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(dynfield1);
 129
 130                 /* init free_flags */
 131                 for (mask = PKT_FIRST_FREE; mask <= PKT_LAST_FREE; mask <<= 1)
 132                         shm->free_flags |= mask;
 133
 134                 process_score();
 135         }
 136
 137         return 0;
 138 }
 139
 140 /* check if this offset can be used */
 141 static int
 142 check_offset(size_t offset, size_t size, size_t align)
 143 {
 144         size_t i;
 145
 146         if ((offset & (align - 1)) != 0)
 147                 return -1;
 148         if (offset + size > sizeof(struct rte_mbuf))
 149                 return -1;
 150
 151         for (i = 0; i < size; i++) {
 152                 if (!shm->free_space[i + offset])
 153                         return -1;
 154         }
 155
 156         return 0;
 157 }
 158
 159 /* assume tailq is locked */
 160 static struct mbuf_dynfield_elt *
 161 __mbuf_dynfield_lookup(const char *name)
 162 {
 163         struct mbuf_dynfield_list *mbuf_dynfield_list;
 164         struct mbuf_dynfield_elt *mbuf_dynfield;
 165         struct rte_tailq_entry *te;
 166
 167         mbuf_dynfield_list = RTE_TAILQ_CAST(
 168                 mbuf_dynfield_tailq.head, mbuf_dynfield_list);
 169
 170         TAILQ_FOREACH(te, mbuf_dynfield_list, next) {
 171                 mbuf_dynfield = (struct mbuf_dynfield_elt *)te->data;
 172                 if (strcmp(name, mbuf_dynfield->params.name) == 0)
 173                         break;
 174         }
 175
 176         if (te == NULL) {
 177                 rte_errno = ENOENT;
 178                 return NULL;
 179         }
 180
 181         return mbuf_dynfield;
 182 }
 183
 184 int
 185 rte_mbuf_dynfield_lookup(const char *name, struct rte_mbuf_dynfield *params)
 186 {
 187         struct mbuf_dynfield_elt *mbuf_dynfield;
 188
 189         if (shm == NULL) {
 190                 rte_errno = ENOENT;
 191                 return -1;
 192         }
 193
 194         rte_mcfg_tailq_read_lock();
 195         mbuf_dynfield = __mbuf_dynfield_lookup(name);
 196         rte_mcfg_tailq_read_unlock();
 197
 198         if (mbuf_dynfield == NULL) {
 199                 rte_errno = ENOENT;
 200                 return -1;
 201         }
 202
 203         if (params != NULL)
 204                 memcpy(params, &mbuf_dynfield->params, sizeof(*params));
 205
 206         return mbuf_dynfield->offset;
 207 }
 208
 209 static int mbuf_dynfield_cmp(const struct rte_mbuf_dynfield *params1,
 210                 const struct rte_mbuf_dynfield *params2)
 211 {
 212         if (strcmp(params1->name, params2->name))
 213                 return -1;
 214         if (params1->size != params2->size)
 215                 return -1;
 216         if (params1->align != params2->align)
 217                 return -1;
 218         if (params1->flags != params2->flags)
 219                 return -1;
 220         return 0;
 221 }
 222
 223 /* assume tailq is locked */
 224 static int
 225 __rte_mbuf_dynfield_register_offset(const struct rte_mbuf_dynfield *params,
 226                                 size_t req)
 227 {
 228         struct mbuf_dynfield_list *mbuf_dynfield_list;
 229         struct mbuf_dynfield_elt *mbuf_dynfield = NULL;
 230         struct rte_tailq_entry *te = NULL;
 231         unsigned int best_zone = UINT_MAX;
 232         size_t i, offset;
 233         int ret;
 234
 235         if (shm == NULL && init_shared_mem() < 0)
 236                 return -1;
 237
 238         mbuf_dynfield = __mbuf_dynfield_lookup(params->name);
 239         if (mbuf_dynfield != NULL) {
 240                 if (req != SIZE_MAX && req != mbuf_dynfield->offset) {
 241                         rte_errno = EEXIST;
 242                         return -1;
 243                 }
 244                 if (mbuf_dynfield_cmp(params, &mbuf_dynfield->params) < 0) {
 245                         rte_errno = EEXIST;
 246                         return -1;
 247                 }
 248                 return mbuf_dynfield->offset;
 249         }
 250
 251         if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
 252                 rte_errno = EPERM;
 253                 return -1;
 254         }
 255
 256         if (req == SIZE_MAX) {
 257                 /* Find the best place to put this field: we search the
 258                  * lowest value of shm->free_space[offset]: the zones
 259                  * containing room for larger fields are kept for later.
 260                  */
 261                 for (offset = 0;
 262                      offset < sizeof(struct rte_mbuf);
 263                      offset++) {
 264                         if (check_offset(offset, params->size,
 265                                                 params->align) == 0 &&
 266                                         shm->free_space[offset] < best_zone) {
 267                                 best_zone = shm->free_space[offset];
 268                                 req = offset;
 269                         }
 270                 }
 271                 if (req == SIZE_MAX) {
 272                         rte_errno = ENOENT;
 273                         return -1;
 274                 }
 275         } else {
 276                 if (check_offset(req, params->size, params->align) < 0) {
 277                         rte_errno = EBUSY;
 278                         return -1;
 279                 }
 280         }
 281
 282         offset = req;
 283         mbuf_dynfield_list = RTE_TAILQ_CAST(
 284                 mbuf_dynfield_tailq.head, mbuf_dynfield_list);
 285
 286         te = rte_zmalloc("MBUF_DYNFIELD_TAILQ_ENTRY", sizeof(*te), 0);
 287         if (te == NULL) {
 288                 rte_errno = ENOMEM;
 289                 return -1;
 290         }
 291
 292         mbuf_dynfield = rte_zmalloc("mbuf_dynfield", sizeof(*mbuf_dynfield), 0);
 293         if (mbuf_dynfield == NULL) {
 294                 rte_free(te);
 295                 rte_errno = ENOMEM;
 296                 return -1;
 297         }
 298
 299         ret = strlcpy(mbuf_dynfield->params.name, params->name,
 300                 sizeof(mbuf_dynfield->params.name));
 301         if (ret < 0 || ret >= (int)sizeof(mbuf_dynfield->params.name)) {
 302                 rte_errno = ENAMETOOLONG;
 303                 rte_free(mbuf_dynfield);
 304                 rte_free(te);
 305                 return -1;
 306         }
 307         memcpy(&mbuf_dynfield->params, params, sizeof(mbuf_dynfield->params));
 308         mbuf_dynfield->offset = offset;
 309         te->data = mbuf_dynfield;
 310
 311         TAILQ_INSERT_TAIL(mbuf_dynfield_list, te, next);
 312
 313         for (i = offset; i < offset + params->size; i++)
 314                 shm->free_space[i] = 0;
 315         process_score();
 316
 317         RTE_LOG(DEBUG, MBUF, "Registered dynamic field %s (sz=%zu, al=%zu, fl=0x%x) -> %zd\n",
 318                 params->name, params->size, params->align, params->flags,
 319                 offset);
 320
 321         return offset;
 322 }
 323
 324 int
 325 rte_mbuf_dynfield_register_offset(const struct rte_mbuf_dynfield *params,
 326                                 size_t req)
 327 {
 328         int ret;
 329
 330         if (params->size >= sizeof(struct rte_mbuf)) {
 331                 rte_errno = EINVAL;
 332                 return -1;
 333         }
 334         if (!rte_is_power_of_2(params->align)) {
 335                 rte_errno = EINVAL;
 336                 return -1;
 337         }
 338         if (params->flags != 0) {
 339                 rte_errno = EINVAL;
 340                 return -1;
 341         }
 342
 343         rte_mcfg_tailq_write_lock();
 344         ret = __rte_mbuf_dynfield_register_offset(params, req);
 345         rte_mcfg_tailq_write_unlock();
 346
 347         return ret;
 348 }
 349
 350 int
 351 rte_mbuf_dynfield_register(const struct rte_mbuf_dynfield *params)
 352 {
 353         return rte_mbuf_dynfield_register_offset(params, SIZE_MAX);
 354 }
 355
 356 /* assume tailq is locked */
 357 static struct mbuf_dynflag_elt *
 358 __mbuf_dynflag_lookup(const char *name)
 359 {
 360         struct mbuf_dynflag_list *mbuf_dynflag_list;
 361         struct mbuf_dynflag_elt *mbuf_dynflag;
 362         struct rte_tailq_entry *te;
 363
 364         mbuf_dynflag_list = RTE_TAILQ_CAST(
 365                 mbuf_dynflag_tailq.head, mbuf_dynflag_list);
 366
 367         TAILQ_FOREACH(te, mbuf_dynflag_list, next) {
 368                 mbuf_dynflag = (struct mbuf_dynflag_elt *)te->data;
 369                 if (strncmp(name, mbuf_dynflag->params.name,
 370                                 RTE_MBUF_DYN_NAMESIZE) == 0)
 371                         break;
 372         }
 373
 374         if (te == NULL) {
 375                 rte_errno = ENOENT;
 376                 return NULL;
 377         }
 378
 379         return mbuf_dynflag;
 380 }
 381
 382 int
 383 rte_mbuf_dynflag_lookup(const char *name,
 384                         struct rte_mbuf_dynflag *params)
 385 {
 386         struct mbuf_dynflag_elt *mbuf_dynflag;
 387
 388         if (shm == NULL) {
 389                 rte_errno = ENOENT;
 390                 return -1;
 391         }
 392
 393         rte_mcfg_tailq_read_lock();
 394         mbuf_dynflag = __mbuf_dynflag_lookup(name);
 395         rte_mcfg_tailq_read_unlock();
 396
 397         if (mbuf_dynflag == NULL) {
 398                 rte_errno = ENOENT;
 399                 return -1;
 400         }
 401
 402         if (params != NULL)
 403                 memcpy(params, &mbuf_dynflag->params, sizeof(*params));
 404
 405         return mbuf_dynflag->bitnum;
 406 }
 407
 408 static int mbuf_dynflag_cmp(const struct rte_mbuf_dynflag *params1,
 409                 const struct rte_mbuf_dynflag *params2)
 410 {
 411         if (strcmp(params1->name, params2->name))
 412                 return -1;
 413         if (params1->flags != params2->flags)
 414                 return -1;
 415         return 0;
 416 }
 417
 418 /* assume tailq is locked */
 419 static int
 420 __rte_mbuf_dynflag_register_bitnum(const struct rte_mbuf_dynflag *params,
 421                                 unsigned int req)
 422 {
 423         struct mbuf_dynflag_list *mbuf_dynflag_list;
 424         struct mbuf_dynflag_elt *mbuf_dynflag = NULL;
 425         struct rte_tailq_entry *te = NULL;
 426         unsigned int bitnum;
 427         int ret;
 428
 429         if (shm == NULL && init_shared_mem() < 0)
 430                 return -1;
 431
 432         mbuf_dynflag = __mbuf_dynflag_lookup(params->name);
 433         if (mbuf_dynflag != NULL) {
 434                 if (req != UINT_MAX && req != mbuf_dynflag->bitnum) {
 435                         rte_errno = EEXIST;
 436                         return -1;
 437                 }
 438                 if (mbuf_dynflag_cmp(params, &mbuf_dynflag->params) < 0) {
 439                         rte_errno = EEXIST;
 440                         return -1;
 441                 }
 442                 return mbuf_dynflag->bitnum;
 443         }
 444
 445         if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
 446                 rte_errno = EPERM;
 447                 return -1;
 448         }
 449
 450         if (req == UINT_MAX) {
 451                 if (shm->free_flags == 0) {
 452                         rte_errno = ENOENT;
 453                         return -1;
 454                 }
 455                 bitnum = rte_bsf64(shm->free_flags);
 456         } else {
 457                 if ((shm->free_flags & (1ULL << req)) == 0) {
 458                         rte_errno = EBUSY;
 459                         return -1;
 460                 }
 461                 bitnum = req;
 462         }
 463
 464         mbuf_dynflag_list = RTE_TAILQ_CAST(
 465                 mbuf_dynflag_tailq.head, mbuf_dynflag_list);
 466
 467         te = rte_zmalloc("MBUF_DYNFLAG_TAILQ_ENTRY", sizeof(*te), 0);
 468         if (te == NULL) {
 469                 rte_errno = ENOMEM;
 470                 return -1;
 471         }
 472
 473         mbuf_dynflag = rte_zmalloc("mbuf_dynflag", sizeof(*mbuf_dynflag), 0);
 474         if (mbuf_dynflag == NULL) {
 475                 rte_free(te);
 476                 rte_errno = ENOMEM;
 477                 return -1;
 478         }
 479
 480         ret = strlcpy(mbuf_dynflag->params.name, params->name,
 481                 sizeof(mbuf_dynflag->params.name));
 482         if (ret < 0 || ret >= (int)sizeof(mbuf_dynflag->params.name)) {
 483                 rte_free(mbuf_dynflag);
 484                 rte_free(te);
 485                 rte_errno = ENAMETOOLONG;
 486                 return -1;
 487         }
 488         mbuf_dynflag->bitnum = bitnum;
 489         te->data = mbuf_dynflag;
 490
 491         TAILQ_INSERT_TAIL(mbuf_dynflag_list, te, next);
 492
 493         shm->free_flags &= ~(1ULL << bitnum);
 494
 495         RTE_LOG(DEBUG, MBUF, "Registered dynamic flag %s (fl=0x%x) -> %u\n",
 496                 params->name, params->flags, bitnum);
 497
 498         return bitnum;
 499 }
 500
 501 int
 502 rte_mbuf_dynflag_register_bitnum(const struct rte_mbuf_dynflag *params,
 503                                 unsigned int req)
 504 {
 505         int ret;
 506
 507         if (req >= RTE_SIZEOF_FIELD(struct rte_mbuf, ol_flags) * CHAR_BIT &&
 508                         req != UINT_MAX) {
 509                 rte_errno = EINVAL;
 510                 return -1;
 511         }
 512
 513         rte_mcfg_tailq_write_lock();
 514         ret = __rte_mbuf_dynflag_register_bitnum(params, req);
 515         rte_mcfg_tailq_write_unlock();
 516
 517         return ret;
 518 }
 519
 520 int
 521 rte_mbuf_dynflag_register(const struct rte_mbuf_dynflag *params)
 522 {
 523         return rte_mbuf_dynflag_register_bitnum(params, UINT_MAX);
 524 }
 525
 526 void rte_mbuf_dyn_dump(FILE *out)
 527 {
 528         struct mbuf_dynfield_list *mbuf_dynfield_list;
 529         struct mbuf_dynfield_elt *dynfield;
 530         struct mbuf_dynflag_list *mbuf_dynflag_list;
 531         struct mbuf_dynflag_elt *dynflag;
 532         struct rte_tailq_entry *te;
 533         size_t i;
 534
 535         rte_mcfg_tailq_write_lock();
 536         init_shared_mem();
 537         fprintf(out, "Reserved fields:\n");
 538         mbuf_dynfield_list = RTE_TAILQ_CAST(
 539                 mbuf_dynfield_tailq.head, mbuf_dynfield_list);
 540         TAILQ_FOREACH(te, mbuf_dynfield_list, next) {
 541                 dynfield = (struct mbuf_dynfield_elt *)te->data;
 542                 fprintf(out, "  name=%s offset=%zd size=%zd align=%zd flags=%x\n",
 543                         dynfield->params.name, dynfield->offset,
 544                         dynfield->params.size, dynfield->params.align,
 545                         dynfield->params.flags);
 546         }
 547         fprintf(out, "Reserved flags:\n");
 548         mbuf_dynflag_list = RTE_TAILQ_CAST(
 549                 mbuf_dynflag_tailq.head, mbuf_dynflag_list);
 550         TAILQ_FOREACH(te, mbuf_dynflag_list, next) {
 551                 dynflag = (struct mbuf_dynflag_elt *)te->data;
 552                 fprintf(out, "  name=%s bitnum=%u flags=%x\n",
 553                         dynflag->params.name, dynflag->bitnum,
 554                         dynflag->params.flags);
 555         }
 556         fprintf(out, "Free space in mbuf (0 = occupied, value = free zone alignment):\n");
 557         for (i = 0; i < sizeof(struct rte_mbuf); i++) {
 558                 if ((i % 8) == 0)
 559                         fprintf(out, "  %4.4zx: ", i);
 560                 fprintf(out, "%2.2x%s", shm->free_space[i],
 561                         (i % 8 != 7) ? " " : "\n");
 562         }
 563         fprintf(out, "Free bit in mbuf->ol_flags (0 = occupied, 1 = free):\n");
 564         for (i = 0; i < sizeof(uint64_t) * CHAR_BIT; i++) {
 565                 if ((i % 8) == 0)
 566                         fprintf(out, "  %4.4zx: ", i);
 567                 fprintf(out, "%1.1x%s", (shm->free_flags & (1ULL << i)) ? 1 : 0,
 568                         (i % 8 != 7) ? " " : "\n");
 569         }
 570
 571         rte_mcfg_tailq_write_unlock();
 572 }
 573
 574 static int
 575 rte_mbuf_dyn_timestamp_register(int *field_offset, uint64_t *flag,
 576                 const char *direction, const char *flag_name)
 577 {
 578         static const struct rte_mbuf_dynfield field_desc = {
 579                 .name = RTE_MBUF_DYNFIELD_TIMESTAMP_NAME,
 580                 .size = sizeof(rte_mbuf_timestamp_t),
 581                 .align = __alignof__(rte_mbuf_timestamp_t),
 582         };
 583         struct rte_mbuf_dynflag flag_desc = {};
 584         int offset;
 585
 586         offset = rte_mbuf_dynfield_register(&field_desc);
 587         if (offset < 0) {
 588                 RTE_LOG(ERR, MBUF,
 589                         "Failed to register mbuf field for timestamp\n");
 590                 return -1;
 591         }
 592         if (field_offset != NULL)
 593                 *field_offset = offset;
 594
 595         strlcpy(flag_desc.name, flag_name, sizeof(flag_desc.name));
 596         offset = rte_mbuf_dynflag_register(&flag_desc);
 597         if (offset < 0) {
 598                 RTE_LOG(ERR, MBUF,
 599                         "Failed to register mbuf flag for %s timestamp\n",
 600                         direction);
 601                 return -1;
 602         }
 603         if (flag != NULL)
 604                 *flag = RTE_BIT64(offset);
 605
 606         return 0;
 607 }
 608
 609 int
 610 rte_mbuf_dyn_rx_timestamp_register(int *field_offset, uint64_t *rx_flag)
 611 {
 612         return rte_mbuf_dyn_timestamp_register(field_offset, rx_flag,
 613                         "Rx", RTE_MBUF_DYNFLAG_RX_TIMESTAMP_NAME);
 614 }