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