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