drivers/pci/iov.c

   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         pci_bus_insert_busn_res(child, busnr, 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_stop_and_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_dev *virtfn;
 156         struct pci_sriov *iov = dev->sriov;
 157
 158         virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
 159                         virtfn_bus(dev, id), virtfn_devfn(dev, id));
 160         if (!virtfn)
 161                 return;
 162
 163         pci_dev_put(virtfn);
 164
 165         if (reset) {
 166                 device_release_driver(&virtfn->dev);
 167                 __pci_reset_function(virtfn);
 168         }
 169
 170         sprintf(buf, "virtfn%u", id);
 171         sysfs_remove_link(&dev->dev.kobj, buf);
 172         /*
 173          * pci_stop_dev() could have been called for this virtfn already,
 174          * so the directory for the virtfn may have been removed before.
 175          * Double check to avoid spurious sysfs warnings.
 176          */
 177         if (virtfn->dev.kobj.sd)
 178                 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
 179
 180         mutex_lock(&iov->dev->sriov->lock);
 181         pci_stop_and_remove_bus_device(virtfn);
 182         virtfn_remove_bus(dev->bus, virtfn_bus(dev, id));
 183         mutex_unlock(&iov->dev->sriov->lock);
 184
 185         pci_dev_put(dev);
 186 }
 187
 188 static int sriov_migration(struct pci_dev *dev)
 189 {
 190         u16 status;
 191         struct pci_sriov *iov = dev->sriov;
 192
 193         if (!iov->nr_virtfn)
 194                 return 0;
 195
 196         if (!(iov->cap & PCI_SRIOV_CAP_VFM))
 197                 return 0;
 198
 199         pci_read_config_word(dev, iov->pos + PCI_SRIOV_STATUS, &status);
 200         if (!(status & PCI_SRIOV_STATUS_VFM))
 201                 return 0;
 202
 203         schedule_work(&iov->mtask);
 204
 205         return 1;
 206 }
 207
 208 static void sriov_migration_task(struct work_struct *work)
 209 {
 210         int i;
 211         u8 state;
 212         u16 status;
 213         struct pci_sriov *iov = container_of(work, struct pci_sriov, mtask);
 214
 215         for (i = iov->initial; i < iov->nr_virtfn; i++) {
 216                 state = readb(iov->mstate + i);
 217                 if (state == PCI_SRIOV_VFM_MI) {
 218                         writeb(PCI_SRIOV_VFM_AV, iov->mstate + i);
 219                         state = readb(iov->mstate + i);
 220                         if (state == PCI_SRIOV_VFM_AV)
 221                                 virtfn_add(iov->self, i, 1);
 222                 } else if (state == PCI_SRIOV_VFM_MO) {
 223                         virtfn_remove(iov->self, i, 1);
 224                         writeb(PCI_SRIOV_VFM_UA, iov->mstate + i);
 225                         state = readb(iov->mstate + i);
 226                         if (state == PCI_SRIOV_VFM_AV)
 227                                 virtfn_add(iov->self, i, 0);
 228                 }
 229         }
 230
 231         pci_read_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, &status);
 232         status &= ~PCI_SRIOV_STATUS_VFM;
 233         pci_write_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, status);
 234 }
 235
 236 static int sriov_enable_migration(struct pci_dev *dev, int nr_virtfn)
 237 {
 238         int bir;
 239         u32 table;
 240         resource_size_t pa;
 241         struct pci_sriov *iov = dev->sriov;
 242
 243         if (nr_virtfn <= iov->initial)
 244                 return 0;
 245
 246         pci_read_config_dword(dev, iov->pos + PCI_SRIOV_VFM, &table);
 247         bir = PCI_SRIOV_VFM_BIR(table);
 248         if (bir > PCI_STD_RESOURCE_END)
 249                 return -EIO;
 250
 251         table = PCI_SRIOV_VFM_OFFSET(table);
 252         if (table + nr_virtfn > pci_resource_len(dev, bir))
 253                 return -EIO;
 254
 255         pa = pci_resource_start(dev, bir) + table;
 256         iov->mstate = ioremap(pa, nr_virtfn);
 257         if (!iov->mstate)
 258                 return -ENOMEM;
 259
 260         INIT_WORK(&iov->mtask, sriov_migration_task);
 261
 262         iov->ctrl |= PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR;
 263         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 264
 265         return 0;
 266 }
 267
 268 static void sriov_disable_migration(struct pci_dev *dev)
 269 {
 270         struct pci_sriov *iov = dev->sriov;
 271
 272         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR);
 273         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 274
 275         cancel_work_sync(&iov->mtask);
 276         iounmap(iov->mstate);
 277 }
 278
 279 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 280 {
 281         int rc;
 282         int i, j;
 283         int nres;
 284         u16 offset, stride, initial;
 285         struct resource *res;
 286         struct pci_dev *pdev;
 287         struct pci_sriov *iov = dev->sriov;
 288         int bars = 0;
 289
 290         if (!nr_virtfn)
 291                 return 0;
 292
 293         if (iov->nr_virtfn)
 294                 return -EINVAL;
 295
 296         pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
 297         if (initial > iov->total ||
 298             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total)))
 299                 return -EIO;
 300
 301         if (nr_virtfn < 0 || nr_virtfn > iov->total ||
 302             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 303                 return -EINVAL;
 304
 305         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
 306         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &offset);
 307         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &stride);
 308         if (!offset || (nr_virtfn > 1 && !stride))
 309                 return -EIO;
 310
 311         nres = 0;
 312         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 313                 bars |= (1 << (i + PCI_IOV_RESOURCES));
 314                 res = dev->resource + PCI_IOV_RESOURCES + i;
 315                 if (res->parent)
 316                         nres++;
 317         }
 318         if (nres != iov->nres) {
 319                 dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
 320                 return -ENOMEM;
 321         }
 322
 323         iov->offset = offset;
 324         iov->stride = stride;
 325
 326         if (virtfn_bus(dev, nr_virtfn - 1) > dev->bus->busn_res.end) {
 327                 dev_err(&dev->dev, "SR-IOV: bus number out of range\n");
 328                 return -ENOMEM;
 329         }
 330
 331         if (pci_enable_resources(dev, bars)) {
 332                 dev_err(&dev->dev, "SR-IOV: IOV BARS not allocated\n");
 333                 return -ENOMEM;
 334         }
 335
 336         if (iov->link != dev->devfn) {
 337                 pdev = pci_get_slot(dev->bus, iov->link);
 338                 if (!pdev)
 339                         return -ENODEV;
 340
 341                 pci_dev_put(pdev);
 342
 343                 if (!pdev->is_physfn)
 344                         return -ENODEV;
 345
 346                 rc = sysfs_create_link(&dev->dev.kobj,
 347                                         &pdev->dev.kobj, "dep_link");
 348                 if (rc)
 349                         return rc;
 350         }
 351
 352         iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 353         pci_cfg_access_lock(dev);
 354         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 355         msleep(100);
 356         pci_cfg_access_unlock(dev);
 357
 358         iov->initial = initial;
 359         if (nr_virtfn < initial)
 360                 initial = nr_virtfn;
 361
 362         for (i = 0; i < initial; i++) {
 363                 rc = virtfn_add(dev, i, 0);
 364                 if (rc)
 365                         goto failed;
 366         }
 367
 368         if (iov->cap & PCI_SRIOV_CAP_VFM) {
 369                 rc = sriov_enable_migration(dev, nr_virtfn);
 370                 if (rc)
 371                         goto failed;
 372         }
 373
 374         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 375         iov->nr_virtfn = nr_virtfn;
 376
 377         return 0;
 378
 379 failed:
 380         for (j = 0; j < i; j++)
 381                 virtfn_remove(dev, j, 0);
 382
 383         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 384         pci_cfg_access_lock(dev);
 385         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 386         ssleep(1);
 387         pci_cfg_access_unlock(dev);
 388
 389         if (iov->link != dev->devfn)
 390                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 391
 392         return rc;
 393 }
 394
 395 static void sriov_disable(struct pci_dev *dev)
 396 {
 397         int i;
 398         struct pci_sriov *iov = dev->sriov;
 399
 400         if (!iov->nr_virtfn)
 401                 return;
 402
 403         if (iov->cap & PCI_SRIOV_CAP_VFM)
 404                 sriov_disable_migration(dev);
 405
 406         for (i = 0; i < iov->nr_virtfn; i++)
 407                 virtfn_remove(dev, i, 0);
 408
 409         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 410         pci_cfg_access_lock(dev);
 411         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 412         ssleep(1);
 413         pci_cfg_access_unlock(dev);
 414
 415         if (iov->link != dev->devfn)
 416                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 417
 418         iov->nr_virtfn = 0;
 419 }
 420
 421 static int sriov_init(struct pci_dev *dev, int pos)
 422 {
 423         int i;
 424         int rc;
 425         int nres;
 426         u32 pgsz;
 427         u16 ctrl, total, offset, stride;
 428         struct pci_sriov *iov;
 429         struct resource *res;
 430         struct pci_dev *pdev;
 431
 432         if (dev->pcie_type != PCI_EXP_TYPE_RC_END &&
 433             dev->pcie_type != PCI_EXP_TYPE_ENDPOINT)
 434                 return -ENODEV;
 435
 436         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 437         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 438                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 439                 ssleep(1);
 440         }
 441
 442         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 443         if (!total)
 444                 return 0;
 445
 446         ctrl = 0;
 447         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 448                 if (pdev->is_physfn)
 449                         goto found;
 450
 451         pdev = NULL;
 452         if (pci_ari_enabled(dev->bus))
 453                 ctrl |= PCI_SRIOV_CTRL_ARI;
 454
 455 found:
 456         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 457         pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
 458         pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
 459         if (!offset || (total > 1 && !stride))
 460                 return -EIO;
 461
 462         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 463         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 464         pgsz &= ~((1 << i) - 1);
 465         if (!pgsz)
 466                 return -EIO;
 467
 468         pgsz &= ~(pgsz - 1);
 469         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 470
 471         nres = 0;
 472         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 473                 res = dev->resource + PCI_IOV_RESOURCES + i;
 474                 i += __pci_read_base(dev, pci_bar_unknown, res,
 475                                      pos + PCI_SRIOV_BAR + i * 4);
 476                 if (!res->flags)
 477                         continue;
 478                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 479                         rc = -EIO;
 480                         goto failed;
 481                 }
 482                 res->end = res->start + resource_size(res) * total - 1;
 483                 nres++;
 484         }
 485
 486         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 487         if (!iov) {
 488                 rc = -ENOMEM;
 489                 goto failed;
 490         }
 491
 492         iov->pos = pos;
 493         iov->nres = nres;
 494         iov->ctrl = ctrl;
 495         iov->total = total;
 496         iov->offset = offset;
 497         iov->stride = stride;
 498         iov->pgsz = pgsz;
 499         iov->self = dev;
 500         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 501         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 502         if (dev->pcie_type == PCI_EXP_TYPE_RC_END)
 503                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 504
 505         if (pdev)
 506                 iov->dev = pci_dev_get(pdev);
 507         else
 508                 iov->dev = dev;
 509
 510         mutex_init(&iov->lock);
 511
 512         dev->sriov = iov;
 513         dev->is_physfn = 1;
 514
 515         return 0;
 516
 517 failed:
 518         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 519                 res = dev->resource + PCI_IOV_RESOURCES + i;
 520                 res->flags = 0;
 521         }
 522
 523         return rc;
 524 }
 525
 526 static void sriov_release(struct pci_dev *dev)
 527 {
 528         BUG_ON(dev->sriov->nr_virtfn);
 529
 530         if (dev != dev->sriov->dev)
 531                 pci_dev_put(dev->sriov->dev);
 532
 533         mutex_destroy(&dev->sriov->lock);
 534
 535         kfree(dev->sriov);
 536         dev->sriov = NULL;
 537 }
 538
 539 static void sriov_restore_state(struct pci_dev *dev)
 540 {
 541         int i;
 542         u16 ctrl;
 543         struct pci_sriov *iov = dev->sriov;
 544
 545         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 546         if (ctrl & PCI_SRIOV_CTRL_VFE)
 547                 return;
 548
 549         for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
 550                 pci_update_resource(dev, i);
 551
 552         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 553         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, iov->nr_virtfn);
 554         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 555         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 556                 msleep(100);
 557 }
 558
 559 /**
 560  * pci_iov_init - initialize the IOV capability
 561  * @dev: the PCI device
 562  *
 563  * Returns 0 on success, or negative on failure.
 564  */
 565 int pci_iov_init(struct pci_dev *dev)
 566 {
 567         int pos;
 568
 569         if (!pci_is_pcie(dev))
 570                 return -ENODEV;
 571
 572         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 573         if (pos)
 574                 return sriov_init(dev, pos);
 575
 576         return -ENODEV;
 577 }
 578
 579 /**
 580  * pci_iov_release - release resources used by the IOV capability
 581  * @dev: the PCI device
 582  */
 583 void pci_iov_release(struct pci_dev *dev)
 584 {
 585         if (dev->is_physfn)
 586                 sriov_release(dev);
 587 }
 588
 589 /**
 590  * pci_iov_resource_bar - get position of the SR-IOV BAR
 591  * @dev: the PCI device
 592  * @resno: the resource number
 593  * @type: the BAR type to be filled in
 594  *
 595  * Returns position of the BAR encapsulated in the SR-IOV capability.
 596  */
 597 int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 598                          enum pci_bar_type *type)
 599 {
 600         if (resno < PCI_IOV_RESOURCES || resno > PCI_IOV_RESOURCE_END)
 601                 return 0;
 602
 603         BUG_ON(!dev->is_physfn);
 604
 605         *type = pci_bar_unknown;
 606
 607         return dev->sriov->pos + PCI_SRIOV_BAR +
 608                 4 * (resno - PCI_IOV_RESOURCES);
 609 }
 610
 611 /**
 612  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 613  * @dev: the PCI device
 614  * @resno: the resource number
 615  *
 616  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 617  * This is not the same as the resource size which is defined as
 618  * the VF BAR size multiplied by the number of VFs.  The alignment
 619  * is just the VF BAR size.
 620  */
 621 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 622 {
 623         struct resource tmp;
 624         enum pci_bar_type type;
 625         int reg = pci_iov_resource_bar(dev, resno, &type);
 626
 627         if (!reg)
 628                 return 0;
 629
 630          __pci_read_base(dev, type, &tmp, reg);
 631         return resource_alignment(&tmp);
 632 }
 633
 634 /**
 635  * pci_restore_iov_state - restore the state of the IOV capability
 636  * @dev: the PCI device
 637  */
 638 void pci_restore_iov_state(struct pci_dev *dev)
 639 {
 640         if (dev->is_physfn)
 641                 sriov_restore_state(dev);
 642 }
 643
 644 /**
 645  * pci_iov_bus_range - find bus range used by Virtual Function
 646  * @bus: the PCI bus
 647  *
 648  * Returns max number of buses (exclude current one) used by Virtual
 649  * Functions.
 650  */
 651 int pci_iov_bus_range(struct pci_bus *bus)
 652 {
 653         int max = 0;
 654         u8 busnr;
 655         struct pci_dev *dev;
 656
 657         list_for_each_entry(dev, &bus->devices, bus_list) {
 658                 if (!dev->is_physfn)
 659                         continue;
 660                 busnr = virtfn_bus(dev, dev->sriov->total - 1);
 661                 if (busnr > max)
 662                         max = busnr;
 663         }
 664
 665         return max ? max - bus->number : 0;
 666 }
 667
 668 /**
 669  * pci_enable_sriov - enable the SR-IOV capability
 670  * @dev: the PCI device
 671  * @nr_virtfn: number of virtual functions to enable
 672  *
 673  * Returns 0 on success, or negative on failure.
 674  */
 675 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 676 {
 677         might_sleep();
 678
 679         if (!dev->is_physfn)
 680                 return -ENODEV;
 681
 682         return sriov_enable(dev, nr_virtfn);
 683 }
 684 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 685
 686 /**
 687  * pci_disable_sriov - disable the SR-IOV capability
 688  * @dev: the PCI device
 689  */
 690 void pci_disable_sriov(struct pci_dev *dev)
 691 {
 692         might_sleep();
 693
 694         if (!dev->is_physfn)
 695                 return;
 696
 697         sriov_disable(dev);
 698 }
 699 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 700
 701 /**
 702  * pci_sriov_migration - notify SR-IOV core of Virtual Function Migration
 703  * @dev: the PCI device
 704  *
 705  * Returns IRQ_HANDLED if the IRQ is handled, or IRQ_NONE if not.
 706  *
 707  * Physical Function driver is responsible to register IRQ handler using
 708  * VF Migration Interrupt Message Number, and call this function when the
 709  * interrupt is generated by the hardware.
 710  */
 711 irqreturn_t pci_sriov_migration(struct pci_dev *dev)
 712 {
 713         if (!dev->is_physfn)
 714                 return IRQ_NONE;
 715
 716         return sriov_migration(dev) ? IRQ_HANDLED : IRQ_NONE;
 717 }
 718 EXPORT_SYMBOL_GPL(pci_sriov_migration);
 719
 720 /**
 721  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 722  * @dev: the PCI device
 723  *
 724  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 725  */
 726 int pci_num_vf(struct pci_dev *dev)
 727 {
 728         if (!dev || !dev->is_physfn)
 729                 return 0;
 730         else
 731                 return dev->sriov->nr_virtfn;
 732 }
 733 EXPORT_SYMBOL_GPL(pci_num_vf);