drivers/pci/iov.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * drivers/pci/iov.c
   4  *
   5  * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com>
   6  *
   7  * PCI Express I/O Virtualization (IOV) support.
   8  *   Single Root IOV 1.0
   9  *   Address Translation Service 1.0
  10  */
  11
  12 #include <linux/pci.h>
  13 #include <linux/slab.h>
  14 #include <linux/mutex.h>
  15 #include <linux/export.h>
  16 #include <linux/string.h>
  17 #include <linux/delay.h>
  18 #include <linux/pci-ats.h>
  19 #include "pci.h"
  20
  21 #define VIRTFN_ID_LEN   16
  22
  23 int pci_iov_virtfn_bus(struct pci_dev *dev, int vf_id)
  24 {
  25         if (!dev->is_physfn)
  26                 return -EINVAL;
  27         return dev->bus->number + ((dev->devfn + dev->sriov->offset +
  28                                     dev->sriov->stride * vf_id) >> 8);
  29 }
  30
  31 int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id)
  32 {
  33         if (!dev->is_physfn)
  34                 return -EINVAL;
  35         return (dev->devfn + dev->sriov->offset +
  36                 dev->sriov->stride * vf_id) & 0xff;
  37 }
  38
  39 /*
  40  * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may
  41  * change when NumVFs changes.
  42  *
  43  * Update iov->offset and iov->stride when NumVFs is written.
  44  */
  45 static inline void pci_iov_set_numvfs(struct pci_dev *dev, int nr_virtfn)
  46 {
  47         struct pci_sriov *iov = dev->sriov;
  48
  49         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
  50         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &iov->offset);
  51         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &iov->stride);
  52 }
  53
  54 /*
  55  * The PF consumes one bus number.  NumVFs, First VF Offset, and VF Stride
  56  * determine how many additional bus numbers will be consumed by VFs.
  57  *
  58  * Iterate over all valid NumVFs, validate offset and stride, and calculate
  59  * the maximum number of bus numbers that could ever be required.
  60  */
  61 static int compute_max_vf_buses(struct pci_dev *dev)
  62 {
  63         struct pci_sriov *iov = dev->sriov;
  64         int nr_virtfn, busnr, rc = 0;
  65
  66         for (nr_virtfn = iov->total_VFs; nr_virtfn; nr_virtfn--) {
  67                 pci_iov_set_numvfs(dev, nr_virtfn);
  68                 if (!iov->offset || (nr_virtfn > 1 && !iov->stride)) {
  69                         rc = -EIO;
  70                         goto out;
  71                 }
  72
  73                 busnr = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
  74                 if (busnr > iov->max_VF_buses)
  75                         iov->max_VF_buses = busnr;
  76         }
  77
  78 out:
  79         pci_iov_set_numvfs(dev, 0);
  80         return rc;
  81 }
  82
  83 static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
  84 {
  85         struct pci_bus *child;
  86
  87         if (bus->number == busnr)
  88                 return bus;
  89
  90         child = pci_find_bus(pci_domain_nr(bus), busnr);
  91         if (child)
  92                 return child;
  93
  94         child = pci_add_new_bus(bus, NULL, busnr);
  95         if (!child)
  96                 return NULL;
  97
  98         pci_bus_insert_busn_res(child, busnr, busnr);
  99
 100         return child;
 101 }
 102
 103 static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus)
 104 {
 105         if (physbus != virtbus && list_empty(&virtbus->devices))
 106                 pci_remove_bus(virtbus);
 107 }
 108
 109 resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
 110 {
 111         if (!dev->is_physfn)
 112                 return 0;
 113
 114         return dev->sriov->barsz[resno - PCI_IOV_RESOURCES];
 115 }
 116
 117 int pci_iov_add_virtfn(struct pci_dev *dev, int id)
 118 {
 119         int i;
 120         int rc = -ENOMEM;
 121         u64 size;
 122         char buf[VIRTFN_ID_LEN];
 123         struct pci_dev *virtfn;
 124         struct resource *res;
 125         struct pci_sriov *iov = dev->sriov;
 126         struct pci_bus *bus;
 127
 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         virtfn->device = iov->vf_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         pci_device_add(virtfn, virtfn->bus);
 162
 163         sprintf(buf, "virtfn%u", id);
 164         rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
 165         if (rc)
 166                 goto failed1;
 167         rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
 168         if (rc)
 169                 goto failed2;
 170
 171         kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
 172
 173         pci_bus_add_device(virtfn);
 174
 175         return 0;
 176
 177 failed2:
 178         sysfs_remove_link(&dev->dev.kobj, buf);
 179 failed1:
 180         pci_dev_put(dev);
 181         pci_stop_and_remove_bus_device(virtfn);
 182 failed0:
 183         virtfn_remove_bus(dev->bus, bus);
 184 failed:
 185
 186         return rc;
 187 }
 188
 189 void pci_iov_remove_virtfn(struct pci_dev *dev, int id)
 190 {
 191         char buf[VIRTFN_ID_LEN];
 192         struct pci_dev *virtfn;
 193
 194         virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
 195                                              pci_iov_virtfn_bus(dev, id),
 196                                              pci_iov_virtfn_devfn(dev, id));
 197         if (!virtfn)
 198                 return;
 199
 200         sprintf(buf, "virtfn%u", id);
 201         sysfs_remove_link(&dev->dev.kobj, buf);
 202         /*
 203          * pci_stop_dev() could have been called for this virtfn already,
 204          * so the directory for the virtfn may have been removed before.
 205          * Double check to avoid spurious sysfs warnings.
 206          */
 207         if (virtfn->dev.kobj.sd)
 208                 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
 209
 210         pci_stop_and_remove_bus_device(virtfn);
 211         virtfn_remove_bus(dev->bus, virtfn->bus);
 212
 213         /* balance pci_get_domain_bus_and_slot() */
 214         pci_dev_put(virtfn);
 215         pci_dev_put(dev);
 216 }
 217
 218 int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
 219 {
 220         return 0;
 221 }
 222
 223 int __weak pcibios_sriov_disable(struct pci_dev *pdev)
 224 {
 225         return 0;
 226 }
 227
 228 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 229 {
 230         int rc;
 231         int i;
 232         int nres;
 233         u16 initial;
 234         struct resource *res;
 235         struct pci_dev *pdev;
 236         struct pci_sriov *iov = dev->sriov;
 237         int bars = 0;
 238         int bus;
 239
 240         if (!nr_virtfn)
 241                 return 0;
 242
 243         if (iov->num_VFs)
 244                 return -EINVAL;
 245
 246         pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
 247         if (initial > iov->total_VFs ||
 248             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
 249                 return -EIO;
 250
 251         if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
 252             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 253                 return -EINVAL;
 254
 255         nres = 0;
 256         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 257                 bars |= (1 << (i + PCI_IOV_RESOURCES));
 258                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 259                 if (res->parent)
 260                         nres++;
 261         }
 262         if (nres != iov->nres) {
 263                 pci_err(dev, "not enough MMIO resources for SR-IOV\n");
 264                 return -ENOMEM;
 265         }
 266
 267         bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
 268         if (bus > dev->bus->busn_res.end) {
 269                 pci_err(dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
 270                         nr_virtfn, bus, &dev->bus->busn_res);
 271                 return -ENOMEM;
 272         }
 273
 274         if (pci_enable_resources(dev, bars)) {
 275                 pci_err(dev, "SR-IOV: IOV BARS not allocated\n");
 276                 return -ENOMEM;
 277         }
 278
 279         if (iov->link != dev->devfn) {
 280                 pdev = pci_get_slot(dev->bus, iov->link);
 281                 if (!pdev)
 282                         return -ENODEV;
 283
 284                 if (!pdev->is_physfn) {
 285                         pci_dev_put(pdev);
 286                         return -ENOSYS;
 287                 }
 288
 289                 rc = sysfs_create_link(&dev->dev.kobj,
 290                                         &pdev->dev.kobj, "dep_link");
 291                 pci_dev_put(pdev);
 292                 if (rc)
 293                         return rc;
 294         }
 295
 296         iov->initial_VFs = initial;
 297         if (nr_virtfn < initial)
 298                 initial = nr_virtfn;
 299
 300         rc = pcibios_sriov_enable(dev, initial);
 301         if (rc) {
 302                 pci_err(dev, "failure %d from pcibios_sriov_enable()\n", rc);
 303                 goto err_pcibios;
 304         }
 305
 306         pci_iov_set_numvfs(dev, nr_virtfn);
 307         iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 308         pci_cfg_access_lock(dev);
 309         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 310         msleep(100);
 311         pci_cfg_access_unlock(dev);
 312
 313         for (i = 0; i < initial; i++) {
 314                 rc = pci_iov_add_virtfn(dev, i);
 315                 if (rc)
 316                         goto failed;
 317         }
 318
 319         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 320         iov->num_VFs = nr_virtfn;
 321
 322         return 0;
 323
 324 failed:
 325         while (i--)
 326                 pci_iov_remove_virtfn(dev, i);
 327
 328 err_pcibios:
 329         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 330         pci_cfg_access_lock(dev);
 331         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 332         ssleep(1);
 333         pci_cfg_access_unlock(dev);
 334
 335         pcibios_sriov_disable(dev);
 336
 337         if (iov->link != dev->devfn)
 338                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 339
 340         pci_iov_set_numvfs(dev, 0);
 341         return rc;
 342 }
 343
 344 static void sriov_disable(struct pci_dev *dev)
 345 {
 346         int i;
 347         struct pci_sriov *iov = dev->sriov;
 348
 349         if (!iov->num_VFs)
 350                 return;
 351
 352         for (i = 0; i < iov->num_VFs; i++)
 353                 pci_iov_remove_virtfn(dev, i);
 354
 355         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 356         pci_cfg_access_lock(dev);
 357         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 358         ssleep(1);
 359         pci_cfg_access_unlock(dev);
 360
 361         pcibios_sriov_disable(dev);
 362
 363         if (iov->link != dev->devfn)
 364                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 365
 366         iov->num_VFs = 0;
 367         pci_iov_set_numvfs(dev, 0);
 368 }
 369
 370 static int sriov_init(struct pci_dev *dev, int pos)
 371 {
 372         int i, bar64;
 373         int rc;
 374         int nres;
 375         u32 pgsz;
 376         u16 ctrl, total;
 377         struct pci_sriov *iov;
 378         struct resource *res;
 379         struct pci_dev *pdev;
 380
 381         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 382         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 383                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 384                 ssleep(1);
 385         }
 386
 387         ctrl = 0;
 388         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 389                 if (pdev->is_physfn)
 390                         goto found;
 391
 392         pdev = NULL;
 393         if (pci_ari_enabled(dev->bus))
 394                 ctrl |= PCI_SRIOV_CTRL_ARI;
 395
 396 found:
 397         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 398
 399         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 400         if (!total)
 401                 return 0;
 402
 403         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 404         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 405         pgsz &= ~((1 << i) - 1);
 406         if (!pgsz)
 407                 return -EIO;
 408
 409         pgsz &= ~(pgsz - 1);
 410         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 411
 412         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 413         if (!iov)
 414                 return -ENOMEM;
 415
 416         nres = 0;
 417         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 418                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 419                 /*
 420                  * If it is already FIXED, don't change it, something
 421                  * (perhaps EA or header fixups) wants it this way.
 422                  */
 423                 if (res->flags & IORESOURCE_PCI_FIXED)
 424                         bar64 = (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
 425                 else
 426                         bar64 = __pci_read_base(dev, pci_bar_unknown, res,
 427                                                 pos + PCI_SRIOV_BAR + i * 4);
 428                 if (!res->flags)
 429                         continue;
 430                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 431                         rc = -EIO;
 432                         goto failed;
 433                 }
 434                 iov->barsz[i] = resource_size(res);
 435                 res->end = res->start + resource_size(res) * total - 1;
 436                 pci_info(dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
 437                          i, res, i, total);
 438                 i += bar64;
 439                 nres++;
 440         }
 441
 442         iov->pos = pos;
 443         iov->nres = nres;
 444         iov->ctrl = ctrl;
 445         iov->total_VFs = total;
 446         pci_read_config_word(dev, pos + PCI_SRIOV_VF_DID, &iov->vf_device);
 447         iov->pgsz = pgsz;
 448         iov->self = dev;
 449         iov->drivers_autoprobe = true;
 450         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 451         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 452         if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
 453                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 454
 455         if (pdev)
 456                 iov->dev = pci_dev_get(pdev);
 457         else
 458                 iov->dev = dev;
 459
 460         dev->sriov = iov;
 461         dev->is_physfn = 1;
 462         rc = compute_max_vf_buses(dev);
 463         if (rc)
 464                 goto fail_max_buses;
 465
 466         return 0;
 467
 468 fail_max_buses:
 469         dev->sriov = NULL;
 470         dev->is_physfn = 0;
 471 failed:
 472         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 473                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 474                 res->flags = 0;
 475         }
 476
 477         kfree(iov);
 478         return rc;
 479 }
 480
 481 static void sriov_release(struct pci_dev *dev)
 482 {
 483         BUG_ON(dev->sriov->num_VFs);
 484
 485         if (dev != dev->sriov->dev)
 486                 pci_dev_put(dev->sriov->dev);
 487
 488         kfree(dev->sriov);
 489         dev->sriov = NULL;
 490 }
 491
 492 static void sriov_restore_state(struct pci_dev *dev)
 493 {
 494         int i;
 495         u16 ctrl;
 496         struct pci_sriov *iov = dev->sriov;
 497
 498         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 499         if (ctrl & PCI_SRIOV_CTRL_VFE)
 500                 return;
 501
 502         /*
 503          * Restore PCI_SRIOV_CTRL_ARI before pci_iov_set_numvfs() because
 504          * it reads offset & stride, which depend on PCI_SRIOV_CTRL_ARI.
 505          */
 506         ctrl &= ~PCI_SRIOV_CTRL_ARI;
 507         ctrl |= iov->ctrl & PCI_SRIOV_CTRL_ARI;
 508         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, ctrl);
 509
 510         for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
 511                 pci_update_resource(dev, i);
 512
 513         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 514         pci_iov_set_numvfs(dev, iov->num_VFs);
 515         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 516         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 517                 msleep(100);
 518 }
 519
 520 /**
 521  * pci_iov_init - initialize the IOV capability
 522  * @dev: the PCI device
 523  *
 524  * Returns 0 on success, or negative on failure.
 525  */
 526 int pci_iov_init(struct pci_dev *dev)
 527 {
 528         int pos;
 529
 530         if (!pci_is_pcie(dev))
 531                 return -ENODEV;
 532
 533         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 534         if (pos)
 535                 return sriov_init(dev, pos);
 536
 537         return -ENODEV;
 538 }
 539
 540 /**
 541  * pci_iov_release - release resources used by the IOV capability
 542  * @dev: the PCI device
 543  */
 544 void pci_iov_release(struct pci_dev *dev)
 545 {
 546         if (dev->is_physfn)
 547                 sriov_release(dev);
 548 }
 549
 550 /**
 551  * pci_iov_update_resource - update a VF BAR
 552  * @dev: the PCI device
 553  * @resno: the resource number
 554  *
 555  * Update a VF BAR in the SR-IOV capability of a PF.
 556  */
 557 void pci_iov_update_resource(struct pci_dev *dev, int resno)
 558 {
 559         struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL;
 560         struct resource *res = dev->resource + resno;
 561         int vf_bar = resno - PCI_IOV_RESOURCES;
 562         struct pci_bus_region region;
 563         u16 cmd;
 564         u32 new;
 565         int reg;
 566
 567         /*
 568          * The generic pci_restore_bars() path calls this for all devices,
 569          * including VFs and non-SR-IOV devices.  If this is not a PF, we
 570          * have nothing to do.
 571          */
 572         if (!iov)
 573                 return;
 574
 575         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &cmd);
 576         if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) {
 577                 dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n",
 578                          vf_bar, res);
 579                 return;
 580         }
 581
 582         /*
 583          * Ignore unimplemented BARs, unused resource slots for 64-bit
 584          * BARs, and non-movable resources, e.g., those described via
 585          * Enhanced Allocation.
 586          */
 587         if (!res->flags)
 588                 return;
 589
 590         if (res->flags & IORESOURCE_UNSET)
 591                 return;
 592
 593         if (res->flags & IORESOURCE_PCI_FIXED)
 594                 return;
 595
 596         pcibios_resource_to_bus(dev->bus, &region, res);
 597         new = region.start;
 598         new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
 599
 600         reg = iov->pos + PCI_SRIOV_BAR + 4 * vf_bar;
 601         pci_write_config_dword(dev, reg, new);
 602         if (res->flags & IORESOURCE_MEM_64) {
 603                 new = region.start >> 16 >> 16;
 604                 pci_write_config_dword(dev, reg + 4, new);
 605         }
 606 }
 607
 608 resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
 609                                                       int resno)
 610 {
 611         return pci_iov_resource_size(dev, resno);
 612 }
 613
 614 /**
 615  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 616  * @dev: the PCI device
 617  * @resno: the resource number
 618  *
 619  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 620  * This is not the same as the resource size which is defined as
 621  * the VF BAR size multiplied by the number of VFs.  The alignment
 622  * is just the VF BAR size.
 623  */
 624 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 625 {
 626         return pcibios_iov_resource_alignment(dev, resno);
 627 }
 628
 629 /**
 630  * pci_restore_iov_state - restore the state of the IOV capability
 631  * @dev: the PCI device
 632  */
 633 void pci_restore_iov_state(struct pci_dev *dev)
 634 {
 635         if (dev->is_physfn)
 636                 sriov_restore_state(dev);
 637 }
 638
 639 /**
 640  * pci_vf_drivers_autoprobe - set PF property drivers_autoprobe for VFs
 641  * @dev: the PCI device
 642  * @auto_probe: set VF drivers auto probe flag
 643  */
 644 void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool auto_probe)
 645 {
 646         if (dev->is_physfn)
 647                 dev->sriov->drivers_autoprobe = auto_probe;
 648 }
 649
 650 /**
 651  * pci_iov_bus_range - find bus range used by Virtual Function
 652  * @bus: the PCI bus
 653  *
 654  * Returns max number of buses (exclude current one) used by Virtual
 655  * Functions.
 656  */
 657 int pci_iov_bus_range(struct pci_bus *bus)
 658 {
 659         int max = 0;
 660         struct pci_dev *dev;
 661
 662         list_for_each_entry(dev, &bus->devices, bus_list) {
 663                 if (!dev->is_physfn)
 664                         continue;
 665                 if (dev->sriov->max_VF_buses > max)
 666                         max = dev->sriov->max_VF_buses;
 667         }
 668
 669         return max ? max - bus->number : 0;
 670 }
 671
 672 /**
 673  * pci_enable_sriov - enable the SR-IOV capability
 674  * @dev: the PCI device
 675  * @nr_virtfn: number of virtual functions to enable
 676  *
 677  * Returns 0 on success, or negative on failure.
 678  */
 679 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 680 {
 681         might_sleep();
 682
 683         if (!dev->is_physfn)
 684                 return -ENOSYS;
 685
 686         return sriov_enable(dev, nr_virtfn);
 687 }
 688 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 689
 690 /**
 691  * pci_disable_sriov - disable the SR-IOV capability
 692  * @dev: the PCI device
 693  */
 694 void pci_disable_sriov(struct pci_dev *dev)
 695 {
 696         might_sleep();
 697
 698         if (!dev->is_physfn)
 699                 return;
 700
 701         sriov_disable(dev);
 702 }
 703 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 704
 705 /**
 706  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 707  * @dev: the PCI device
 708  *
 709  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 710  */
 711 int pci_num_vf(struct pci_dev *dev)
 712 {
 713         if (!dev->is_physfn)
 714                 return 0;
 715
 716         return dev->sriov->num_VFs;
 717 }
 718 EXPORT_SYMBOL_GPL(pci_num_vf);
 719
 720 /**
 721  * pci_vfs_assigned - returns number of VFs are assigned to a guest
 722  * @dev: the PCI device
 723  *
 724  * Returns number of VFs belonging to this device that are assigned to a guest.
 725  * If device is not a physical function returns 0.
 726  */
 727 int pci_vfs_assigned(struct pci_dev *dev)
 728 {
 729         struct pci_dev *vfdev;
 730         unsigned int vfs_assigned = 0;
 731         unsigned short dev_id;
 732
 733         /* only search if we are a PF */
 734         if (!dev->is_physfn)
 735                 return 0;
 736
 737         /*
 738          * determine the device ID for the VFs, the vendor ID will be the
 739          * same as the PF so there is no need to check for that one
 740          */
 741         dev_id = dev->sriov->vf_device;
 742
 743         /* loop through all the VFs to see if we own any that are assigned */
 744         vfdev = pci_get_device(dev->vendor, dev_id, NULL);
 745         while (vfdev) {
 746                 /*
 747                  * It is considered assigned if it is a virtual function with
 748                  * our dev as the physical function and the assigned bit is set
 749                  */
 750                 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
 751                         pci_is_dev_assigned(vfdev))
 752                         vfs_assigned++;
 753
 754                 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
 755         }
 756
 757         return vfs_assigned;
 758 }
 759 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
 760
 761 /**
 762  * pci_sriov_set_totalvfs -- reduce the TotalVFs available
 763  * @dev: the PCI PF device
 764  * @numvfs: number that should be used for TotalVFs supported
 765  *
 766  * Should be called from PF driver's probe routine with
 767  * device's mutex held.
 768  *
 769  * Returns 0 if PF is an SRIOV-capable device and
 770  * value of numvfs valid. If not a PF return -ENOSYS;
 771  * if numvfs is invalid return -EINVAL;
 772  * if VFs already enabled, return -EBUSY.
 773  */
 774 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
 775 {
 776         if (!dev->is_physfn)
 777                 return -ENOSYS;
 778         if (numvfs > dev->sriov->total_VFs)
 779                 return -EINVAL;
 780
 781         /* Shouldn't change if VFs already enabled */
 782         if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
 783                 return -EBUSY;
 784         else
 785                 dev->sriov->driver_max_VFs = numvfs;
 786
 787         return 0;
 788 }
 789 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
 790
 791 /**
 792  * pci_sriov_get_totalvfs -- get total VFs supported on this device
 793  * @dev: the PCI PF device
 794  *
 795  * For a PCIe device with SRIOV support, return the PCIe
 796  * SRIOV capability value of TotalVFs or the value of driver_max_VFs
 797  * if the driver reduced it.  Otherwise 0.
 798  */
 799 int pci_sriov_get_totalvfs(struct pci_dev *dev)
 800 {
 801         if (!dev->is_physfn)
 802                 return 0;
 803
 804         if (dev->sriov->driver_max_VFs)
 805                 return dev->sriov->driver_max_VFs;
 806
 807         return dev->sriov->total_VFs;
 808 }
 809 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);