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/export.h>
  13 #include <linux/string.h>
  14 #include <linux/delay.h>
  15 #include "pci.h"
  16
  17 #define VIRTFN_ID_LEN   16
  18
  19 int pci_iov_virtfn_bus(struct pci_dev *dev, int vf_id)
  20 {
  21         if (!dev->is_physfn)
  22                 return -EINVAL;
  23         return dev->bus->number + ((dev->devfn + dev->sriov->offset +
  24                                     dev->sriov->stride * vf_id) >> 8);
  25 }
  26
  27 int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id)
  28 {
  29         if (!dev->is_physfn)
  30                 return -EINVAL;
  31         return (dev->devfn + dev->sriov->offset +
  32                 dev->sriov->stride * vf_id) & 0xff;
  33 }
  34
  35 /*
  36  * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may
  37  * change when NumVFs changes.
  38  *
  39  * Update iov->offset and iov->stride when NumVFs is written.
  40  */
  41 static inline void pci_iov_set_numvfs(struct pci_dev *dev, int nr_virtfn)
  42 {
  43         struct pci_sriov *iov = dev->sriov;
  44
  45         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
  46         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &iov->offset);
  47         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &iov->stride);
  48 }
  49
  50 /*
  51  * The PF consumes one bus number.  NumVFs, First VF Offset, and VF Stride
  52  * determine how many additional bus numbers will be consumed by VFs.
  53  *
  54  * Iterate over all valid NumVFs, validate offset and stride, and calculate
  55  * the maximum number of bus numbers that could ever be required.
  56  */
  57 static int compute_max_vf_buses(struct pci_dev *dev)
  58 {
  59         struct pci_sriov *iov = dev->sriov;
  60         int nr_virtfn, busnr, rc = 0;
  61
  62         for (nr_virtfn = iov->total_VFs; nr_virtfn; nr_virtfn--) {
  63                 pci_iov_set_numvfs(dev, nr_virtfn);
  64                 if (!iov->offset || (nr_virtfn > 1 && !iov->stride)) {
  65                         rc = -EIO;
  66                         goto out;
  67                 }
  68
  69                 busnr = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
  70                 if (busnr > iov->max_VF_buses)
  71                         iov->max_VF_buses = busnr;
  72         }
  73
  74 out:
  75         pci_iov_set_numvfs(dev, 0);
  76         return rc;
  77 }
  78
  79 static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
  80 {
  81         struct pci_bus *child;
  82
  83         if (bus->number == busnr)
  84                 return bus;
  85
  86         child = pci_find_bus(pci_domain_nr(bus), busnr);
  87         if (child)
  88                 return child;
  89
  90         child = pci_add_new_bus(bus, NULL, busnr);
  91         if (!child)
  92                 return NULL;
  93
  94         pci_bus_insert_busn_res(child, busnr, busnr);
  95
  96         return child;
  97 }
  98
  99 static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus)
 100 {
 101         if (physbus != virtbus && list_empty(&virtbus->devices))
 102                 pci_remove_bus(virtbus);
 103 }
 104
 105 resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
 106 {
 107         if (!dev->is_physfn)
 108                 return 0;
 109
 110         return dev->sriov->barsz[resno - PCI_IOV_RESOURCES];
 111 }
 112
 113 static void pci_read_vf_config_common(struct pci_dev *virtfn)
 114 {
 115         struct pci_dev *physfn = virtfn->physfn;
 116
 117         /*
 118          * Some config registers are the same across all associated VFs.
 119          * Read them once from VF0 so we can skip reading them from the
 120          * other VFs.
 121          *
 122          * PCIe r4.0, sec 9.3.4.1, technically doesn't require all VFs to
 123          * have the same Revision ID and Subsystem ID, but we assume they
 124          * do.
 125          */
 126         pci_read_config_dword(virtfn, PCI_CLASS_REVISION,
 127                               &physfn->sriov->class);
 128         pci_read_config_byte(virtfn, PCI_HEADER_TYPE,
 129                              &physfn->sriov->hdr_type);
 130         pci_read_config_word(virtfn, PCI_SUBSYSTEM_VENDOR_ID,
 131                              &physfn->sriov->subsystem_vendor);
 132         pci_read_config_word(virtfn, PCI_SUBSYSTEM_ID,
 133                              &physfn->sriov->subsystem_device);
 134 }
 135
 136 int pci_iov_sysfs_link(struct pci_dev *dev,
 137                 struct pci_dev *virtfn, int id)
 138 {
 139         char buf[VIRTFN_ID_LEN];
 140         int rc;
 141
 142         sprintf(buf, "virtfn%u", id);
 143         rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
 144         if (rc)
 145                 goto failed;
 146         rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
 147         if (rc)
 148                 goto failed1;
 149
 150         kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
 151
 152         return 0;
 153
 154 failed1:
 155         sysfs_remove_link(&dev->dev.kobj, buf);
 156 failed:
 157         return rc;
 158 }
 159
 160 int pci_iov_add_virtfn(struct pci_dev *dev, int id)
 161 {
 162         int i;
 163         int rc = -ENOMEM;
 164         u64 size;
 165         struct pci_dev *virtfn;
 166         struct resource *res;
 167         struct pci_sriov *iov = dev->sriov;
 168         struct pci_bus *bus;
 169
 170         bus = virtfn_add_bus(dev->bus, pci_iov_virtfn_bus(dev, id));
 171         if (!bus)
 172                 goto failed;
 173
 174         virtfn = pci_alloc_dev(bus);
 175         if (!virtfn)
 176                 goto failed0;
 177
 178         virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
 179         virtfn->vendor = dev->vendor;
 180         virtfn->device = iov->vf_device;
 181         virtfn->is_virtfn = 1;
 182         virtfn->physfn = pci_dev_get(dev);
 183
 184         if (id == 0)
 185                 pci_read_vf_config_common(virtfn);
 186
 187         rc = pci_setup_device(virtfn);
 188         if (rc)
 189                 goto failed1;
 190
 191         virtfn->dev.parent = dev->dev.parent;
 192         virtfn->multifunction = 0;
 193
 194         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 195                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 196                 if (!res->parent)
 197                         continue;
 198                 virtfn->resource[i].name = pci_name(virtfn);
 199                 virtfn->resource[i].flags = res->flags;
 200                 size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
 201                 virtfn->resource[i].start = res->start + size * id;
 202                 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
 203                 rc = request_resource(res, &virtfn->resource[i]);
 204                 BUG_ON(rc);
 205         }
 206
 207         pci_device_add(virtfn, virtfn->bus);
 208         rc = pci_iov_sysfs_link(dev, virtfn, id);
 209         if (rc)
 210                 goto failed1;
 211
 212         pci_bus_add_device(virtfn);
 213
 214         return 0;
 215
 216 failed1:
 217         pci_stop_and_remove_bus_device(virtfn);
 218         pci_dev_put(dev);
 219 failed0:
 220         virtfn_remove_bus(dev->bus, bus);
 221 failed:
 222
 223         return rc;
 224 }
 225
 226 void pci_iov_remove_virtfn(struct pci_dev *dev, int id)
 227 {
 228         char buf[VIRTFN_ID_LEN];
 229         struct pci_dev *virtfn;
 230
 231         virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
 232                                              pci_iov_virtfn_bus(dev, id),
 233                                              pci_iov_virtfn_devfn(dev, id));
 234         if (!virtfn)
 235                 return;
 236
 237         sprintf(buf, "virtfn%u", id);
 238         sysfs_remove_link(&dev->dev.kobj, buf);
 239         /*
 240          * pci_stop_dev() could have been called for this virtfn already,
 241          * so the directory for the virtfn may have been removed before.
 242          * Double check to avoid spurious sysfs warnings.
 243          */
 244         if (virtfn->dev.kobj.sd)
 245                 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
 246
 247         pci_stop_and_remove_bus_device(virtfn);
 248         virtfn_remove_bus(dev->bus, virtfn->bus);
 249
 250         /* balance pci_get_domain_bus_and_slot() */
 251         pci_dev_put(virtfn);
 252         pci_dev_put(dev);
 253 }
 254
 255 static ssize_t sriov_totalvfs_show(struct device *dev,
 256                                    struct device_attribute *attr,
 257                                    char *buf)
 258 {
 259         struct pci_dev *pdev = to_pci_dev(dev);
 260
 261         return sprintf(buf, "%u\n", pci_sriov_get_totalvfs(pdev));
 262 }
 263
 264 static ssize_t sriov_numvfs_show(struct device *dev,
 265                                  struct device_attribute *attr,
 266                                  char *buf)
 267 {
 268         struct pci_dev *pdev = to_pci_dev(dev);
 269         u16 num_vfs;
 270
 271         /* Serialize vs sriov_numvfs_store() so readers see valid num_VFs */
 272         device_lock(&pdev->dev);
 273         num_vfs = pdev->sriov->num_VFs;
 274         device_unlock(&pdev->dev);
 275
 276         return sprintf(buf, "%u\n", num_vfs);
 277 }
 278
 279 /*
 280  * num_vfs > 0; number of VFs to enable
 281  * num_vfs = 0; disable all VFs
 282  *
 283  * Note: SRIOV spec does not allow partial VF
 284  *       disable, so it's all or none.
 285  */
 286 static ssize_t sriov_numvfs_store(struct device *dev,
 287                                   struct device_attribute *attr,
 288                                   const char *buf, size_t count)
 289 {
 290         struct pci_dev *pdev = to_pci_dev(dev);
 291         int ret;
 292         u16 num_vfs;
 293
 294         ret = kstrtou16(buf, 0, &num_vfs);
 295         if (ret < 0)
 296                 return ret;
 297
 298         if (num_vfs > pci_sriov_get_totalvfs(pdev))
 299                 return -ERANGE;
 300
 301         device_lock(&pdev->dev);
 302
 303         if (num_vfs == pdev->sriov->num_VFs)
 304                 goto exit;
 305
 306         /* is PF driver loaded w/callback */
 307         if (!pdev->driver || !pdev->driver->sriov_configure) {
 308                 pci_info(pdev, "Driver does not support SRIOV configuration via sysfs\n");
 309                 ret = -ENOENT;
 310                 goto exit;
 311         }
 312
 313         if (num_vfs == 0) {
 314                 /* disable VFs */
 315                 ret = pdev->driver->sriov_configure(pdev, 0);
 316                 goto exit;
 317         }
 318
 319         /* enable VFs */
 320         if (pdev->sriov->num_VFs) {
 321                 pci_warn(pdev, "%d VFs already enabled. Disable before enabling %d VFs\n",
 322                          pdev->sriov->num_VFs, num_vfs);
 323                 ret = -EBUSY;
 324                 goto exit;
 325         }
 326
 327         ret = pdev->driver->sriov_configure(pdev, num_vfs);
 328         if (ret < 0)
 329                 goto exit;
 330
 331         if (ret != num_vfs)
 332                 pci_warn(pdev, "%d VFs requested; only %d enabled\n",
 333                          num_vfs, ret);
 334
 335 exit:
 336         device_unlock(&pdev->dev);
 337
 338         if (ret < 0)
 339                 return ret;
 340
 341         return count;
 342 }
 343
 344 static ssize_t sriov_offset_show(struct device *dev,
 345                                  struct device_attribute *attr,
 346                                  char *buf)
 347 {
 348         struct pci_dev *pdev = to_pci_dev(dev);
 349
 350         return sprintf(buf, "%u\n", pdev->sriov->offset);
 351 }
 352
 353 static ssize_t sriov_stride_show(struct device *dev,
 354                                  struct device_attribute *attr,
 355                                  char *buf)
 356 {
 357         struct pci_dev *pdev = to_pci_dev(dev);
 358
 359         return sprintf(buf, "%u\n", pdev->sriov->stride);
 360 }
 361
 362 static ssize_t sriov_vf_device_show(struct device *dev,
 363                                     struct device_attribute *attr,
 364                                     char *buf)
 365 {
 366         struct pci_dev *pdev = to_pci_dev(dev);
 367
 368         return sprintf(buf, "%x\n", pdev->sriov->vf_device);
 369 }
 370
 371 static ssize_t sriov_drivers_autoprobe_show(struct device *dev,
 372                                             struct device_attribute *attr,
 373                                             char *buf)
 374 {
 375         struct pci_dev *pdev = to_pci_dev(dev);
 376
 377         return sprintf(buf, "%u\n", pdev->sriov->drivers_autoprobe);
 378 }
 379
 380 static ssize_t sriov_drivers_autoprobe_store(struct device *dev,
 381                                              struct device_attribute *attr,
 382                                              const char *buf, size_t count)
 383 {
 384         struct pci_dev *pdev = to_pci_dev(dev);
 385         bool drivers_autoprobe;
 386
 387         if (kstrtobool(buf, &drivers_autoprobe) < 0)
 388                 return -EINVAL;
 389
 390         pdev->sriov->drivers_autoprobe = drivers_autoprobe;
 391
 392         return count;
 393 }
 394
 395 static DEVICE_ATTR_RO(sriov_totalvfs);
 396 static DEVICE_ATTR_RW(sriov_numvfs);
 397 static DEVICE_ATTR_RO(sriov_offset);
 398 static DEVICE_ATTR_RO(sriov_stride);
 399 static DEVICE_ATTR_RO(sriov_vf_device);
 400 static DEVICE_ATTR_RW(sriov_drivers_autoprobe);
 401
 402 static struct attribute *sriov_dev_attrs[] = {
 403         &dev_attr_sriov_totalvfs.attr,
 404         &dev_attr_sriov_numvfs.attr,
 405         &dev_attr_sriov_offset.attr,
 406         &dev_attr_sriov_stride.attr,
 407         &dev_attr_sriov_vf_device.attr,
 408         &dev_attr_sriov_drivers_autoprobe.attr,
 409         NULL,
 410 };
 411
 412 static umode_t sriov_attrs_are_visible(struct kobject *kobj,
 413                                        struct attribute *a, int n)
 414 {
 415         struct device *dev = kobj_to_dev(kobj);
 416
 417         if (!dev_is_pf(dev))
 418                 return 0;
 419
 420         return a->mode;
 421 }
 422
 423 const struct attribute_group sriov_dev_attr_group = {
 424         .attrs = sriov_dev_attrs,
 425         .is_visible = sriov_attrs_are_visible,
 426 };
 427
 428 int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
 429 {
 430         return 0;
 431 }
 432
 433 int __weak pcibios_sriov_disable(struct pci_dev *pdev)
 434 {
 435         return 0;
 436 }
 437
 438 static int sriov_add_vfs(struct pci_dev *dev, u16 num_vfs)
 439 {
 440         unsigned int i;
 441         int rc;
 442
 443         if (dev->no_vf_scan)
 444                 return 0;
 445
 446         for (i = 0; i < num_vfs; i++) {
 447                 rc = pci_iov_add_virtfn(dev, i);
 448                 if (rc)
 449                         goto failed;
 450         }
 451         return 0;
 452 failed:
 453         while (i--)
 454                 pci_iov_remove_virtfn(dev, i);
 455
 456         return rc;
 457 }
 458
 459 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 460 {
 461         int rc;
 462         int i;
 463         int nres;
 464         u16 initial;
 465         struct resource *res;
 466         struct pci_dev *pdev;
 467         struct pci_sriov *iov = dev->sriov;
 468         int bars = 0;
 469         int bus;
 470
 471         if (!nr_virtfn)
 472                 return 0;
 473
 474         if (iov->num_VFs)
 475                 return -EINVAL;
 476
 477         pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
 478         if (initial > iov->total_VFs ||
 479             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
 480                 return -EIO;
 481
 482         if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
 483             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 484                 return -EINVAL;
 485
 486         nres = 0;
 487         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 488                 bars |= (1 << (i + PCI_IOV_RESOURCES));
 489                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 490                 if (res->parent)
 491                         nres++;
 492         }
 493         if (nres != iov->nres) {
 494                 pci_err(dev, "not enough MMIO resources for SR-IOV\n");
 495                 return -ENOMEM;
 496         }
 497
 498         bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
 499         if (bus > dev->bus->busn_res.end) {
 500                 pci_err(dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
 501                         nr_virtfn, bus, &dev->bus->busn_res);
 502                 return -ENOMEM;
 503         }
 504
 505         if (pci_enable_resources(dev, bars)) {
 506                 pci_err(dev, "SR-IOV: IOV BARS not allocated\n");
 507                 return -ENOMEM;
 508         }
 509
 510         if (iov->link != dev->devfn) {
 511                 pdev = pci_get_slot(dev->bus, iov->link);
 512                 if (!pdev)
 513                         return -ENODEV;
 514
 515                 if (!pdev->is_physfn) {
 516                         pci_dev_put(pdev);
 517                         return -ENOSYS;
 518                 }
 519
 520                 rc = sysfs_create_link(&dev->dev.kobj,
 521                                         &pdev->dev.kobj, "dep_link");
 522                 pci_dev_put(pdev);
 523                 if (rc)
 524                         return rc;
 525         }
 526
 527         iov->initial_VFs = initial;
 528         if (nr_virtfn < initial)
 529                 initial = nr_virtfn;
 530
 531         rc = pcibios_sriov_enable(dev, initial);
 532         if (rc) {
 533                 pci_err(dev, "failure %d from pcibios_sriov_enable()\n", rc);
 534                 goto err_pcibios;
 535         }
 536
 537         pci_iov_set_numvfs(dev, nr_virtfn);
 538         iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 539         pci_cfg_access_lock(dev);
 540         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 541         msleep(100);
 542         pci_cfg_access_unlock(dev);
 543
 544         rc = sriov_add_vfs(dev, initial);
 545         if (rc)
 546                 goto err_pcibios;
 547
 548         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 549         iov->num_VFs = nr_virtfn;
 550
 551         return 0;
 552
 553 err_pcibios:
 554         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 555         pci_cfg_access_lock(dev);
 556         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 557         ssleep(1);
 558         pci_cfg_access_unlock(dev);
 559
 560         pcibios_sriov_disable(dev);
 561
 562         if (iov->link != dev->devfn)
 563                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 564
 565         pci_iov_set_numvfs(dev, 0);
 566         return rc;
 567 }
 568
 569 static void sriov_del_vfs(struct pci_dev *dev)
 570 {
 571         struct pci_sriov *iov = dev->sriov;
 572         int i;
 573
 574         for (i = 0; i < iov->num_VFs; i++)
 575                 pci_iov_remove_virtfn(dev, i);
 576 }
 577
 578 static void sriov_disable(struct pci_dev *dev)
 579 {
 580         struct pci_sriov *iov = dev->sriov;
 581
 582         if (!iov->num_VFs)
 583                 return;
 584
 585         sriov_del_vfs(dev);
 586         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 587         pci_cfg_access_lock(dev);
 588         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 589         ssleep(1);
 590         pci_cfg_access_unlock(dev);
 591
 592         pcibios_sriov_disable(dev);
 593
 594         if (iov->link != dev->devfn)
 595                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 596
 597         iov->num_VFs = 0;
 598         pci_iov_set_numvfs(dev, 0);
 599 }
 600
 601 static int sriov_init(struct pci_dev *dev, int pos)
 602 {
 603         int i, bar64;
 604         int rc;
 605         int nres;
 606         u32 pgsz;
 607         u16 ctrl, total;
 608         struct pci_sriov *iov;
 609         struct resource *res;
 610         struct pci_dev *pdev;
 611
 612         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 613         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 614                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 615                 ssleep(1);
 616         }
 617
 618         ctrl = 0;
 619         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 620                 if (pdev->is_physfn)
 621                         goto found;
 622
 623         pdev = NULL;
 624         if (pci_ari_enabled(dev->bus))
 625                 ctrl |= PCI_SRIOV_CTRL_ARI;
 626
 627 found:
 628         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 629
 630         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 631         if (!total)
 632                 return 0;
 633
 634         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 635         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 636         pgsz &= ~((1 << i) - 1);
 637         if (!pgsz)
 638                 return -EIO;
 639
 640         pgsz &= ~(pgsz - 1);
 641         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 642
 643         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 644         if (!iov)
 645                 return -ENOMEM;
 646
 647         nres = 0;
 648         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 649                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 650                 /*
 651                  * If it is already FIXED, don't change it, something
 652                  * (perhaps EA or header fixups) wants it this way.
 653                  */
 654                 if (res->flags & IORESOURCE_PCI_FIXED)
 655                         bar64 = (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
 656                 else
 657                         bar64 = __pci_read_base(dev, pci_bar_unknown, res,
 658                                                 pos + PCI_SRIOV_BAR + i * 4);
 659                 if (!res->flags)
 660                         continue;
 661                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 662                         rc = -EIO;
 663                         goto failed;
 664                 }
 665                 iov->barsz[i] = resource_size(res);
 666                 res->end = res->start + resource_size(res) * total - 1;
 667                 pci_info(dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
 668                          i, res, i, total);
 669                 i += bar64;
 670                 nres++;
 671         }
 672
 673         iov->pos = pos;
 674         iov->nres = nres;
 675         iov->ctrl = ctrl;
 676         iov->total_VFs = total;
 677         iov->driver_max_VFs = total;
 678         pci_read_config_word(dev, pos + PCI_SRIOV_VF_DID, &iov->vf_device);
 679         iov->pgsz = pgsz;
 680         iov->self = dev;
 681         iov->drivers_autoprobe = true;
 682         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 683         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 684         if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
 685                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 686
 687         if (pdev)
 688                 iov->dev = pci_dev_get(pdev);
 689         else
 690                 iov->dev = dev;
 691
 692         dev->sriov = iov;
 693         dev->is_physfn = 1;
 694         rc = compute_max_vf_buses(dev);
 695         if (rc)
 696                 goto fail_max_buses;
 697
 698         return 0;
 699
 700 fail_max_buses:
 701         dev->sriov = NULL;
 702         dev->is_physfn = 0;
 703 failed:
 704         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 705                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 706                 res->flags = 0;
 707         }
 708
 709         kfree(iov);
 710         return rc;
 711 }
 712
 713 static void sriov_release(struct pci_dev *dev)
 714 {
 715         BUG_ON(dev->sriov->num_VFs);
 716
 717         if (dev != dev->sriov->dev)
 718                 pci_dev_put(dev->sriov->dev);
 719
 720         kfree(dev->sriov);
 721         dev->sriov = NULL;
 722 }
 723
 724 static void sriov_restore_state(struct pci_dev *dev)
 725 {
 726         int i;
 727         u16 ctrl;
 728         struct pci_sriov *iov = dev->sriov;
 729
 730         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 731         if (ctrl & PCI_SRIOV_CTRL_VFE)
 732                 return;
 733
 734         /*
 735          * Restore PCI_SRIOV_CTRL_ARI before pci_iov_set_numvfs() because
 736          * it reads offset & stride, which depend on PCI_SRIOV_CTRL_ARI.
 737          */
 738         ctrl &= ~PCI_SRIOV_CTRL_ARI;
 739         ctrl |= iov->ctrl & PCI_SRIOV_CTRL_ARI;
 740         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, ctrl);
 741
 742         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++)
 743                 pci_update_resource(dev, i + PCI_IOV_RESOURCES);
 744
 745         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 746         pci_iov_set_numvfs(dev, iov->num_VFs);
 747         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 748         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 749                 msleep(100);
 750 }
 751
 752 /**
 753  * pci_iov_init - initialize the IOV capability
 754  * @dev: the PCI device
 755  *
 756  * Returns 0 on success, or negative on failure.
 757  */
 758 int pci_iov_init(struct pci_dev *dev)
 759 {
 760         int pos;
 761
 762         if (!pci_is_pcie(dev))
 763                 return -ENODEV;
 764
 765         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 766         if (pos)
 767                 return sriov_init(dev, pos);
 768
 769         return -ENODEV;
 770 }
 771
 772 /**
 773  * pci_iov_release - release resources used by the IOV capability
 774  * @dev: the PCI device
 775  */
 776 void pci_iov_release(struct pci_dev *dev)
 777 {
 778         if (dev->is_physfn)
 779                 sriov_release(dev);
 780 }
 781
 782 /**
 783  * pci_iov_remove - clean up SR-IOV state after PF driver is detached
 784  * @dev: the PCI device
 785  */
 786 void pci_iov_remove(struct pci_dev *dev)
 787 {
 788         struct pci_sriov *iov = dev->sriov;
 789
 790         if (!dev->is_physfn)
 791                 return;
 792
 793         iov->driver_max_VFs = iov->total_VFs;
 794         if (iov->num_VFs)
 795                 pci_warn(dev, "driver left SR-IOV enabled after remove\n");
 796 }
 797
 798 /**
 799  * pci_iov_update_resource - update a VF BAR
 800  * @dev: the PCI device
 801  * @resno: the resource number
 802  *
 803  * Update a VF BAR in the SR-IOV capability of a PF.
 804  */
 805 void pci_iov_update_resource(struct pci_dev *dev, int resno)
 806 {
 807         struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL;
 808         struct resource *res = dev->resource + resno;
 809         int vf_bar = resno - PCI_IOV_RESOURCES;
 810         struct pci_bus_region region;
 811         u16 cmd;
 812         u32 new;
 813         int reg;
 814
 815         /*
 816          * The generic pci_restore_bars() path calls this for all devices,
 817          * including VFs and non-SR-IOV devices.  If this is not a PF, we
 818          * have nothing to do.
 819          */
 820         if (!iov)
 821                 return;
 822
 823         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &cmd);
 824         if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) {
 825                 dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n",
 826                          vf_bar, res);
 827                 return;
 828         }
 829
 830         /*
 831          * Ignore unimplemented BARs, unused resource slots for 64-bit
 832          * BARs, and non-movable resources, e.g., those described via
 833          * Enhanced Allocation.
 834          */
 835         if (!res->flags)
 836                 return;
 837
 838         if (res->flags & IORESOURCE_UNSET)
 839                 return;
 840
 841         if (res->flags & IORESOURCE_PCI_FIXED)
 842                 return;
 843
 844         pcibios_resource_to_bus(dev->bus, &region, res);
 845         new = region.start;
 846         new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
 847
 848         reg = iov->pos + PCI_SRIOV_BAR + 4 * vf_bar;
 849         pci_write_config_dword(dev, reg, new);
 850         if (res->flags & IORESOURCE_MEM_64) {
 851                 new = region.start >> 16 >> 16;
 852                 pci_write_config_dword(dev, reg + 4, new);
 853         }
 854 }
 855
 856 resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
 857                                                       int resno)
 858 {
 859         return pci_iov_resource_size(dev, resno);
 860 }
 861
 862 /**
 863  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 864  * @dev: the PCI device
 865  * @resno: the resource number
 866  *
 867  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 868  * This is not the same as the resource size which is defined as
 869  * the VF BAR size multiplied by the number of VFs.  The alignment
 870  * is just the VF BAR size.
 871  */
 872 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 873 {
 874         return pcibios_iov_resource_alignment(dev, resno);
 875 }
 876
 877 /**
 878  * pci_restore_iov_state - restore the state of the IOV capability
 879  * @dev: the PCI device
 880  */
 881 void pci_restore_iov_state(struct pci_dev *dev)
 882 {
 883         if (dev->is_physfn)
 884                 sriov_restore_state(dev);
 885 }
 886
 887 /**
 888  * pci_vf_drivers_autoprobe - set PF property drivers_autoprobe for VFs
 889  * @dev: the PCI device
 890  * @auto_probe: set VF drivers auto probe flag
 891  */
 892 void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool auto_probe)
 893 {
 894         if (dev->is_physfn)
 895                 dev->sriov->drivers_autoprobe = auto_probe;
 896 }
 897
 898 /**
 899  * pci_iov_bus_range - find bus range used by Virtual Function
 900  * @bus: the PCI bus
 901  *
 902  * Returns max number of buses (exclude current one) used by Virtual
 903  * Functions.
 904  */
 905 int pci_iov_bus_range(struct pci_bus *bus)
 906 {
 907         int max = 0;
 908         struct pci_dev *dev;
 909
 910         list_for_each_entry(dev, &bus->devices, bus_list) {
 911                 if (!dev->is_physfn)
 912                         continue;
 913                 if (dev->sriov->max_VF_buses > max)
 914                         max = dev->sriov->max_VF_buses;
 915         }
 916
 917         return max ? max - bus->number : 0;
 918 }
 919
 920 /**
 921  * pci_enable_sriov - enable the SR-IOV capability
 922  * @dev: the PCI device
 923  * @nr_virtfn: number of virtual functions to enable
 924  *
 925  * Returns 0 on success, or negative on failure.
 926  */
 927 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 928 {
 929         might_sleep();
 930
 931         if (!dev->is_physfn)
 932                 return -ENOSYS;
 933
 934         return sriov_enable(dev, nr_virtfn);
 935 }
 936 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 937
 938 /**
 939  * pci_disable_sriov - disable the SR-IOV capability
 940  * @dev: the PCI device
 941  */
 942 void pci_disable_sriov(struct pci_dev *dev)
 943 {
 944         might_sleep();
 945
 946         if (!dev->is_physfn)
 947                 return;
 948
 949         sriov_disable(dev);
 950 }
 951 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 952
 953 /**
 954  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 955  * @dev: the PCI device
 956  *
 957  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 958  */
 959 int pci_num_vf(struct pci_dev *dev)
 960 {
 961         if (!dev->is_physfn)
 962                 return 0;
 963
 964         return dev->sriov->num_VFs;
 965 }
 966 EXPORT_SYMBOL_GPL(pci_num_vf);
 967
 968 /**
 969  * pci_vfs_assigned - returns number of VFs are assigned to a guest
 970  * @dev: the PCI device
 971  *
 972  * Returns number of VFs belonging to this device that are assigned to a guest.
 973  * If device is not a physical function returns 0.
 974  */
 975 int pci_vfs_assigned(struct pci_dev *dev)
 976 {
 977         struct pci_dev *vfdev;
 978         unsigned int vfs_assigned = 0;
 979         unsigned short dev_id;
 980
 981         /* only search if we are a PF */
 982         if (!dev->is_physfn)
 983                 return 0;
 984
 985         /*
 986          * determine the device ID for the VFs, the vendor ID will be the
 987          * same as the PF so there is no need to check for that one
 988          */
 989         dev_id = dev->sriov->vf_device;
 990
 991         /* loop through all the VFs to see if we own any that are assigned */
 992         vfdev = pci_get_device(dev->vendor, dev_id, NULL);
 993         while (vfdev) {
 994                 /*
 995                  * It is considered assigned if it is a virtual function with
 996                  * our dev as the physical function and the assigned bit is set
 997                  */
 998                 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
 999                         pci_is_dev_assigned(vfdev))
1000                         vfs_assigned++;
1001
1002                 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
1003         }
1004
1005         return vfs_assigned;
1006 }
1007 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
1008
1009 /**
1010  * pci_sriov_set_totalvfs -- reduce the TotalVFs available
1011  * @dev: the PCI PF device
1012  * @numvfs: number that should be used for TotalVFs supported
1013  *
1014  * Should be called from PF driver's probe routine with
1015  * device's mutex held.
1016  *
1017  * Returns 0 if PF is an SRIOV-capable device and
1018  * value of numvfs valid. If not a PF return -ENOSYS;
1019  * if numvfs is invalid return -EINVAL;
1020  * if VFs already enabled, return -EBUSY.
1021  */
1022 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
1023 {
1024         if (!dev->is_physfn)
1025                 return -ENOSYS;
1026
1027         if (numvfs > dev->sriov->total_VFs)
1028                 return -EINVAL;
1029
1030         /* Shouldn't change if VFs already enabled */
1031         if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
1032                 return -EBUSY;
1033
1034         dev->sriov->driver_max_VFs = numvfs;
1035         return 0;
1036 }
1037 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
1038
1039 /**
1040  * pci_sriov_get_totalvfs -- get total VFs supported on this device
1041  * @dev: the PCI PF device
1042  *
1043  * For a PCIe device with SRIOV support, return the PCIe
1044  * SRIOV capability value of TotalVFs or the value of driver_max_VFs
1045  * if the driver reduced it.  Otherwise 0.
1046  */
1047 int pci_sriov_get_totalvfs(struct pci_dev *dev)
1048 {
1049         if (!dev->is_physfn)
1050                 return 0;
1051
1052         return dev->sriov->driver_max_VFs;
1053 }
1054 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);
1055
1056 /**
1057  * pci_sriov_configure_simple - helper to configure SR-IOV
1058  * @dev: the PCI device
1059  * @nr_virtfn: number of virtual functions to enable, 0 to disable
1060  *
1061  * Enable or disable SR-IOV for devices that don't require any PF setup
1062  * before enabling SR-IOV.  Return value is negative on error, or number of
1063  * VFs allocated on success.
1064  */
1065 int pci_sriov_configure_simple(struct pci_dev *dev, int nr_virtfn)
1066 {
1067         int rc;
1068
1069         might_sleep();
1070
1071         if (!dev->is_physfn)
1072                 return -ENODEV;
1073
1074         if (pci_vfs_assigned(dev)) {
1075                 pci_warn(dev, "Cannot modify SR-IOV while VFs are assigned\n");
1076                 return -EPERM;
1077         }
1078
1079         if (nr_virtfn == 0) {
1080                 sriov_disable(dev);
1081                 return 0;
1082         }
1083
1084         rc = sriov_enable(dev, nr_virtfn);
1085         if (rc < 0)
1086                 return rc;
1087
1088         return nr_virtfn;
1089 }
1090 EXPORT_SYMBOL_GPL(pci_sriov_configure_simple);