lib/librte_distributor/rte_distributor.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2017 Intel Corporation
   3  */
   4
   5 #include <stdio.h>
   6 #include <sys/queue.h>
   7 #include <string.h>
   8 #include <rte_mbuf.h>
   9 #include <rte_memory.h>
  10 #include <rte_cycles.h>
  11 #include <rte_memzone.h>
  12 #include <rte_errno.h>
  13 #include <rte_string_fns.h>
  14 #include <rte_eal_memconfig.h>
  15 #include <rte_pause.h>
  16 #include <rte_tailq.h>
  17
  18 #include "rte_distributor.h"
  19 #include "rte_distributor_single.h"
  20 #include "distributor_private.h"
  21
  22 TAILQ_HEAD(rte_dist_burst_list, rte_distributor);
  23
  24 static struct rte_tailq_elem rte_dist_burst_tailq = {
  25         .name = "RTE_DIST_BURST",
  26 };
  27 EAL_REGISTER_TAILQ(rte_dist_burst_tailq)
  28
  29 /**** APIs called by workers ****/
  30
  31 /**** Burst Packet APIs called by workers ****/
  32
  33 void
  34 rte_distributor_request_pkt(struct rte_distributor *d,
  35                 unsigned int worker_id, struct rte_mbuf **oldpkt,
  36                 unsigned int count)
  37 {
  38         struct rte_distributor_buffer *buf = &(d->bufs[worker_id]);
  39         unsigned int i;
  40
  41         volatile int64_t *retptr64;
  42
  43         if (unlikely(d->alg_type == RTE_DIST_ALG_SINGLE)) {
  44                 rte_distributor_request_pkt_single(d->d_single,
  45                         worker_id, count ? oldpkt[0] : NULL);
  46                 return;
  47         }
  48
  49         retptr64 = &(buf->retptr64[0]);
  50         /* Spin while handshake bits are set (scheduler clears it).
  51          * Sync with worker on GET_BUF flag.
  52          */
  53         while (unlikely(__atomic_load_n(retptr64, __ATOMIC_ACQUIRE)
  54                         & (RTE_DISTRIB_GET_BUF | RTE_DISTRIB_RETURN_BUF))) {
  55                 rte_pause();
  56                 uint64_t t = rte_rdtsc()+100;
  57
  58                 while (rte_rdtsc() < t)
  59                         rte_pause();
  60         }
  61
  62         /*
  63          * OK, if we've got here, then the scheduler has just cleared the
  64          * handshake bits. Populate the retptrs with returning packets.
  65          */
  66
  67         for (i = count; i < RTE_DIST_BURST_SIZE; i++)
  68                 buf->retptr64[i] = 0;
  69
  70         /* Set VALID_BUF bit for each packet returned */
  71         for (i = count; i-- > 0; )
  72                 buf->retptr64[i] =
  73                         (((int64_t)(uintptr_t)(oldpkt[i])) <<
  74                         RTE_DISTRIB_FLAG_BITS) | RTE_DISTRIB_VALID_BUF;
  75
  76         /*
  77          * Finally, set the GET_BUF  to signal to distributor that cache
  78          * line is ready for processing
  79          * Sync with distributor to release retptrs
  80          */
  81         __atomic_store_n(retptr64, *retptr64 | RTE_DISTRIB_GET_BUF,
  82                         __ATOMIC_RELEASE);
  83 }
  84
  85 int
  86 rte_distributor_poll_pkt(struct rte_distributor *d,
  87                 unsigned int worker_id, struct rte_mbuf **pkts)
  88 {
  89         struct rte_distributor_buffer *buf = &d->bufs[worker_id];
  90         uint64_t ret;
  91         int count = 0;
  92         unsigned int i;
  93
  94         if (unlikely(d->alg_type == RTE_DIST_ALG_SINGLE)) {
  95                 pkts[0] = rte_distributor_poll_pkt_single(d->d_single,
  96                         worker_id);
  97                 return (pkts[0]) ? 1 : 0;
  98         }
  99
 100         /* If any of below bits is set, return.
 101          * GET_BUF is set when distributor hasn't sent any packets yet
 102          * RETURN_BUF is set when distributor must retrieve in-flight packets
 103          * Sync with distributor to acquire bufptrs
 104          */
 105         if (__atomic_load_n(&(buf->bufptr64[0]), __ATOMIC_ACQUIRE)
 106                 & (RTE_DISTRIB_GET_BUF | RTE_DISTRIB_RETURN_BUF))
 107                 return -1;
 108
 109         /* since bufptr64 is signed, this should be an arithmetic shift */
 110         for (i = 0; i < RTE_DIST_BURST_SIZE; i++) {
 111                 if (likely(buf->bufptr64[i] & RTE_DISTRIB_VALID_BUF)) {
 112                         ret = buf->bufptr64[i] >> RTE_DISTRIB_FLAG_BITS;
 113                         pkts[count++] = (struct rte_mbuf *)((uintptr_t)(ret));
 114                 }
 115         }
 116
 117         /*
 118          * so now we've got the contents of the cacheline into an array of
 119          * mbuf pointers, so toggle the bit so scheduler can start working
 120          * on the next cacheline while we're working.
 121          * Sync with distributor on GET_BUF flag. Release bufptrs.
 122          */
 123         __atomic_store_n(&(buf->bufptr64[0]),
 124                 buf->bufptr64[0] | RTE_DISTRIB_GET_BUF, __ATOMIC_RELEASE);
 125
 126         return count;
 127 }
 128
 129 int
 130 rte_distributor_get_pkt(struct rte_distributor *d,
 131                 unsigned int worker_id, struct rte_mbuf **pkts,
 132                 struct rte_mbuf **oldpkt, unsigned int return_count)
 133 {
 134         int count;
 135
 136         if (unlikely(d->alg_type == RTE_DIST_ALG_SINGLE)) {
 137                 if (return_count <= 1) {
 138                         pkts[0] = rte_distributor_get_pkt_single(d->d_single,
 139                                 worker_id, return_count ? oldpkt[0] : NULL);
 140                         return (pkts[0]) ? 1 : 0;
 141                 } else
 142                         return -EINVAL;
 143         }
 144
 145         rte_distributor_request_pkt(d, worker_id, oldpkt, return_count);
 146
 147         count = rte_distributor_poll_pkt(d, worker_id, pkts);
 148         while (count == -1) {
 149                 uint64_t t = rte_rdtsc() + 100;
 150
 151                 while (rte_rdtsc() < t)
 152                         rte_pause();
 153
 154                 count = rte_distributor_poll_pkt(d, worker_id, pkts);
 155         }
 156         return count;
 157 }
 158
 159 int
 160 rte_distributor_return_pkt(struct rte_distributor *d,
 161                 unsigned int worker_id, struct rte_mbuf **oldpkt, int num)
 162 {
 163         struct rte_distributor_buffer *buf = &d->bufs[worker_id];
 164         unsigned int i;
 165
 166         if (unlikely(d->alg_type == RTE_DIST_ALG_SINGLE)) {
 167                 if (num == 1)
 168                         return rte_distributor_return_pkt_single(d->d_single,
 169                                 worker_id, oldpkt[0]);
 170                 else
 171                         return -EINVAL;
 172         }
 173
 174         /* Spin while handshake bits are set (scheduler clears it).
 175          * Sync with worker on GET_BUF flag.
 176          */
 177         while (unlikely(__atomic_load_n(&(buf->retptr64[0]), __ATOMIC_RELAXED)
 178                         & (RTE_DISTRIB_GET_BUF | RTE_DISTRIB_RETURN_BUF))) {
 179                 rte_pause();
 180                 uint64_t t = rte_rdtsc()+100;
 181
 182                 while (rte_rdtsc() < t)
 183                         rte_pause();
 184         }
 185
 186         /* Sync with distributor to acquire retptrs */
 187         __atomic_thread_fence(__ATOMIC_ACQUIRE);
 188         for (i = 0; i < RTE_DIST_BURST_SIZE; i++)
 189                 /* Switch off the return bit first */
 190                 buf->retptr64[i] = 0;
 191
 192         for (i = num; i-- > 0; )
 193                 buf->retptr64[i] = (((int64_t)(uintptr_t)oldpkt[i]) <<
 194                         RTE_DISTRIB_FLAG_BITS) | RTE_DISTRIB_VALID_BUF;
 195
 196         /* Use RETURN_BUF on bufptr64 to notify distributor that
 197          * we won't read any mbufs from there even if GET_BUF is set.
 198          * This allows distributor to retrieve in-flight already sent packets.
 199          */
 200         __atomic_or_fetch(&(buf->bufptr64[0]), RTE_DISTRIB_RETURN_BUF,
 201                 __ATOMIC_ACQ_REL);
 202
 203         /* set the RETURN_BUF on retptr64 even if we got no returns.
 204          * Sync with distributor on RETURN_BUF flag. Release retptrs.
 205          * Notify distributor that we don't request more packets any more.
 206          */
 207         __atomic_store_n(&(buf->retptr64[0]),
 208                 buf->retptr64[0] | RTE_DISTRIB_RETURN_BUF, __ATOMIC_RELEASE);
 209
 210         return 0;
 211 }
 212
 213 /**** APIs called on distributor core ***/
 214
 215 /* stores a packet returned from a worker inside the returns array */
 216 static inline void
 217 store_return(uintptr_t oldbuf, struct rte_distributor *d,
 218                 unsigned int *ret_start, unsigned int *ret_count)
 219 {
 220         if (!oldbuf)
 221                 return;
 222         /* store returns in a circular buffer */
 223         d->returns.mbufs[(*ret_start + *ret_count) & RTE_DISTRIB_RETURNS_MASK]
 224                         = (void *)oldbuf;
 225         *ret_start += (*ret_count == RTE_DISTRIB_RETURNS_MASK);
 226         *ret_count += (*ret_count != RTE_DISTRIB_RETURNS_MASK);
 227 }
 228
 229 /*
 230  * Match then flow_ids (tags) of the incoming packets to the flow_ids
 231  * of the inflight packets (both inflight on the workers and in each worker
 232  * backlog). This will then allow us to pin those packets to the relevant
 233  * workers to give us our atomic flow pinning.
 234  */
 235 void
 236 find_match_scalar(struct rte_distributor *d,
 237                         uint16_t *data_ptr,
 238                         uint16_t *output_ptr)
 239 {
 240         struct rte_distributor_backlog *bl;
 241         uint16_t i, j, w;
 242
 243         /*
 244          * Function overview:
 245          * 1. Loop through all worker ID's
 246          * 2. Compare the current inflights to the incoming tags
 247          * 3. Compare the current backlog to the incoming tags
 248          * 4. Add any matches to the output
 249          */
 250
 251         for (j = 0 ; j < RTE_DIST_BURST_SIZE; j++)
 252                 output_ptr[j] = 0;
 253
 254         for (i = 0; i < d->num_workers; i++) {
 255                 bl = &d->backlog[i];
 256
 257                 for (j = 0; j < RTE_DIST_BURST_SIZE ; j++)
 258                         for (w = 0; w < RTE_DIST_BURST_SIZE; w++)
 259                                 if (d->in_flight_tags[i][j] == data_ptr[w]) {
 260                                         output_ptr[j] = i+1;
 261                                         break;
 262                                 }
 263                 for (j = 0; j < RTE_DIST_BURST_SIZE; j++)
 264                         for (w = 0; w < RTE_DIST_BURST_SIZE; w++)
 265                                 if (bl->tags[j] == data_ptr[w]) {
 266                                         output_ptr[j] = i+1;
 267                                         break;
 268                                 }
 269         }
 270
 271         /*
 272          * At this stage, the output contains 8 16-bit values, with
 273          * each non-zero value containing the worker ID on which the
 274          * corresponding flow is pinned to.
 275          */
 276 }
 277
 278 /*
 279  * When worker called rte_distributor_return_pkt()
 280  * and passed RTE_DISTRIB_RETURN_BUF handshake through retptr64,
 281  * distributor must retrieve both inflight and backlog packets assigned
 282  * to the worker and reprocess them to another worker.
 283  */
 284 static void
 285 handle_worker_shutdown(struct rte_distributor *d, unsigned int wkr)
 286 {
 287         struct rte_distributor_buffer *buf = &(d->bufs[wkr]);
 288         /* double BURST size for storing both inflights and backlog */
 289         struct rte_mbuf *pkts[RTE_DIST_BURST_SIZE * 2];
 290         unsigned int pkts_count = 0;
 291         unsigned int i;
 292
 293         /* If GET_BUF is cleared there are in-flight packets sent
 294          * to worker which does not require new packets.
 295          * They must be retrieved and assigned to another worker.
 296          */
 297         if (!(__atomic_load_n(&(buf->bufptr64[0]), __ATOMIC_ACQUIRE)
 298                 & RTE_DISTRIB_GET_BUF))
 299                 for (i = 0; i < RTE_DIST_BURST_SIZE; i++)
 300                         if (buf->bufptr64[i] & RTE_DISTRIB_VALID_BUF)
 301                                 pkts[pkts_count++] = (void *)((uintptr_t)
 302                                         (buf->bufptr64[i]
 303                                                 >> RTE_DISTRIB_FLAG_BITS));
 304
 305         /* Make following operations on handshake flags on bufptr64:
 306          * - set GET_BUF to indicate that distributor can overwrite buffer
 307          *     with new packets if worker will make a new request.
 308          * - clear RETURN_BUF to unlock reads on worker side.
 309          */
 310         __atomic_store_n(&(buf->bufptr64[0]), RTE_DISTRIB_GET_BUF,
 311                 __ATOMIC_RELEASE);
 312
 313         /* Collect backlog packets from worker */
 314         for (i = 0; i < d->backlog[wkr].count; i++)
 315                 pkts[pkts_count++] = (void *)((uintptr_t)
 316                         (d->backlog[wkr].pkts[i] >> RTE_DISTRIB_FLAG_BITS));
 317
 318         d->backlog[wkr].count = 0;
 319
 320         /* Clear both inflight and backlog tags */
 321         for (i = 0; i < RTE_DIST_BURST_SIZE; i++) {
 322                 d->in_flight_tags[wkr][i] = 0;
 323                 d->backlog[wkr].tags[i] = 0;
 324         }
 325
 326         /* Recursive call */
 327         if (pkts_count > 0)
 328                 rte_distributor_process(d, pkts, pkts_count);
 329 }
 330
 331
 332 /*
 333  * When the handshake bits indicate that there are packets coming
 334  * back from the worker, this function is called to copy and store
 335  * the valid returned pointers (store_return).
 336  */
 337 static unsigned int
 338 handle_returns(struct rte_distributor *d, unsigned int wkr)
 339 {
 340         struct rte_distributor_buffer *buf = &(d->bufs[wkr]);
 341         uintptr_t oldbuf;
 342         unsigned int ret_start = d->returns.start,
 343                         ret_count = d->returns.count;
 344         unsigned int count = 0;
 345         unsigned int i;
 346
 347         /* Sync on GET_BUF flag. Acquire retptrs. */
 348         if (__atomic_load_n(&(buf->retptr64[0]), __ATOMIC_ACQUIRE)
 349                 & (RTE_DISTRIB_GET_BUF | RTE_DISTRIB_RETURN_BUF)) {
 350                 for (i = 0; i < RTE_DIST_BURST_SIZE; i++) {
 351                         if (buf->retptr64[i] & RTE_DISTRIB_VALID_BUF) {
 352                                 oldbuf = ((uintptr_t)(buf->retptr64[i] >>
 353                                         RTE_DISTRIB_FLAG_BITS));
 354                                 /* store returns in a circular buffer */
 355                                 store_return(oldbuf, d, &ret_start, &ret_count);
 356                                 count++;
 357                                 buf->retptr64[i] &= ~RTE_DISTRIB_VALID_BUF;
 358                         }
 359                 }
 360                 d->returns.start = ret_start;
 361                 d->returns.count = ret_count;
 362
 363                 /* If worker requested packets with GET_BUF, set it to active
 364                  * otherwise (RETURN_BUF), set it to not active.
 365                  */
 366                 d->activesum -= d->active[wkr];
 367                 d->active[wkr] = !!(buf->retptr64[0] & RTE_DISTRIB_GET_BUF);
 368                 d->activesum += d->active[wkr];
 369
 370                 /* If worker returned packets without requesting new ones,
 371                  * handle all in-flights and backlog packets assigned to it.
 372                  */
 373                 if (unlikely(buf->retptr64[0] & RTE_DISTRIB_RETURN_BUF))
 374                         handle_worker_shutdown(d, wkr);
 375
 376                 /* Clear for the worker to populate with more returns.
 377                  * Sync with distributor on GET_BUF flag. Release retptrs.
 378                  */
 379                 __atomic_store_n(&(buf->retptr64[0]), 0, __ATOMIC_RELEASE);
 380         }
 381         return count;
 382 }
 383
 384 /*
 385  * This function releases a burst (cache line) to a worker.
 386  * It is called from the process function when a cacheline is
 387  * full to make room for more packets for that worker, or when
 388  * all packets have been assigned to bursts and need to be flushed
 389  * to the workers.
 390  * It also needs to wait for any outstanding packets from the worker
 391  * before sending out new packets.
 392  */
 393 static unsigned int
 394 release(struct rte_distributor *d, unsigned int wkr)
 395 {
 396         struct rte_distributor_buffer *buf = &(d->bufs[wkr]);
 397         unsigned int i;
 398
 399         handle_returns(d, wkr);
 400         if (unlikely(!d->active[wkr]))
 401                 return 0;
 402
 403         /* Sync with worker on GET_BUF flag */
 404         while (!(__atomic_load_n(&(d->bufs[wkr].bufptr64[0]), __ATOMIC_ACQUIRE)
 405                 & RTE_DISTRIB_GET_BUF)) {
 406                 handle_returns(d, wkr);
 407                 if (unlikely(!d->active[wkr]))
 408                         return 0;
 409                 rte_pause();
 410         }
 411
 412         buf->count = 0;
 413
 414         for (i = 0; i < d->backlog[wkr].count; i++) {
 415                 d->bufs[wkr].bufptr64[i] = d->backlog[wkr].pkts[i] |
 416                                 RTE_DISTRIB_GET_BUF | RTE_DISTRIB_VALID_BUF;
 417                 d->in_flight_tags[wkr][i] = d->backlog[wkr].tags[i];
 418         }
 419         buf->count = i;
 420         for ( ; i < RTE_DIST_BURST_SIZE ; i++) {
 421                 buf->bufptr64[i] = RTE_DISTRIB_GET_BUF;
 422                 d->in_flight_tags[wkr][i] = 0;
 423         }
 424
 425         d->backlog[wkr].count = 0;
 426
 427         /* Clear the GET bit.
 428          * Sync with worker on GET_BUF flag. Release bufptrs.
 429          */
 430         __atomic_store_n(&(buf->bufptr64[0]),
 431                 buf->bufptr64[0] & ~RTE_DISTRIB_GET_BUF, __ATOMIC_RELEASE);
 432         return  buf->count;
 433
 434 }
 435
 436
 437 /* process a set of packets to distribute them to workers */
 438 int
 439 rte_distributor_process(struct rte_distributor *d,
 440                 struct rte_mbuf **mbufs, unsigned int num_mbufs)
 441 {
 442         unsigned int next_idx = 0;
 443         static unsigned int wkr;
 444         struct rte_mbuf *next_mb = NULL;
 445         int64_t next_value = 0;
 446         uint16_t new_tag = 0;
 447         uint16_t flows[RTE_DIST_BURST_SIZE] __rte_cache_aligned;
 448         unsigned int i, j, w, wid, matching_required;
 449
 450         if (d->alg_type == RTE_DIST_ALG_SINGLE) {
 451                 /* Call the old API */
 452                 return rte_distributor_process_single(d->d_single,
 453                         mbufs, num_mbufs);
 454         }
 455
 456         for (wid = 0 ; wid < d->num_workers; wid++)
 457                 handle_returns(d, wid);
 458
 459         if (unlikely(num_mbufs == 0)) {
 460                 /* Flush out all non-full cache-lines to workers. */
 461                 for (wid = 0 ; wid < d->num_workers; wid++) {
 462                         /* Sync with worker on GET_BUF flag. */
 463                         if (__atomic_load_n(&(d->bufs[wid].bufptr64[0]),
 464                                 __ATOMIC_ACQUIRE) & RTE_DISTRIB_GET_BUF) {
 465                                 release(d, wid);
 466                                 handle_returns(d, wid);
 467                         }
 468                 }
 469                 return 0;
 470         }
 471
 472         if (unlikely(!d->activesum))
 473                 return 0;
 474
 475         while (next_idx < num_mbufs) {
 476                 uint16_t matches[RTE_DIST_BURST_SIZE];
 477                 unsigned int pkts;
 478
 479                 /* Sync with worker on GET_BUF flag. */
 480                 if (__atomic_load_n(&(d->bufs[wkr].bufptr64[0]),
 481                         __ATOMIC_ACQUIRE) & RTE_DISTRIB_GET_BUF)
 482                         d->bufs[wkr].count = 0;
 483
 484                 if ((num_mbufs - next_idx) < RTE_DIST_BURST_SIZE)
 485                         pkts = num_mbufs - next_idx;
 486                 else
 487                         pkts = RTE_DIST_BURST_SIZE;
 488
 489                 for (i = 0; i < pkts; i++) {
 490                         if (mbufs[next_idx + i]) {
 491                                 /* flows have to be non-zero */
 492                                 flows[i] = mbufs[next_idx + i]->hash.usr | 1;
 493                         } else
 494                                 flows[i] = 0;
 495                 }
 496                 for (; i < RTE_DIST_BURST_SIZE; i++)
 497                         flows[i] = 0;
 498
 499                 matching_required = 1;
 500
 501                 for (j = 0; j < pkts; j++) {
 502                         if (unlikely(!d->activesum))
 503                                 return next_idx;
 504
 505                         if (unlikely(matching_required)) {
 506                                 switch (d->dist_match_fn) {
 507                                 case RTE_DIST_MATCH_VECTOR:
 508                                         find_match_vec(d, &flows[0],
 509                                                 &matches[0]);
 510                                         break;
 511                                 default:
 512                                         find_match_scalar(d, &flows[0],
 513                                                 &matches[0]);
 514                                 }
 515                                 matching_required = 0;
 516                         }
 517                 /*
 518                  * Matches array now contain the intended worker ID (+1) of
 519                  * the incoming packets. Any zeroes need to be assigned
 520                  * workers.
 521                  */
 522
 523                         next_mb = mbufs[next_idx++];
 524                         next_value = (((int64_t)(uintptr_t)next_mb) <<
 525                                         RTE_DISTRIB_FLAG_BITS);
 526                         /*
 527                          * User is advocated to set tag value for each
 528                          * mbuf before calling rte_distributor_process.
 529                          * User defined tags are used to identify flows,
 530                          * or sessions.
 531                          */
 532                         /* flows MUST be non-zero */
 533                         new_tag = (uint16_t)(next_mb->hash.usr) | 1;
 534
 535                         /*
 536                          * Uncommenting the next line will cause the find_match
 537                          * function to be optimized out, making this function
 538                          * do parallel (non-atomic) distribution
 539                          */
 540                         /* matches[j] = 0; */
 541
 542                         if (matches[j] && d->active[matches[j]-1]) {
 543                                 struct rte_distributor_backlog *bl =
 544                                                 &d->backlog[matches[j]-1];
 545                                 if (unlikely(bl->count ==
 546                                                 RTE_DIST_BURST_SIZE)) {
 547                                         release(d, matches[j]-1);
 548                                         if (!d->active[matches[j]-1]) {
 549                                                 j--;
 550                                                 next_idx--;
 551                                                 matching_required = 1;
 552                                                 continue;
 553                                         }
 554                                 }
 555
 556                                 /* Add to worker that already has flow */
 557                                 unsigned int idx = bl->count++;
 558
 559                                 bl->tags[idx] = new_tag;
 560                                 bl->pkts[idx] = next_value;
 561
 562                         } else {
 563                                 struct rte_distributor_backlog *bl;
 564
 565                                 while (unlikely(!d->active[wkr]))
 566                                         wkr = (wkr + 1) % d->num_workers;
 567                                 bl = &d->backlog[wkr];
 568
 569                                 if (unlikely(bl->count ==
 570                                                 RTE_DIST_BURST_SIZE)) {
 571                                         release(d, wkr);
 572                                         if (!d->active[wkr]) {
 573                                                 j--;
 574                                                 next_idx--;
 575                                                 matching_required = 1;
 576                                                 continue;
 577                                         }
 578                                 }
 579
 580                                 /* Add to current worker worker */
 581                                 unsigned int idx = bl->count++;
 582
 583                                 bl->tags[idx] = new_tag;
 584                                 bl->pkts[idx] = next_value;
 585                                 /*
 586                                  * Now that we've just added an unpinned flow
 587                                  * to a worker, we need to ensure that all
 588                                  * other packets with that same flow will go
 589                                  * to the same worker in this burst.
 590                                  */
 591                                 for (w = j; w < pkts; w++)
 592                                         if (flows[w] == new_tag)
 593                                                 matches[w] = wkr+1;
 594                         }
 595                 }
 596                 wkr = (wkr + 1) % d->num_workers;
 597         }
 598
 599         /* Flush out all non-full cache-lines to workers. */
 600         for (wid = 0 ; wid < d->num_workers; wid++)
 601                 /* Sync with worker on GET_BUF flag. */
 602                 if ((__atomic_load_n(&(d->bufs[wid].bufptr64[0]),
 603                         __ATOMIC_ACQUIRE) & RTE_DISTRIB_GET_BUF))
 604                         release(d, wid);
 605
 606         return num_mbufs;
 607 }
 608
 609 /* return to the caller, packets returned from workers */
 610 int
 611 rte_distributor_returned_pkts(struct rte_distributor *d,
 612                 struct rte_mbuf **mbufs, unsigned int max_mbufs)
 613 {
 614         struct rte_distributor_returned_pkts *returns = &d->returns;
 615         unsigned int retval = (max_mbufs < returns->count) ?
 616                         max_mbufs : returns->count;
 617         unsigned int i;
 618
 619         if (d->alg_type == RTE_DIST_ALG_SINGLE) {
 620                 /* Call the old API */
 621                 return rte_distributor_returned_pkts_single(d->d_single,
 622                                 mbufs, max_mbufs);
 623         }
 624
 625         for (i = 0; i < retval; i++) {
 626                 unsigned int idx = (returns->start + i) &
 627                                 RTE_DISTRIB_RETURNS_MASK;
 628
 629                 mbufs[i] = returns->mbufs[idx];
 630         }
 631         returns->start += i;
 632         returns->count -= i;
 633
 634         return retval;
 635 }
 636
 637 /*
 638  * Return the number of packets in-flight in a distributor, i.e. packets
 639  * being worked on or queued up in a backlog.
 640  */
 641 static inline unsigned int
 642 total_outstanding(const struct rte_distributor *d)
 643 {
 644         unsigned int wkr, total_outstanding = 0;
 645
 646         for (wkr = 0; wkr < d->num_workers; wkr++)
 647                 total_outstanding += d->backlog[wkr].count;
 648
 649         return total_outstanding;
 650 }
 651
 652 /*
 653  * Flush the distributor, so that there are no outstanding packets in flight or
 654  * queued up.
 655  */
 656 int
 657 rte_distributor_flush(struct rte_distributor *d)
 658 {
 659         unsigned int flushed;
 660         unsigned int wkr;
 661
 662         if (d->alg_type == RTE_DIST_ALG_SINGLE) {
 663                 /* Call the old API */
 664                 return rte_distributor_flush_single(d->d_single);
 665         }
 666
 667         flushed = total_outstanding(d);
 668
 669         while (total_outstanding(d) > 0)
 670                 rte_distributor_process(d, NULL, 0);
 671
 672         /* wait 10ms to allow all worker drain the pkts */
 673         rte_delay_us(10000);
 674
 675         /*
 676          * Send empty burst to all workers to allow them to exit
 677          * gracefully, should they need to.
 678          */
 679         rte_distributor_process(d, NULL, 0);
 680
 681         for (wkr = 0; wkr < d->num_workers; wkr++)
 682                 handle_returns(d, wkr);
 683
 684         return flushed;
 685 }
 686
 687 /* clears the internal returns array in the distributor */
 688 void
 689 rte_distributor_clear_returns(struct rte_distributor *d)
 690 {
 691         unsigned int wkr;
 692
 693         if (d->alg_type == RTE_DIST_ALG_SINGLE) {
 694                 /* Call the old API */
 695                 rte_distributor_clear_returns_single(d->d_single);
 696                 return;
 697         }
 698
 699         /* throw away returns, so workers can exit */
 700         for (wkr = 0; wkr < d->num_workers; wkr++)
 701                 /* Sync with worker. Release retptrs. */
 702                 __atomic_store_n(&(d->bufs[wkr].retptr64[0]), 0,
 703                                 __ATOMIC_RELEASE);
 704 }
 705
 706 /* creates a distributor instance */
 707 struct rte_distributor *
 708 rte_distributor_create(const char *name,
 709                 unsigned int socket_id,
 710                 unsigned int num_workers,
 711                 unsigned int alg_type)
 712 {
 713         struct rte_distributor *d;
 714         struct rte_dist_burst_list *dist_burst_list;
 715         char mz_name[RTE_MEMZONE_NAMESIZE];
 716         const struct rte_memzone *mz;
 717         unsigned int i;
 718
 719         /* TODO Reorganise function properly around RTE_DIST_ALG_SINGLE/BURST */
 720
 721         /* compilation-time checks */
 722         RTE_BUILD_BUG_ON((sizeof(*d) & RTE_CACHE_LINE_MASK) != 0);
 723         RTE_BUILD_BUG_ON((RTE_DISTRIB_MAX_WORKERS & 7) != 0);
 724
 725         if (name == NULL || num_workers >=
 726                 (unsigned int)RTE_MIN(RTE_DISTRIB_MAX_WORKERS, RTE_MAX_LCORE)) {
 727                 rte_errno = EINVAL;
 728                 return NULL;
 729         }
 730
 731         if (alg_type == RTE_DIST_ALG_SINGLE) {
 732                 d = malloc(sizeof(struct rte_distributor));
 733                 if (d == NULL) {
 734                         rte_errno = ENOMEM;
 735                         return NULL;
 736                 }
 737                 d->d_single = rte_distributor_create_single(name,
 738                                 socket_id, num_workers);
 739                 if (d->d_single == NULL) {
 740                         free(d);
 741                         /* rte_errno will have been set */
 742                         return NULL;
 743                 }
 744                 d->alg_type = alg_type;
 745                 return d;
 746         }
 747
 748         snprintf(mz_name, sizeof(mz_name), RTE_DISTRIB_PREFIX"%s", name);
 749         mz = rte_memzone_reserve(mz_name, sizeof(*d), socket_id, NO_FLAGS);
 750         if (mz == NULL) {
 751                 rte_errno = ENOMEM;
 752                 return NULL;
 753         }
 754
 755         d = mz->addr;
 756         strlcpy(d->name, name, sizeof(d->name));
 757         d->num_workers = num_workers;
 758         d->alg_type = alg_type;
 759
 760         d->dist_match_fn = RTE_DIST_MATCH_SCALAR;
 761 #if defined(RTE_ARCH_X86)
 762         d->dist_match_fn = RTE_DIST_MATCH_VECTOR;
 763 #endif
 764
 765         /*
 766          * Set up the backlog tags so they're pointing at the second cache
 767          * line for performance during flow matching
 768          */
 769         for (i = 0 ; i < num_workers ; i++)
 770                 d->backlog[i].tags = &d->in_flight_tags[i][RTE_DIST_BURST_SIZE];
 771
 772         memset(d->active, 0, sizeof(d->active));
 773         d->activesum = 0;
 774
 775         dist_burst_list = RTE_TAILQ_CAST(rte_dist_burst_tailq.head,
 776                                           rte_dist_burst_list);
 777
 778
 779         rte_mcfg_tailq_write_lock();
 780         TAILQ_INSERT_TAIL(dist_burst_list, d, next);
 781         rte_mcfg_tailq_write_unlock();
 782
 783         return d;
 784 }