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 <linux/pci-ats.h>
  17 #include "pci.h"
  18
  19 #define VIRTFN_ID_LEN   16
  20
  21 int pci_iov_virtfn_bus(struct pci_dev *dev, int vf_id)
  22 {
  23         if (!dev->is_physfn)
  24                 return -EINVAL;
  25         return dev->bus->number + ((dev->devfn + dev->sriov->offset +
  26                                     dev->sriov->stride * vf_id) >> 8);
  27 }
  28
  29 int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id)
  30 {
  31         if (!dev->is_physfn)
  32                 return -EINVAL;
  33         return (dev->devfn + dev->sriov->offset +
  34                 dev->sriov->stride * vf_id) & 0xff;
  35 }
  36
  37 /*
  38  * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may
  39  * change when NumVFs changes.
  40  *
  41  * Update iov->offset and iov->stride when NumVFs is written.
  42  */
  43 static inline void pci_iov_set_numvfs(struct pci_dev *dev, int nr_virtfn)
  44 {
  45         struct pci_sriov *iov = dev->sriov;
  46
  47         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
  48         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &iov->offset);
  49         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &iov->stride);
  50 }
  51
  52 /*
  53  * The PF consumes one bus number.  NumVFs, First VF Offset, and VF Stride
  54  * determine how many additional bus numbers will be consumed by VFs.
  55  *
  56  * Iterate over all valid NumVFs, validate offset and stride, and calculate
  57  * the maximum number of bus numbers that could ever be required.
  58  */
  59 static int compute_max_vf_buses(struct pci_dev *dev)
  60 {
  61         struct pci_sriov *iov = dev->sriov;
  62         int nr_virtfn, busnr, rc = 0;
  63
  64         for (nr_virtfn = iov->total_VFs; nr_virtfn; nr_virtfn--) {
  65                 pci_iov_set_numvfs(dev, nr_virtfn);
  66                 if (!iov->offset || (nr_virtfn > 1 && !iov->stride)) {
  67                         rc = -EIO;
  68                         goto out;
  69                 }
  70
  71                 busnr = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
  72                 if (busnr > iov->max_VF_buses)
  73                         iov->max_VF_buses = busnr;
  74         }
  75
  76 out:
  77         pci_iov_set_numvfs(dev, 0);
  78         return rc;
  79 }
  80
  81 static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
  82 {
  83         struct pci_bus *child;
  84
  85         if (bus->number == busnr)
  86                 return bus;
  87
  88         child = pci_find_bus(pci_domain_nr(bus), busnr);
  89         if (child)
  90                 return child;
  91
  92         child = pci_add_new_bus(bus, NULL, busnr);
  93         if (!child)
  94                 return NULL;
  95
  96         pci_bus_insert_busn_res(child, busnr, busnr);
  97
  98         return child;
  99 }
 100
 101 static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus)
 102 {
 103         if (physbus != virtbus && list_empty(&virtbus->devices))
 104                 pci_remove_bus(virtbus);
 105 }
 106
 107 resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
 108 {
 109         if (!dev->is_physfn)
 110                 return 0;
 111
 112         return dev->sriov->barsz[resno - PCI_IOV_RESOURCES];
 113 }
 114
 115 static void pci_read_vf_config_common(struct pci_dev *virtfn)
 116 {
 117         struct pci_dev *physfn = virtfn->physfn;
 118
 119         /*
 120          * Some config registers are the same across all associated VFs.
 121          * Read them once from VF0 so we can skip reading them from the
 122          * other VFs.
 123          *
 124          * PCIe r4.0, sec 9.3.4.1, technically doesn't require all VFs to
 125          * have the same Revision ID and Subsystem ID, but we assume they
 126          * do.
 127          */
 128         pci_read_config_dword(virtfn, PCI_CLASS_REVISION,
 129                               &physfn->sriov->class);
 130         pci_read_config_byte(virtfn, PCI_HEADER_TYPE,
 131                              &physfn->sriov->hdr_type);
 132         pci_read_config_word(virtfn, PCI_SUBSYSTEM_VENDOR_ID,
 133                              &physfn->sriov->subsystem_vendor);
 134         pci_read_config_word(virtfn, PCI_SUBSYSTEM_ID,
 135                              &physfn->sriov->subsystem_device);
 136 }
 137
 138 int pci_iov_add_virtfn(struct pci_dev *dev, int id)
 139 {
 140         int i;
 141         int rc = -ENOMEM;
 142         u64 size;
 143         char buf[VIRTFN_ID_LEN];
 144         struct pci_dev *virtfn;
 145         struct resource *res;
 146         struct pci_sriov *iov = dev->sriov;
 147         struct pci_bus *bus;
 148
 149         bus = virtfn_add_bus(dev->bus, pci_iov_virtfn_bus(dev, id));
 150         if (!bus)
 151                 goto failed;
 152
 153         virtfn = pci_alloc_dev(bus);
 154         if (!virtfn)
 155                 goto failed0;
 156
 157         virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
 158         virtfn->vendor = dev->vendor;
 159         virtfn->device = iov->vf_device;
 160         virtfn->is_virtfn = 1;
 161         virtfn->physfn = pci_dev_get(dev);
 162
 163         if (id == 0)
 164                 pci_read_vf_config_common(virtfn);
 165
 166         rc = pci_setup_device(virtfn);
 167         if (rc)
 168                 goto failed1;
 169
 170         virtfn->dev.parent = dev->dev.parent;
 171         virtfn->multifunction = 0;
 172
 173         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 174                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 175                 if (!res->parent)
 176                         continue;
 177                 virtfn->resource[i].name = pci_name(virtfn);
 178                 virtfn->resource[i].flags = res->flags;
 179                 size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
 180                 virtfn->resource[i].start = res->start + size * id;
 181                 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
 182                 rc = request_resource(res, &virtfn->resource[i]);
 183                 BUG_ON(rc);
 184         }
 185
 186         pci_device_add(virtfn, virtfn->bus);
 187
 188         sprintf(buf, "virtfn%u", id);
 189         rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
 190         if (rc)
 191                 goto failed2;
 192         rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
 193         if (rc)
 194                 goto failed3;
 195
 196         kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
 197
 198         pci_bus_add_device(virtfn);
 199
 200         return 0;
 201
 202 failed3:
 203         sysfs_remove_link(&dev->dev.kobj, buf);
 204 failed2:
 205         pci_stop_and_remove_bus_device(virtfn);
 206 failed1:
 207         pci_dev_put(dev);
 208 failed0:
 209         virtfn_remove_bus(dev->bus, bus);
 210 failed:
 211
 212         return rc;
 213 }
 214
 215 void pci_iov_remove_virtfn(struct pci_dev *dev, int id)
 216 {
 217         char buf[VIRTFN_ID_LEN];
 218         struct pci_dev *virtfn;
 219
 220         virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
 221                                              pci_iov_virtfn_bus(dev, id),
 222                                              pci_iov_virtfn_devfn(dev, id));
 223         if (!virtfn)
 224                 return;
 225
 226         sprintf(buf, "virtfn%u", id);
 227         sysfs_remove_link(&dev->dev.kobj, buf);
 228         /*
 229          * pci_stop_dev() could have been called for this virtfn already,
 230          * so the directory for the virtfn may have been removed before.
 231          * Double check to avoid spurious sysfs warnings.
 232          */
 233         if (virtfn->dev.kobj.sd)
 234                 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
 235
 236         pci_stop_and_remove_bus_device(virtfn);
 237         virtfn_remove_bus(dev->bus, virtfn->bus);
 238
 239         /* balance pci_get_domain_bus_and_slot() */
 240         pci_dev_put(virtfn);
 241         pci_dev_put(dev);
 242 }
 243
 244 int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
 245 {
 246         return 0;
 247 }
 248
 249 int __weak pcibios_sriov_disable(struct pci_dev *pdev)
 250 {
 251         return 0;
 252 }
 253
 254 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 255 {
 256         int rc;
 257         int i;
 258         int nres;
 259         u16 initial;
 260         struct resource *res;
 261         struct pci_dev *pdev;
 262         struct pci_sriov *iov = dev->sriov;
 263         int bars = 0;
 264         int bus;
 265
 266         if (!nr_virtfn)
 267                 return 0;
 268
 269         if (iov->num_VFs)
 270                 return -EINVAL;
 271
 272         pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
 273         if (initial > iov->total_VFs ||
 274             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
 275                 return -EIO;
 276
 277         if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
 278             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 279                 return -EINVAL;
 280
 281         nres = 0;
 282         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 283                 bars |= (1 << (i + PCI_IOV_RESOURCES));
 284                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 285                 if (res->parent)
 286                         nres++;
 287         }
 288         if (nres != iov->nres) {
 289                 pci_err(dev, "not enough MMIO resources for SR-IOV\n");
 290                 return -ENOMEM;
 291         }
 292
 293         bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
 294         if (bus > dev->bus->busn_res.end) {
 295                 pci_err(dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
 296                         nr_virtfn, bus, &dev->bus->busn_res);
 297                 return -ENOMEM;
 298         }
 299
 300         if (pci_enable_resources(dev, bars)) {
 301                 pci_err(dev, "SR-IOV: IOV BARS not allocated\n");
 302                 return -ENOMEM;
 303         }
 304
 305         if (iov->link != dev->devfn) {
 306                 pdev = pci_get_slot(dev->bus, iov->link);
 307                 if (!pdev)
 308                         return -ENODEV;
 309
 310                 if (!pdev->is_physfn) {
 311                         pci_dev_put(pdev);
 312                         return -ENOSYS;
 313                 }
 314
 315                 rc = sysfs_create_link(&dev->dev.kobj,
 316                                         &pdev->dev.kobj, "dep_link");
 317                 pci_dev_put(pdev);
 318                 if (rc)
 319                         return rc;
 320         }
 321
 322         iov->initial_VFs = initial;
 323         if (nr_virtfn < initial)
 324                 initial = nr_virtfn;
 325
 326         rc = pcibios_sriov_enable(dev, initial);
 327         if (rc) {
 328                 pci_err(dev, "failure %d from pcibios_sriov_enable()\n", rc);
 329                 goto err_pcibios;
 330         }
 331
 332         pci_iov_set_numvfs(dev, nr_virtfn);
 333         iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 334         pci_cfg_access_lock(dev);
 335         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 336         msleep(100);
 337         pci_cfg_access_unlock(dev);
 338
 339         for (i = 0; i < initial; i++) {
 340                 rc = pci_iov_add_virtfn(dev, i);
 341                 if (rc)
 342                         goto failed;
 343         }
 344
 345         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 346         iov->num_VFs = nr_virtfn;
 347
 348         return 0;
 349
 350 failed:
 351         while (i--)
 352                 pci_iov_remove_virtfn(dev, i);
 353
 354 err_pcibios:
 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         pci_iov_set_numvfs(dev, 0);
 367         return rc;
 368 }
 369
 370 static void sriov_disable(struct pci_dev *dev)
 371 {
 372         int i;
 373         struct pci_sriov *iov = dev->sriov;
 374
 375         if (!iov->num_VFs)
 376                 return;
 377
 378         for (i = 0; i < iov->num_VFs; i++)
 379                 pci_iov_remove_virtfn(dev, i);
 380
 381         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 382         pci_cfg_access_lock(dev);
 383         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 384         ssleep(1);
 385         pci_cfg_access_unlock(dev);
 386
 387         pcibios_sriov_disable(dev);
 388
 389         if (iov->link != dev->devfn)
 390                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 391
 392         iov->num_VFs = 0;
 393         pci_iov_set_numvfs(dev, 0);
 394 }
 395
 396 static int sriov_init(struct pci_dev *dev, int pos)
 397 {
 398         int i, bar64;
 399         int rc;
 400         int nres;
 401         u32 pgsz;
 402         u16 ctrl, total;
 403         struct pci_sriov *iov;
 404         struct resource *res;
 405         struct pci_dev *pdev;
 406
 407         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 408         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 409                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 410                 ssleep(1);
 411         }
 412
 413         ctrl = 0;
 414         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 415                 if (pdev->is_physfn)
 416                         goto found;
 417
 418         pdev = NULL;
 419         if (pci_ari_enabled(dev->bus))
 420                 ctrl |= PCI_SRIOV_CTRL_ARI;
 421
 422 found:
 423         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 424
 425         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 426         if (!total)
 427                 return 0;
 428
 429         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 430         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 431         pgsz &= ~((1 << i) - 1);
 432         if (!pgsz)
 433                 return -EIO;
 434
 435         pgsz &= ~(pgsz - 1);
 436         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 437
 438         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 439         if (!iov)
 440                 return -ENOMEM;
 441
 442         nres = 0;
 443         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 444                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 445                 /*
 446                  * If it is already FIXED, don't change it, something
 447                  * (perhaps EA or header fixups) wants it this way.
 448                  */
 449                 if (res->flags & IORESOURCE_PCI_FIXED)
 450                         bar64 = (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
 451                 else
 452                         bar64 = __pci_read_base(dev, pci_bar_unknown, res,
 453                                                 pos + PCI_SRIOV_BAR + i * 4);
 454                 if (!res->flags)
 455                         continue;
 456                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 457                         rc = -EIO;
 458                         goto failed;
 459                 }
 460                 iov->barsz[i] = resource_size(res);
 461                 res->end = res->start + resource_size(res) * total - 1;
 462                 pci_info(dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
 463                          i, res, i, total);
 464                 i += bar64;
 465                 nres++;
 466         }
 467
 468         iov->pos = pos;
 469         iov->nres = nres;
 470         iov->ctrl = ctrl;
 471         iov->total_VFs = total;
 472         iov->driver_max_VFs = total;
 473         pci_read_config_word(dev, pos + PCI_SRIOV_VF_DID, &iov->vf_device);
 474         iov->pgsz = pgsz;
 475         iov->self = dev;
 476         iov->drivers_autoprobe = true;
 477         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 478         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 479         if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
 480                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 481
 482         if (pdev)
 483                 iov->dev = pci_dev_get(pdev);
 484         else
 485                 iov->dev = dev;
 486
 487         dev->sriov = iov;
 488         dev->is_physfn = 1;
 489         rc = compute_max_vf_buses(dev);
 490         if (rc)
 491                 goto fail_max_buses;
 492
 493         return 0;
 494
 495 fail_max_buses:
 496         dev->sriov = NULL;
 497         dev->is_physfn = 0;
 498 failed:
 499         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 500                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 501                 res->flags = 0;
 502         }
 503
 504         kfree(iov);
 505         return rc;
 506 }
 507
 508 static void sriov_release(struct pci_dev *dev)
 509 {
 510         BUG_ON(dev->sriov->num_VFs);
 511
 512         if (dev != dev->sriov->dev)
 513                 pci_dev_put(dev->sriov->dev);
 514
 515         kfree(dev->sriov);
 516         dev->sriov = NULL;
 517 }
 518
 519 static void sriov_restore_state(struct pci_dev *dev)
 520 {
 521         int i;
 522         u16 ctrl;
 523         struct pci_sriov *iov = dev->sriov;
 524
 525         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 526         if (ctrl & PCI_SRIOV_CTRL_VFE)
 527                 return;
 528
 529         /*
 530          * Restore PCI_SRIOV_CTRL_ARI before pci_iov_set_numvfs() because
 531          * it reads offset & stride, which depend on PCI_SRIOV_CTRL_ARI.
 532          */
 533         ctrl &= ~PCI_SRIOV_CTRL_ARI;
 534         ctrl |= iov->ctrl & PCI_SRIOV_CTRL_ARI;
 535         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, ctrl);
 536
 537         for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
 538                 pci_update_resource(dev, i);
 539
 540         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 541         pci_iov_set_numvfs(dev, iov->num_VFs);
 542         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 543         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 544                 msleep(100);
 545 }
 546
 547 /**
 548  * pci_iov_init - initialize the IOV capability
 549  * @dev: the PCI device
 550  *
 551  * Returns 0 on success, or negative on failure.
 552  */
 553 int pci_iov_init(struct pci_dev *dev)
 554 {
 555         int pos;
 556
 557         if (!pci_is_pcie(dev))
 558                 return -ENODEV;
 559
 560         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 561         if (pos)
 562                 return sriov_init(dev, pos);
 563
 564         return -ENODEV;
 565 }
 566
 567 /**
 568  * pci_iov_release - release resources used by the IOV capability
 569  * @dev: the PCI device
 570  */
 571 void pci_iov_release(struct pci_dev *dev)
 572 {
 573         if (dev->is_physfn)
 574                 sriov_release(dev);
 575 }
 576
 577 /**
 578  * pci_iov_remove - clean up SR-IOV state after PF driver is detached
 579  * @dev: the PCI device
 580  */
 581 void pci_iov_remove(struct pci_dev *dev)
 582 {
 583         struct pci_sriov *iov = dev->sriov;
 584
 585         if (!dev->is_physfn)
 586                 return;
 587
 588         iov->driver_max_VFs = iov->total_VFs;
 589         if (iov->num_VFs)
 590                 pci_warn(dev, "driver left SR-IOV enabled after remove\n");
 591 }
 592
 593 /**
 594  * pci_iov_update_resource - update a VF BAR
 595  * @dev: the PCI device
 596  * @resno: the resource number
 597  *
 598  * Update a VF BAR in the SR-IOV capability of a PF.
 599  */
 600 void pci_iov_update_resource(struct pci_dev *dev, int resno)
 601 {
 602         struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL;
 603         struct resource *res = dev->resource + resno;
 604         int vf_bar = resno - PCI_IOV_RESOURCES;
 605         struct pci_bus_region region;
 606         u16 cmd;
 607         u32 new;
 608         int reg;
 609
 610         /*
 611          * The generic pci_restore_bars() path calls this for all devices,
 612          * including VFs and non-SR-IOV devices.  If this is not a PF, we
 613          * have nothing to do.
 614          */
 615         if (!iov)
 616                 return;
 617
 618         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &cmd);
 619         if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) {
 620                 dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n",
 621                          vf_bar, res);
 622                 return;
 623         }
 624
 625         /*
 626          * Ignore unimplemented BARs, unused resource slots for 64-bit
 627          * BARs, and non-movable resources, e.g., those described via
 628          * Enhanced Allocation.
 629          */
 630         if (!res->flags)
 631                 return;
 632
 633         if (res->flags & IORESOURCE_UNSET)
 634                 return;
 635
 636         if (res->flags & IORESOURCE_PCI_FIXED)
 637                 return;
 638
 639         pcibios_resource_to_bus(dev->bus, &region, res);
 640         new = region.start;
 641         new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
 642
 643         reg = iov->pos + PCI_SRIOV_BAR + 4 * vf_bar;
 644         pci_write_config_dword(dev, reg, new);
 645         if (res->flags & IORESOURCE_MEM_64) {
 646                 new = region.start >> 16 >> 16;
 647                 pci_write_config_dword(dev, reg + 4, new);
 648         }
 649 }
 650
 651 resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
 652                                                       int resno)
 653 {
 654         return pci_iov_resource_size(dev, resno);
 655 }
 656
 657 /**
 658  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 659  * @dev: the PCI device
 660  * @resno: the resource number
 661  *
 662  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 663  * This is not the same as the resource size which is defined as
 664  * the VF BAR size multiplied by the number of VFs.  The alignment
 665  * is just the VF BAR size.
 666  */
 667 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 668 {
 669         return pcibios_iov_resource_alignment(dev, resno);
 670 }
 671
 672 /**
 673  * pci_restore_iov_state - restore the state of the IOV capability
 674  * @dev: the PCI device
 675  */
 676 void pci_restore_iov_state(struct pci_dev *dev)
 677 {
 678         if (dev->is_physfn)
 679                 sriov_restore_state(dev);
 680 }
 681
 682 /**
 683  * pci_vf_drivers_autoprobe - set PF property drivers_autoprobe for VFs
 684  * @dev: the PCI device
 685  * @auto_probe: set VF drivers auto probe flag
 686  */
 687 void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool auto_probe)
 688 {
 689         if (dev->is_physfn)
 690                 dev->sriov->drivers_autoprobe = auto_probe;
 691 }
 692
 693 /**
 694  * pci_iov_bus_range - find bus range used by Virtual Function
 695  * @bus: the PCI bus
 696  *
 697  * Returns max number of buses (exclude current one) used by Virtual
 698  * Functions.
 699  */
 700 int pci_iov_bus_range(struct pci_bus *bus)
 701 {
 702         int max = 0;
 703         struct pci_dev *dev;
 704
 705         list_for_each_entry(dev, &bus->devices, bus_list) {
 706                 if (!dev->is_physfn)
 707                         continue;
 708                 if (dev->sriov->max_VF_buses > max)
 709                         max = dev->sriov->max_VF_buses;
 710         }
 711
 712         return max ? max - bus->number : 0;
 713 }
 714
 715 /**
 716  * pci_enable_sriov - enable the SR-IOV capability
 717  * @dev: the PCI device
 718  * @nr_virtfn: number of virtual functions to enable
 719  *
 720  * Returns 0 on success, or negative on failure.
 721  */
 722 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 723 {
 724         might_sleep();
 725
 726         if (!dev->is_physfn)
 727                 return -ENOSYS;
 728
 729         return sriov_enable(dev, nr_virtfn);
 730 }
 731 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 732
 733 /**
 734  * pci_disable_sriov - disable the SR-IOV capability
 735  * @dev: the PCI device
 736  */
 737 void pci_disable_sriov(struct pci_dev *dev)
 738 {
 739         might_sleep();
 740
 741         if (!dev->is_physfn)
 742                 return;
 743
 744         sriov_disable(dev);
 745 }
 746 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 747
 748 /**
 749  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 750  * @dev: the PCI device
 751  *
 752  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 753  */
 754 int pci_num_vf(struct pci_dev *dev)
 755 {
 756         if (!dev->is_physfn)
 757                 return 0;
 758
 759         return dev->sriov->num_VFs;
 760 }
 761 EXPORT_SYMBOL_GPL(pci_num_vf);
 762
 763 /**
 764  * pci_vfs_assigned - returns number of VFs are assigned to a guest
 765  * @dev: the PCI device
 766  *
 767  * Returns number of VFs belonging to this device that are assigned to a guest.
 768  * If device is not a physical function returns 0.
 769  */
 770 int pci_vfs_assigned(struct pci_dev *dev)
 771 {
 772         struct pci_dev *vfdev;
 773         unsigned int vfs_assigned = 0;
 774         unsigned short dev_id;
 775
 776         /* only search if we are a PF */
 777         if (!dev->is_physfn)
 778                 return 0;
 779
 780         /*
 781          * determine the device ID for the VFs, the vendor ID will be the
 782          * same as the PF so there is no need to check for that one
 783          */
 784         dev_id = dev->sriov->vf_device;
 785
 786         /* loop through all the VFs to see if we own any that are assigned */
 787         vfdev = pci_get_device(dev->vendor, dev_id, NULL);
 788         while (vfdev) {
 789                 /*
 790                  * It is considered assigned if it is a virtual function with
 791                  * our dev as the physical function and the assigned bit is set
 792                  */
 793                 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
 794                         pci_is_dev_assigned(vfdev))
 795                         vfs_assigned++;
 796
 797                 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
 798         }
 799
 800         return vfs_assigned;
 801 }
 802 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
 803
 804 /**
 805  * pci_sriov_set_totalvfs -- reduce the TotalVFs available
 806  * @dev: the PCI PF device
 807  * @numvfs: number that should be used for TotalVFs supported
 808  *
 809  * Should be called from PF driver's probe routine with
 810  * device's mutex held.
 811  *
 812  * Returns 0 if PF is an SRIOV-capable device and
 813  * value of numvfs valid. If not a PF return -ENOSYS;
 814  * if numvfs is invalid return -EINVAL;
 815  * if VFs already enabled, return -EBUSY.
 816  */
 817 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
 818 {
 819         if (!dev->is_physfn)
 820                 return -ENOSYS;
 821         if (numvfs > dev->sriov->total_VFs)
 822                 return -EINVAL;
 823
 824         /* Shouldn't change if VFs already enabled */
 825         if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
 826                 return -EBUSY;
 827         else
 828                 dev->sriov->driver_max_VFs = numvfs;
 829
 830         return 0;
 831 }
 832 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
 833
 834 /**
 835  * pci_sriov_get_totalvfs -- get total VFs supported on this device
 836  * @dev: the PCI PF device
 837  *
 838  * For a PCIe device with SRIOV support, return the PCIe
 839  * SRIOV capability value of TotalVFs or the value of driver_max_VFs
 840  * if the driver reduced it.  Otherwise 0.
 841  */
 842 int pci_sriov_get_totalvfs(struct pci_dev *dev)
 843 {
 844         if (!dev->is_physfn)
 845                 return 0;
 846
 847         return dev->sriov->driver_max_VFs;
 848 }
 849 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);
 850
 851 /**
 852  * pci_sriov_configure_simple - helper to configure SR-IOV
 853  * @dev: the PCI device
 854  * @nr_virtfn: number of virtual functions to enable, 0 to disable
 855  *
 856  * Enable or disable SR-IOV for devices that don't require any PF setup
 857  * before enabling SR-IOV.  Return value is negative on error, or number of
 858  * VFs allocated on success.
 859  */
 860 int pci_sriov_configure_simple(struct pci_dev *dev, int nr_virtfn)
 861 {
 862         int rc;
 863
 864         might_sleep();
 865
 866         if (!dev->is_physfn)
 867                 return -ENODEV;
 868
 869         if (pci_vfs_assigned(dev)) {
 870                 pci_warn(dev, "Cannot modify SR-IOV while VFs are assigned\n");
 871                 return -EPERM;
 872         }
 873
 874         if (nr_virtfn == 0) {
 875                 sriov_disable(dev);
 876                 return 0;
 877         }
 878
 879         rc = sriov_enable(dev, nr_virtfn);
 880         if (rc < 0)
 881                 return rc;
 882
 883         return nr_virtfn;
 884 }
 885 EXPORT_SYMBOL_GPL(pci_sriov_configure_simple);