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