drivers/pci/iov.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * PCI Express I/O Virtualization (IOV) support
   4  *   Single Root IOV 1.0
   5  *   Address Translation Service 1.0
   6  *
   7  * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com>
   8  */
   9
  10 #include <linux/pci.h>
  11 #include <linux/slab.h>
  12 #include <linux/mutex.h>
  13 #include <linux/export.h>
  14 #include <linux/string.h>
  15 #include <linux/delay.h>
  16 #include "pci.h"
  17
  18 #define VIRTFN_ID_LEN   16
  19
  20 int pci_iov_virtfn_bus(struct pci_dev *dev, int vf_id)
  21 {
  22         if (!dev->is_physfn)
  23                 return -EINVAL;
  24         return dev->bus->number + ((dev->devfn + dev->sriov->offset +
  25                                     dev->sriov->stride * vf_id) >> 8);
  26 }
  27
  28 int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id)
  29 {
  30         if (!dev->is_physfn)
  31                 return -EINVAL;
  32         return (dev->devfn + dev->sriov->offset +
  33                 dev->sriov->stride * vf_id) & 0xff;
  34 }
  35
  36 /*
  37  * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may
  38  * change when NumVFs changes.
  39  *
  40  * Update iov->offset and iov->stride when NumVFs is written.
  41  */
  42 static inline void pci_iov_set_numvfs(struct pci_dev *dev, int nr_virtfn)
  43 {
  44         struct pci_sriov *iov = dev->sriov;
  45
  46         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
  47         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &iov->offset);
  48         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &iov->stride);
  49 }
  50
  51 /*
  52  * The PF consumes one bus number.  NumVFs, First VF Offset, and VF Stride
  53  * determine how many additional bus numbers will be consumed by VFs.
  54  *
  55  * Iterate over all valid NumVFs, validate offset and stride, and calculate
  56  * the maximum number of bus numbers that could ever be required.
  57  */
  58 static int compute_max_vf_buses(struct pci_dev *dev)
  59 {
  60         struct pci_sriov *iov = dev->sriov;
  61         int nr_virtfn, busnr, rc = 0;
  62
  63         for (nr_virtfn = iov->total_VFs; nr_virtfn; nr_virtfn--) {
  64                 pci_iov_set_numvfs(dev, nr_virtfn);
  65                 if (!iov->offset || (nr_virtfn > 1 && !iov->stride)) {
  66                         rc = -EIO;
  67                         goto out;
  68                 }
  69
  70                 busnr = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
  71                 if (busnr > iov->max_VF_buses)
  72                         iov->max_VF_buses = busnr;
  73         }
  74
  75 out:
  76         pci_iov_set_numvfs(dev, 0);
  77         return rc;
  78 }
  79
  80 static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
  81 {
  82         struct pci_bus *child;
  83
  84         if (bus->number == busnr)
  85                 return bus;
  86
  87         child = pci_find_bus(pci_domain_nr(bus), busnr);
  88         if (child)
  89                 return child;
  90
  91         child = pci_add_new_bus(bus, NULL, busnr);
  92         if (!child)
  93                 return NULL;
  94
  95         pci_bus_insert_busn_res(child, busnr, busnr);
  96
  97         return child;
  98 }
  99
 100 static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus)
 101 {
 102         if (physbus != virtbus && list_empty(&virtbus->devices))
 103                 pci_remove_bus(virtbus);
 104 }
 105
 106 resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
 107 {
 108         if (!dev->is_physfn)
 109                 return 0;
 110
 111         return dev->sriov->barsz[resno - PCI_IOV_RESOURCES];
 112 }
 113
 114 static void pci_read_vf_config_common(struct pci_dev *virtfn)
 115 {
 116         struct pci_dev *physfn = virtfn->physfn;
 117
 118         /*
 119          * Some config registers are the same across all associated VFs.
 120          * Read them once from VF0 so we can skip reading them from the
 121          * other VFs.
 122          *
 123          * PCIe r4.0, sec 9.3.4.1, technically doesn't require all VFs to
 124          * have the same Revision ID and Subsystem ID, but we assume they
 125          * do.
 126          */
 127         pci_read_config_dword(virtfn, PCI_CLASS_REVISION,
 128                               &physfn->sriov->class);
 129         pci_read_config_byte(virtfn, PCI_HEADER_TYPE,
 130                              &physfn->sriov->hdr_type);
 131         pci_read_config_word(virtfn, PCI_SUBSYSTEM_VENDOR_ID,
 132                              &physfn->sriov->subsystem_vendor);
 133         pci_read_config_word(virtfn, PCI_SUBSYSTEM_ID,
 134                              &physfn->sriov->subsystem_device);
 135 }
 136
 137 int pci_iov_add_virtfn(struct pci_dev *dev, int id)
 138 {
 139         int i;
 140         int rc = -ENOMEM;
 141         u64 size;
 142         char buf[VIRTFN_ID_LEN];
 143         struct pci_dev *virtfn;
 144         struct resource *res;
 145         struct pci_sriov *iov = dev->sriov;
 146         struct pci_bus *bus;
 147
 148         bus = virtfn_add_bus(dev->bus, pci_iov_virtfn_bus(dev, id));
 149         if (!bus)
 150                 goto failed;
 151
 152         virtfn = pci_alloc_dev(bus);
 153         if (!virtfn)
 154                 goto failed0;
 155
 156         virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
 157         virtfn->vendor = dev->vendor;
 158         virtfn->device = iov->vf_device;
 159         virtfn->is_virtfn = 1;
 160         virtfn->physfn = pci_dev_get(dev);
 161
 162         if (id == 0)
 163                 pci_read_vf_config_common(virtfn);
 164
 165         rc = pci_setup_device(virtfn);
 166         if (rc)
 167                 goto failed1;
 168
 169         virtfn->dev.parent = dev->dev.parent;
 170         virtfn->multifunction = 0;
 171
 172         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 173                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 174                 if (!res->parent)
 175                         continue;
 176                 virtfn->resource[i].name = pci_name(virtfn);
 177                 virtfn->resource[i].flags = res->flags;
 178                 size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
 179                 virtfn->resource[i].start = res->start + size * id;
 180                 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
 181                 rc = request_resource(res, &virtfn->resource[i]);
 182                 BUG_ON(rc);
 183         }
 184
 185         pci_device_add(virtfn, virtfn->bus);
 186
 187         sprintf(buf, "virtfn%u", id);
 188         rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
 189         if (rc)
 190                 goto failed2;
 191         rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
 192         if (rc)
 193                 goto failed3;
 194
 195         kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
 196
 197         pci_bus_add_device(virtfn);
 198
 199         return 0;
 200
 201 failed3:
 202         sysfs_remove_link(&dev->dev.kobj, buf);
 203 failed2:
 204         pci_stop_and_remove_bus_device(virtfn);
 205 failed1:
 206         pci_dev_put(dev);
 207 failed0:
 208         virtfn_remove_bus(dev->bus, bus);
 209 failed:
 210
 211         return rc;
 212 }
 213
 214 void pci_iov_remove_virtfn(struct pci_dev *dev, int id)
 215 {
 216         char buf[VIRTFN_ID_LEN];
 217         struct pci_dev *virtfn;
 218
 219         virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
 220                                              pci_iov_virtfn_bus(dev, id),
 221                                              pci_iov_virtfn_devfn(dev, id));
 222         if (!virtfn)
 223                 return;
 224
 225         sprintf(buf, "virtfn%u", id);
 226         sysfs_remove_link(&dev->dev.kobj, buf);
 227         /*
 228          * pci_stop_dev() could have been called for this virtfn already,
 229          * so the directory for the virtfn may have been removed before.
 230          * Double check to avoid spurious sysfs warnings.
 231          */
 232         if (virtfn->dev.kobj.sd)
 233                 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
 234
 235         pci_stop_and_remove_bus_device(virtfn);
 236         virtfn_remove_bus(dev->bus, virtfn->bus);
 237
 238         /* balance pci_get_domain_bus_and_slot() */
 239         pci_dev_put(virtfn);
 240         pci_dev_put(dev);
 241 }
 242
 243 int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
 244 {
 245         return 0;
 246 }
 247
 248 int __weak pcibios_sriov_disable(struct pci_dev *pdev)
 249 {
 250         return 0;
 251 }
 252
 253 static int sriov_add_vfs(struct pci_dev *dev, u16 num_vfs)
 254 {
 255         unsigned int i;
 256         int rc;
 257
 258         if (dev->no_vf_scan)
 259                 return 0;
 260
 261         for (i = 0; i < num_vfs; i++) {
 262                 rc = pci_iov_add_virtfn(dev, i);
 263                 if (rc)
 264                         goto failed;
 265         }
 266         return 0;
 267 failed:
 268         while (i--)
 269                 pci_iov_remove_virtfn(dev, i);
 270
 271         return rc;
 272 }
 273
 274 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 275 {
 276         int rc;
 277         int i;
 278         int nres;
 279         u16 initial;
 280         struct resource *res;
 281         struct pci_dev *pdev;
 282         struct pci_sriov *iov = dev->sriov;
 283         int bars = 0;
 284         int bus;
 285
 286         if (!nr_virtfn)
 287                 return 0;
 288
 289         if (iov->num_VFs)
 290                 return -EINVAL;
 291
 292         pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
 293         if (initial > iov->total_VFs ||
 294             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
 295                 return -EIO;
 296
 297         if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
 298             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 299                 return -EINVAL;
 300
 301         nres = 0;
 302         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 303                 bars |= (1 << (i + PCI_IOV_RESOURCES));
 304                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 305                 if (res->parent)
 306                         nres++;
 307         }
 308         if (nres != iov->nres) {
 309                 pci_err(dev, "not enough MMIO resources for SR-IOV\n");
 310                 return -ENOMEM;
 311         }
 312
 313         bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
 314         if (bus > dev->bus->busn_res.end) {
 315                 pci_err(dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
 316                         nr_virtfn, bus, &dev->bus->busn_res);
 317                 return -ENOMEM;
 318         }
 319
 320         if (pci_enable_resources(dev, bars)) {
 321                 pci_err(dev, "SR-IOV: IOV BARS not allocated\n");
 322                 return -ENOMEM;
 323         }
 324
 325         if (iov->link != dev->devfn) {
 326                 pdev = pci_get_slot(dev->bus, iov->link);
 327                 if (!pdev)
 328                         return -ENODEV;
 329
 330                 if (!pdev->is_physfn) {
 331                         pci_dev_put(pdev);
 332                         return -ENOSYS;
 333                 }
 334
 335                 rc = sysfs_create_link(&dev->dev.kobj,
 336                                         &pdev->dev.kobj, "dep_link");
 337                 pci_dev_put(pdev);
 338                 if (rc)
 339                         return rc;
 340         }
 341
 342         iov->initial_VFs = initial;
 343         if (nr_virtfn < initial)
 344                 initial = nr_virtfn;
 345
 346         rc = pcibios_sriov_enable(dev, initial);
 347         if (rc) {
 348                 pci_err(dev, "failure %d from pcibios_sriov_enable()\n", rc);
 349                 goto err_pcibios;
 350         }
 351
 352         pci_iov_set_numvfs(dev, nr_virtfn);
 353         iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 354         pci_cfg_access_lock(dev);
 355         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 356         msleep(100);
 357         pci_cfg_access_unlock(dev);
 358
 359         rc = sriov_add_vfs(dev, initial);
 360         if (rc)
 361                 goto err_pcibios;
 362
 363         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 364         iov->num_VFs = nr_virtfn;
 365
 366         return 0;
 367
 368 err_pcibios:
 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         pcibios_sriov_disable(dev);
 376
 377         if (iov->link != dev->devfn)
 378                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 379
 380         pci_iov_set_numvfs(dev, 0);
 381         return rc;
 382 }
 383
 384 static void sriov_del_vfs(struct pci_dev *dev)
 385 {
 386         struct pci_sriov *iov = dev->sriov;
 387         int i;
 388
 389         if (dev->no_vf_scan)
 390                 return;
 391
 392         for (i = 0; i < iov->num_VFs; i++)
 393                 pci_iov_remove_virtfn(dev, i);
 394 }
 395
 396 static void sriov_disable(struct pci_dev *dev)
 397 {
 398         struct pci_sriov *iov = dev->sriov;
 399
 400         if (!iov->num_VFs)
 401                 return;
 402
 403         sriov_del_vfs(dev);
 404         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 405         pci_cfg_access_lock(dev);
 406         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 407         ssleep(1);
 408         pci_cfg_access_unlock(dev);
 409
 410         pcibios_sriov_disable(dev);
 411
 412         if (iov->link != dev->devfn)
 413                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 414
 415         iov->num_VFs = 0;
 416         pci_iov_set_numvfs(dev, 0);
 417 }
 418
 419 static int sriov_init(struct pci_dev *dev, int pos)
 420 {
 421         int i, bar64;
 422         int rc;
 423         int nres;
 424         u32 pgsz;
 425         u16 ctrl, total;
 426         struct pci_sriov *iov;
 427         struct resource *res;
 428         struct pci_dev *pdev;
 429
 430         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 431         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 432                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 433                 ssleep(1);
 434         }
 435
 436         ctrl = 0;
 437         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 438                 if (pdev->is_physfn)
 439                         goto found;
 440
 441         pdev = NULL;
 442         if (pci_ari_enabled(dev->bus))
 443                 ctrl |= PCI_SRIOV_CTRL_ARI;
 444
 445 found:
 446         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 447
 448         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 449         if (!total)
 450                 return 0;
 451
 452         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 453         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 454         pgsz &= ~((1 << i) - 1);
 455         if (!pgsz)
 456                 return -EIO;
 457
 458         pgsz &= ~(pgsz - 1);
 459         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 460
 461         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 462         if (!iov)
 463                 return -ENOMEM;
 464
 465         nres = 0;
 466         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 467                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 468                 /*
 469                  * If it is already FIXED, don't change it, something
 470                  * (perhaps EA or header fixups) wants it this way.
 471                  */
 472                 if (res->flags & IORESOURCE_PCI_FIXED)
 473                         bar64 = (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
 474                 else
 475                         bar64 = __pci_read_base(dev, pci_bar_unknown, res,
 476                                                 pos + PCI_SRIOV_BAR + i * 4);
 477                 if (!res->flags)
 478                         continue;
 479                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 480                         rc = -EIO;
 481                         goto failed;
 482                 }
 483                 iov->barsz[i] = resource_size(res);
 484                 res->end = res->start + resource_size(res) * total - 1;
 485                 pci_info(dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
 486                          i, res, i, total);
 487                 i += bar64;
 488                 nres++;
 489         }
 490
 491         iov->pos = pos;
 492         iov->nres = nres;
 493         iov->ctrl = ctrl;
 494         iov->total_VFs = total;
 495         iov->driver_max_VFs = total;
 496         pci_read_config_word(dev, pos + PCI_SRIOV_VF_DID, &iov->vf_device);
 497         iov->pgsz = pgsz;
 498         iov->self = dev;
 499         iov->drivers_autoprobe = true;
 500         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 501         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 502         if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
 503                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 504
 505         if (pdev)
 506                 iov->dev = pci_dev_get(pdev);
 507         else
 508                 iov->dev = dev;
 509
 510         dev->sriov = iov;
 511         dev->is_physfn = 1;
 512         rc = compute_max_vf_buses(dev);
 513         if (rc)
 514                 goto fail_max_buses;
 515
 516         return 0;
 517
 518 fail_max_buses:
 519         dev->sriov = NULL;
 520         dev->is_physfn = 0;
 521 failed:
 522         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 523                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 524                 res->flags = 0;
 525         }
 526
 527         kfree(iov);
 528         return rc;
 529 }
 530
 531 static void sriov_release(struct pci_dev *dev)
 532 {
 533         BUG_ON(dev->sriov->num_VFs);
 534
 535         if (dev != dev->sriov->dev)
 536                 pci_dev_put(dev->sriov->dev);
 537
 538         kfree(dev->sriov);
 539         dev->sriov = NULL;
 540 }
 541
 542 static void sriov_restore_state(struct pci_dev *dev)
 543 {
 544         int i;
 545         u16 ctrl;
 546         struct pci_sriov *iov = dev->sriov;
 547
 548         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 549         if (ctrl & PCI_SRIOV_CTRL_VFE)
 550                 return;
 551
 552         /*
 553          * Restore PCI_SRIOV_CTRL_ARI before pci_iov_set_numvfs() because
 554          * it reads offset & stride, which depend on PCI_SRIOV_CTRL_ARI.
 555          */
 556         ctrl &= ~PCI_SRIOV_CTRL_ARI;
 557         ctrl |= iov->ctrl & PCI_SRIOV_CTRL_ARI;
 558         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, ctrl);
 559
 560         for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
 561                 pci_update_resource(dev, i);
 562
 563         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 564         pci_iov_set_numvfs(dev, iov->num_VFs);
 565         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 566         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 567                 msleep(100);
 568 }
 569
 570 /**
 571  * pci_iov_init - initialize the IOV capability
 572  * @dev: the PCI device
 573  *
 574  * Returns 0 on success, or negative on failure.
 575  */
 576 int pci_iov_init(struct pci_dev *dev)
 577 {
 578         int pos;
 579
 580         if (!pci_is_pcie(dev))
 581                 return -ENODEV;
 582
 583         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 584         if (pos)
 585                 return sriov_init(dev, pos);
 586
 587         return -ENODEV;
 588 }
 589
 590 /**
 591  * pci_iov_release - release resources used by the IOV capability
 592  * @dev: the PCI device
 593  */
 594 void pci_iov_release(struct pci_dev *dev)
 595 {
 596         if (dev->is_physfn)
 597                 sriov_release(dev);
 598 }
 599
 600 /**
 601  * pci_iov_remove - clean up SR-IOV state after PF driver is detached
 602  * @dev: the PCI device
 603  */
 604 void pci_iov_remove(struct pci_dev *dev)
 605 {
 606         struct pci_sriov *iov = dev->sriov;
 607
 608         if (!dev->is_physfn)
 609                 return;
 610
 611         iov->driver_max_VFs = iov->total_VFs;
 612         if (iov->num_VFs)
 613                 pci_warn(dev, "driver left SR-IOV enabled after remove\n");
 614 }
 615
 616 /**
 617  * pci_iov_update_resource - update a VF BAR
 618  * @dev: the PCI device
 619  * @resno: the resource number
 620  *
 621  * Update a VF BAR in the SR-IOV capability of a PF.
 622  */
 623 void pci_iov_update_resource(struct pci_dev *dev, int resno)
 624 {
 625         struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL;
 626         struct resource *res = dev->resource + resno;
 627         int vf_bar = resno - PCI_IOV_RESOURCES;
 628         struct pci_bus_region region;
 629         u16 cmd;
 630         u32 new;
 631         int reg;
 632
 633         /*
 634          * The generic pci_restore_bars() path calls this for all devices,
 635          * including VFs and non-SR-IOV devices.  If this is not a PF, we
 636          * have nothing to do.
 637          */
 638         if (!iov)
 639                 return;
 640
 641         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &cmd);
 642         if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) {
 643                 dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n",
 644                          vf_bar, res);
 645                 return;
 646         }
 647
 648         /*
 649          * Ignore unimplemented BARs, unused resource slots for 64-bit
 650          * BARs, and non-movable resources, e.g., those described via
 651          * Enhanced Allocation.
 652          */
 653         if (!res->flags)
 654                 return;
 655
 656         if (res->flags & IORESOURCE_UNSET)
 657                 return;
 658
 659         if (res->flags & IORESOURCE_PCI_FIXED)
 660                 return;
 661
 662         pcibios_resource_to_bus(dev->bus, &region, res);
 663         new = region.start;
 664         new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
 665
 666         reg = iov->pos + PCI_SRIOV_BAR + 4 * vf_bar;
 667         pci_write_config_dword(dev, reg, new);
 668         if (res->flags & IORESOURCE_MEM_64) {
 669                 new = region.start >> 16 >> 16;
 670                 pci_write_config_dword(dev, reg + 4, new);
 671         }
 672 }
 673
 674 resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
 675                                                       int resno)
 676 {
 677         return pci_iov_resource_size(dev, resno);
 678 }
 679
 680 /**
 681  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 682  * @dev: the PCI device
 683  * @resno: the resource number
 684  *
 685  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 686  * This is not the same as the resource size which is defined as
 687  * the VF BAR size multiplied by the number of VFs.  The alignment
 688  * is just the VF BAR size.
 689  */
 690 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 691 {
 692         return pcibios_iov_resource_alignment(dev, resno);
 693 }
 694
 695 /**
 696  * pci_restore_iov_state - restore the state of the IOV capability
 697  * @dev: the PCI device
 698  */
 699 void pci_restore_iov_state(struct pci_dev *dev)
 700 {
 701         if (dev->is_physfn)
 702                 sriov_restore_state(dev);
 703 }
 704
 705 /**
 706  * pci_vf_drivers_autoprobe - set PF property drivers_autoprobe for VFs
 707  * @dev: the PCI device
 708  * @auto_probe: set VF drivers auto probe flag
 709  */
 710 void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool auto_probe)
 711 {
 712         if (dev->is_physfn)
 713                 dev->sriov->drivers_autoprobe = auto_probe;
 714 }
 715
 716 /**
 717  * pci_iov_bus_range - find bus range used by Virtual Function
 718  * @bus: the PCI bus
 719  *
 720  * Returns max number of buses (exclude current one) used by Virtual
 721  * Functions.
 722  */
 723 int pci_iov_bus_range(struct pci_bus *bus)
 724 {
 725         int max = 0;
 726         struct pci_dev *dev;
 727
 728         list_for_each_entry(dev, &bus->devices, bus_list) {
 729                 if (!dev->is_physfn)
 730                         continue;
 731                 if (dev->sriov->max_VF_buses > max)
 732                         max = dev->sriov->max_VF_buses;
 733         }
 734
 735         return max ? max - bus->number : 0;
 736 }
 737
 738 /**
 739  * pci_enable_sriov - enable the SR-IOV capability
 740  * @dev: the PCI device
 741  * @nr_virtfn: number of virtual functions to enable
 742  *
 743  * Returns 0 on success, or negative on failure.
 744  */
 745 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 746 {
 747         might_sleep();
 748
 749         if (!dev->is_physfn)
 750                 return -ENOSYS;
 751
 752         return sriov_enable(dev, nr_virtfn);
 753 }
 754 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 755
 756 /**
 757  * pci_disable_sriov - disable the SR-IOV capability
 758  * @dev: the PCI device
 759  */
 760 void pci_disable_sriov(struct pci_dev *dev)
 761 {
 762         might_sleep();
 763
 764         if (!dev->is_physfn)
 765                 return;
 766
 767         sriov_disable(dev);
 768 }
 769 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 770
 771 /**
 772  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 773  * @dev: the PCI device
 774  *
 775  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 776  */
 777 int pci_num_vf(struct pci_dev *dev)
 778 {
 779         if (!dev->is_physfn)
 780                 return 0;
 781
 782         return dev->sriov->num_VFs;
 783 }
 784 EXPORT_SYMBOL_GPL(pci_num_vf);
 785
 786 /**
 787  * pci_vfs_assigned - returns number of VFs are assigned to a guest
 788  * @dev: the PCI device
 789  *
 790  * Returns number of VFs belonging to this device that are assigned to a guest.
 791  * If device is not a physical function returns 0.
 792  */
 793 int pci_vfs_assigned(struct pci_dev *dev)
 794 {
 795         struct pci_dev *vfdev;
 796         unsigned int vfs_assigned = 0;
 797         unsigned short dev_id;
 798
 799         /* only search if we are a PF */
 800         if (!dev->is_physfn)
 801                 return 0;
 802
 803         /*
 804          * determine the device ID for the VFs, the vendor ID will be the
 805          * same as the PF so there is no need to check for that one
 806          */
 807         dev_id = dev->sriov->vf_device;
 808
 809         /* loop through all the VFs to see if we own any that are assigned */
 810         vfdev = pci_get_device(dev->vendor, dev_id, NULL);
 811         while (vfdev) {
 812                 /*
 813                  * It is considered assigned if it is a virtual function with
 814                  * our dev as the physical function and the assigned bit is set
 815                  */
 816                 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
 817                         pci_is_dev_assigned(vfdev))
 818                         vfs_assigned++;
 819
 820                 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
 821         }
 822
 823         return vfs_assigned;
 824 }
 825 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
 826
 827 /**
 828  * pci_sriov_set_totalvfs -- reduce the TotalVFs available
 829  * @dev: the PCI PF device
 830  * @numvfs: number that should be used for TotalVFs supported
 831  *
 832  * Should be called from PF driver's probe routine with
 833  * device's mutex held.
 834  *
 835  * Returns 0 if PF is an SRIOV-capable device and
 836  * value of numvfs valid. If not a PF return -ENOSYS;
 837  * if numvfs is invalid return -EINVAL;
 838  * if VFs already enabled, return -EBUSY.
 839  */
 840 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
 841 {
 842         if (!dev->is_physfn)
 843                 return -ENOSYS;
 844
 845         if (numvfs > dev->sriov->total_VFs)
 846                 return -EINVAL;
 847
 848         /* Shouldn't change if VFs already enabled */
 849         if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
 850                 return -EBUSY;
 851
 852         dev->sriov->driver_max_VFs = numvfs;
 853         return 0;
 854 }
 855 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
 856
 857 /**
 858  * pci_sriov_get_totalvfs -- get total VFs supported on this device
 859  * @dev: the PCI PF device
 860  *
 861  * For a PCIe device with SRIOV support, return the PCIe
 862  * SRIOV capability value of TotalVFs or the value of driver_max_VFs
 863  * if the driver reduced it.  Otherwise 0.
 864  */
 865 int pci_sriov_get_totalvfs(struct pci_dev *dev)
 866 {
 867         if (!dev->is_physfn)
 868                 return 0;
 869
 870         return dev->sriov->driver_max_VFs;
 871 }
 872 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);
 873
 874 /**
 875  * pci_sriov_configure_simple - helper to configure SR-IOV
 876  * @dev: the PCI device
 877  * @nr_virtfn: number of virtual functions to enable, 0 to disable
 878  *
 879  * Enable or disable SR-IOV for devices that don't require any PF setup
 880  * before enabling SR-IOV.  Return value is negative on error, or number of
 881  * VFs allocated on success.
 882  */
 883 int pci_sriov_configure_simple(struct pci_dev *dev, int nr_virtfn)
 884 {
 885         int rc;
 886
 887         might_sleep();
 888
 889         if (!dev->is_physfn)
 890                 return -ENODEV;
 891
 892         if (pci_vfs_assigned(dev)) {
 893                 pci_warn(dev, "Cannot modify SR-IOV while VFs are assigned\n");
 894                 return -EPERM;
 895         }
 896
 897         if (nr_virtfn == 0) {
 898                 sriov_disable(dev);
 899                 return 0;
 900         }
 901
 902         rc = sriov_enable(dev, nr_virtfn);
 903         if (rc < 0)
 904                 return rc;
 905
 906         return nr_virtfn;
 907 }
 908 EXPORT_SYMBOL_GPL(pci_sriov_configure_simple);