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         mutex_lock(&iov->dev->sriov->lock);
 128         bus = virtfn_add_bus(dev->bus, pci_iov_virtfn_bus(dev, id));
 129         if (!bus)
 130                 goto failed;
 131
 132         virtfn = pci_alloc_dev(bus);
 133         if (!virtfn)
 134                 goto failed0;
 135
 136         virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
 137         virtfn->vendor = dev->vendor;
 138         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
 139         rc = pci_setup_device(virtfn);
 140         if (rc)
 141                 goto failed0;
 142
 143         virtfn->dev.parent = dev->dev.parent;
 144         virtfn->physfn = pci_dev_get(dev);
 145         virtfn->is_virtfn = 1;
 146         virtfn->multifunction = 0;
 147
 148         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 149                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 150                 if (!res->parent)
 151                         continue;
 152                 virtfn->resource[i].name = pci_name(virtfn);
 153                 virtfn->resource[i].flags = res->flags;
 154                 size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
 155                 virtfn->resource[i].start = res->start + size * id;
 156                 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
 157                 rc = request_resource(res, &virtfn->resource[i]);
 158                 BUG_ON(rc);
 159         }
 160
 161         if (reset)
 162                 __pci_reset_function(virtfn);
 163
 164         pci_device_add(virtfn, virtfn->bus);
 165         mutex_unlock(&iov->dev->sriov->lock);
 166
 167         sprintf(buf, "virtfn%u", id);
 168         rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
 169         if (rc)
 170                 goto failed1;
 171         rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
 172         if (rc)
 173                 goto failed2;
 174
 175         kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
 176
 177         pci_bus_add_device(virtfn);
 178
 179         return 0;
 180
 181 failed2:
 182         sysfs_remove_link(&dev->dev.kobj, buf);
 183 failed1:
 184         pci_stop_and_remove_bus_device(virtfn);
 185         pci_dev_put(dev);
 186         mutex_lock(&iov->dev->sriov->lock);
 187         pci_stop_and_remove_bus_device(virtfn);
 188 failed0:
 189         virtfn_remove_bus(dev->bus, bus);
 190 failed:
 191         mutex_unlock(&iov->dev->sriov->lock);
 192
 193         return rc;
 194 }
 195
 196 void pci_iov_remove_virtfn(struct pci_dev *dev, int id, int reset)
 197 {
 198         char buf[VIRTFN_ID_LEN];
 199         struct pci_dev *virtfn;
 200         struct pci_sriov *iov = dev->sriov;
 201
 202         virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
 203                                              pci_iov_virtfn_bus(dev, id),
 204                                              pci_iov_virtfn_devfn(dev, id));
 205         if (!virtfn)
 206                 return;
 207
 208         if (reset) {
 209                 device_release_driver(&virtfn->dev);
 210                 __pci_reset_function(virtfn);
 211         }
 212
 213         sprintf(buf, "virtfn%u", id);
 214         sysfs_remove_link(&dev->dev.kobj, buf);
 215         /*
 216          * pci_stop_dev() could have been called for this virtfn already,
 217          * so the directory for the virtfn may have been removed before.
 218          * Double check to avoid spurious sysfs warnings.
 219          */
 220         if (virtfn->dev.kobj.sd)
 221                 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
 222
 223         mutex_lock(&iov->dev->sriov->lock);
 224         pci_stop_and_remove_bus_device(virtfn);
 225         virtfn_remove_bus(dev->bus, virtfn->bus);
 226         mutex_unlock(&iov->dev->sriov->lock);
 227
 228         /* balance pci_get_domain_bus_and_slot() */
 229         pci_dev_put(virtfn);
 230         pci_dev_put(dev);
 231 }
 232
 233 int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
 234 {
 235         return 0;
 236 }
 237
 238 int __weak pcibios_sriov_disable(struct pci_dev *pdev)
 239 {
 240         return 0;
 241 }
 242
 243 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 244 {
 245         int rc;
 246         int i;
 247         int nres;
 248         u16 initial;
 249         struct resource *res;
 250         struct pci_dev *pdev;
 251         struct pci_sriov *iov = dev->sriov;
 252         int bars = 0;
 253         int bus;
 254
 255         if (!nr_virtfn)
 256                 return 0;
 257
 258         if (iov->num_VFs)
 259                 return -EINVAL;
 260
 261         pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
 262         if (initial > iov->total_VFs ||
 263             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
 264                 return -EIO;
 265
 266         if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
 267             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 268                 return -EINVAL;
 269
 270         nres = 0;
 271         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 272                 bars |= (1 << (i + PCI_IOV_RESOURCES));
 273                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 274                 if (res->parent)
 275                         nres++;
 276         }
 277         if (nres != iov->nres) {
 278                 dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
 279                 return -ENOMEM;
 280         }
 281
 282         bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
 283         if (bus > dev->bus->busn_res.end) {
 284                 dev_err(&dev->dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
 285                         nr_virtfn, bus, &dev->bus->busn_res);
 286                 return -ENOMEM;
 287         }
 288
 289         if (pci_enable_resources(dev, bars)) {
 290                 dev_err(&dev->dev, "SR-IOV: IOV BARS not allocated\n");
 291                 return -ENOMEM;
 292         }
 293
 294         if (iov->link != dev->devfn) {
 295                 pdev = pci_get_slot(dev->bus, iov->link);
 296                 if (!pdev)
 297                         return -ENODEV;
 298
 299                 if (!pdev->is_physfn) {
 300                         pci_dev_put(pdev);
 301                         return -ENOSYS;
 302                 }
 303
 304                 rc = sysfs_create_link(&dev->dev.kobj,
 305                                         &pdev->dev.kobj, "dep_link");
 306                 pci_dev_put(pdev);
 307                 if (rc)
 308                         return rc;
 309         }
 310
 311         iov->initial_VFs = initial;
 312         if (nr_virtfn < initial)
 313                 initial = nr_virtfn;
 314
 315         rc = pcibios_sriov_enable(dev, initial);
 316         if (rc) {
 317                 dev_err(&dev->dev, "failure %d from pcibios_sriov_enable()\n", rc);
 318                 goto err_pcibios;
 319         }
 320
 321         pci_iov_set_numvfs(dev, nr_virtfn);
 322         iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 323         pci_cfg_access_lock(dev);
 324         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 325         msleep(100);
 326         pci_cfg_access_unlock(dev);
 327
 328         for (i = 0; i < initial; i++) {
 329                 rc = pci_iov_add_virtfn(dev, i, 0);
 330                 if (rc)
 331                         goto failed;
 332         }
 333
 334         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 335         iov->num_VFs = nr_virtfn;
 336
 337         return 0;
 338
 339 failed:
 340         while (i--)
 341                 pci_iov_remove_virtfn(dev, i, 0);
 342
 343         pcibios_sriov_disable(dev);
 344 err_pcibios:
 345         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 346         pci_cfg_access_lock(dev);
 347         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 348         ssleep(1);
 349         pci_cfg_access_unlock(dev);
 350
 351         if (iov->link != dev->devfn)
 352                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 353
 354         pci_iov_set_numvfs(dev, 0);
 355         return rc;
 356 }
 357
 358 static void sriov_disable(struct pci_dev *dev)
 359 {
 360         int i;
 361         struct pci_sriov *iov = dev->sriov;
 362
 363         if (!iov->num_VFs)
 364                 return;
 365
 366         for (i = 0; i < iov->num_VFs; i++)
 367                 pci_iov_remove_virtfn(dev, i, 0);
 368
 369         pcibios_sriov_disable(dev);
 370
 371         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 372         pci_cfg_access_lock(dev);
 373         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 374         ssleep(1);
 375         pci_cfg_access_unlock(dev);
 376
 377         if (iov->link != dev->devfn)
 378                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 379
 380         iov->num_VFs = 0;
 381         pci_iov_set_numvfs(dev, 0);
 382 }
 383
 384 static int sriov_init(struct pci_dev *dev, int pos)
 385 {
 386         int i, bar64;
 387         int rc;
 388         int nres;
 389         u32 pgsz;
 390         u16 ctrl, total;
 391         struct pci_sriov *iov;
 392         struct resource *res;
 393         struct pci_dev *pdev;
 394
 395         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 396         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 397                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 398                 ssleep(1);
 399         }
 400
 401         ctrl = 0;
 402         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 403                 if (pdev->is_physfn)
 404                         goto found;
 405
 406         pdev = NULL;
 407         if (pci_ari_enabled(dev->bus))
 408                 ctrl |= PCI_SRIOV_CTRL_ARI;
 409
 410 found:
 411         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 412
 413         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 414         if (!total)
 415                 return 0;
 416
 417         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 418         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 419         pgsz &= ~((1 << i) - 1);
 420         if (!pgsz)
 421                 return -EIO;
 422
 423         pgsz &= ~(pgsz - 1);
 424         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 425
 426         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 427         if (!iov)
 428                 return -ENOMEM;
 429
 430         nres = 0;
 431         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 432                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 433                 /*
 434                  * If it is already FIXED, don't change it, something
 435                  * (perhaps EA or header fixups) wants it this way.
 436                  */
 437                 if (res->flags & IORESOURCE_PCI_FIXED)
 438                         bar64 = (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
 439                 else
 440                         bar64 = __pci_read_base(dev, pci_bar_unknown, res,
 441                                                 pos + PCI_SRIOV_BAR + i * 4);
 442                 if (!res->flags)
 443                         continue;
 444                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 445                         rc = -EIO;
 446                         goto failed;
 447                 }
 448                 iov->barsz[i] = resource_size(res);
 449                 res->end = res->start + resource_size(res) * total - 1;
 450                 dev_info(&dev->dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
 451                          i, res, i, total);
 452                 i += bar64;
 453                 nres++;
 454         }
 455
 456         iov->pos = pos;
 457         iov->nres = nres;
 458         iov->ctrl = ctrl;
 459         iov->total_VFs = total;
 460         iov->pgsz = pgsz;
 461         iov->self = dev;
 462         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 463         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 464         if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
 465                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 466
 467         if (pdev)
 468                 iov->dev = pci_dev_get(pdev);
 469         else
 470                 iov->dev = dev;
 471
 472         mutex_init(&iov->lock);
 473
 474         dev->sriov = iov;
 475         dev->is_physfn = 1;
 476         rc = compute_max_vf_buses(dev);
 477         if (rc)
 478                 goto fail_max_buses;
 479
 480         return 0;
 481
 482 fail_max_buses:
 483         dev->sriov = NULL;
 484         dev->is_physfn = 0;
 485 failed:
 486         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 487                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 488                 res->flags = 0;
 489         }
 490
 491         kfree(iov);
 492         return rc;
 493 }
 494
 495 static void sriov_release(struct pci_dev *dev)
 496 {
 497         BUG_ON(dev->sriov->num_VFs);
 498
 499         if (dev != dev->sriov->dev)
 500                 pci_dev_put(dev->sriov->dev);
 501
 502         mutex_destroy(&dev->sriov->lock);
 503
 504         kfree(dev->sriov);
 505         dev->sriov = NULL;
 506 }
 507
 508 static void sriov_restore_state(struct pci_dev *dev)
 509 {
 510         int i;
 511         u16 ctrl;
 512         struct pci_sriov *iov = dev->sriov;
 513
 514         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 515         if (ctrl & PCI_SRIOV_CTRL_VFE)
 516                 return;
 517
 518         for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
 519                 pci_update_resource(dev, i);
 520
 521         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 522         pci_iov_set_numvfs(dev, iov->num_VFs);
 523         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 524         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 525                 msleep(100);
 526 }
 527
 528 /**
 529  * pci_iov_init - initialize the IOV capability
 530  * @dev: the PCI device
 531  *
 532  * Returns 0 on success, or negative on failure.
 533  */
 534 int pci_iov_init(struct pci_dev *dev)
 535 {
 536         int pos;
 537
 538         if (!pci_is_pcie(dev))
 539                 return -ENODEV;
 540
 541         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 542         if (pos)
 543                 return sriov_init(dev, pos);
 544
 545         return -ENODEV;
 546 }
 547
 548 /**
 549  * pci_iov_release - release resources used by the IOV capability
 550  * @dev: the PCI device
 551  */
 552 void pci_iov_release(struct pci_dev *dev)
 553 {
 554         if (dev->is_physfn)
 555                 sriov_release(dev);
 556 }
 557
 558 /**
 559  * pci_iov_update_resource - update a VF BAR
 560  * @dev: the PCI device
 561  * @resno: the resource number
 562  *
 563  * Update a VF BAR in the SR-IOV capability of a PF.
 564  */
 565 void pci_iov_update_resource(struct pci_dev *dev, int resno)
 566 {
 567         struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL;
 568         struct resource *res = dev->resource + resno;
 569         int vf_bar = resno - PCI_IOV_RESOURCES;
 570         struct pci_bus_region region;
 571         u16 cmd;
 572         u32 new;
 573         int reg;
 574
 575         /*
 576          * The generic pci_restore_bars() path calls this for all devices,
 577          * including VFs and non-SR-IOV devices.  If this is not a PF, we
 578          * have nothing to do.
 579          */
 580         if (!iov)
 581                 return;
 582
 583         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &cmd);
 584         if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) {
 585                 dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n",
 586                          vf_bar, res);
 587                 return;
 588         }
 589
 590         /*
 591          * Ignore unimplemented BARs, unused resource slots for 64-bit
 592          * BARs, and non-movable resources, e.g., those described via
 593          * Enhanced Allocation.
 594          */
 595         if (!res->flags)
 596                 return;
 597
 598         if (res->flags & IORESOURCE_UNSET)
 599                 return;
 600
 601         if (res->flags & IORESOURCE_PCI_FIXED)
 602                 return;
 603
 604         pcibios_resource_to_bus(dev->bus, &region, res);
 605         new = region.start;
 606         new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
 607
 608         reg = iov->pos + PCI_SRIOV_BAR + 4 * vf_bar;
 609         pci_write_config_dword(dev, reg, new);
 610         if (res->flags & IORESOURCE_MEM_64) {
 611                 new = region.start >> 16 >> 16;
 612                 pci_write_config_dword(dev, reg + 4, new);
 613         }
 614 }
 615
 616 resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
 617                                                       int resno)
 618 {
 619         return pci_iov_resource_size(dev, resno);
 620 }
 621
 622 /**
 623  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 624  * @dev: the PCI device
 625  * @resno: the resource number
 626  *
 627  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 628  * This is not the same as the resource size which is defined as
 629  * the VF BAR size multiplied by the number of VFs.  The alignment
 630  * is just the VF BAR size.
 631  */
 632 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 633 {
 634         return pcibios_iov_resource_alignment(dev, resno);
 635 }
 636
 637 /**
 638  * pci_restore_iov_state - restore the state of the IOV capability
 639  * @dev: the PCI device
 640  */
 641 void pci_restore_iov_state(struct pci_dev *dev)
 642 {
 643         if (dev->is_physfn)
 644                 sriov_restore_state(dev);
 645 }
 646
 647 /**
 648  * pci_iov_bus_range - find bus range used by Virtual Function
 649  * @bus: the PCI bus
 650  *
 651  * Returns max number of buses (exclude current one) used by Virtual
 652  * Functions.
 653  */
 654 int pci_iov_bus_range(struct pci_bus *bus)
 655 {
 656         int max = 0;
 657         struct pci_dev *dev;
 658
 659         list_for_each_entry(dev, &bus->devices, bus_list) {
 660                 if (!dev->is_physfn)
 661                         continue;
 662                 if (dev->sriov->max_VF_buses > max)
 663                         max = dev->sriov->max_VF_buses;
 664         }
 665
 666         return max ? max - bus->number : 0;
 667 }
 668
 669 /**
 670  * pci_enable_sriov - enable the SR-IOV capability
 671  * @dev: the PCI device
 672  * @nr_virtfn: number of virtual functions to enable
 673  *
 674  * Returns 0 on success, or negative on failure.
 675  */
 676 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 677 {
 678         might_sleep();
 679
 680         if (!dev->is_physfn)
 681                 return -ENOSYS;
 682
 683         return sriov_enable(dev, nr_virtfn);
 684 }
 685 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 686
 687 /**
 688  * pci_disable_sriov - disable the SR-IOV capability
 689  * @dev: the PCI device
 690  */
 691 void pci_disable_sriov(struct pci_dev *dev)
 692 {
 693         might_sleep();
 694
 695         if (!dev->is_physfn)
 696                 return;
 697
 698         sriov_disable(dev);
 699 }
 700 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 701
 702 /**
 703  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 704  * @dev: the PCI device
 705  *
 706  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 707  */
 708 int pci_num_vf(struct pci_dev *dev)
 709 {
 710         if (!dev->is_physfn)
 711                 return 0;
 712
 713         return dev->sriov->num_VFs;
 714 }
 715 EXPORT_SYMBOL_GPL(pci_num_vf);
 716
 717 /**
 718  * pci_vfs_assigned - returns number of VFs are assigned to a guest
 719  * @dev: the PCI device
 720  *
 721  * Returns number of VFs belonging to this device that are assigned to a guest.
 722  * If device is not a physical function returns 0.
 723  */
 724 int pci_vfs_assigned(struct pci_dev *dev)
 725 {
 726         struct pci_dev *vfdev;
 727         unsigned int vfs_assigned = 0;
 728         unsigned short dev_id;
 729
 730         /* only search if we are a PF */
 731         if (!dev->is_physfn)
 732                 return 0;
 733
 734         /*
 735          * determine the device ID for the VFs, the vendor ID will be the
 736          * same as the PF so there is no need to check for that one
 737          */
 738         pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_VF_DID, &dev_id);
 739
 740         /* loop through all the VFs to see if we own any that are assigned */
 741         vfdev = pci_get_device(dev->vendor, dev_id, NULL);
 742         while (vfdev) {
 743                 /*
 744                  * It is considered assigned if it is a virtual function with
 745                  * our dev as the physical function and the assigned bit is set
 746                  */
 747                 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
 748                         pci_is_dev_assigned(vfdev))
 749                         vfs_assigned++;
 750
 751                 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
 752         }
 753
 754         return vfs_assigned;
 755 }
 756 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
 757
 758 /**
 759  * pci_sriov_set_totalvfs -- reduce the TotalVFs available
 760  * @dev: the PCI PF device
 761  * @numvfs: number that should be used for TotalVFs supported
 762  *
 763  * Should be called from PF driver's probe routine with
 764  * device's mutex held.
 765  *
 766  * Returns 0 if PF is an SRIOV-capable device and
 767  * value of numvfs valid. If not a PF return -ENOSYS;
 768  * if numvfs is invalid return -EINVAL;
 769  * if VFs already enabled, return -EBUSY.
 770  */
 771 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
 772 {
 773         if (!dev->is_physfn)
 774                 return -ENOSYS;
 775         if (numvfs > dev->sriov->total_VFs)
 776                 return -EINVAL;
 777
 778         /* Shouldn't change if VFs already enabled */
 779         if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
 780                 return -EBUSY;
 781         else
 782                 dev->sriov->driver_max_VFs = numvfs;
 783
 784         return 0;
 785 }
 786 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
 787
 788 /**
 789  * pci_sriov_get_totalvfs -- get total VFs supported on this device
 790  * @dev: the PCI PF device
 791  *
 792  * For a PCIe device with SRIOV support, return the PCIe
 793  * SRIOV capability value of TotalVFs or the value of driver_max_VFs
 794  * if the driver reduced it.  Otherwise 0.
 795  */
 796 int pci_sriov_get_totalvfs(struct pci_dev *dev)
 797 {
 798         if (!dev->is_physfn)
 799                 return 0;
 800
 801         if (dev->sriov->driver_max_VFs)
 802                 return dev->sriov->driver_max_VFs;
 803
 804         return dev->sriov->total_VFs;
 805 }
 806 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);