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         virtfn->no_command_memory = 1;
 184
 185         if (id == 0)
 186                 pci_read_vf_config_common(virtfn);
 187
 188         rc = pci_setup_device(virtfn);
 189         if (rc)
 190                 goto failed1;
 191
 192         virtfn->dev.parent = dev->dev.parent;
 193         virtfn->multifunction = 0;
 194
 195         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 196                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 197                 if (!res->parent)
 198                         continue;
 199                 virtfn->resource[i].name = pci_name(virtfn);
 200                 virtfn->resource[i].flags = res->flags;
 201                 size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
 202                 virtfn->resource[i].start = res->start + size * id;
 203                 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
 204                 rc = request_resource(res, &virtfn->resource[i]);
 205                 BUG_ON(rc);
 206         }
 207
 208         pci_device_add(virtfn, virtfn->bus);
 209         rc = pci_iov_sysfs_link(dev, virtfn, id);
 210         if (rc)
 211                 goto failed1;
 212
 213         pci_bus_add_device(virtfn);
 214
 215         return 0;
 216
 217 failed1:
 218         pci_stop_and_remove_bus_device(virtfn);
 219         pci_dev_put(dev);
 220 failed0:
 221         virtfn_remove_bus(dev->bus, bus);
 222 failed:
 223
 224         return rc;
 225 }
 226
 227 void pci_iov_remove_virtfn(struct pci_dev *dev, int id)
 228 {
 229         char buf[VIRTFN_ID_LEN];
 230         struct pci_dev *virtfn;
 231
 232         virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
 233                                              pci_iov_virtfn_bus(dev, id),
 234                                              pci_iov_virtfn_devfn(dev, id));
 235         if (!virtfn)
 236                 return;
 237
 238         sprintf(buf, "virtfn%u", id);
 239         sysfs_remove_link(&dev->dev.kobj, buf);
 240         /*
 241          * pci_stop_dev() could have been called for this virtfn already,
 242          * so the directory for the virtfn may have been removed before.
 243          * Double check to avoid spurious sysfs warnings.
 244          */
 245         if (virtfn->dev.kobj.sd)
 246                 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
 247
 248         pci_stop_and_remove_bus_device(virtfn);
 249         virtfn_remove_bus(dev->bus, virtfn->bus);
 250
 251         /* balance pci_get_domain_bus_and_slot() */
 252         pci_dev_put(virtfn);
 253         pci_dev_put(dev);
 254 }
 255
 256 static ssize_t sriov_totalvfs_show(struct device *dev,
 257                                    struct device_attribute *attr,
 258                                    char *buf)
 259 {
 260         struct pci_dev *pdev = to_pci_dev(dev);
 261
 262         return sprintf(buf, "%u\n", pci_sriov_get_totalvfs(pdev));
 263 }
 264
 265 static ssize_t sriov_numvfs_show(struct device *dev,
 266                                  struct device_attribute *attr,
 267                                  char *buf)
 268 {
 269         struct pci_dev *pdev = to_pci_dev(dev);
 270         u16 num_vfs;
 271
 272         /* Serialize vs sriov_numvfs_store() so readers see valid num_VFs */
 273         device_lock(&pdev->dev);
 274         num_vfs = pdev->sriov->num_VFs;
 275         device_unlock(&pdev->dev);
 276
 277         return sprintf(buf, "%u\n", num_vfs);
 278 }
 279
 280 /*
 281  * num_vfs > 0; number of VFs to enable
 282  * num_vfs = 0; disable all VFs
 283  *
 284  * Note: SRIOV spec does not allow partial VF
 285  *       disable, so it's all or none.
 286  */
 287 static ssize_t sriov_numvfs_store(struct device *dev,
 288                                   struct device_attribute *attr,
 289                                   const char *buf, size_t count)
 290 {
 291         struct pci_dev *pdev = to_pci_dev(dev);
 292         int ret;
 293         u16 num_vfs;
 294
 295         ret = kstrtou16(buf, 0, &num_vfs);
 296         if (ret < 0)
 297                 return ret;
 298
 299         if (num_vfs > pci_sriov_get_totalvfs(pdev))
 300                 return -ERANGE;
 301
 302         device_lock(&pdev->dev);
 303
 304         if (num_vfs == pdev->sriov->num_VFs)
 305                 goto exit;
 306
 307         /* is PF driver loaded w/callback */
 308         if (!pdev->driver || !pdev->driver->sriov_configure) {
 309                 pci_info(pdev, "Driver does not support SRIOV configuration via sysfs\n");
 310                 ret = -ENOENT;
 311                 goto exit;
 312         }
 313
 314         if (num_vfs == 0) {
 315                 /* disable VFs */
 316                 ret = pdev->driver->sriov_configure(pdev, 0);
 317                 goto exit;
 318         }
 319
 320         /* enable VFs */
 321         if (pdev->sriov->num_VFs) {
 322                 pci_warn(pdev, "%d VFs already enabled. Disable before enabling %d VFs\n",
 323                          pdev->sriov->num_VFs, num_vfs);
 324                 ret = -EBUSY;
 325                 goto exit;
 326         }
 327
 328         ret = pdev->driver->sriov_configure(pdev, num_vfs);
 329         if (ret < 0)
 330                 goto exit;
 331
 332         if (ret != num_vfs)
 333                 pci_warn(pdev, "%d VFs requested; only %d enabled\n",
 334                          num_vfs, ret);
 335
 336 exit:
 337         device_unlock(&pdev->dev);
 338
 339         if (ret < 0)
 340                 return ret;
 341
 342         return count;
 343 }
 344
 345 static ssize_t sriov_offset_show(struct device *dev,
 346                                  struct device_attribute *attr,
 347                                  char *buf)
 348 {
 349         struct pci_dev *pdev = to_pci_dev(dev);
 350
 351         return sprintf(buf, "%u\n", pdev->sriov->offset);
 352 }
 353
 354 static ssize_t sriov_stride_show(struct device *dev,
 355                                  struct device_attribute *attr,
 356                                  char *buf)
 357 {
 358         struct pci_dev *pdev = to_pci_dev(dev);
 359
 360         return sprintf(buf, "%u\n", pdev->sriov->stride);
 361 }
 362
 363 static ssize_t sriov_vf_device_show(struct device *dev,
 364                                     struct device_attribute *attr,
 365                                     char *buf)
 366 {
 367         struct pci_dev *pdev = to_pci_dev(dev);
 368
 369         return sprintf(buf, "%x\n", pdev->sriov->vf_device);
 370 }
 371
 372 static ssize_t sriov_drivers_autoprobe_show(struct device *dev,
 373                                             struct device_attribute *attr,
 374                                             char *buf)
 375 {
 376         struct pci_dev *pdev = to_pci_dev(dev);
 377
 378         return sprintf(buf, "%u\n", pdev->sriov->drivers_autoprobe);
 379 }
 380
 381 static ssize_t sriov_drivers_autoprobe_store(struct device *dev,
 382                                              struct device_attribute *attr,
 383                                              const char *buf, size_t count)
 384 {
 385         struct pci_dev *pdev = to_pci_dev(dev);
 386         bool drivers_autoprobe;
 387
 388         if (kstrtobool(buf, &drivers_autoprobe) < 0)
 389                 return -EINVAL;
 390
 391         pdev->sriov->drivers_autoprobe = drivers_autoprobe;
 392
 393         return count;
 394 }
 395
 396 static DEVICE_ATTR_RO(sriov_totalvfs);
 397 static DEVICE_ATTR_RW(sriov_numvfs);
 398 static DEVICE_ATTR_RO(sriov_offset);
 399 static DEVICE_ATTR_RO(sriov_stride);
 400 static DEVICE_ATTR_RO(sriov_vf_device);
 401 static DEVICE_ATTR_RW(sriov_drivers_autoprobe);
 402
 403 static struct attribute *sriov_dev_attrs[] = {
 404         &dev_attr_sriov_totalvfs.attr,
 405         &dev_attr_sriov_numvfs.attr,
 406         &dev_attr_sriov_offset.attr,
 407         &dev_attr_sriov_stride.attr,
 408         &dev_attr_sriov_vf_device.attr,
 409         &dev_attr_sriov_drivers_autoprobe.attr,
 410         NULL,
 411 };
 412
 413 static umode_t sriov_attrs_are_visible(struct kobject *kobj,
 414                                        struct attribute *a, int n)
 415 {
 416         struct device *dev = kobj_to_dev(kobj);
 417
 418         if (!dev_is_pf(dev))
 419                 return 0;
 420
 421         return a->mode;
 422 }
 423
 424 const struct attribute_group sriov_dev_attr_group = {
 425         .attrs = sriov_dev_attrs,
 426         .is_visible = sriov_attrs_are_visible,
 427 };
 428
 429 int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
 430 {
 431         return 0;
 432 }
 433
 434 int __weak pcibios_sriov_disable(struct pci_dev *pdev)
 435 {
 436         return 0;
 437 }
 438
 439 static int sriov_add_vfs(struct pci_dev *dev, u16 num_vfs)
 440 {
 441         unsigned int i;
 442         int rc;
 443
 444         if (dev->no_vf_scan)
 445                 return 0;
 446
 447         for (i = 0; i < num_vfs; i++) {
 448                 rc = pci_iov_add_virtfn(dev, i);
 449                 if (rc)
 450                         goto failed;
 451         }
 452         return 0;
 453 failed:
 454         while (i--)
 455                 pci_iov_remove_virtfn(dev, i);
 456
 457         return rc;
 458 }
 459
 460 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 461 {
 462         int rc;
 463         int i;
 464         int nres;
 465         u16 initial;
 466         struct resource *res;
 467         struct pci_dev *pdev;
 468         struct pci_sriov *iov = dev->sriov;
 469         int bars = 0;
 470         int bus;
 471
 472         if (!nr_virtfn)
 473                 return 0;
 474
 475         if (iov->num_VFs)
 476                 return -EINVAL;
 477
 478         pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
 479         if (initial > iov->total_VFs ||
 480             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
 481                 return -EIO;
 482
 483         if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
 484             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 485                 return -EINVAL;
 486
 487         nres = 0;
 488         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 489                 bars |= (1 << (i + PCI_IOV_RESOURCES));
 490                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 491                 if (res->parent)
 492                         nres++;
 493         }
 494         if (nres != iov->nres) {
 495                 pci_err(dev, "not enough MMIO resources for SR-IOV\n");
 496                 return -ENOMEM;
 497         }
 498
 499         bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
 500         if (bus > dev->bus->busn_res.end) {
 501                 pci_err(dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
 502                         nr_virtfn, bus, &dev->bus->busn_res);
 503                 return -ENOMEM;
 504         }
 505
 506         if (pci_enable_resources(dev, bars)) {
 507                 pci_err(dev, "SR-IOV: IOV BARS not allocated\n");
 508                 return -ENOMEM;
 509         }
 510
 511         if (iov->link != dev->devfn) {
 512                 pdev = pci_get_slot(dev->bus, iov->link);
 513                 if (!pdev)
 514                         return -ENODEV;
 515
 516                 if (!pdev->is_physfn) {
 517                         pci_dev_put(pdev);
 518                         return -ENOSYS;
 519                 }
 520
 521                 rc = sysfs_create_link(&dev->dev.kobj,
 522                                         &pdev->dev.kobj, "dep_link");
 523                 pci_dev_put(pdev);
 524                 if (rc)
 525                         return rc;
 526         }
 527
 528         iov->initial_VFs = initial;
 529         if (nr_virtfn < initial)
 530                 initial = nr_virtfn;
 531
 532         rc = pcibios_sriov_enable(dev, initial);
 533         if (rc) {
 534                 pci_err(dev, "failure %d from pcibios_sriov_enable()\n", rc);
 535                 goto err_pcibios;
 536         }
 537
 538         pci_iov_set_numvfs(dev, nr_virtfn);
 539         iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 540         pci_cfg_access_lock(dev);
 541         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 542         msleep(100);
 543         pci_cfg_access_unlock(dev);
 544
 545         rc = sriov_add_vfs(dev, initial);
 546         if (rc)
 547                 goto err_pcibios;
 548
 549         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 550         iov->num_VFs = nr_virtfn;
 551
 552         return 0;
 553
 554 err_pcibios:
 555         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 556         pci_cfg_access_lock(dev);
 557         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 558         ssleep(1);
 559         pci_cfg_access_unlock(dev);
 560
 561         pcibios_sriov_disable(dev);
 562
 563         if (iov->link != dev->devfn)
 564                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 565
 566         pci_iov_set_numvfs(dev, 0);
 567         return rc;
 568 }
 569
 570 static void sriov_del_vfs(struct pci_dev *dev)
 571 {
 572         struct pci_sriov *iov = dev->sriov;
 573         int i;
 574
 575         for (i = 0; i < iov->num_VFs; i++)
 576                 pci_iov_remove_virtfn(dev, i);
 577 }
 578
 579 static void sriov_disable(struct pci_dev *dev)
 580 {
 581         struct pci_sriov *iov = dev->sriov;
 582
 583         if (!iov->num_VFs)
 584                 return;
 585
 586         sriov_del_vfs(dev);
 587         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 588         pci_cfg_access_lock(dev);
 589         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 590         ssleep(1);
 591         pci_cfg_access_unlock(dev);
 592
 593         pcibios_sriov_disable(dev);
 594
 595         if (iov->link != dev->devfn)
 596                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 597
 598         iov->num_VFs = 0;
 599         pci_iov_set_numvfs(dev, 0);
 600 }
 601
 602 static int sriov_init(struct pci_dev *dev, int pos)
 603 {
 604         int i, bar64;
 605         int rc;
 606         int nres;
 607         u32 pgsz;
 608         u16 ctrl, total;
 609         struct pci_sriov *iov;
 610         struct resource *res;
 611         struct pci_dev *pdev;
 612
 613         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 614         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 615                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 616                 ssleep(1);
 617         }
 618
 619         ctrl = 0;
 620         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 621                 if (pdev->is_physfn)
 622                         goto found;
 623
 624         pdev = NULL;
 625         if (pci_ari_enabled(dev->bus))
 626                 ctrl |= PCI_SRIOV_CTRL_ARI;
 627
 628 found:
 629         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 630
 631         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 632         if (!total)
 633                 return 0;
 634
 635         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 636         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 637         pgsz &= ~((1 << i) - 1);
 638         if (!pgsz)
 639                 return -EIO;
 640
 641         pgsz &= ~(pgsz - 1);
 642         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 643
 644         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 645         if (!iov)
 646                 return -ENOMEM;
 647
 648         nres = 0;
 649         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 650                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 651                 /*
 652                  * If it is already FIXED, don't change it, something
 653                  * (perhaps EA or header fixups) wants it this way.
 654                  */
 655                 if (res->flags & IORESOURCE_PCI_FIXED)
 656                         bar64 = (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
 657                 else
 658                         bar64 = __pci_read_base(dev, pci_bar_unknown, res,
 659                                                 pos + PCI_SRIOV_BAR + i * 4);
 660                 if (!res->flags)
 661                         continue;
 662                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 663                         rc = -EIO;
 664                         goto failed;
 665                 }
 666                 iov->barsz[i] = resource_size(res);
 667                 res->end = res->start + resource_size(res) * total - 1;
 668                 pci_info(dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
 669                          i, res, i, total);
 670                 i += bar64;
 671                 nres++;
 672         }
 673
 674         iov->pos = pos;
 675         iov->nres = nres;
 676         iov->ctrl = ctrl;
 677         iov->total_VFs = total;
 678         iov->driver_max_VFs = total;
 679         pci_read_config_word(dev, pos + PCI_SRIOV_VF_DID, &iov->vf_device);
 680         iov->pgsz = pgsz;
 681         iov->self = dev;
 682         iov->drivers_autoprobe = true;
 683         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 684         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 685         if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
 686                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 687
 688         if (pdev)
 689                 iov->dev = pci_dev_get(pdev);
 690         else
 691                 iov->dev = dev;
 692
 693         dev->sriov = iov;
 694         dev->is_physfn = 1;
 695         rc = compute_max_vf_buses(dev);
 696         if (rc)
 697                 goto fail_max_buses;
 698
 699         return 0;
 700
 701 fail_max_buses:
 702         dev->sriov = NULL;
 703         dev->is_physfn = 0;
 704 failed:
 705         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 706                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 707                 res->flags = 0;
 708         }
 709
 710         kfree(iov);
 711         return rc;
 712 }
 713
 714 static void sriov_release(struct pci_dev *dev)
 715 {
 716         BUG_ON(dev->sriov->num_VFs);
 717
 718         if (dev != dev->sriov->dev)
 719                 pci_dev_put(dev->sriov->dev);
 720
 721         kfree(dev->sriov);
 722         dev->sriov = NULL;
 723 }
 724
 725 static void sriov_restore_state(struct pci_dev *dev)
 726 {
 727         int i;
 728         u16 ctrl;
 729         struct pci_sriov *iov = dev->sriov;
 730
 731         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 732         if (ctrl & PCI_SRIOV_CTRL_VFE)
 733                 return;
 734
 735         /*
 736          * Restore PCI_SRIOV_CTRL_ARI before pci_iov_set_numvfs() because
 737          * it reads offset & stride, which depend on PCI_SRIOV_CTRL_ARI.
 738          */
 739         ctrl &= ~PCI_SRIOV_CTRL_ARI;
 740         ctrl |= iov->ctrl & PCI_SRIOV_CTRL_ARI;
 741         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, ctrl);
 742
 743         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++)
 744                 pci_update_resource(dev, i + PCI_IOV_RESOURCES);
 745
 746         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 747         pci_iov_set_numvfs(dev, iov->num_VFs);
 748         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 749         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 750                 msleep(100);
 751 }
 752
 753 /**
 754  * pci_iov_init - initialize the IOV capability
 755  * @dev: the PCI device
 756  *
 757  * Returns 0 on success, or negative on failure.
 758  */
 759 int pci_iov_init(struct pci_dev *dev)
 760 {
 761         int pos;
 762
 763         if (!pci_is_pcie(dev))
 764                 return -ENODEV;
 765
 766         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 767         if (pos)
 768                 return sriov_init(dev, pos);
 769
 770         return -ENODEV;
 771 }
 772
 773 /**
 774  * pci_iov_release - release resources used by the IOV capability
 775  * @dev: the PCI device
 776  */
 777 void pci_iov_release(struct pci_dev *dev)
 778 {
 779         if (dev->is_physfn)
 780                 sriov_release(dev);
 781 }
 782
 783 /**
 784  * pci_iov_remove - clean up SR-IOV state after PF driver is detached
 785  * @dev: the PCI device
 786  */
 787 void pci_iov_remove(struct pci_dev *dev)
 788 {
 789         struct pci_sriov *iov = dev->sriov;
 790
 791         if (!dev->is_physfn)
 792                 return;
 793
 794         iov->driver_max_VFs = iov->total_VFs;
 795         if (iov->num_VFs)
 796                 pci_warn(dev, "driver left SR-IOV enabled after remove\n");
 797 }
 798
 799 /**
 800  * pci_iov_update_resource - update a VF BAR
 801  * @dev: the PCI device
 802  * @resno: the resource number
 803  *
 804  * Update a VF BAR in the SR-IOV capability of a PF.
 805  */
 806 void pci_iov_update_resource(struct pci_dev *dev, int resno)
 807 {
 808         struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL;
 809         struct resource *res = dev->resource + resno;
 810         int vf_bar = resno - PCI_IOV_RESOURCES;
 811         struct pci_bus_region region;
 812         u16 cmd;
 813         u32 new;
 814         int reg;
 815
 816         /*
 817          * The generic pci_restore_bars() path calls this for all devices,
 818          * including VFs and non-SR-IOV devices.  If this is not a PF, we
 819          * have nothing to do.
 820          */
 821         if (!iov)
 822                 return;
 823
 824         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &cmd);
 825         if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) {
 826                 dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n",
 827                          vf_bar, res);
 828                 return;
 829         }
 830
 831         /*
 832          * Ignore unimplemented BARs, unused resource slots for 64-bit
 833          * BARs, and non-movable resources, e.g., those described via
 834          * Enhanced Allocation.
 835          */
 836         if (!res->flags)
 837                 return;
 838
 839         if (res->flags & IORESOURCE_UNSET)
 840                 return;
 841
 842         if (res->flags & IORESOURCE_PCI_FIXED)
 843                 return;
 844
 845         pcibios_resource_to_bus(dev->bus, &region, res);
 846         new = region.start;
 847         new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
 848
 849         reg = iov->pos + PCI_SRIOV_BAR + 4 * vf_bar;
 850         pci_write_config_dword(dev, reg, new);
 851         if (res->flags & IORESOURCE_MEM_64) {
 852                 new = region.start >> 16 >> 16;
 853                 pci_write_config_dword(dev, reg + 4, new);
 854         }
 855 }
 856
 857 resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
 858                                                       int resno)
 859 {
 860         return pci_iov_resource_size(dev, resno);
 861 }
 862
 863 /**
 864  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 865  * @dev: the PCI device
 866  * @resno: the resource number
 867  *
 868  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 869  * This is not the same as the resource size which is defined as
 870  * the VF BAR size multiplied by the number of VFs.  The alignment
 871  * is just the VF BAR size.
 872  */
 873 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 874 {
 875         return pcibios_iov_resource_alignment(dev, resno);
 876 }
 877
 878 /**
 879  * pci_restore_iov_state - restore the state of the IOV capability
 880  * @dev: the PCI device
 881  */
 882 void pci_restore_iov_state(struct pci_dev *dev)
 883 {
 884         if (dev->is_physfn)
 885                 sriov_restore_state(dev);
 886 }
 887
 888 /**
 889  * pci_vf_drivers_autoprobe - set PF property drivers_autoprobe for VFs
 890  * @dev: the PCI device
 891  * @auto_probe: set VF drivers auto probe flag
 892  */
 893 void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool auto_probe)
 894 {
 895         if (dev->is_physfn)
 896                 dev->sriov->drivers_autoprobe = auto_probe;
 897 }
 898
 899 /**
 900  * pci_iov_bus_range - find bus range used by Virtual Function
 901  * @bus: the PCI bus
 902  *
 903  * Returns max number of buses (exclude current one) used by Virtual
 904  * Functions.
 905  */
 906 int pci_iov_bus_range(struct pci_bus *bus)
 907 {
 908         int max = 0;
 909         struct pci_dev *dev;
 910
 911         list_for_each_entry(dev, &bus->devices, bus_list) {
 912                 if (!dev->is_physfn)
 913                         continue;
 914                 if (dev->sriov->max_VF_buses > max)
 915                         max = dev->sriov->max_VF_buses;
 916         }
 917
 918         return max ? max - bus->number : 0;
 919 }
 920
 921 /**
 922  * pci_enable_sriov - enable the SR-IOV capability
 923  * @dev: the PCI device
 924  * @nr_virtfn: number of virtual functions to enable
 925  *
 926  * Returns 0 on success, or negative on failure.
 927  */
 928 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 929 {
 930         might_sleep();
 931
 932         if (!dev->is_physfn)
 933                 return -ENOSYS;
 934
 935         return sriov_enable(dev, nr_virtfn);
 936 }
 937 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 938
 939 /**
 940  * pci_disable_sriov - disable the SR-IOV capability
 941  * @dev: the PCI device
 942  */
 943 void pci_disable_sriov(struct pci_dev *dev)
 944 {
 945         might_sleep();
 946
 947         if (!dev->is_physfn)
 948                 return;
 949
 950         sriov_disable(dev);
 951 }
 952 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 953
 954 /**
 955  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 956  * @dev: the PCI device
 957  *
 958  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 959  */
 960 int pci_num_vf(struct pci_dev *dev)
 961 {
 962         if (!dev->is_physfn)
 963                 return 0;
 964
 965         return dev->sriov->num_VFs;
 966 }
 967 EXPORT_SYMBOL_GPL(pci_num_vf);
 968
 969 /**
 970  * pci_vfs_assigned - returns number of VFs are assigned to a guest
 971  * @dev: the PCI device
 972  *
 973  * Returns number of VFs belonging to this device that are assigned to a guest.
 974  * If device is not a physical function returns 0.
 975  */
 976 int pci_vfs_assigned(struct pci_dev *dev)
 977 {
 978         struct pci_dev *vfdev;
 979         unsigned int vfs_assigned = 0;
 980         unsigned short dev_id;
 981
 982         /* only search if we are a PF */
 983         if (!dev->is_physfn)
 984                 return 0;
 985
 986         /*
 987          * determine the device ID for the VFs, the vendor ID will be the
 988          * same as the PF so there is no need to check for that one
 989          */
 990         dev_id = dev->sriov->vf_device;
 991
 992         /* loop through all the VFs to see if we own any that are assigned */
 993         vfdev = pci_get_device(dev->vendor, dev_id, NULL);
 994         while (vfdev) {
 995                 /*
 996                  * It is considered assigned if it is a virtual function with
 997                  * our dev as the physical function and the assigned bit is set
 998                  */
 999                 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
1000                         pci_is_dev_assigned(vfdev))
1001                         vfs_assigned++;
1002
1003                 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
1004         }
1005
1006         return vfs_assigned;
1007 }
1008 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
1009
1010 /**
1011  * pci_sriov_set_totalvfs -- reduce the TotalVFs available
1012  * @dev: the PCI PF device
1013  * @numvfs: number that should be used for TotalVFs supported
1014  *
1015  * Should be called from PF driver's probe routine with
1016  * device's mutex held.
1017  *
1018  * Returns 0 if PF is an SRIOV-capable device and
1019  * value of numvfs valid. If not a PF return -ENOSYS;
1020  * if numvfs is invalid return -EINVAL;
1021  * if VFs already enabled, return -EBUSY.
1022  */
1023 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
1024 {
1025         if (!dev->is_physfn)
1026                 return -ENOSYS;
1027
1028         if (numvfs > dev->sriov->total_VFs)
1029                 return -EINVAL;
1030
1031         /* Shouldn't change if VFs already enabled */
1032         if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
1033                 return -EBUSY;
1034
1035         dev->sriov->driver_max_VFs = numvfs;
1036         return 0;
1037 }
1038 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
1039
1040 /**
1041  * pci_sriov_get_totalvfs -- get total VFs supported on this device
1042  * @dev: the PCI PF device
1043  *
1044  * For a PCIe device with SRIOV support, return the PCIe
1045  * SRIOV capability value of TotalVFs or the value of driver_max_VFs
1046  * if the driver reduced it.  Otherwise 0.
1047  */
1048 int pci_sriov_get_totalvfs(struct pci_dev *dev)
1049 {
1050         if (!dev->is_physfn)
1051                 return 0;
1052
1053         return dev->sriov->driver_max_VFs;
1054 }
1055 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);
1056
1057 /**
1058  * pci_sriov_configure_simple - helper to configure SR-IOV
1059  * @dev: the PCI device
1060  * @nr_virtfn: number of virtual functions to enable, 0 to disable
1061  *
1062  * Enable or disable SR-IOV for devices that don't require any PF setup
1063  * before enabling SR-IOV.  Return value is negative on error, or number of
1064  * VFs allocated on success.
1065  */
1066 int pci_sriov_configure_simple(struct pci_dev *dev, int nr_virtfn)
1067 {
1068         int rc;
1069
1070         might_sleep();
1071
1072         if (!dev->is_physfn)
1073                 return -ENODEV;
1074
1075         if (pci_vfs_assigned(dev)) {
1076                 pci_warn(dev, "Cannot modify SR-IOV while VFs are assigned\n");
1077                 return -EPERM;
1078         }
1079
1080         if (nr_virtfn == 0) {
1081                 sriov_disable(dev);
1082                 return 0;
1083         }
1084
1085         rc = sriov_enable(dev, nr_virtfn);
1086         if (rc < 0)
1087                 return rc;
1088
1089         return nr_virtfn;
1090 }
1091 EXPORT_SYMBOL_GPL(pci_sriov_configure_simple);