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         physfn->sriov->cfg_size = pci_cfg_space_size(virtfn);
 137 }
 138
 139 int pci_iov_add_virtfn(struct pci_dev *dev, int id)
 140 {
 141         int i;
 142         int rc = -ENOMEM;
 143         u64 size;
 144         char buf[VIRTFN_ID_LEN];
 145         struct pci_dev *virtfn;
 146         struct resource *res;
 147         struct pci_sriov *iov = dev->sriov;
 148         struct pci_bus *bus;
 149
 150         bus = virtfn_add_bus(dev->bus, pci_iov_virtfn_bus(dev, id));
 151         if (!bus)
 152                 goto failed;
 153
 154         virtfn = pci_alloc_dev(bus);
 155         if (!virtfn)
 156                 goto failed0;
 157
 158         virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
 159         virtfn->vendor = dev->vendor;
 160         virtfn->device = iov->vf_device;
 161         virtfn->is_virtfn = 1;
 162         virtfn->physfn = pci_dev_get(dev);
 163
 164         if (id == 0)
 165                 pci_read_vf_config_common(virtfn);
 166
 167         rc = pci_setup_device(virtfn);
 168         if (rc)
 169                 goto failed1;
 170
 171         virtfn->dev.parent = dev->dev.parent;
 172         virtfn->multifunction = 0;
 173
 174         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 175                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 176                 if (!res->parent)
 177                         continue;
 178                 virtfn->resource[i].name = pci_name(virtfn);
 179                 virtfn->resource[i].flags = res->flags;
 180                 size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
 181                 virtfn->resource[i].start = res->start + size * id;
 182                 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
 183                 rc = request_resource(res, &virtfn->resource[i]);
 184                 BUG_ON(rc);
 185         }
 186
 187         pci_device_add(virtfn, virtfn->bus);
 188
 189         sprintf(buf, "virtfn%u", id);
 190         rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
 191         if (rc)
 192                 goto failed2;
 193         rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
 194         if (rc)
 195                 goto failed3;
 196
 197         kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
 198
 199         pci_bus_add_device(virtfn);
 200
 201         return 0;
 202
 203 failed3:
 204         sysfs_remove_link(&dev->dev.kobj, buf);
 205 failed2:
 206         pci_stop_and_remove_bus_device(virtfn);
 207 failed1:
 208         pci_dev_put(dev);
 209 failed0:
 210         virtfn_remove_bus(dev->bus, bus);
 211 failed:
 212
 213         return rc;
 214 }
 215
 216 void pci_iov_remove_virtfn(struct pci_dev *dev, int id)
 217 {
 218         char buf[VIRTFN_ID_LEN];
 219         struct pci_dev *virtfn;
 220
 221         virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
 222                                              pci_iov_virtfn_bus(dev, id),
 223                                              pci_iov_virtfn_devfn(dev, id));
 224         if (!virtfn)
 225                 return;
 226
 227         sprintf(buf, "virtfn%u", id);
 228         sysfs_remove_link(&dev->dev.kobj, buf);
 229         /*
 230          * pci_stop_dev() could have been called for this virtfn already,
 231          * so the directory for the virtfn may have been removed before.
 232          * Double check to avoid spurious sysfs warnings.
 233          */
 234         if (virtfn->dev.kobj.sd)
 235                 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
 236
 237         pci_stop_and_remove_bus_device(virtfn);
 238         virtfn_remove_bus(dev->bus, virtfn->bus);
 239
 240         /* balance pci_get_domain_bus_and_slot() */
 241         pci_dev_put(virtfn);
 242         pci_dev_put(dev);
 243 }
 244
 245 int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
 246 {
 247         return 0;
 248 }
 249
 250 int __weak pcibios_sriov_disable(struct pci_dev *pdev)
 251 {
 252         return 0;
 253 }
 254
 255 static int sriov_add_vfs(struct pci_dev *dev, u16 num_vfs)
 256 {
 257         unsigned int i;
 258         int rc;
 259
 260         if (dev->no_vf_scan)
 261                 return 0;
 262
 263         for (i = 0; i < num_vfs; i++) {
 264                 rc = pci_iov_add_virtfn(dev, i);
 265                 if (rc)
 266                         goto failed;
 267         }
 268         return 0;
 269 failed:
 270         while (i--)
 271                 pci_iov_remove_virtfn(dev, i);
 272
 273         return rc;
 274 }
 275
 276 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 277 {
 278         int rc;
 279         int i;
 280         int nres;
 281         u16 initial;
 282         struct resource *res;
 283         struct pci_dev *pdev;
 284         struct pci_sriov *iov = dev->sriov;
 285         int bars = 0;
 286         int bus;
 287
 288         if (!nr_virtfn)
 289                 return 0;
 290
 291         if (iov->num_VFs)
 292                 return -EINVAL;
 293
 294         pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
 295         if (initial > iov->total_VFs ||
 296             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
 297                 return -EIO;
 298
 299         if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
 300             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 301                 return -EINVAL;
 302
 303         nres = 0;
 304         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 305                 bars |= (1 << (i + PCI_IOV_RESOURCES));
 306                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 307                 if (res->parent)
 308                         nres++;
 309         }
 310         if (nres != iov->nres) {
 311                 pci_err(dev, "not enough MMIO resources for SR-IOV\n");
 312                 return -ENOMEM;
 313         }
 314
 315         bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
 316         if (bus > dev->bus->busn_res.end) {
 317                 pci_err(dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
 318                         nr_virtfn, bus, &dev->bus->busn_res);
 319                 return -ENOMEM;
 320         }
 321
 322         if (pci_enable_resources(dev, bars)) {
 323                 pci_err(dev, "SR-IOV: IOV BARS not allocated\n");
 324                 return -ENOMEM;
 325         }
 326
 327         if (iov->link != dev->devfn) {
 328                 pdev = pci_get_slot(dev->bus, iov->link);
 329                 if (!pdev)
 330                         return -ENODEV;
 331
 332                 if (!pdev->is_physfn) {
 333                         pci_dev_put(pdev);
 334                         return -ENOSYS;
 335                 }
 336
 337                 rc = sysfs_create_link(&dev->dev.kobj,
 338                                         &pdev->dev.kobj, "dep_link");
 339                 pci_dev_put(pdev);
 340                 if (rc)
 341                         return rc;
 342         }
 343
 344         iov->initial_VFs = initial;
 345         if (nr_virtfn < initial)
 346                 initial = nr_virtfn;
 347
 348         rc = pcibios_sriov_enable(dev, initial);
 349         if (rc) {
 350                 pci_err(dev, "failure %d from pcibios_sriov_enable()\n", rc);
 351                 goto err_pcibios;
 352         }
 353
 354         pci_iov_set_numvfs(dev, nr_virtfn);
 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         msleep(100);
 359         pci_cfg_access_unlock(dev);
 360
 361         rc = sriov_add_vfs(dev, initial);
 362         if (rc)
 363                 goto err_pcibios;
 364
 365         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 366         iov->num_VFs = nr_virtfn;
 367
 368         return 0;
 369
 370 err_pcibios:
 371         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 372         pci_cfg_access_lock(dev);
 373         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 374         ssleep(1);
 375         pci_cfg_access_unlock(dev);
 376
 377         pcibios_sriov_disable(dev);
 378
 379         if (iov->link != dev->devfn)
 380                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 381
 382         pci_iov_set_numvfs(dev, 0);
 383         return rc;
 384 }
 385
 386 static void sriov_del_vfs(struct pci_dev *dev)
 387 {
 388         struct pci_sriov *iov = dev->sriov;
 389         int i;
 390
 391         if (dev->no_vf_scan)
 392                 return;
 393
 394         for (i = 0; i < iov->num_VFs; i++)
 395                 pci_iov_remove_virtfn(dev, i);
 396 }
 397
 398 static void sriov_disable(struct pci_dev *dev)
 399 {
 400         struct pci_sriov *iov = dev->sriov;
 401
 402         if (!iov->num_VFs)
 403                 return;
 404
 405         sriov_del_vfs(dev);
 406         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 407         pci_cfg_access_lock(dev);
 408         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 409         ssleep(1);
 410         pci_cfg_access_unlock(dev);
 411
 412         pcibios_sriov_disable(dev);
 413
 414         if (iov->link != dev->devfn)
 415                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 416
 417         iov->num_VFs = 0;
 418         pci_iov_set_numvfs(dev, 0);
 419 }
 420
 421 static int sriov_init(struct pci_dev *dev, int pos)
 422 {
 423         int i, bar64;
 424         int rc;
 425         int nres;
 426         u32 pgsz;
 427         u16 ctrl, total;
 428         struct pci_sriov *iov;
 429         struct resource *res;
 430         struct pci_dev *pdev;
 431
 432         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 433         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 434                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 435                 ssleep(1);
 436         }
 437
 438         ctrl = 0;
 439         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 440                 if (pdev->is_physfn)
 441                         goto found;
 442
 443         pdev = NULL;
 444         if (pci_ari_enabled(dev->bus))
 445                 ctrl |= PCI_SRIOV_CTRL_ARI;
 446
 447 found:
 448         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 449
 450         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 451         if (!total)
 452                 return 0;
 453
 454         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 455         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 456         pgsz &= ~((1 << i) - 1);
 457         if (!pgsz)
 458                 return -EIO;
 459
 460         pgsz &= ~(pgsz - 1);
 461         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 462
 463         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 464         if (!iov)
 465                 return -ENOMEM;
 466
 467         nres = 0;
 468         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 469                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 470                 /*
 471                  * If it is already FIXED, don't change it, something
 472                  * (perhaps EA or header fixups) wants it this way.
 473                  */
 474                 if (res->flags & IORESOURCE_PCI_FIXED)
 475                         bar64 = (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
 476                 else
 477                         bar64 = __pci_read_base(dev, pci_bar_unknown, res,
 478                                                 pos + PCI_SRIOV_BAR + i * 4);
 479                 if (!res->flags)
 480                         continue;
 481                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 482                         rc = -EIO;
 483                         goto failed;
 484                 }
 485                 iov->barsz[i] = resource_size(res);
 486                 res->end = res->start + resource_size(res) * total - 1;
 487                 pci_info(dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
 488                          i, res, i, total);
 489                 i += bar64;
 490                 nres++;
 491         }
 492
 493         iov->pos = pos;
 494         iov->nres = nres;
 495         iov->ctrl = ctrl;
 496         iov->total_VFs = total;
 497         iov->driver_max_VFs = total;
 498         pci_read_config_word(dev, pos + PCI_SRIOV_VF_DID, &iov->vf_device);
 499         iov->pgsz = pgsz;
 500         iov->self = dev;
 501         iov->drivers_autoprobe = true;
 502         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 503         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 504         if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
 505                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 506
 507         if (pdev)
 508                 iov->dev = pci_dev_get(pdev);
 509         else
 510                 iov->dev = dev;
 511
 512         dev->sriov = iov;
 513         dev->is_physfn = 1;
 514         rc = compute_max_vf_buses(dev);
 515         if (rc)
 516                 goto fail_max_buses;
 517
 518         return 0;
 519
 520 fail_max_buses:
 521         dev->sriov = NULL;
 522         dev->is_physfn = 0;
 523 failed:
 524         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 525                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 526                 res->flags = 0;
 527         }
 528
 529         kfree(iov);
 530         return rc;
 531 }
 532
 533 static void sriov_release(struct pci_dev *dev)
 534 {
 535         BUG_ON(dev->sriov->num_VFs);
 536
 537         if (dev != dev->sriov->dev)
 538                 pci_dev_put(dev->sriov->dev);
 539
 540         kfree(dev->sriov);
 541         dev->sriov = NULL;
 542 }
 543
 544 static void sriov_restore_state(struct pci_dev *dev)
 545 {
 546         int i;
 547         u16 ctrl;
 548         struct pci_sriov *iov = dev->sriov;
 549
 550         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 551         if (ctrl & PCI_SRIOV_CTRL_VFE)
 552                 return;
 553
 554         /*
 555          * Restore PCI_SRIOV_CTRL_ARI before pci_iov_set_numvfs() because
 556          * it reads offset & stride, which depend on PCI_SRIOV_CTRL_ARI.
 557          */
 558         ctrl &= ~PCI_SRIOV_CTRL_ARI;
 559         ctrl |= iov->ctrl & PCI_SRIOV_CTRL_ARI;
 560         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, ctrl);
 561
 562         for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
 563                 pci_update_resource(dev, i);
 564
 565         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 566         pci_iov_set_numvfs(dev, iov->num_VFs);
 567         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 568         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 569                 msleep(100);
 570 }
 571
 572 /**
 573  * pci_iov_init - initialize the IOV capability
 574  * @dev: the PCI device
 575  *
 576  * Returns 0 on success, or negative on failure.
 577  */
 578 int pci_iov_init(struct pci_dev *dev)
 579 {
 580         int pos;
 581
 582         if (!pci_is_pcie(dev))
 583                 return -ENODEV;
 584
 585         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 586         if (pos)
 587                 return sriov_init(dev, pos);
 588
 589         return -ENODEV;
 590 }
 591
 592 /**
 593  * pci_iov_release - release resources used by the IOV capability
 594  * @dev: the PCI device
 595  */
 596 void pci_iov_release(struct pci_dev *dev)
 597 {
 598         if (dev->is_physfn)
 599                 sriov_release(dev);
 600 }
 601
 602 /**
 603  * pci_iov_remove - clean up SR-IOV state after PF driver is detached
 604  * @dev: the PCI device
 605  */
 606 void pci_iov_remove(struct pci_dev *dev)
 607 {
 608         struct pci_sriov *iov = dev->sriov;
 609
 610         if (!dev->is_physfn)
 611                 return;
 612
 613         iov->driver_max_VFs = iov->total_VFs;
 614         if (iov->num_VFs)
 615                 pci_warn(dev, "driver left SR-IOV enabled after remove\n");
 616 }
 617
 618 /**
 619  * pci_iov_update_resource - update a VF BAR
 620  * @dev: the PCI device
 621  * @resno: the resource number
 622  *
 623  * Update a VF BAR in the SR-IOV capability of a PF.
 624  */
 625 void pci_iov_update_resource(struct pci_dev *dev, int resno)
 626 {
 627         struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL;
 628         struct resource *res = dev->resource + resno;
 629         int vf_bar = resno - PCI_IOV_RESOURCES;
 630         struct pci_bus_region region;
 631         u16 cmd;
 632         u32 new;
 633         int reg;
 634
 635         /*
 636          * The generic pci_restore_bars() path calls this for all devices,
 637          * including VFs and non-SR-IOV devices.  If this is not a PF, we
 638          * have nothing to do.
 639          */
 640         if (!iov)
 641                 return;
 642
 643         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &cmd);
 644         if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) {
 645                 dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n",
 646                          vf_bar, res);
 647                 return;
 648         }
 649
 650         /*
 651          * Ignore unimplemented BARs, unused resource slots for 64-bit
 652          * BARs, and non-movable resources, e.g., those described via
 653          * Enhanced Allocation.
 654          */
 655         if (!res->flags)
 656                 return;
 657
 658         if (res->flags & IORESOURCE_UNSET)
 659                 return;
 660
 661         if (res->flags & IORESOURCE_PCI_FIXED)
 662                 return;
 663
 664         pcibios_resource_to_bus(dev->bus, &region, res);
 665         new = region.start;
 666         new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
 667
 668         reg = iov->pos + PCI_SRIOV_BAR + 4 * vf_bar;
 669         pci_write_config_dword(dev, reg, new);
 670         if (res->flags & IORESOURCE_MEM_64) {
 671                 new = region.start >> 16 >> 16;
 672                 pci_write_config_dword(dev, reg + 4, new);
 673         }
 674 }
 675
 676 resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
 677                                                       int resno)
 678 {
 679         return pci_iov_resource_size(dev, resno);
 680 }
 681
 682 /**
 683  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 684  * @dev: the PCI device
 685  * @resno: the resource number
 686  *
 687  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 688  * This is not the same as the resource size which is defined as
 689  * the VF BAR size multiplied by the number of VFs.  The alignment
 690  * is just the VF BAR size.
 691  */
 692 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 693 {
 694         return pcibios_iov_resource_alignment(dev, resno);
 695 }
 696
 697 /**
 698  * pci_restore_iov_state - restore the state of the IOV capability
 699  * @dev: the PCI device
 700  */
 701 void pci_restore_iov_state(struct pci_dev *dev)
 702 {
 703         if (dev->is_physfn)
 704                 sriov_restore_state(dev);
 705 }
 706
 707 /**
 708  * pci_vf_drivers_autoprobe - set PF property drivers_autoprobe for VFs
 709  * @dev: the PCI device
 710  * @auto_probe: set VF drivers auto probe flag
 711  */
 712 void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool auto_probe)
 713 {
 714         if (dev->is_physfn)
 715                 dev->sriov->drivers_autoprobe = auto_probe;
 716 }
 717
 718 /**
 719  * pci_iov_bus_range - find bus range used by Virtual Function
 720  * @bus: the PCI bus
 721  *
 722  * Returns max number of buses (exclude current one) used by Virtual
 723  * Functions.
 724  */
 725 int pci_iov_bus_range(struct pci_bus *bus)
 726 {
 727         int max = 0;
 728         struct pci_dev *dev;
 729
 730         list_for_each_entry(dev, &bus->devices, bus_list) {
 731                 if (!dev->is_physfn)
 732                         continue;
 733                 if (dev->sriov->max_VF_buses > max)
 734                         max = dev->sriov->max_VF_buses;
 735         }
 736
 737         return max ? max - bus->number : 0;
 738 }
 739
 740 /**
 741  * pci_enable_sriov - enable the SR-IOV capability
 742  * @dev: the PCI device
 743  * @nr_virtfn: number of virtual functions to enable
 744  *
 745  * Returns 0 on success, or negative on failure.
 746  */
 747 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 748 {
 749         might_sleep();
 750
 751         if (!dev->is_physfn)
 752                 return -ENOSYS;
 753
 754         return sriov_enable(dev, nr_virtfn);
 755 }
 756 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 757
 758 /**
 759  * pci_disable_sriov - disable the SR-IOV capability
 760  * @dev: the PCI device
 761  */
 762 void pci_disable_sriov(struct pci_dev *dev)
 763 {
 764         might_sleep();
 765
 766         if (!dev->is_physfn)
 767                 return;
 768
 769         sriov_disable(dev);
 770 }
 771 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 772
 773 /**
 774  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 775  * @dev: the PCI device
 776  *
 777  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 778  */
 779 int pci_num_vf(struct pci_dev *dev)
 780 {
 781         if (!dev->is_physfn)
 782                 return 0;
 783
 784         return dev->sriov->num_VFs;
 785 }
 786 EXPORT_SYMBOL_GPL(pci_num_vf);
 787
 788 /**
 789  * pci_vfs_assigned - returns number of VFs are assigned to a guest
 790  * @dev: the PCI device
 791  *
 792  * Returns number of VFs belonging to this device that are assigned to a guest.
 793  * If device is not a physical function returns 0.
 794  */
 795 int pci_vfs_assigned(struct pci_dev *dev)
 796 {
 797         struct pci_dev *vfdev;
 798         unsigned int vfs_assigned = 0;
 799         unsigned short dev_id;
 800
 801         /* only search if we are a PF */
 802         if (!dev->is_physfn)
 803                 return 0;
 804
 805         /*
 806          * determine the device ID for the VFs, the vendor ID will be the
 807          * same as the PF so there is no need to check for that one
 808          */
 809         dev_id = dev->sriov->vf_device;
 810
 811         /* loop through all the VFs to see if we own any that are assigned */
 812         vfdev = pci_get_device(dev->vendor, dev_id, NULL);
 813         while (vfdev) {
 814                 /*
 815                  * It is considered assigned if it is a virtual function with
 816                  * our dev as the physical function and the assigned bit is set
 817                  */
 818                 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
 819                         pci_is_dev_assigned(vfdev))
 820                         vfs_assigned++;
 821
 822                 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
 823         }
 824
 825         return vfs_assigned;
 826 }
 827 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
 828
 829 /**
 830  * pci_sriov_set_totalvfs -- reduce the TotalVFs available
 831  * @dev: the PCI PF device
 832  * @numvfs: number that should be used for TotalVFs supported
 833  *
 834  * Should be called from PF driver's probe routine with
 835  * device's mutex held.
 836  *
 837  * Returns 0 if PF is an SRIOV-capable device and
 838  * value of numvfs valid. If not a PF return -ENOSYS;
 839  * if numvfs is invalid return -EINVAL;
 840  * if VFs already enabled, return -EBUSY.
 841  */
 842 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
 843 {
 844         if (!dev->is_physfn)
 845                 return -ENOSYS;
 846
 847         if (numvfs > dev->sriov->total_VFs)
 848                 return -EINVAL;
 849
 850         /* Shouldn't change if VFs already enabled */
 851         if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
 852                 return -EBUSY;
 853
 854         dev->sriov->driver_max_VFs = numvfs;
 855         return 0;
 856 }
 857 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
 858
 859 /**
 860  * pci_sriov_get_totalvfs -- get total VFs supported on this device
 861  * @dev: the PCI PF device
 862  *
 863  * For a PCIe device with SRIOV support, return the PCIe
 864  * SRIOV capability value of TotalVFs or the value of driver_max_VFs
 865  * if the driver reduced it.  Otherwise 0.
 866  */
 867 int pci_sriov_get_totalvfs(struct pci_dev *dev)
 868 {
 869         if (!dev->is_physfn)
 870                 return 0;
 871
 872         return dev->sriov->driver_max_VFs;
 873 }
 874 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);
 875
 876 /**
 877  * pci_sriov_configure_simple - helper to configure SR-IOV
 878  * @dev: the PCI device
 879  * @nr_virtfn: number of virtual functions to enable, 0 to disable
 880  *
 881  * Enable or disable SR-IOV for devices that don't require any PF setup
 882  * before enabling SR-IOV.  Return value is negative on error, or number of
 883  * VFs allocated on success.
 884  */
 885 int pci_sriov_configure_simple(struct pci_dev *dev, int nr_virtfn)
 886 {
 887         int rc;
 888
 889         might_sleep();
 890
 891         if (!dev->is_physfn)
 892                 return -ENODEV;
 893
 894         if (pci_vfs_assigned(dev)) {
 895                 pci_warn(dev, "Cannot modify SR-IOV while VFs are assigned\n");
 896                 return -EPERM;
 897         }
 898
 899         if (nr_virtfn == 0) {
 900                 sriov_disable(dev);
 901                 return 0;
 902         }
 903
 904         rc = sriov_enable(dev, nr_virtfn);
 905         if (rc < 0)
 906                 return rc;
 907
 908         return nr_virtfn;
 909 }
 910 EXPORT_SYMBOL_GPL(pci_sriov_configure_simple);