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 int pci_iov_virtfn_bus(struct pci_dev *dev, int vf_id)
  23 {
  24         if (!dev->is_physfn)
  25                 return -EINVAL;
  26         return dev->bus->number + ((dev->devfn + dev->sriov->offset +
  27                                     dev->sriov->stride * vf_id) >> 8);
  28 }
  29
  30 int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id)
  31 {
  32         if (!dev->is_physfn)
  33                 return -EINVAL;
  34         return (dev->devfn + dev->sriov->offset +
  35                 dev->sriov->stride * vf_id) & 0xff;
  36 }
  37
  38 /*
  39  * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may
  40  * change when NumVFs changes.
  41  *
  42  * Update iov->offset and iov->stride when NumVFs is written.
  43  */
  44 static inline void pci_iov_set_numvfs(struct pci_dev *dev, int nr_virtfn)
  45 {
  46         struct pci_sriov *iov = dev->sriov;
  47
  48         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
  49         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &iov->offset);
  50         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &iov->stride);
  51 }
  52
  53 /*
  54  * The PF consumes one bus number.  NumVFs, First VF Offset, and VF Stride
  55  * determine how many additional bus numbers will be consumed by VFs.
  56  *
  57  * Iterate over all valid NumVFs and calculate the maximum number of bus
  58  * numbers that could ever be required.
  59  */
  60 static inline u8 virtfn_max_buses(struct pci_dev *dev)
  61 {
  62         struct pci_sriov *iov = dev->sriov;
  63         int nr_virtfn;
  64         u8 max = 0;
  65         int busnr;
  66
  67         for (nr_virtfn = 1; nr_virtfn <= iov->total_VFs; nr_virtfn++) {
  68                 pci_iov_set_numvfs(dev, nr_virtfn);
  69                 busnr = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
  70                 if (busnr > max)
  71                         max = busnr;
  72         }
  73
  74         return max;
  75 }
  76
  77 static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
  78 {
  79         struct pci_bus *child;
  80
  81         if (bus->number == busnr)
  82                 return bus;
  83
  84         child = pci_find_bus(pci_domain_nr(bus), busnr);
  85         if (child)
  86                 return child;
  87
  88         child = pci_add_new_bus(bus, NULL, busnr);
  89         if (!child)
  90                 return NULL;
  91
  92         pci_bus_insert_busn_res(child, busnr, busnr);
  93
  94         return child;
  95 }
  96
  97 static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus)
  98 {
  99         if (physbus != virtbus && list_empty(&virtbus->devices))
 100                 pci_remove_bus(virtbus);
 101 }
 102
 103 resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
 104 {
 105         if (!dev->is_physfn)
 106                 return 0;
 107
 108         return dev->sriov->barsz[resno - PCI_IOV_RESOURCES];
 109 }
 110
 111 static int virtfn_add(struct pci_dev *dev, int id, int reset)
 112 {
 113         int i;
 114         int rc = -ENOMEM;
 115         u64 size;
 116         char buf[VIRTFN_ID_LEN];
 117         struct pci_dev *virtfn;
 118         struct resource *res;
 119         struct pci_sriov *iov = dev->sriov;
 120         struct pci_bus *bus;
 121
 122         mutex_lock(&iov->dev->sriov->lock);
 123         bus = virtfn_add_bus(dev->bus, pci_iov_virtfn_bus(dev, id));
 124         if (!bus)
 125                 goto failed;
 126
 127         virtfn = pci_alloc_dev(bus);
 128         if (!virtfn)
 129                 goto failed0;
 130
 131         virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
 132         virtfn->vendor = dev->vendor;
 133         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
 134         pci_setup_device(virtfn);
 135         virtfn->dev.parent = dev->dev.parent;
 136         virtfn->physfn = pci_dev_get(dev);
 137         virtfn->is_virtfn = 1;
 138         virtfn->multifunction = 0;
 139
 140         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 141                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 142                 if (!res->parent)
 143                         continue;
 144                 virtfn->resource[i].name = pci_name(virtfn);
 145                 virtfn->resource[i].flags = res->flags;
 146                 size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
 147                 virtfn->resource[i].start = res->start + size * id;
 148                 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
 149                 rc = request_resource(res, &virtfn->resource[i]);
 150                 BUG_ON(rc);
 151         }
 152
 153         if (reset)
 154                 __pci_reset_function(virtfn);
 155
 156         pci_device_add(virtfn, virtfn->bus);
 157         mutex_unlock(&iov->dev->sriov->lock);
 158
 159         pci_bus_add_device(virtfn);
 160         sprintf(buf, "virtfn%u", id);
 161         rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
 162         if (rc)
 163                 goto failed1;
 164         rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
 165         if (rc)
 166                 goto failed2;
 167
 168         kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
 169
 170         return 0;
 171
 172 failed2:
 173         sysfs_remove_link(&dev->dev.kobj, buf);
 174 failed1:
 175         pci_dev_put(dev);
 176         mutex_lock(&iov->dev->sriov->lock);
 177         pci_stop_and_remove_bus_device(virtfn);
 178 failed0:
 179         virtfn_remove_bus(dev->bus, bus);
 180 failed:
 181         mutex_unlock(&iov->dev->sriov->lock);
 182
 183         return rc;
 184 }
 185
 186 static void virtfn_remove(struct pci_dev *dev, int id, int reset)
 187 {
 188         char buf[VIRTFN_ID_LEN];
 189         struct pci_dev *virtfn;
 190         struct pci_sriov *iov = dev->sriov;
 191
 192         virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
 193                                              pci_iov_virtfn_bus(dev, id),
 194                                              pci_iov_virtfn_devfn(dev, id));
 195         if (!virtfn)
 196                 return;
 197
 198         if (reset) {
 199                 device_release_driver(&virtfn->dev);
 200                 __pci_reset_function(virtfn);
 201         }
 202
 203         sprintf(buf, "virtfn%u", id);
 204         sysfs_remove_link(&dev->dev.kobj, buf);
 205         /*
 206          * pci_stop_dev() could have been called for this virtfn already,
 207          * so the directory for the virtfn may have been removed before.
 208          * Double check to avoid spurious sysfs warnings.
 209          */
 210         if (virtfn->dev.kobj.sd)
 211                 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
 212
 213         mutex_lock(&iov->dev->sriov->lock);
 214         pci_stop_and_remove_bus_device(virtfn);
 215         virtfn_remove_bus(dev->bus, virtfn->bus);
 216         mutex_unlock(&iov->dev->sriov->lock);
 217
 218         /* balance pci_get_domain_bus_and_slot() */
 219         pci_dev_put(virtfn);
 220         pci_dev_put(dev);
 221 }
 222
 223 int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
 224 {
 225        return 0;
 226 }
 227
 228 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 229 {
 230         int rc;
 231         int i, j;
 232         int nres;
 233         u16 offset, stride, initial;
 234         struct resource *res;
 235         struct pci_dev *pdev;
 236         struct pci_sriov *iov = dev->sriov;
 237         int bars = 0;
 238         int bus;
 239         int retval;
 240
 241         if (!nr_virtfn)
 242                 return 0;
 243
 244         if (iov->num_VFs)
 245                 return -EINVAL;
 246
 247         pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
 248         if (initial > iov->total_VFs ||
 249             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
 250                 return -EIO;
 251
 252         if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
 253             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 254                 return -EINVAL;
 255
 256         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &offset);
 257         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &stride);
 258         if (!offset || (nr_virtfn > 1 && !stride))
 259                 return -EIO;
 260
 261         nres = 0;
 262         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 263                 bars |= (1 << (i + PCI_IOV_RESOURCES));
 264                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 265                 if (res->parent)
 266                         nres++;
 267         }
 268         if (nres != iov->nres) {
 269                 dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
 270                 return -ENOMEM;
 271         }
 272
 273         iov->offset = offset;
 274         iov->stride = stride;
 275
 276         bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
 277         if (bus > dev->bus->busn_res.end) {
 278                 dev_err(&dev->dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
 279                         nr_virtfn, bus, &dev->bus->busn_res);
 280                 return -ENOMEM;
 281         }
 282
 283         if (pci_enable_resources(dev, bars)) {
 284                 dev_err(&dev->dev, "SR-IOV: IOV BARS not allocated\n");
 285                 return -ENOMEM;
 286         }
 287
 288         if (iov->link != dev->devfn) {
 289                 pdev = pci_get_slot(dev->bus, iov->link);
 290                 if (!pdev)
 291                         return -ENODEV;
 292
 293                 if (!pdev->is_physfn) {
 294                         pci_dev_put(pdev);
 295                         return -ENOSYS;
 296                 }
 297
 298                 rc = sysfs_create_link(&dev->dev.kobj,
 299                                         &pdev->dev.kobj, "dep_link");
 300                 pci_dev_put(pdev);
 301                 if (rc)
 302                         return rc;
 303         }
 304
 305         pci_iov_set_numvfs(dev, nr_virtfn);
 306         iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 307         pci_cfg_access_lock(dev);
 308         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 309         msleep(100);
 310         pci_cfg_access_unlock(dev);
 311
 312         iov->initial_VFs = initial;
 313         if (nr_virtfn < initial)
 314                 initial = nr_virtfn;
 315
 316         if ((retval = pcibios_sriov_enable(dev, initial))) {
 317                 dev_err(&dev->dev, "failure %d from pcibios_sriov_enable()\n",
 318                         retval);
 319                 return retval;
 320         }
 321
 322         for (i = 0; i < initial; i++) {
 323                 rc = virtfn_add(dev, i, 0);
 324                 if (rc)
 325                         goto failed;
 326         }
 327
 328         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 329         iov->num_VFs = nr_virtfn;
 330
 331         return 0;
 332
 333 failed:
 334         for (j = 0; j < i; j++)
 335                 virtfn_remove(dev, j, 0);
 336
 337         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 338         pci_cfg_access_lock(dev);
 339         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 340         pci_iov_set_numvfs(dev, 0);
 341         ssleep(1);
 342         pci_cfg_access_unlock(dev);
 343
 344         if (iov->link != dev->devfn)
 345                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 346
 347         return rc;
 348 }
 349
 350 int __weak pcibios_sriov_disable(struct pci_dev *pdev)
 351 {
 352        return 0;
 353 }
 354
 355 static void sriov_disable(struct pci_dev *dev)
 356 {
 357         int i;
 358         struct pci_sriov *iov = dev->sriov;
 359
 360         if (!iov->num_VFs)
 361                 return;
 362
 363         for (i = 0; i < iov->num_VFs; i++)
 364                 virtfn_remove(dev, i, 0);
 365
 366         pcibios_sriov_disable(dev);
 367
 368         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 369         pci_cfg_access_lock(dev);
 370         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 371         ssleep(1);
 372         pci_cfg_access_unlock(dev);
 373
 374         if (iov->link != dev->devfn)
 375                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 376
 377         iov->num_VFs = 0;
 378         pci_iov_set_numvfs(dev, 0);
 379 }
 380
 381 static int sriov_init(struct pci_dev *dev, int pos)
 382 {
 383         int i, bar64;
 384         int rc;
 385         int nres;
 386         u32 pgsz;
 387         u16 ctrl, total, offset, stride;
 388         struct pci_sriov *iov;
 389         struct resource *res;
 390         struct pci_dev *pdev;
 391
 392         if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END &&
 393             pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT)
 394                 return -ENODEV;
 395
 396         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 397         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 398                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 399                 ssleep(1);
 400         }
 401
 402         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 403         if (!total)
 404                 return 0;
 405
 406         ctrl = 0;
 407         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 408                 if (pdev->is_physfn)
 409                         goto found;
 410
 411         pdev = NULL;
 412         if (pci_ari_enabled(dev->bus))
 413                 ctrl |= PCI_SRIOV_CTRL_ARI;
 414
 415 found:
 416         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 417         pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0);
 418         pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
 419         pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
 420         if (!offset || (total > 1 && !stride))
 421                 return -EIO;
 422
 423         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 424         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 425         pgsz &= ~((1 << i) - 1);
 426         if (!pgsz)
 427                 return -EIO;
 428
 429         pgsz &= ~(pgsz - 1);
 430         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 431
 432         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 433         if (!iov)
 434                 return -ENOMEM;
 435
 436         nres = 0;
 437         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 438                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 439                 bar64 = __pci_read_base(dev, pci_bar_unknown, res,
 440                                         pos + PCI_SRIOV_BAR + i * 4);
 441                 if (!res->flags)
 442                         continue;
 443                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 444                         rc = -EIO;
 445                         goto failed;
 446                 }
 447                 iov->barsz[i] = resource_size(res);
 448                 res->end = res->start + resource_size(res) * total - 1;
 449                 dev_info(&dev->dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
 450                          i, res, i, total);
 451                 i += bar64;
 452                 nres++;
 453         }
 454
 455         iov->pos = pos;
 456         iov->nres = nres;
 457         iov->ctrl = ctrl;
 458         iov->total_VFs = total;
 459         iov->offset = offset;
 460         iov->stride = stride;
 461         iov->pgsz = pgsz;
 462         iov->self = dev;
 463         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 464         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 465         if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
 466                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 467
 468         if (pdev)
 469                 iov->dev = pci_dev_get(pdev);
 470         else
 471                 iov->dev = dev;
 472
 473         mutex_init(&iov->lock);
 474
 475         dev->sriov = iov;
 476         dev->is_physfn = 1;
 477         iov->max_VF_buses = virtfn_max_buses(dev);
 478
 479         return 0;
 480
 481 failed:
 482         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 483                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 484                 res->flags = 0;
 485         }
 486
 487         kfree(iov);
 488         return rc;
 489 }
 490
 491 static void sriov_release(struct pci_dev *dev)
 492 {
 493         BUG_ON(dev->sriov->num_VFs);
 494
 495         if (dev != dev->sriov->dev)
 496                 pci_dev_put(dev->sriov->dev);
 497
 498         mutex_destroy(&dev->sriov->lock);
 499
 500         kfree(dev->sriov);
 501         dev->sriov = NULL;
 502 }
 503
 504 static void sriov_restore_state(struct pci_dev *dev)
 505 {
 506         int i;
 507         u16 ctrl;
 508         struct pci_sriov *iov = dev->sriov;
 509
 510         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 511         if (ctrl & PCI_SRIOV_CTRL_VFE)
 512                 return;
 513
 514         for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
 515                 pci_update_resource(dev, i);
 516
 517         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 518         pci_iov_set_numvfs(dev, iov->num_VFs);
 519         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 520         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 521                 msleep(100);
 522 }
 523
 524 /**
 525  * pci_iov_init - initialize the IOV capability
 526  * @dev: the PCI device
 527  *
 528  * Returns 0 on success, or negative on failure.
 529  */
 530 int pci_iov_init(struct pci_dev *dev)
 531 {
 532         int pos;
 533
 534         if (!pci_is_pcie(dev))
 535                 return -ENODEV;
 536
 537         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 538         if (pos)
 539                 return sriov_init(dev, pos);
 540
 541         return -ENODEV;
 542 }
 543
 544 /**
 545  * pci_iov_release - release resources used by the IOV capability
 546  * @dev: the PCI device
 547  */
 548 void pci_iov_release(struct pci_dev *dev)
 549 {
 550         if (dev->is_physfn)
 551                 sriov_release(dev);
 552 }
 553
 554 /**
 555  * pci_iov_resource_bar - get position of the SR-IOV BAR
 556  * @dev: the PCI device
 557  * @resno: the resource number
 558  *
 559  * Returns position of the BAR encapsulated in the SR-IOV capability.
 560  */
 561 int pci_iov_resource_bar(struct pci_dev *dev, int resno)
 562 {
 563         if (resno < PCI_IOV_RESOURCES || resno > PCI_IOV_RESOURCE_END)
 564                 return 0;
 565
 566         BUG_ON(!dev->is_physfn);
 567
 568         return dev->sriov->pos + PCI_SRIOV_BAR +
 569                 4 * (resno - PCI_IOV_RESOURCES);
 570 }
 571
 572 resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
 573                                                       int resno)
 574 {
 575         return pci_iov_resource_size(dev, resno);
 576 }
 577
 578 /**
 579  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 580  * @dev: the PCI device
 581  * @resno: the resource number
 582  *
 583  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 584  * This is not the same as the resource size which is defined as
 585  * the VF BAR size multiplied by the number of VFs.  The alignment
 586  * is just the VF BAR size.
 587  */
 588 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 589 {
 590         return pcibios_iov_resource_alignment(dev, resno);
 591 }
 592
 593 /**
 594  * pci_restore_iov_state - restore the state of the IOV capability
 595  * @dev: the PCI device
 596  */
 597 void pci_restore_iov_state(struct pci_dev *dev)
 598 {
 599         if (dev->is_physfn)
 600                 sriov_restore_state(dev);
 601 }
 602
 603 /**
 604  * pci_iov_bus_range - find bus range used by Virtual Function
 605  * @bus: the PCI bus
 606  *
 607  * Returns max number of buses (exclude current one) used by Virtual
 608  * Functions.
 609  */
 610 int pci_iov_bus_range(struct pci_bus *bus)
 611 {
 612         int max = 0;
 613         struct pci_dev *dev;
 614
 615         list_for_each_entry(dev, &bus->devices, bus_list) {
 616                 if (!dev->is_physfn)
 617                         continue;
 618                 if (dev->sriov->max_VF_buses > max)
 619                         max = dev->sriov->max_VF_buses;
 620         }
 621
 622         return max ? max - bus->number : 0;
 623 }
 624
 625 /**
 626  * pci_enable_sriov - enable the SR-IOV capability
 627  * @dev: the PCI device
 628  * @nr_virtfn: number of virtual functions to enable
 629  *
 630  * Returns 0 on success, or negative on failure.
 631  */
 632 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 633 {
 634         might_sleep();
 635
 636         if (!dev->is_physfn)
 637                 return -ENOSYS;
 638
 639         return sriov_enable(dev, nr_virtfn);
 640 }
 641 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 642
 643 /**
 644  * pci_disable_sriov - disable the SR-IOV capability
 645  * @dev: the PCI device
 646  */
 647 void pci_disable_sriov(struct pci_dev *dev)
 648 {
 649         might_sleep();
 650
 651         if (!dev->is_physfn)
 652                 return;
 653
 654         sriov_disable(dev);
 655 }
 656 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 657
 658 /**
 659  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 660  * @dev: the PCI device
 661  *
 662  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 663  */
 664 int pci_num_vf(struct pci_dev *dev)
 665 {
 666         if (!dev->is_physfn)
 667                 return 0;
 668
 669         return dev->sriov->num_VFs;
 670 }
 671 EXPORT_SYMBOL_GPL(pci_num_vf);
 672
 673 /**
 674  * pci_vfs_assigned - returns number of VFs are assigned to a guest
 675  * @dev: the PCI device
 676  *
 677  * Returns number of VFs belonging to this device that are assigned to a guest.
 678  * If device is not a physical function returns 0.
 679  */
 680 int pci_vfs_assigned(struct pci_dev *dev)
 681 {
 682         struct pci_dev *vfdev;
 683         unsigned int vfs_assigned = 0;
 684         unsigned short dev_id;
 685
 686         /* only search if we are a PF */
 687         if (!dev->is_physfn)
 688                 return 0;
 689
 690         /*
 691          * determine the device ID for the VFs, the vendor ID will be the
 692          * same as the PF so there is no need to check for that one
 693          */
 694         pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_VF_DID, &dev_id);
 695
 696         /* loop through all the VFs to see if we own any that are assigned */
 697         vfdev = pci_get_device(dev->vendor, dev_id, NULL);
 698         while (vfdev) {
 699                 /*
 700                  * It is considered assigned if it is a virtual function with
 701                  * our dev as the physical function and the assigned bit is set
 702                  */
 703                 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
 704                         pci_is_dev_assigned(vfdev))
 705                         vfs_assigned++;
 706
 707                 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
 708         }
 709
 710         return vfs_assigned;
 711 }
 712 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
 713
 714 /**
 715  * pci_sriov_set_totalvfs -- reduce the TotalVFs available
 716  * @dev: the PCI PF device
 717  * @numvfs: number that should be used for TotalVFs supported
 718  *
 719  * Should be called from PF driver's probe routine with
 720  * device's mutex held.
 721  *
 722  * Returns 0 if PF is an SRIOV-capable device and
 723  * value of numvfs valid. If not a PF return -ENOSYS;
 724  * if numvfs is invalid return -EINVAL;
 725  * if VFs already enabled, return -EBUSY.
 726  */
 727 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
 728 {
 729         if (!dev->is_physfn)
 730                 return -ENOSYS;
 731         if (numvfs > dev->sriov->total_VFs)
 732                 return -EINVAL;
 733
 734         /* Shouldn't change if VFs already enabled */
 735         if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
 736                 return -EBUSY;
 737         else
 738                 dev->sriov->driver_max_VFs = numvfs;
 739
 740         return 0;
 741 }
 742 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
 743
 744 /**
 745  * pci_sriov_get_totalvfs -- get total VFs supported on this device
 746  * @dev: the PCI PF device
 747  *
 748  * For a PCIe device with SRIOV support, return the PCIe
 749  * SRIOV capability value of TotalVFs or the value of driver_max_VFs
 750  * if the driver reduced it.  Otherwise 0.
 751  */
 752 int pci_sriov_get_totalvfs(struct pci_dev *dev)
 753 {
 754         if (!dev->is_physfn)
 755                 return 0;
 756
 757         if (dev->sriov->driver_max_VFs)
 758                 return dev->sriov->driver_max_VFs;
 759
 760         return dev->sriov->total_VFs;
 761 }
 762 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);