1 /* 2 * drivers/pci/iov.c 3 * 4 * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com> 5 * 6 * PCI Express I/O Virtualization (IOV) support. 7 * Single Root IOV 1.0 8 * Address Translation Service 1.0 9 */ 10 11 #include <linux/pci.h> 12 #include <linux/slab.h> 13 #include <linux/mutex.h> 14 #include <linux/export.h> 15 #include <linux/string.h> 16 #include <linux/delay.h> 17 #include <linux/pci-ats.h> 18 #include "pci.h" 19 20 #define VIRTFN_ID_LEN 16 21 22 static inline u8 virtfn_bus(struct pci_dev *dev, int id) 23 { 24 return dev->bus->number + ((dev->devfn + dev->sriov->offset + 25 dev->sriov->stride * id) >> 8); 26 } 27 28 static inline u8 virtfn_devfn(struct pci_dev *dev, int id) 29 { 30 return (dev->devfn + dev->sriov->offset + 31 dev->sriov->stride * id) & 0xff; 32 } 33 34 static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr) 35 { 36 int rc; 37 struct pci_bus *child; 38 39 if (bus->number == busnr) 40 return bus; 41 42 child = pci_find_bus(pci_domain_nr(bus), busnr); 43 if (child) 44 return child; 45 46 child = pci_add_new_bus(bus, NULL, busnr); 47 if (!child) 48 return NULL; 49 50 child->subordinate = busnr; 51 child->dev.parent = bus->bridge; 52 rc = pci_bus_add_child(child); 53 if (rc) { 54 pci_remove_bus(child); 55 return NULL; 56 } 57 58 return child; 59 } 60 61 static void virtfn_remove_bus(struct pci_bus *bus, int busnr) 62 { 63 struct pci_bus *child; 64 65 if (bus->number == busnr) 66 return; 67 68 child = pci_find_bus(pci_domain_nr(bus), busnr); 69 BUG_ON(!child); 70 71 if (list_empty(&child->devices)) 72 pci_remove_bus(child); 73 } 74 75 static int virtfn_add(struct pci_dev *dev, int id, int reset) 76 { 77 int i; 78 int rc; 79 u64 size; 80 char buf[VIRTFN_ID_LEN]; 81 struct pci_dev *virtfn; 82 struct resource *res; 83 struct pci_sriov *iov = dev->sriov; 84 85 virtfn = alloc_pci_dev(); 86 if (!virtfn) 87 return -ENOMEM; 88 89 mutex_lock(&iov->dev->sriov->lock); 90 virtfn->bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id)); 91 if (!virtfn->bus) { 92 kfree(virtfn); 93 mutex_unlock(&iov->dev->sriov->lock); 94 return -ENOMEM; 95 } 96 virtfn->devfn = virtfn_devfn(dev, id); 97 virtfn->vendor = dev->vendor; 98 pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device); 99 pci_setup_device(virtfn); 100 virtfn->dev.parent = dev->dev.parent; 101 102 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) { 103 res = dev->resource + PCI_IOV_RESOURCES + i; 104 if (!res->parent) 105 continue; 106 virtfn->resource[i].name = pci_name(virtfn); 107 virtfn->resource[i].flags = res->flags; 108 size = resource_size(res); 109 do_div(size, iov->total); 110 virtfn->resource[i].start = res->start + size * id; 111 virtfn->resource[i].end = virtfn->resource[i].start + size - 1; 112 rc = request_resource(res, &virtfn->resource[i]); 113 BUG_ON(rc); 114 } 115 116 if (reset) 117 __pci_reset_function(virtfn); 118 119 pci_device_add(virtfn, virtfn->bus); 120 mutex_unlock(&iov->dev->sriov->lock); 121 122 virtfn->physfn = pci_dev_get(dev); 123 virtfn->is_virtfn = 1; 124 125 rc = pci_bus_add_device(virtfn); 126 if (rc) 127 goto failed1; 128 sprintf(buf, "virtfn%u", id); 129 rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf); 130 if (rc) 131 goto failed1; 132 rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn"); 133 if (rc) 134 goto failed2; 135 136 kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE); 137 138 return 0; 139 140 failed2: 141 sysfs_remove_link(&dev->dev.kobj, buf); 142 failed1: 143 pci_dev_put(dev); 144 mutex_lock(&iov->dev->sriov->lock); 145 pci_remove_bus_device(virtfn); 146 virtfn_remove_bus(dev->bus, virtfn_bus(dev, id)); 147 mutex_unlock(&iov->dev->sriov->lock); 148 149 return rc; 150 } 151 152 static void virtfn_remove(struct pci_dev *dev, int id, int reset) 153 { 154 char buf[VIRTFN_ID_LEN]; 155 struct pci_bus *bus; 156 struct pci_dev *virtfn; 157 struct pci_sriov *iov = dev->sriov; 158 159 bus = pci_find_bus(pci_domain_nr(dev->bus), virtfn_bus(dev, id)); 160 if (!bus) 161 return; 162 163 virtfn = pci_get_slot(bus, virtfn_devfn(dev, id)); 164 if (!virtfn) 165 return; 166 167 pci_dev_put(virtfn); 168 169 if (reset) { 170 device_release_driver(&virtfn->dev); 171 __pci_reset_function(virtfn); 172 } 173 174 sprintf(buf, "virtfn%u", id); 175 sysfs_remove_link(&dev->dev.kobj, buf); 176 sysfs_remove_link(&virtfn->dev.kobj, "physfn"); 177 178 mutex_lock(&iov->dev->sriov->lock); 179 pci_remove_bus_device(virtfn); 180 virtfn_remove_bus(dev->bus, virtfn_bus(dev, id)); 181 mutex_unlock(&iov->dev->sriov->lock); 182 183 pci_dev_put(dev); 184 } 185 186 static int sriov_migration(struct pci_dev *dev) 187 { 188 u16 status; 189 struct pci_sriov *iov = dev->sriov; 190 191 if (!iov->nr_virtfn) 192 return 0; 193 194 if (!(iov->cap & PCI_SRIOV_CAP_VFM)) 195 return 0; 196 197 pci_read_config_word(dev, iov->pos + PCI_SRIOV_STATUS, &status); 198 if (!(status & PCI_SRIOV_STATUS_VFM)) 199 return 0; 200 201 schedule_work(&iov->mtask); 202 203 return 1; 204 } 205 206 static void sriov_migration_task(struct work_struct *work) 207 { 208 int i; 209 u8 state; 210 u16 status; 211 struct pci_sriov *iov = container_of(work, struct pci_sriov, mtask); 212 213 for (i = iov->initial; i < iov->nr_virtfn; i++) { 214 state = readb(iov->mstate + i); 215 if (state == PCI_SRIOV_VFM_MI) { 216 writeb(PCI_SRIOV_VFM_AV, iov->mstate + i); 217 state = readb(iov->mstate + i); 218 if (state == PCI_SRIOV_VFM_AV) 219 virtfn_add(iov->self, i, 1); 220 } else if (state == PCI_SRIOV_VFM_MO) { 221 virtfn_remove(iov->self, i, 1); 222 writeb(PCI_SRIOV_VFM_UA, iov->mstate + i); 223 state = readb(iov->mstate + i); 224 if (state == PCI_SRIOV_VFM_AV) 225 virtfn_add(iov->self, i, 0); 226 } 227 } 228 229 pci_read_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, &status); 230 status &= ~PCI_SRIOV_STATUS_VFM; 231 pci_write_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, status); 232 } 233 234 static int sriov_enable_migration(struct pci_dev *dev, int nr_virtfn) 235 { 236 int bir; 237 u32 table; 238 resource_size_t pa; 239 struct pci_sriov *iov = dev->sriov; 240 241 if (nr_virtfn <= iov->initial) 242 return 0; 243 244 pci_read_config_dword(dev, iov->pos + PCI_SRIOV_VFM, &table); 245 bir = PCI_SRIOV_VFM_BIR(table); 246 if (bir > PCI_STD_RESOURCE_END) 247 return -EIO; 248 249 table = PCI_SRIOV_VFM_OFFSET(table); 250 if (table + nr_virtfn > pci_resource_len(dev, bir)) 251 return -EIO; 252 253 pa = pci_resource_start(dev, bir) + table; 254 iov->mstate = ioremap(pa, nr_virtfn); 255 if (!iov->mstate) 256 return -ENOMEM; 257 258 INIT_WORK(&iov->mtask, sriov_migration_task); 259 260 iov->ctrl |= PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR; 261 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl); 262 263 return 0; 264 } 265 266 static void sriov_disable_migration(struct pci_dev *dev) 267 { 268 struct pci_sriov *iov = dev->sriov; 269 270 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR); 271 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl); 272 273 cancel_work_sync(&iov->mtask); 274 iounmap(iov->mstate); 275 } 276 277 static int sriov_enable(struct pci_dev *dev, int nr_virtfn) 278 { 279 int rc; 280 int i, j; 281 int nres; 282 u16 offset, stride, initial; 283 struct resource *res; 284 struct pci_dev *pdev; 285 struct pci_sriov *iov = dev->sriov; 286 int bars = 0; 287 288 if (!nr_virtfn) 289 return 0; 290 291 if (iov->nr_virtfn) 292 return -EINVAL; 293 294 pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial); 295 if (initial > iov->total || 296 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total))) 297 return -EIO; 298 299 if (nr_virtfn < 0 || nr_virtfn > iov->total || 300 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial))) 301 return -EINVAL; 302 303 pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn); 304 pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &offset); 305 pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &stride); 306 if (!offset || (nr_virtfn > 1 && !stride)) 307 return -EIO; 308 309 nres = 0; 310 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) { 311 bars |= (1 << (i + PCI_IOV_RESOURCES)); 312 res = dev->resource + PCI_IOV_RESOURCES + i; 313 if (res->parent) 314 nres++; 315 } 316 if (nres != iov->nres) { 317 dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n"); 318 return -ENOMEM; 319 } 320 321 iov->offset = offset; 322 iov->stride = stride; 323 324 if (virtfn_bus(dev, nr_virtfn - 1) > dev->bus->subordinate) { 325 dev_err(&dev->dev, "SR-IOV: bus number out of range\n"); 326 return -ENOMEM; 327 } 328 329 if (pci_enable_resources(dev, bars)) { 330 dev_err(&dev->dev, "SR-IOV: IOV BARS not allocated\n"); 331 return -ENOMEM; 332 } 333 334 if (iov->link != dev->devfn) { 335 pdev = pci_get_slot(dev->bus, iov->link); 336 if (!pdev) 337 return -ENODEV; 338 339 pci_dev_put(pdev); 340 341 if (!pdev->is_physfn) 342 return -ENODEV; 343 344 rc = sysfs_create_link(&dev->dev.kobj, 345 &pdev->dev.kobj, "dep_link"); 346 if (rc) 347 return rc; 348 } 349 350 iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE; 351 pci_cfg_access_lock(dev); 352 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl); 353 msleep(100); 354 pci_cfg_access_unlock(dev); 355 356 iov->initial = initial; 357 if (nr_virtfn < initial) 358 initial = nr_virtfn; 359 360 for (i = 0; i < initial; i++) { 361 rc = virtfn_add(dev, i, 0); 362 if (rc) 363 goto failed; 364 } 365 366 if (iov->cap & PCI_SRIOV_CAP_VFM) { 367 rc = sriov_enable_migration(dev, nr_virtfn); 368 if (rc) 369 goto failed; 370 } 371 372 kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE); 373 iov->nr_virtfn = nr_virtfn; 374 375 return 0; 376 377 failed: 378 for (j = 0; j < i; j++) 379 virtfn_remove(dev, j, 0); 380 381 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE); 382 pci_cfg_access_lock(dev); 383 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl); 384 ssleep(1); 385 pci_cfg_access_unlock(dev); 386 387 if (iov->link != dev->devfn) 388 sysfs_remove_link(&dev->dev.kobj, "dep_link"); 389 390 return rc; 391 } 392 393 static void sriov_disable(struct pci_dev *dev) 394 { 395 int i; 396 struct pci_sriov *iov = dev->sriov; 397 398 if (!iov->nr_virtfn) 399 return; 400 401 if (iov->cap & PCI_SRIOV_CAP_VFM) 402 sriov_disable_migration(dev); 403 404 for (i = 0; i < iov->nr_virtfn; i++) 405 virtfn_remove(dev, i, 0); 406 407 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE); 408 pci_cfg_access_lock(dev); 409 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl); 410 ssleep(1); 411 pci_cfg_access_unlock(dev); 412 413 if (iov->link != dev->devfn) 414 sysfs_remove_link(&dev->dev.kobj, "dep_link"); 415 416 iov->nr_virtfn = 0; 417 } 418 419 static int sriov_init(struct pci_dev *dev, int pos) 420 { 421 int i; 422 int rc; 423 int nres; 424 u32 pgsz; 425 u16 ctrl, total, offset, stride; 426 struct pci_sriov *iov; 427 struct resource *res; 428 struct pci_dev *pdev; 429 430 if (dev->pcie_type != PCI_EXP_TYPE_RC_END && 431 dev->pcie_type != PCI_EXP_TYPE_ENDPOINT) 432 return -ENODEV; 433 434 pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl); 435 if (ctrl & PCI_SRIOV_CTRL_VFE) { 436 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0); 437 ssleep(1); 438 } 439 440 pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total); 441 if (!total) 442 return 0; 443 444 ctrl = 0; 445 list_for_each_entry(pdev, &dev->bus->devices, bus_list) 446 if (pdev->is_physfn) 447 goto found; 448 449 pdev = NULL; 450 if (pci_ari_enabled(dev->bus)) 451 ctrl |= PCI_SRIOV_CTRL_ARI; 452 453 found: 454 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl); 455 pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset); 456 pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride); 457 if (!offset || (total > 1 && !stride)) 458 return -EIO; 459 460 pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz); 461 i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0; 462 pgsz &= ~((1 << i) - 1); 463 if (!pgsz) 464 return -EIO; 465 466 pgsz &= ~(pgsz - 1); 467 pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz); 468 469 nres = 0; 470 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) { 471 res = dev->resource + PCI_IOV_RESOURCES + i; 472 i += __pci_read_base(dev, pci_bar_unknown, res, 473 pos + PCI_SRIOV_BAR + i * 4); 474 if (!res->flags) 475 continue; 476 if (resource_size(res) & (PAGE_SIZE - 1)) { 477 rc = -EIO; 478 goto failed; 479 } 480 res->end = res->start + resource_size(res) * total - 1; 481 nres++; 482 } 483 484 iov = kzalloc(sizeof(*iov), GFP_KERNEL); 485 if (!iov) { 486 rc = -ENOMEM; 487 goto failed; 488 } 489 490 iov->pos = pos; 491 iov->nres = nres; 492 iov->ctrl = ctrl; 493 iov->total = total; 494 iov->offset = offset; 495 iov->stride = stride; 496 iov->pgsz = pgsz; 497 iov->self = dev; 498 pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap); 499 pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link); 500 if (dev->pcie_type == PCI_EXP_TYPE_RC_END) 501 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link); 502 503 if (pdev) 504 iov->dev = pci_dev_get(pdev); 505 else 506 iov->dev = dev; 507 508 mutex_init(&iov->lock); 509 510 dev->sriov = iov; 511 dev->is_physfn = 1; 512 513 return 0; 514 515 failed: 516 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) { 517 res = dev->resource + PCI_IOV_RESOURCES + i; 518 res->flags = 0; 519 } 520 521 return rc; 522 } 523 524 static void sriov_release(struct pci_dev *dev) 525 { 526 BUG_ON(dev->sriov->nr_virtfn); 527 528 if (dev != dev->sriov->dev) 529 pci_dev_put(dev->sriov->dev); 530 531 mutex_destroy(&dev->sriov->lock); 532 533 kfree(dev->sriov); 534 dev->sriov = NULL; 535 } 536 537 static void sriov_restore_state(struct pci_dev *dev) 538 { 539 int i; 540 u16 ctrl; 541 struct pci_sriov *iov = dev->sriov; 542 543 pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl); 544 if (ctrl & PCI_SRIOV_CTRL_VFE) 545 return; 546 547 for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++) 548 pci_update_resource(dev, i); 549 550 pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz); 551 pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, iov->nr_virtfn); 552 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl); 553 if (iov->ctrl & PCI_SRIOV_CTRL_VFE) 554 msleep(100); 555 } 556 557 /** 558 * pci_iov_init - initialize the IOV capability 559 * @dev: the PCI device 560 * 561 * Returns 0 on success, or negative on failure. 562 */ 563 int pci_iov_init(struct pci_dev *dev) 564 { 565 int pos; 566 567 if (!pci_is_pcie(dev)) 568 return -ENODEV; 569 570 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV); 571 if (pos) 572 return sriov_init(dev, pos); 573 574 return -ENODEV; 575 } 576 577 /** 578 * pci_iov_release - release resources used by the IOV capability 579 * @dev: the PCI device 580 */ 581 void pci_iov_release(struct pci_dev *dev) 582 { 583 if (dev->is_physfn) 584 sriov_release(dev); 585 } 586 587 /** 588 * pci_iov_resource_bar - get position of the SR-IOV BAR 589 * @dev: the PCI device 590 * @resno: the resource number 591 * @type: the BAR type to be filled in 592 * 593 * Returns position of the BAR encapsulated in the SR-IOV capability. 594 */ 595 int pci_iov_resource_bar(struct pci_dev *dev, int resno, 596 enum pci_bar_type *type) 597 { 598 if (resno < PCI_IOV_RESOURCES || resno > PCI_IOV_RESOURCE_END) 599 return 0; 600 601 BUG_ON(!dev->is_physfn); 602 603 *type = pci_bar_unknown; 604 605 return dev->sriov->pos + PCI_SRIOV_BAR + 606 4 * (resno - PCI_IOV_RESOURCES); 607 } 608 609 /** 610 * pci_sriov_resource_alignment - get resource alignment for VF BAR 611 * @dev: the PCI device 612 * @resno: the resource number 613 * 614 * Returns the alignment of the VF BAR found in the SR-IOV capability. 615 * This is not the same as the resource size which is defined as 616 * the VF BAR size multiplied by the number of VFs. The alignment 617 * is just the VF BAR size. 618 */ 619 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno) 620 { 621 struct resource tmp; 622 enum pci_bar_type type; 623 int reg = pci_iov_resource_bar(dev, resno, &type); 624 625 if (!reg) 626 return 0; 627 628 __pci_read_base(dev, type, &tmp, reg); 629 return resource_alignment(&tmp); 630 } 631 632 /** 633 * pci_restore_iov_state - restore the state of the IOV capability 634 * @dev: the PCI device 635 */ 636 void pci_restore_iov_state(struct pci_dev *dev) 637 { 638 if (dev->is_physfn) 639 sriov_restore_state(dev); 640 } 641 642 /** 643 * pci_iov_bus_range - find bus range used by Virtual Function 644 * @bus: the PCI bus 645 * 646 * Returns max number of buses (exclude current one) used by Virtual 647 * Functions. 648 */ 649 int pci_iov_bus_range(struct pci_bus *bus) 650 { 651 int max = 0; 652 u8 busnr; 653 struct pci_dev *dev; 654 655 list_for_each_entry(dev, &bus->devices, bus_list) { 656 if (!dev->is_physfn) 657 continue; 658 busnr = virtfn_bus(dev, dev->sriov->total - 1); 659 if (busnr > max) 660 max = busnr; 661 } 662 663 return max ? max - bus->number : 0; 664 } 665 666 /** 667 * pci_enable_sriov - enable the SR-IOV capability 668 * @dev: the PCI device 669 * @nr_virtfn: number of virtual functions to enable 670 * 671 * Returns 0 on success, or negative on failure. 672 */ 673 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn) 674 { 675 might_sleep(); 676 677 if (!dev->is_physfn) 678 return -ENODEV; 679 680 return sriov_enable(dev, nr_virtfn); 681 } 682 EXPORT_SYMBOL_GPL(pci_enable_sriov); 683 684 /** 685 * pci_disable_sriov - disable the SR-IOV capability 686 * @dev: the PCI device 687 */ 688 void pci_disable_sriov(struct pci_dev *dev) 689 { 690 might_sleep(); 691 692 if (!dev->is_physfn) 693 return; 694 695 sriov_disable(dev); 696 } 697 EXPORT_SYMBOL_GPL(pci_disable_sriov); 698 699 /** 700 * pci_sriov_migration - notify SR-IOV core of Virtual Function Migration 701 * @dev: the PCI device 702 * 703 * Returns IRQ_HANDLED if the IRQ is handled, or IRQ_NONE if not. 704 * 705 * Physical Function driver is responsible to register IRQ handler using 706 * VF Migration Interrupt Message Number, and call this function when the 707 * interrupt is generated by the hardware. 708 */ 709 irqreturn_t pci_sriov_migration(struct pci_dev *dev) 710 { 711 if (!dev->is_physfn) 712 return IRQ_NONE; 713 714 return sriov_migration(dev) ? IRQ_HANDLED : IRQ_NONE; 715 } 716 EXPORT_SYMBOL_GPL(pci_sriov_migration); 717 718 /** 719 * pci_num_vf - return number of VFs associated with a PF device_release_driver 720 * @dev: the PCI device 721 * 722 * Returns number of VFs, or 0 if SR-IOV is not enabled. 723 */ 724 int pci_num_vf(struct pci_dev *dev) 725 { 726 if (!dev || !dev->is_physfn) 727 return 0; 728 else 729 return dev->sriov->nr_virtfn; 730 } 731 EXPORT_SYMBOL_GPL(pci_num_vf); 732