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