield_cmp(const struct rte_mbuf_dynfield *params1,
 207                 const struct rte_mbuf_dynfield *params2)
 208 {
 209         if (strcmp(params1->name, params2->name))
 210                 return -1;
 211         if (params1->size != params2->size)
 212                 return -1;
 213         if (params1->align != params2->align)
 214                 return -1;
 215         if (params1->flags != params2->flags)
 216                 return -1;
 217         return 0;
 218 }
 219
 220 /* assume tailq is locked */
 221 static int
 222 __rte_mbuf_dynfield_register_offset(const struct rte_mbuf_dynfield *params,
 223                                 size_t req)
 224 {
 225         struct mbuf_dynfield_list *mbuf_dynfield_list;
 226         struct mbuf_dynfield_elt *mbuf_dynfield = NULL;
 227         struct rte_tailq_entry *te = NULL;
 228         unsigned int best_zone = UINT_MAX;
 229         size_t i, offset;
 230         int ret;
 231
 232         if (shm == NULL && init_shared_mem() < 0)
 233                 return -1;
 234
 235         mbuf_dynfield = __mbuf_dynfield_lookup(params->name);
 236         if (mbuf_dynfield != NULL) {
 237                 if (req != SIZE_MAX && req != mbuf_dynfield->offset) {
 238                         rte_errno = EEXIST;
 239                         return -1;
 240                 }
 241                 if (mbuf_dynfield_cmp(params, &mbuf_dynfield->params) < 0) {
 242                         rte_errno = EEXIST;
 243                         return -1;
 244                 }
 245                 return mbuf_dynfield->offset;
 246         }
 247
 248         if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
 249                 rte_errno = EPERM;
 250                 return -1;
 251         }
 252
 253         if (req == SIZE_MAX) {
 254                 /* Find the best place to put this field: we search the
 255                  * lowest value of shm->free_space[offset]: the zones
 256                  * containing room for larger fields are kept for later.
 257                  */
 258                 for (offset = 0;
 259                      offset < sizeof(struct rte_mbuf);
 260                      offset++) {
 261                         if (check_offset(offset, params->size,
 262                                                 params->align) == 0 &&
 263                                         shm->free_space[offset] < best_zone) {
 264                                 best_zone = shm->free_space[offset];
 265                                 req = offset;
 266                         }
 267                 }
 268                 if (req == SIZE_MAX) {
 269                         rte_errno = ENOENT;
 270                         return -1;
 271                 }
 272         } else {
 273                 if (check_offset(req, params->size, params->align) < 0) {
 274                         rte_errno = EBUSY;
 275                         return -1;
 276                 }
 277         }
 278
 279         offset = req;
 280         mbuf_dynfield_list = RTE_TAILQ_CAST(
 281                 mbuf_dynfield_tailq.head, mbuf_dynfield_list);
 282
 283         te = rte_zmalloc("MBUF_DYNFIELD_TAILQ_ENTRY", sizeof(*te), 0);
 284         if (te == NULL) {
 285                 rte_errno = ENOMEM;
 286                 return -1;
 287         }
 288
 289         mbuf_dynfield = rte_zmalloc("mbuf_dynfield", sizeof(*mbuf_dynfield), 0);
 290         if (mbuf_dynfield == NULL) {
 291                 rte_free(te);
 292                 rte_errno = ENOMEM;
 293                 return -1;
 294         }
 295
 296         ret = strlcpy(mbuf_dynfield->params.name, params->name,
 297                 sizeof(mbuf_dynfield->params.name));
 298         if (ret < 0 || ret >= (int)sizeof(mbuf_dynfield->params.name)) {
 299                 rte_errno = ENAMETOOLONG;
 300                 rte_free(mbuf_dynfield);
 301                 rte_free(te);
 302                 return -1;
 303         }
 304         memcpy(&mbuf_dynfield->params, params, sizeof(mbuf_dynfield->params));
 305         mbuf_dynfield->offset = offset;
 306         te->data = mbuf_dynfield;
 307
 308         TAILQ_INSERT_TAIL(mbuf_dynfield_list, te, next);
 309
 310         for (i = offset; i < offset + params->size; i++)
 311                 shm->free_space[i] = 0;
 312         process_score();
 313
 314         RTE_LOG(DEBUG, MBUF, "Registered dynamic field %s (sz=%zu, al=%zu, fl=0x%x) -> %zd\n",
 315                 params->name, params->size, params->align, params->flags,
 316                 offset);
 317
 318         return offset;
 319 }
 320
 321 int
 322 rte_mbuf_dynfield_register_offset(const struct rte_mbuf_dynfield *params,
 323                                 size_t req)
 324 {
 325         int ret;
 326
 327         if (params->size >= sizeof(struct rte_mbuf)) {
 328                 rte_errno = EINVAL;
 329                 return -1;
 330         }
 331         if (!rte_is_power_of_2(params->align)) {
 332                 rte_errno = EINVAL;
 333                 return -1;
 334         }
 335         if (params->flags != 0) {
 336                 rte_errno = EINVAL;
 337                 return -1;
 338         }
 339
 340         rte_mcfg_tailq_write_lock();
 341         ret = __rte_mbuf_dynfield_register_offset(params, req);
 342         rte_mcfg_tailq_write_unlock();
 343
 344         return ret;
 345 }
 346
 347 int
 348 rte_mbuf_dynfield_register(const struct rte_mbuf_dynfield *params)
 349 {
 350         return rte_mbuf_dynfield_register_offset(params, SIZE_MAX);
 351 }
 352
 353 /* assume tailq is locked */
 354 static struct mbuf_dynflag_elt *
 355 __mbuf_dynflag_lookup(const char *name)
 356 {
 357         struct mbuf_dynflag_list *mbuf_dynflag_list;
 358         struct mbuf_dynflag_elt *mbuf_dynflag;
 359         struct rte_tailq_entry *te;
 360
 361         mbuf_dynflag_list = RTE_TAILQ_CAST(
 362                 mbuf_dynflag_tailq.head, mbuf_dynflag_list);
 363
 364         TAILQ_FOREACH(te, mbuf_dynflag_list, next) {
 365                 mbuf_dynflag = (struct mbuf_dynflag_elt *)te->data;
 366                 if (strncmp(name, mbuf_dynflag->params.name,
 367                                 RTE_MBUF_DYN_NAMESIZE) == 0)
 368                         break;
 369         }
 370
 371         if (te == NULL) {
 372                 rte_errno = ENOENT;
 373                 return NULL;
 374         }
 375
 376         return mbuf_dynflag;
 377 }
 378
 379 int
 380 rte_mbuf_dynflag_lookup(const char *name,
 381                         struct rte_mbuf_dynflag *params)
 382 {
 383         struct mbuf_dynflag_elt *mbuf_dynflag;
 384
 385         rte_mcfg_tailq_read_lock();
 386         if (shm == NULL && init_shared_mem() < 0)
 387                 mbuf_dynflag = NULL;
 388         else
 389                 mbuf_dynflag = __mbuf_dynflag_lookup(name);
 390         rte_mcfg_tailq_read_unlock();
 391
 392         if (mbuf_dynflag == NULL)
 393                 return -1;
 394
 395         if (params != NULL)
 396                 memcpy(params, &mbuf_dynflag->params, sizeof(*params));
 397
 398         return mbuf_dynflag->bitnum;
 399 }
 400
 401 static int mbuf_dynflag_cmp(const struct rte_mbuf_dynflag *params1,
 402                 const struct rte_mbuf_dynflag *params2)
 403 {
 404         if (strcmp(params1->name, params2->name))
 405                 return -1;
 406         if (params1->flags != params2->flags)
 407                 return -1;
 408         return 0;
 409 }
 410
 411 /* assume tailq is locked */
 412 static int
 413 __rte_mbuf_dynflag_register_bitnum(const struct rte_mbuf_dynflag *params,
 414                                 unsigned int req)
 415 {
 416         struct mbuf_dynflag_list *mbuf_dynflag_list;
 417         struct mbuf_dynflag_elt *mbuf_dynflag = NULL;
 418         struct rte_tailq_entry *te = NULL;
 419         unsigned int bitnum;
 420         int ret;
 421
 422         if (shm == NULL && init_shared_mem() < 0)
 423                 return -1;
 424
 425         mbuf_dynflag = __mbuf_dynflag_lookup(params->name);
 426         if (mbuf_dynflag != NULL) {
 427                 if (req != UINT_MAX && req != mbuf_dynflag->bitnum) {
 428                         rte_errno = EEXIST;
 429                         return -1;
 430                 }
 431                 if (mbuf_dynflag_cmp(params, &mbuf_dynflag->params) < 0) {
 432                         rte_errno = EEXIST;
 433                         return -1;
 434                 }
 435                 return mbuf_dynflag->bitnum;
 436         }
 437
 438         if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
 439                 rte_errno = EPERM;
 440                 return -1;
 441         }
 442
 443         if (req == UINT_MAX) {
 444                 if (shm->free_flags == 0) {
 445                         rte_errno = ENOENT;
 446                         return -1;
 447                 }
 448                 bitnum = rte_bsf64(shm->free_flags);
 449         } else {
 450                 if ((shm->free_flags & (1ULL << req)) == 0) {
 451                         rte_errno = EBUSY;
 452                         return -1;
 453                 }
 454                 bitnum = req;
 455         }
 456
 457         mbuf_dynflag_list = RTE_TAILQ_CAST(
 458                 mbuf_dynflag_tailq.head, mbuf_dynflag_list);
 459
 460         te = rte_zmalloc("MBUF_DYNFLAG_TAILQ_ENTRY", sizeof(*te), 0);
 461         if (te == NULL) {
 462                 rte_errno = ENOMEM;
 463                 return -1;
 464         }
 465
 466         mbuf_dynflag = rte_zmalloc("mbuf_dynflag", sizeof(*mbuf_dynflag), 0);
 467         if (mbuf_dynflag == NULL) {
 468                 rte_free(te);
 469                 rte_errno = ENOMEM;
 470                 return -1;
 471         }
 472
 473         ret = strlcpy(mbuf_dynflag->params.name, params->name,
 474                 sizeof(mbuf_dynflag->params.name));
 475         if (ret < 0 || ret >= (int)sizeof(mbuf_dynflag->params.name)) {
 476                 rte_free(mbuf_dynflag);
 477                 rte_free(te);
 478                 rte_errno = ENAMETOOLONG;
 479                 return -1;
 480         }
 481         mbuf_dynflag->bitnum = bitnum;
 482         te->data = mbuf_dynflag;
 483
 484         TAILQ_INSERT_TAIL(mbuf_dynflag_list, te, next);
 485
 486         shm->free_flags &= ~(1ULL << bitnum);
 487
 488         RTE_LOG(DEBUG, MBUF, "Registered dynamic flag %s (fl=0x%x) -> %u\n",
 489                 params->name, params->flags, bitnum);
 490
 491         return bitnum;
 492 }
 493
 494 int
 495 rte_mbuf_dynflag_register_bitnum(const struct rte_mbuf_dynflag *params,
 496                                 unsigned int req)
 497 {
 498         int ret;
 499
 500         if (req >= RTE_SIZEOF_FIELD(struct rte_mbuf, ol_flags) * CHAR_BIT &&
 501                         req != UINT_MAX) {
 502                 rte_errno = EINVAL;
 503                 return -1;
 504         }
 505
 506         rte_mcfg_tailq_write_lock();
 507         ret = __rte_mbuf_dynflag_register_bitnum(params, req);
 508         rte_mcfg_tailq_write_unlock();
 509
 510         return ret;
 511 }
 512
 513 int
 514 rte_mbuf_dynflag_register(const struct rte_mbuf_dynflag *params)
 515 {
 516         return rte_mbuf_dynflag_register_bitnum(params, UINT_MAX);
 517 }
 518
 519 void rte_mbuf_dyn_dump(FILE *out)
 520 {
 521         struct mbuf_dynfield_list *mbuf_dynfield_list;
 522         struct mbuf_dynfield_elt *dynfield;
 523         struct mbuf_dynflag_list *mbuf_dynflag_list;
 524         struct mbuf_dynflag_elt *dynflag;
 525         struct rte_tailq_entry *te;
 526         size_t i;
 527
 528         rte_mcfg_tailq_write_lock();
 529         init_shared_mem();
 530         fprintf(out, "Reserved fields:\n");
 531         mbuf_dynfield_list = RTE_TAILQ_CAST(
 532                 mbuf_dynfield_tailq.head, mbuf_dynfield_list);
 533         TAILQ_FOREACH(te, mbuf_dynfield_list, next) {
 534                 dynfield = (struct mbuf_dynfield_elt *)te->data;
 535                 fprintf(out, "  name=%s offset=%zd size=%zd align=%zd flags=%x\n",
 536                         dynfield->params.name, dynfield->offset,
 537                         dynfield->params.size, dynfield->params.align,
 538                         dynfield->params.flags);
 539         }
 540         fprintf(out, "Reserved flags:\n");
 541         mbuf_dynflag_list = RTE_TAILQ_CAST(
 542                 mbuf_dynflag_tailq.head, mbuf_dynflag_list);
 543         TAILQ_FOREACH(te, mbuf_dynflag_list, next) {
 544                 dynflag = (struct mbuf_dynflag_elt *)te->data;
 545                 fprintf(out, "  name=%s bitnum=%u flags=%x\n",
 546                         dynflag->params.name, dynflag->bitnum,
 547                         dynflag->params.flags);
 548         }
 549         fprintf(out, "Free space in mbuf (0 = occupied, value = free zone alignment):\n");
 550         for (i = 0; i < sizeof(struct rte_mbuf); i++) {
 551                 if ((i % 8) == 0)
 552                         fprintf(out, "  %4.4zx: ", i);
 553                 fprintf(out, "%2.2x%s", shm->free_space[i],
 554                         (i % 8 != 7) ? " " : "\n");
 555         }
 556         fprintf(out, "Free bit in mbuf->ol_flags (0 = occupied, 1 = free):\n");
 557         for (i = 0; i < sizeof(uint64_t) * CHAR_BIT; i++) {
 558                 if ((i % 8) == 0)
 559                         fprintf(out, "  %4.4zx: ", i);
 560                 fprintf(out, "%1.1x%s", (shm->free_flags & (1ULL << i)) ? 1 : 0,
 561                         (i % 8 != 7) ? " " : "\n");
 562         }
 563
 564         rte_mcfg_tailq_write_unlock();
 565 }
 566
 567 static int
 568 rte_mbuf_dyn_timestamp_register(int *field_offset, uint64_t *flag,
 569                 const char *direction, const char *flag_name)
 570 {
 571         static const struct rte_mbuf_dynfield field_desc = {
 572                 .name = RTE_MBUF_DYNFIELD_TIMESTAMP_NAME,
 573                 .size = sizeof(rte_mbuf_timestamp_t),
 574                 .align = __alignof__(rte_mbuf_timestamp_t),
 575         };
 576         struct rte_mbuf_dynflag flag_desc = {};
 577         int offset;
 578
 579         offset = rte_mbuf_dynfield_register(&field_desc);
 580         if (offset < 0) {
 581                 RTE_LOG(ERR, MBUF,
 582                         "Failed to register mbuf field for timestamp\n");
 583                 return -1;
 584         }
 585         if (field_offset != NULL)
 586                 *field_offset = offset;
 587
 588         strlcpy(flag_desc.name, flag_name, sizeof(flag_desc.name));
 589         offset = rte_mbuf_dynflag_register(&flag_desc);
 590         if (offset < 0) {
 591                 RTE_LOG(ERR, MBUF,
 592                         "Failed to register mbuf flag for %s timestamp\n",
 593                         direction);
 594                 return -1;
 595         }
 596         if (flag != NULL)
 597                 *flag = RTE_BIT64(offset);
 598
 599         return 0;
 600 }
 601
 602 int
 603 rte_mbuf_dyn_rx_timestamp_register(int *field_offset, uint64_t *rx_flag)
 604 {
 605         return rte_mbuf_dyn_timestamp_register(field_offset, rx_flag,
 606                         "Rx", RTE_MBUF_DYNFLAG_RX_TIMESTAMP_NAME);
 607 }
 608
 609 int
 610 rte_mbuf_dyn_tx_timestamp_register(int *field_offset, uint64_t *tx_flag)
 611 {
 612         return rte_mbuf_dyn_timestamp_register(field_offset, tx_flag,
 613                         "Tx", RTE_MBUF_DYNFLAG_TX_TIMESTAMP_NAME);
 614 }