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, validate offset and stride, and calculate
  58  * the maximum number of bus numbers that could ever be required.
  59  */
  60 static int compute_max_vf_buses(struct pci_dev *dev)
  61 {
  62         struct pci_sriov *iov = dev->sriov;
  63         int nr_virtfn, busnr, rc = 0;
  64
  65         for (nr_virtfn = iov->total_VFs; nr_virtfn; nr_virtfn--) {
  66                 pci_iov_set_numvfs(dev, nr_virtfn);
  67                 if (!iov->offset || (nr_virtfn > 1 && !iov->stride)) {
  68                         rc = -EIO;
  69                         goto out;
  70                 }
  71
  72                 busnr = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
  73                 if (busnr > iov->max_VF_buses)
  74                         iov->max_VF_buses = busnr;
  75         }
  76
  77 out:
  78         pci_iov_set_numvfs(dev, 0);
  79         return rc;
  80 }
  81
  82 static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
  83 {
  84         struct pci_bus *child;
  85
  86         if (bus->number == busnr)
  87                 return bus;
  88
  89         child = pci_find_bus(pci_domain_nr(bus), busnr);
  90         if (child)
  91                 return child;
  92
  93         child = pci_add_new_bus(bus, NULL, busnr);
  94         if (!child)
  95                 return NULL;
  96
  97         pci_bus_insert_busn_res(child, busnr, busnr);
  98
  99         return child;
 100 }
 101
 102 static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus)
 103 {
 104         if (physbus != virtbus && list_empty(&virtbus->devices))
 105                 pci_remove_bus(virtbus);
 106 }
 107
 108 resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
 109 {
 110         if (!dev->is_physfn)
 111                 return 0;
 112
 113         return dev->sriov->barsz[resno - PCI_IOV_RESOURCES];
 114 }
 115
 116 int pci_iov_add_virtfn(struct pci_dev *dev, int id, int reset)
 117 {
 118         int i;
 119         int rc = -ENOMEM;
 120         u64 size;
 121         char buf[VIRTFN_ID_LEN];
 122         struct pci_dev *virtfn;
 123         struct resource *res;
 124         struct pci_sriov *iov = dev->sriov;
 125         struct pci_bus *bus;
 126
 127         bus = virtfn_add_bus(dev->bus, pci_iov_virtfn_bus(dev, id));
 128         if (!bus)
 129                 goto failed;
 130
 131         virtfn = pci_alloc_dev(bus);
 132         if (!virtfn)
 133                 goto failed0;
 134
 135         virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
 136         virtfn->vendor = dev->vendor;
 137         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
 138         rc = pci_setup_device(virtfn);
 139         if (rc)
 140                 goto failed0;
 141
 142         virtfn->dev.parent = dev->dev.parent;
 143         virtfn->physfn = pci_dev_get(dev);
 144         virtfn->is_virtfn = 1;
 145         virtfn->multifunction = 0;
 146
 147         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 148                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 149                 if (!res->parent)
 150                         continue;
 151                 virtfn->resource[i].name = pci_name(virtfn);
 152                 virtfn->resource[i].flags = res->flags;
 153                 size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
 154                 virtfn->resource[i].start = res->start + size * id;
 155                 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
 156                 rc = request_resource(res, &virtfn->resource[i]);
 157                 BUG_ON(rc);
 158         }
 159
 160         if (reset)
 161                 __pci_reset_function(virtfn);
 162
 163         pci_device_add(virtfn, virtfn->bus);
 164
 165         sprintf(buf, "virtfn%u", id);
 166         rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
 167         if (rc)
 168                 goto failed1;
 169         rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
 170         if (rc)
 171                 goto failed2;
 172
 173         kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
 174
 175         pci_bus_add_device(virtfn);
 176
 177         return 0;
 178
 179 failed2:
 180         sysfs_remove_link(&dev->dev.kobj, buf);
 181 failed1:
 182         pci_dev_put(dev);
 183         pci_stop_and_remove_bus_device(virtfn);
 184 failed0:
 185         virtfn_remove_bus(dev->bus, bus);
 186 failed:
 187
 188         return rc;
 189 }
 190
 191 void pci_iov_remove_virtfn(struct pci_dev *dev, int id, int reset)
 192 {
 193         char buf[VIRTFN_ID_LEN];
 194         struct pci_dev *virtfn;
 195
 196         virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
 197                                              pci_iov_virtfn_bus(dev, id),
 198                                              pci_iov_virtfn_devfn(dev, id));
 199         if (!virtfn)
 200                 return;
 201
 202         if (reset) {
 203                 device_release_driver(&virtfn->dev);
 204                 __pci_reset_function(virtfn);
 205         }
 206
 207         sprintf(buf, "virtfn%u", id);
 208         sysfs_remove_link(&dev->dev.kobj, buf);
 209         /*
 210          * pci_stop_dev() could have been called for this virtfn already,
 211          * so the directory for the virtfn may have been removed before.
 212          * Double check to avoid spurious sysfs warnings.
 213          */
 214         if (virtfn->dev.kobj.sd)
 215                 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
 216
 217         pci_stop_and_remove_bus_device(virtfn);
 218         virtfn_remove_bus(dev->bus, virtfn->bus);
 219
 220         /* balance pci_get_domain_bus_and_slot() */
 221         pci_dev_put(virtfn);
 222         pci_dev_put(dev);
 223 }
 224
 225 int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
 226 {
 227         return 0;
 228 }
 229
 230 int __weak pcibios_sriov_disable(struct pci_dev *pdev)
 231 {
 232         return 0;
 233 }
 234
 235 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 236 {
 237         int rc;
 238         int i;
 239         int nres;
 240         u16 initial;
 241         struct resource *res;
 242         struct pci_dev *pdev;
 243         struct pci_sriov *iov = dev->sriov;
 244         int bars = 0;
 245         int bus;
 246
 247         if (!nr_virtfn)
 248                 return 0;
 249
 250         if (iov->num_VFs)
 251                 return -EINVAL;
 252
 253         pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
 254         if (initial > iov->total_VFs ||
 255             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
 256                 return -EIO;
 257
 258         if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
 259             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 260                 return -EINVAL;
 261
 262         nres = 0;
 263         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 264                 bars |= (1 << (i + PCI_IOV_RESOURCES));
 265                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 266                 if (res->parent)
 267                         nres++;
 268         }
 269         if (nres != iov->nres) {
 270                 dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
 271                 return -ENOMEM;
 272         }
 273
 274         bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
 275         if (bus > dev->bus->busn_res.end) {
 276                 dev_err(&dev->dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
 277                         nr_virtfn, bus, &dev->bus->busn_res);
 278                 return -ENOMEM;
 279         }
 280
 281         if (pci_enable_resources(dev, bars)) {
 282                 dev_err(&dev->dev, "SR-IOV: IOV BARS not allocated\n");
 283                 return -ENOMEM;
 284         }
 285
 286         if (iov->link != dev->devfn) {
 287                 pdev = pci_get_slot(dev->bus, iov->link);
 288                 if (!pdev)
 289                         return -ENODEV;
 290
 291                 if (!pdev->is_physfn) {
 292                         pci_dev_put(pdev);
 293                         return -ENOSYS;
 294                 }
 295
 296                 rc = sysfs_create_link(&dev->dev.kobj,
 297                                         &pdev->dev.kobj, "dep_link");
 298                 pci_dev_put(pdev);
 299                 if (rc)
 300                         return rc;
 301         }
 302
 303         iov->initial_VFs = initial;
 304         if (nr_virtfn < initial)
 305                 initial = nr_virtfn;
 306
 307         rc = pcibios_sriov_enable(dev, initial);
 308         if (rc) {
 309                 dev_err(&dev->dev, "failure %d from pcibios_sriov_enable()\n", rc);
 310                 goto err_pcibios;
 311         }
 312
 313         pci_iov_set_numvfs(dev, nr_virtfn);
 314         iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 315         pci_cfg_access_lock(dev);
 316         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 317         msleep(100);
 318         pci_cfg_access_unlock(dev);
 319
 320         for (i = 0; i < initial; i++) {
 321                 rc = pci_iov_add_virtfn(dev, i, 0);
 322                 if (rc)
 323                         goto failed;
 324         }
 325
 326         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 327         iov->num_VFs = nr_virtfn;
 328
 329         return 0;
 330
 331 failed:
 332         while (i--)
 333                 pci_iov_remove_virtfn(dev, i, 0);
 334
 335 err_pcibios:
 336         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 337         pci_cfg_access_lock(dev);
 338         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 339         ssleep(1);
 340         pci_cfg_access_unlock(dev);
 341
 342         pcibios_sriov_disable(dev);
 343
 344         if (iov->link != dev->devfn)
 345                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 346
 347         pci_iov_set_numvfs(dev, 0);
 348         return rc;
 349 }
 350
 351 static void sriov_disable(struct pci_dev *dev)
 352 {
 353         int i;
 354         struct pci_sriov *iov = dev->sriov;
 355
 356         if (!iov->num_VFs)
 357                 return;
 358
 359         for (i = 0; i < iov->num_VFs; i++)
 360                 pci_iov_remove_virtfn(dev, i, 0);
 361
 362         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 363         pci_cfg_access_lock(dev);
 364         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 365         ssleep(1);
 366         pci_cfg_access_unlock(dev);
 367
 368         pcibios_sriov_disable(dev);
 369
 370         if (iov->link != dev->devfn)
 371                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 372
 373         iov->num_VFs = 0;
 374         pci_iov_set_numvfs(dev, 0);
 375 }
 376
 377 static int sriov_init(struct pci_dev *dev, int pos)
 378 {
 379         int i, bar64;
 380         int rc;
 381         int nres;
 382         u32 pgsz;
 383         u16 ctrl, total;
 384         struct pci_sriov *iov;
 385         struct resource *res;
 386         struct pci_dev *pdev;
 387
 388         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 389         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 390                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 391                 ssleep(1);
 392         }
 393
 394         ctrl = 0;
 395         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 396                 if (pdev->is_physfn)
 397                         goto found;
 398
 399         pdev = NULL;
 400         if (pci_ari_enabled(dev->bus))
 401                 ctrl |= PCI_SRIOV_CTRL_ARI;
 402
 403 found:
 404         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 405
 406         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 407         if (!total)
 408                 return 0;
 409
 410         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 411         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 412         pgsz &= ~((1 << i) - 1);
 413         if (!pgsz)
 414                 return -EIO;
 415
 416         pgsz &= ~(pgsz - 1);
 417         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 418
 419         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 420         if (!iov)
 421                 return -ENOMEM;
 422
 423         nres = 0;
 424         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 425                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 426                 /*
 427                  * If it is already FIXED, don't change it, something
 428                  * (perhaps EA or header fixups) wants it this way.
 429                  */
 430                 if (res->flags & IORESOURCE_PCI_FIXED)
 431                         bar64 = (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
 432                 else
 433                         bar64 = __pci_read_base(dev, pci_bar_unknown, res,
 434                                                 pos + PCI_SRIOV_BAR + i * 4);
 435                 if (!res->flags)
 436                         continue;
 437                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 438                         rc = -EIO;
 439                         goto failed;
 440                 }
 441                 iov->barsz[i] = resource_size(res);
 442                 res->end = res->start + resource_size(res) * total - 1;
 443                 dev_info(&dev->dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
 444                          i, res, i, total);
 445                 i += bar64;
 446                 nres++;
 447         }
 448
 449         iov->pos = pos;
 450         iov->nres = nres;
 451         iov->ctrl = ctrl;
 452         iov->total_VFs = total;
 453         iov->pgsz = pgsz;
 454         iov->self = dev;
 455         iov->drivers_autoprobe = true;
 456         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 457         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 458         if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
 459                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 460
 461         if (pdev)
 462                 iov->dev = pci_dev_get(pdev);
 463         else
 464                 iov->dev = dev;
 465
 466         dev->sriov = iov;
 467         dev->is_physfn = 1;
 468         rc = compute_max_vf_buses(dev);
 469         if (rc)
 470                 goto fail_max_buses;
 471
 472         return 0;
 473
 474 fail_max_buses:
 475         dev->sriov = NULL;
 476         dev->is_physfn = 0;
 477 failed:
 478         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 479                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 480                 res->flags = 0;
 481         }
 482
 483         kfree(iov);
 484         return rc;
 485 }
 486
 487 static void sriov_release(struct pci_dev *dev)
 488 {
 489         BUG_ON(dev->sriov->num_VFs);
 490
 491         if (dev != dev->sriov->dev)
 492                 pci_dev_put(dev->sriov->dev);
 493
 494         kfree(dev->sriov);
 495         dev->sriov = NULL;
 496 }
 497
 498 static void sriov_restore_state(struct pci_dev *dev)
 499 {
 500         int i;
 501         u16 ctrl;
 502         struct pci_sriov *iov = dev->sriov;
 503
 504         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 505         if (ctrl & PCI_SRIOV_CTRL_VFE)
 506                 return;
 507
 508         for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
 509                 pci_update_resource(dev, i);
 510
 511         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 512         pci_iov_set_numvfs(dev, iov->num_VFs);
 513         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 514         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 515                 msleep(100);
 516 }
 517
 518 /**
 519  * pci_iov_init - initialize the IOV capability
 520  * @dev: the PCI device
 521  *
 522  * Returns 0 on success, or negative on failure.
 523  */
 524 int pci_iov_init(struct pci_dev *dev)
 525 {
 526         int pos;
 527
 528         if (!pci_is_pcie(dev))
 529                 return -ENODEV;
 530
 531         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 532         if (pos)
 533                 return sriov_init(dev, pos);
 534
 535         return -ENODEV;
 536 }
 537
 538 /**
 539  * pci_iov_release - release resources used by the IOV capability
 540  * @dev: the PCI device
 541  */
 542 void pci_iov_release(struct pci_dev *dev)
 543 {
 544         if (dev->is_physfn)
 545                 sriov_release(dev);
 546 }
 547
 548 /**
 549  * pci_iov_update_resource - update a VF BAR
 550  * @dev: the PCI device
 551  * @resno: the resource number
 552  *
 553  * Update a VF BAR in the SR-IOV capability of a PF.
 554  */
 555 void pci_iov_update_resource(struct pci_dev *dev, int resno)
 556 {
 557         struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL;
 558         struct resource *res = dev->resource + resno;
 559         int vf_bar = resno - PCI_IOV_RESOURCES;
 560         struct pci_bus_region region;
 561         u16 cmd;
 562         u32 new;
 563         int reg;
 564
 565         /*
 566          * The generic pci_restore_bars() path calls this for all devices,
 567          * including VFs and non-SR-IOV devices.  If this is not a PF, we
 568          * have nothing to do.
 569          */
 570         if (!iov)
 571                 return;
 572
 573         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &cmd);
 574         if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) {
 575                 dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n",
 576                          vf_bar, res);
 577                 return;
 578         }
 579
 580         /*
 581          * Ignore unimplemented BARs, unused resource slots for 64-bit
 582          * BARs, and non-movable resources, e.g., those described via
 583          * Enhanced Allocation.
 584          */
 585         if (!res->flags)
 586                 return;
 587
 588         if (res->flags & IORESOURCE_UNSET)
 589                 return;
 590
 591         if (res->flags & IORESOURCE_PCI_FIXED)
 592                 return;
 593
 594         pcibios_resource_to_bus(dev->bus, &region, res);
 595         new = region.start;
 596         new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
 597
 598         reg = iov->pos + PCI_SRIOV_BAR + 4 * vf_bar;
 599         pci_write_config_dword(dev, reg, new);
 600         if (res->flags & IORESOURCE_MEM_64) {
 601                 new = region.start >> 16 >> 16;
 602                 pci_write_config_dword(dev, reg + 4, new);
 603         }
 604 }
 605
 606 resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
 607                                                       int resno)
 608 {
 609         return pci_iov_resource_size(dev, resno);
 610 }
 611
 612 /**
 613  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 614  * @dev: the PCI device
 615  * @resno: the resource number
 616  *
 617  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 618  * This is not the same as the resource size which is defined as
 619  * the VF BAR size multiplied by the number of VFs.  The alignment
 620  * is just the VF BAR size.
 621  */
 622 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 623 {
 624         return pcibios_iov_resource_alignment(dev, resno);
 625 }
 626
 627 /**
 628  * pci_restore_iov_state - restore the state of the IOV capability
 629  * @dev: the PCI device
 630  */
 631 void pci_restore_iov_state(struct pci_dev *dev)
 632 {
 633         if (dev->is_physfn)
 634                 sriov_restore_state(dev);
 635 }
 636
 637 /**
 638  * pci_iov_bus_range - find bus range used by Virtual Function
 639  * @bus: the PCI bus
 640  *
 641  * Returns max number of buses (exclude current one) used by Virtual
 642  * Functions.
 643  */
 644 int pci_iov_bus_range(struct pci_bus *bus)
 645 {
 646         int max = 0;
 647         struct pci_dev *dev;
 648
 649         list_for_each_entry(dev, &bus->devices, bus_list) {
 650                 if (!dev->is_physfn)
 651                         continue;
 652                 if (dev->sriov->max_VF_buses > max)
 653                         max = dev->sriov->max_VF_buses;
 654         }
 655
 656         return max ? max - bus->number : 0;
 657 }
 658
 659 /**
 660  * pci_enable_sriov - enable the SR-IOV capability
 661  * @dev: the PCI device
 662  * @nr_virtfn: number of virtual functions to enable
 663  *
 664  * Returns 0 on success, or negative on failure.
 665  */
 666 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 667 {
 668         might_sleep();
 669
 670         if (!dev->is_physfn)
 671                 return -ENOSYS;
 672
 673         return sriov_enable(dev, nr_virtfn);
 674 }
 675 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 676
 677 /**
 678  * pci_disable_sriov - disable the SR-IOV capability
 679  * @dev: the PCI device
 680  */
 681 void pci_disable_sriov(struct pci_dev *dev)
 682 {
 683         might_sleep();
 684
 685         if (!dev->is_physfn)
 686                 return;
 687
 688         sriov_disable(dev);
 689 }
 690 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 691
 692 /**
 693  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 694  * @dev: the PCI device
 695  *
 696  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 697  */
 698 int pci_num_vf(struct pci_dev *dev)
 699 {
 700         if (!dev->is_physfn)
 701                 return 0;
 702
 703         return dev->sriov->num_VFs;
 704 }
 705 EXPORT_SYMBOL_GPL(pci_num_vf);
 706
 707 /**
 708  * pci_vfs_assigned - returns number of VFs are assigned to a guest
 709  * @dev: the PCI device
 710  *
 711  * Returns number of VFs belonging to this device that are assigned to a guest.
 712  * If device is not a physical function returns 0.
 713  */
 714 int pci_vfs_assigned(struct pci_dev *dev)
 715 {
 716         struct pci_dev *vfdev;
 717         unsigned int vfs_assigned = 0;
 718         unsigned short dev_id;
 719
 720         /* only search if we are a PF */
 721         if (!dev->is_physfn)
 722                 return 0;
 723
 724         /*
 725          * determine the device ID for the VFs, the vendor ID will be the
 726          * same as the PF so there is no need to check for that one
 727          */
 728         pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_VF_DID, &dev_id);
 729
 730         /* loop through all the VFs to see if we own any that are assigned */
 731         vfdev = pci_get_device(dev->vendor, dev_id, NULL);
 732         while (vfdev) {
 733                 /*
 734                  * It is considered assigned if it is a virtual function with
 735                  * our dev as the physical function and the assigned bit is set
 736                  */
 737                 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
 738                         pci_is_dev_assigned(vfdev))
 739                         vfs_assigned++;
 740
 741                 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
 742         }
 743
 744         return vfs_assigned;
 745 }
 746 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
 747
 748 /**
 749  * pci_sriov_set_totalvfs -- reduce the TotalVFs available
 750  * @dev: the PCI PF device
 751  * @numvfs: number that should be used for TotalVFs supported
 752  *
 753  * Should be called from PF driver's probe routine with
 754  * device's mutex held.
 755  *
 756  * Returns 0 if PF is an SRIOV-capable device and
 757  * value of numvfs valid. If not a PF return -ENOSYS;
 758  * if numvfs is invalid return -EINVAL;
 759  * if VFs already enabled, return -EBUSY.
 760  */
 761 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
 762 {
 763         if (!dev->is_physfn)
 764                 return -ENOSYS;
 765         if (numvfs > dev->sriov->total_VFs)
 766                 return -EINVAL;
 767
 768         /* Shouldn't change if VFs already enabled */
 769         if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
 770                 return -EBUSY;
 771         else
 772                 dev->sriov->driver_max_VFs = numvfs;
 773
 774         return 0;
 775 }
 776 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
 777
 778 /**
 779  * pci_sriov_get_totalvfs -- get total VFs supported on this device
 780  * @dev: the PCI PF device
 781  *
 782  * For a PCIe device with SRIOV support, return the PCIe
 783  * SRIOV capability value of TotalVFs or the value of driver_max_VFs
 784  * if the driver reduced it.  Otherwise 0.
 785  */
 786 int pci_sriov_get_totalvfs(struct pci_dev *dev)
 787 {
 788         if (!dev->is_physfn)
 789                 return 0;
 790
 791         if (dev->sriov->driver_max_VFs)
 792                 return dev->sriov->driver_max_VFs;
 793
 794         return dev->sriov->total_VFs;
 795 }
 796 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);