lib/librte_eal/common/eal_common_dev.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2014 Intel Corporation.
   3  * Copyright(c) 2014 6WIND S.A.
   4  */
   5
   6 #include <stdio.h>
   7 #include <string.h>
   8 #include <inttypes.h>
   9 #include <sys/queue.h>
  10
  11 #include <rte_compat.h>
  12 #include <rte_bus.h>
  13 #include <rte_class.h>
  14 #include <rte_dev.h>
  15 #include <rte_devargs.h>
  16 #include <rte_debug.h>
  17 #include <rte_errno.h>
  18 #include <rte_kvargs.h>
  19 #include <rte_log.h>
  20 #include <rte_spinlock.h>
  21 #include <rte_malloc.h>
  22 #include <rte_string_fns.h>
  23
  24 #include "eal_private.h"
  25 #include "hotplug_mp.h"
  26
  27 /**
  28  * The device event callback description.
  29  *
  30  * It contains callback address to be registered by user application,
  31  * the pointer to the parameters for callback, and the device name.
  32  */
  33 struct dev_event_callback {
  34         TAILQ_ENTRY(dev_event_callback) next; /**< Callbacks list */
  35         rte_dev_event_cb_fn cb_fn;            /**< Callback address */
  36         void *cb_arg;                         /**< Callback parameter */
  37         char *dev_name;  /**< Callback device name, NULL is for all device */
  38         uint32_t active;                      /**< Callback is executing */
  39 };
  40
  41 /** @internal Structure to keep track of registered callbacks */
  42 TAILQ_HEAD(dev_event_cb_list, dev_event_callback);
  43
  44 /* The device event callback list for all registered callbacks. */
  45 static struct dev_event_cb_list dev_event_cbs;
  46
  47 /* spinlock for device callbacks */
  48 static rte_spinlock_t dev_event_lock = RTE_SPINLOCK_INITIALIZER;
  49
  50 struct dev_next_ctx {
  51         struct rte_dev_iterator *it;
  52         const char *bus_str;
  53         const char *cls_str;
  54 };
  55
  56 #define CTX(it, bus_str, cls_str) \
  57         (&(const struct dev_next_ctx){ \
  58                 .it = it, \
  59                 .bus_str = bus_str, \
  60                 .cls_str = cls_str, \
  61         })
  62
  63 #define ITCTX(ptr) \
  64         (((struct dev_next_ctx *)(intptr_t)ptr)->it)
  65
  66 #define BUSCTX(ptr) \
  67         (((struct dev_next_ctx *)(intptr_t)ptr)->bus_str)
  68
  69 #define CLSCTX(ptr) \
  70         (((struct dev_next_ctx *)(intptr_t)ptr)->cls_str)
  71
  72 static int cmp_dev_name(const struct rte_device *dev, const void *_name)
  73 {
  74         const char *name = _name;
  75
  76         return strcmp(dev->name, name);
  77 }
  78
  79 int __rte_experimental
  80 rte_dev_is_probed(const struct rte_device *dev)
  81 {
  82         /* The field driver should be set only when the probe is successful. */
  83         return dev->driver != NULL;
  84 }
  85
  86 int rte_eal_dev_attach(const char *name, const char *devargs)
  87 {
  88         struct rte_bus *bus;
  89
  90         if (name == NULL || devargs == NULL) {
  91                 RTE_LOG(ERR, EAL, "Invalid device or arguments provided\n");
  92                 return -EINVAL;
  93         }
  94
  95         bus = rte_bus_find_by_device_name(name);
  96         if (bus == NULL) {
  97                 RTE_LOG(ERR, EAL, "Unable to find a bus for the device '%s'\n",
  98                         name);
  99                 return -EINVAL;
 100         }
 101         if (strcmp(bus->name, "pci") == 0 || strcmp(bus->name, "vdev") == 0)
 102                 return rte_eal_hotplug_add(bus->name, name, devargs);
 103
 104         RTE_LOG(ERR, EAL,
 105                 "Device attach is only supported for PCI and vdev devices.\n");
 106
 107         return -ENOTSUP;
 108 }
 109
 110 int rte_eal_dev_detach(struct rte_device *dev)
 111 {
 112         struct rte_bus *bus;
 113         int ret;
 114
 115         if (dev == NULL) {
 116                 RTE_LOG(ERR, EAL, "Invalid device provided.\n");
 117                 return -EINVAL;
 118         }
 119
 120         bus = rte_bus_find_by_device(dev);
 121         if (bus == NULL) {
 122                 RTE_LOG(ERR, EAL, "Cannot find bus for device (%s)\n",
 123                         dev->name);
 124                 return -EINVAL;
 125         }
 126
 127         if (bus->unplug == NULL) {
 128                 RTE_LOG(ERR, EAL, "Bus function not supported\n");
 129                 return -ENOTSUP;
 130         }
 131
 132         ret = bus->unplug(dev);
 133         if (ret)
 134                 RTE_LOG(ERR, EAL, "Driver cannot detach the device (%s)\n",
 135                         dev->name);
 136         return ret;
 137 }
 138
 139 /* helper function to build devargs, caller should free the memory */
 140 static int
 141 build_devargs(const char *busname, const char *devname,
 142               const char *drvargs, char **devargs)
 143 {
 144         int length;
 145
 146         length = snprintf(NULL, 0, "%s:%s,%s", busname, devname, drvargs);
 147         if (length < 0)
 148                 return -EINVAL;
 149
 150         *devargs = malloc(length + 1);
 151         if (*devargs == NULL)
 152                 return -ENOMEM;
 153
 154         length = snprintf(*devargs, length + 1, "%s:%s,%s",
 155                         busname, devname, drvargs);
 156         if (length < 0) {
 157                 free(*devargs);
 158                 return -EINVAL;
 159         }
 160
 161         return 0;
 162 }
 163
 164 int
 165 rte_eal_hotplug_add(const char *busname, const char *devname,
 166                     const char *drvargs)
 167 {
 168
 169         char *devargs;
 170         int ret;
 171
 172         ret = build_devargs(busname, devname, drvargs, &devargs);
 173         if (ret != 0)
 174                 return ret;
 175
 176         ret = rte_dev_probe(devargs);
 177         free(devargs);
 178
 179         return ret;
 180 }
 181
 182 /* probe device at local process. */
 183 int
 184 local_dev_probe(const char *devargs, struct rte_device **new_dev)
 185 {
 186         struct rte_device *dev;
 187         struct rte_devargs *da;
 188         int ret;
 189
 190         *new_dev = NULL;
 191         da = calloc(1, sizeof(*da));
 192         if (da == NULL)
 193                 return -ENOMEM;
 194
 195         ret = rte_devargs_parse(da, devargs);
 196         if (ret)
 197                 goto err_devarg;
 198
 199         if (da->bus->plug == NULL) {
 200                 RTE_LOG(ERR, EAL, "Function plug not supported by bus (%s)\n",
 201                         da->bus->name);
 202                 ret = -ENOTSUP;
 203                 goto err_devarg;
 204         }
 205
 206         ret = rte_devargs_insert(da);
 207         if (ret)
 208                 goto err_devarg;
 209
 210         ret = da->bus->scan();
 211         if (ret)
 212                 goto err_devarg;
 213
 214         dev = da->bus->find_device(NULL, cmp_dev_name, da->name);
 215         if (dev == NULL) {
 216                 RTE_LOG(ERR, EAL, "Cannot find device (%s)\n",
 217                         da->name);
 218                 ret = -ENODEV;
 219                 goto err_devarg;
 220         }
 221
 222         ret = dev->bus->plug(dev);
 223         if (ret) {
 224                 if (rte_dev_is_probed(dev)) /* if already succeeded earlier */
 225                         return ret; /* no rollback */
 226                 RTE_LOG(ERR, EAL, "Driver cannot attach the device (%s)\n",
 227                         dev->name);
 228                 goto err_devarg;
 229         }
 230
 231         *new_dev = dev;
 232         return 0;
 233
 234 err_devarg:
 235         if (rte_devargs_remove(da) != 0) {
 236                 free(da->args);
 237                 free(da);
 238         }
 239         return ret;
 240 }
 241
 242 int __rte_experimental
 243 rte_dev_probe(const char *devargs)
 244 {
 245         struct eal_dev_mp_req req;
 246         struct rte_device *dev;
 247         int ret;
 248
 249         memset(&req, 0, sizeof(req));
 250         req.t = EAL_DEV_REQ_TYPE_ATTACH;
 251         strlcpy(req.devargs, devargs, EAL_DEV_MP_DEV_ARGS_MAX_LEN);
 252
 253         if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
 254                 /**
 255                  * If in secondary process, just send IPC request to
 256                  * primary process.
 257                  */
 258                 ret = eal_dev_hotplug_request_to_primary(&req);
 259                 if (ret != 0) {
 260                         RTE_LOG(ERR, EAL,
 261                                 "Failed to send hotplug request to primary\n");
 262                         return -ENOMSG;
 263                 }
 264                 if (req.result != 0)
 265                         RTE_LOG(ERR, EAL,
 266                                 "Failed to hotplug add device\n");
 267                 return req.result;
 268         }
 269
 270         /* attach a shared device from primary start from here: */
 271
 272         /* primary attach the new device itself. */
 273         ret = local_dev_probe(devargs, &dev);
 274
 275         if (ret != 0) {
 276                 RTE_LOG(ERR, EAL,
 277                         "Failed to attach device on primary process\n");
 278
 279                 /**
 280                  * it is possible that secondary process failed to attached a
 281                  * device that primary process have during initialization,
 282                  * so for -EEXIST case, we still need to sync with secondary
 283                  * process.
 284                  */
 285                 if (ret != -EEXIST)
 286                         return ret;
 287         }
 288
 289         /* primary send attach sync request to secondary. */
 290         ret = eal_dev_hotplug_request_to_secondary(&req);
 291
 292         /* if any communication error, we need to rollback. */
 293         if (ret != 0) {
 294                 RTE_LOG(ERR, EAL,
 295                         "Failed to send hotplug add request to secondary\n");
 296                 ret = -ENOMSG;
 297                 goto rollback;
 298         }
 299
 300         /**
 301          * if any secondary failed to attach, we need to consider if rollback
 302          * is necessary.
 303          */
 304         if (req.result != 0) {
 305                 RTE_LOG(ERR, EAL,
 306                         "Failed to attach device on secondary process\n");
 307                 ret = req.result;
 308
 309                 /* for -EEXIST, we don't need to rollback. */
 310                 if (ret == -EEXIST)
 311                         return ret;
 312                 goto rollback;
 313         }
 314
 315         return 0;
 316
 317 rollback:
 318         req.t = EAL_DEV_REQ_TYPE_ATTACH_ROLLBACK;
 319
 320         /* primary send rollback request to secondary. */
 321         if (eal_dev_hotplug_request_to_secondary(&req) != 0)
 322                 RTE_LOG(WARNING, EAL,
 323                         "Failed to rollback device attach on secondary."
 324                         "Devices in secondary may not sync with primary\n");
 325
 326         /* primary rollback itself. */
 327         if (local_dev_remove(dev) != 0)
 328                 RTE_LOG(WARNING, EAL,
 329                         "Failed to rollback device attach on primary."
 330                         "Devices in secondary may not sync with primary\n");
 331
 332         return ret;
 333 }
 334
 335 int
 336 rte_eal_hotplug_remove(const char *busname, const char *devname)
 337 {
 338         struct rte_device *dev;
 339         struct rte_bus *bus;
 340
 341         bus = rte_bus_find_by_name(busname);
 342         if (bus == NULL) {
 343                 RTE_LOG(ERR, EAL, "Cannot find bus (%s)\n", busname);
 344                 return -ENOENT;
 345         }
 346
 347         dev = bus->find_device(NULL, cmp_dev_name, devname);
 348         if (dev == NULL) {
 349                 RTE_LOG(ERR, EAL, "Cannot find plugged device (%s)\n", devname);
 350                 return -EINVAL;
 351         }
 352
 353         return rte_dev_remove(dev);
 354 }
 355
 356 /* remove device at local process. */
 357 int
 358 local_dev_remove(struct rte_device *dev)
 359 {
 360         int ret;
 361
 362         if (dev->bus->unplug == NULL) {
 363                 RTE_LOG(ERR, EAL, "Function unplug not supported by bus (%s)\n",
 364                         dev->bus->name);
 365                 return -ENOTSUP;
 366         }
 367
 368         ret = dev->bus->unplug(dev);
 369         if (ret) {
 370                 RTE_LOG(ERR, EAL, "Driver cannot detach the device (%s)\n",
 371                         dev->name);
 372                 return ret;
 373         }
 374
 375         return 0;
 376 }
 377
 378 int __rte_experimental
 379 rte_dev_remove(struct rte_device *dev)
 380 {
 381         struct eal_dev_mp_req req;
 382         char *devargs;
 383         int ret;
 384
 385         if (!rte_dev_is_probed(dev)) {
 386                 RTE_LOG(ERR, EAL, "Device is not probed\n");
 387                 return -ENOENT;
 388         }
 389
 390         ret = build_devargs(dev->devargs->bus->name, dev->name, "", &devargs);
 391         if (ret != 0)
 392                 return ret;
 393
 394         memset(&req, 0, sizeof(req));
 395         req.t = EAL_DEV_REQ_TYPE_DETACH;
 396         strlcpy(req.devargs, devargs, EAL_DEV_MP_DEV_ARGS_MAX_LEN);
 397         free(devargs);
 398
 399         if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
 400                 /**
 401                  * If in secondary process, just send IPC request to
 402                  * primary process.
 403                  */
 404                 ret = eal_dev_hotplug_request_to_primary(&req);
 405                 if (ret != 0) {
 406                         RTE_LOG(ERR, EAL,
 407                                 "Failed to send hotplug request to primary\n");
 408                         return -ENOMSG;
 409                 }
 410                 if (req.result != 0)
 411                         RTE_LOG(ERR, EAL,
 412                                 "Failed to hotplug remove device\n");
 413                 return req.result;
 414         }
 415
 416         /* detach a device from primary start from here: */
 417
 418         /* primary send detach sync request to secondary */
 419         ret = eal_dev_hotplug_request_to_secondary(&req);
 420
 421         /**
 422          * if communication error, we need to rollback, because it is possible
 423          * part of the secondary processes still detached it successfully.
 424          */
 425         if (ret != 0) {
 426                 RTE_LOG(ERR, EAL,
 427                         "Failed to send device detach request to secondary\n");
 428                 ret = -ENOMSG;
 429                 goto rollback;
 430         }
 431
 432         /**
 433          * if any secondary failed to detach, we need to consider if rollback
 434          * is necessary.
 435          */
 436         if (req.result != 0) {
 437                 RTE_LOG(ERR, EAL,
 438                         "Failed to detach device on secondary process\n");
 439                 ret = req.result;
 440                 /**
 441                  * if -ENOENT, we don't need to rollback, since devices is
 442                  * already detached on secondary process.
 443                  */
 444                 if (ret != -ENOENT)
 445                         goto rollback;
 446         }
 447
 448         /* primary detach the device itself. */
 449         ret = local_dev_remove(dev);
 450
 451         /* if primary failed, still need to consider if rollback is necessary */
 452         if (ret != 0) {
 453                 RTE_LOG(ERR, EAL,
 454                         "Failed to detach device on primary process\n");
 455                 /* if -ENOENT, we don't need to rollback */
 456                 if (ret == -ENOENT)
 457                         return ret;
 458                 goto rollback;
 459         }
 460
 461         return 0;
 462
 463 rollback:
 464         req.t = EAL_DEV_REQ_TYPE_DETACH_ROLLBACK;
 465
 466         /* primary send rollback request to secondary. */
 467         if (eal_dev_hotplug_request_to_secondary(&req) != 0)
 468                 RTE_LOG(WARNING, EAL,
 469                         "Failed to rollback device detach on secondary."
 470                         "Devices in secondary may not sync with primary\n");
 471
 472         return ret;
 473 }
 474
 475 int __rte_experimental
 476 rte_dev_event_callback_register(const char *device_name,
 477                                 rte_dev_event_cb_fn cb_fn,
 478                                 void *cb_arg)
 479 {
 480         struct dev_event_callback *event_cb;
 481         int ret;
 482
 483         if (!cb_fn)
 484                 return -EINVAL;
 485
 486         rte_spinlock_lock(&dev_event_lock);
 487
 488         if (TAILQ_EMPTY(&dev_event_cbs))
 489                 TAILQ_INIT(&dev_event_cbs);
 490
 491         TAILQ_FOREACH(event_cb, &dev_event_cbs, next) {
 492                 if (event_cb->cb_fn == cb_fn && event_cb->cb_arg == cb_arg) {
 493                         if (device_name == NULL && event_cb->dev_name == NULL)
 494                                 break;
 495                         if (device_name == NULL || event_cb->dev_name == NULL)
 496                                 continue;
 497                         if (!strcmp(event_cb->dev_name, device_name))
 498                                 break;
 499                 }
 500         }
 501
 502         /* create a new callback. */
 503         if (event_cb == NULL) {
 504                 event_cb = malloc(sizeof(struct dev_event_callback));
 505                 if (event_cb != NULL) {
 506                         event_cb->cb_fn = cb_fn;
 507                         event_cb->cb_arg = cb_arg;
 508                         event_cb->active = 0;
 509                         if (!device_name) {
 510                                 event_cb->dev_name = NULL;
 511                         } else {
 512                                 event_cb->dev_name = strdup(device_name);
 513                                 if (event_cb->dev_name == NULL) {
 514                                         ret = -ENOMEM;
 515                                         goto error;
 516                                 }
 517                         }
 518                         TAILQ_INSERT_TAIL(&dev_event_cbs, event_cb, next);
 519                 } else {
 520                         RTE_LOG(ERR, EAL,
 521                                 "Failed to allocate memory for device "
 522                                 "event callback.");
 523                         ret = -ENOMEM;
 524                         goto error;
 525                 }
 526         } else {
 527                 RTE_LOG(ERR, EAL,
 528                         "The callback is already exist, no need "
 529                         "to register again.\n");
 530                 ret = -EEXIST;
 531         }
 532
 533         rte_spinlock_unlock(&dev_event_lock);
 534         return 0;
 535 error:
 536         free(event_cb);
 537         rte_spinlock_unlock(&dev_event_lock);
 538         return ret;
 539 }
 540
 541 int __rte_experimental
 542 rte_dev_event_callback_unregister(const char *device_name,
 543                                   rte_dev_event_cb_fn cb_fn,
 544                                   void *cb_arg)
 545 {
 546         int ret = 0;
 547         struct dev_event_callback *event_cb, *next;
 548
 549         if (!cb_fn)
 550                 return -EINVAL;
 551
 552         rte_spinlock_lock(&dev_event_lock);
 553         /*walk through the callbacks and remove all that match. */
 554         for (event_cb = TAILQ_FIRST(&dev_event_cbs); event_cb != NULL;
 555              event_cb = next) {
 556
 557                 next = TAILQ_NEXT(event_cb, next);
 558
 559                 if (device_name != NULL && event_cb->dev_name != NULL) {
 560                         if (!strcmp(event_cb->dev_name, device_name)) {
 561                                 if (event_cb->cb_fn != cb_fn ||
 562                                     (cb_arg != (void *)-1 &&
 563                                     event_cb->cb_arg != cb_arg))
 564                                         continue;
 565                         }
 566                 } else if (device_name != NULL) {
 567                         continue;
 568                 }
 569
 570                 /*
 571                  * if this callback is not executing right now,
 572                  * then remove it.
 573                  */
 574                 if (event_cb->active == 0) {
 575                         TAILQ_REMOVE(&dev_event_cbs, event_cb, next);
 576                         free(event_cb);
 577                         ret++;
 578                 } else {
 579                         continue;
 580                 }
 581         }
 582         rte_spinlock_unlock(&dev_event_lock);
 583         return ret;
 584 }
 585
 586 void __rte_experimental
 587 rte_dev_event_callback_process(const char *device_name,
 588                                enum rte_dev_event_type event)
 589 {
 590         struct dev_event_callback *cb_lst;
 591
 592         if (device_name == NULL)
 593                 return;
 594
 595         rte_spinlock_lock(&dev_event_lock);
 596
 597         TAILQ_FOREACH(cb_lst, &dev_event_cbs, next) {
 598                 if (cb_lst->dev_name) {
 599                         if (strcmp(cb_lst->dev_name, device_name))
 600                                 continue;
 601                 }
 602                 cb_lst->active = 1;
 603                 rte_spinlock_unlock(&dev_event_lock);
 604                 cb_lst->cb_fn(device_name, event,
 605                                 cb_lst->cb_arg);
 606                 rte_spinlock_lock(&dev_event_lock);
 607                 cb_lst->active = 0;
 608         }
 609         rte_spinlock_unlock(&dev_event_lock);
 610 }
 611
 612 __rte_experimental
 613 int
 614 rte_dev_iterator_init(struct rte_dev_iterator *it,
 615                       const char *dev_str)
 616 {
 617         struct rte_devargs devargs;
 618         struct rte_class *cls = NULL;
 619         struct rte_bus *bus = NULL;
 620
 621         /* Having both bus_str and cls_str NULL is illegal,
 622          * marking this iterator as invalid unless
 623          * everything goes well.
 624          */
 625         it->bus_str = NULL;
 626         it->cls_str = NULL;
 627
 628         devargs.data = dev_str;
 629         if (rte_devargs_layers_parse(&devargs, dev_str))
 630                 goto get_out;
 631
 632         bus = devargs.bus;
 633         cls = devargs.cls;
 634         /* The string should have at least
 635          * one layer specified.
 636          */
 637         if (bus == NULL && cls == NULL) {
 638                 RTE_LOG(ERR, EAL,
 639                         "Either bus or class must be specified.\n");
 640                 rte_errno = EINVAL;
 641                 goto get_out;
 642         }
 643         if (bus != NULL && bus->dev_iterate == NULL) {
 644                 RTE_LOG(ERR, EAL, "Bus %s not supported\n", bus->name);
 645                 rte_errno = ENOTSUP;
 646                 goto get_out;
 647         }
 648         if (cls != NULL && cls->dev_iterate == NULL) {
 649                 RTE_LOG(ERR, EAL, "Class %s not supported\n", cls->name);
 650                 rte_errno = ENOTSUP;
 651                 goto get_out;
 652         }
 653         it->bus_str = devargs.bus_str;
 654         it->cls_str = devargs.cls_str;
 655         it->dev_str = dev_str;
 656         it->bus = bus;
 657         it->cls = cls;
 658         it->device = NULL;
 659         it->class_device = NULL;
 660 get_out:
 661         return -rte_errno;
 662 }
 663
 664 static char *
 665 dev_str_sane_copy(const char *str)
 666 {
 667         size_t end;
 668         char *copy;
 669
 670         end = strcspn(str, ",/");
 671         if (str[end] == ',') {
 672                 copy = strdup(&str[end + 1]);
 673         } else {
 674                 /* '/' or '\0' */
 675                 copy = strdup("");
 676         }
 677         if (copy == NULL) {
 678                 rte_errno = ENOMEM;
 679         } else {
 680                 char *slash;
 681
 682                 slash = strchr(copy, '/');
 683                 if (slash != NULL)
 684                         slash[0] = '\0';
 685         }
 686         return copy;
 687 }
 688
 689 static int
 690 class_next_dev_cmp(const struct rte_class *cls,
 691                    const void *ctx)
 692 {
 693         struct rte_dev_iterator *it;
 694         const char *cls_str = NULL;
 695         void *dev;
 696
 697         if (cls->dev_iterate == NULL)
 698                 return 1;
 699         it = ITCTX(ctx);
 700         cls_str = CLSCTX(ctx);
 701         dev = it->class_device;
 702         /* it->cls_str != NULL means a class
 703          * was specified in the devstr.
 704          */
 705         if (it->cls_str != NULL && cls != it->cls)
 706                 return 1;
 707         /* If an error occurred previously,
 708          * no need to test further.
 709          */
 710         if (rte_errno != 0)
 711                 return -1;
 712         dev = cls->dev_iterate(dev, cls_str, it);
 713         it->class_device = dev;
 714         return dev == NULL;
 715 }
 716
 717 static int
 718 bus_next_dev_cmp(const struct rte_bus *bus,
 719                  const void *ctx)
 720 {
 721         struct rte_device *dev = NULL;
 722         struct rte_class *cls = NULL;
 723         struct rte_dev_iterator *it;
 724         const char *bus_str = NULL;
 725
 726         if (bus->dev_iterate == NULL)
 727                 return 1;
 728         it = ITCTX(ctx);
 729         bus_str = BUSCTX(ctx);
 730         dev = it->device;
 731         /* it->bus_str != NULL means a bus
 732          * was specified in the devstr.
 733          */
 734         if (it->bus_str != NULL && bus != it->bus)
 735                 return 1;
 736         /* If an error occurred previously,
 737          * no need to test further.
 738          */
 739         if (rte_errno != 0)
 740                 return -1;
 741         if (it->cls_str == NULL) {
 742                 dev = bus->dev_iterate(dev, bus_str, it);
 743                 goto end;
 744         }
 745         /* cls_str != NULL */
 746         if (dev == NULL) {
 747 next_dev_on_bus:
 748                 dev = bus->dev_iterate(dev, bus_str, it);
 749                 it->device = dev;
 750         }
 751         if (dev == NULL)
 752                 return 1;
 753         if (it->cls != NULL)
 754                 cls = TAILQ_PREV(it->cls, rte_class_list, next);
 755         cls = rte_class_find(cls, class_next_dev_cmp, ctx);
 756         if (cls != NULL) {
 757                 it->cls = cls;
 758                 goto end;
 759         }
 760         goto next_dev_on_bus;
 761 end:
 762         it->device = dev;
 763         return dev == NULL;
 764 }
 765 __rte_experimental
 766 struct rte_device *
 767 rte_dev_iterator_next(struct rte_dev_iterator *it)
 768 {
 769         struct rte_bus *bus = NULL;
 770         int old_errno = rte_errno;
 771         char *bus_str = NULL;
 772         char *cls_str = NULL;
 773
 774         rte_errno = 0;
 775         if (it->bus_str == NULL && it->cls_str == NULL) {
 776                 /* Invalid iterator. */
 777                 rte_errno = EINVAL;
 778                 return NULL;
 779         }
 780         if (it->bus != NULL)
 781                 bus = TAILQ_PREV(it->bus, rte_bus_list, next);
 782         if (it->bus_str != NULL) {
 783                 bus_str = dev_str_sane_copy(it->bus_str);
 784                 if (bus_str == NULL)
 785                         goto out;
 786         }
 787         if (it->cls_str != NULL) {
 788                 cls_str = dev_str_sane_copy(it->cls_str);
 789                 if (cls_str == NULL)
 790                         goto out;
 791         }
 792         while ((bus = rte_bus_find(bus, bus_next_dev_cmp,
 793                                    CTX(it, bus_str, cls_str)))) {
 794                 if (it->device != NULL) {
 795                         it->bus = bus;
 796                         goto out;
 797                 }
 798                 if (it->bus_str != NULL ||
 799                     rte_errno != 0)
 800                         break;
 801         }
 802         if (rte_errno == 0)
 803                 rte_errno = old_errno;
 804 out:
 805         free(bus_str);
 806         free(cls_str);
 807         return it->device;
 808 }