drivers/pci/iov.c

   1 /*
   2  * drivers/pci/iov.c
   3  *
   4  * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com>
   5  *
   6  * PCI Express I/O Virtualization (IOV) support.
   7  *   Single Root IOV 1.0
   8  *   Address Translation Service 1.0
   9  */
  10
  11 #include <linux/pci.h>
  12 #include <linux/slab.h>
  13 #include <linux/mutex.h>
  14 #include <linux/export.h>
  15 #include <linux/string.h>
  16 #include <linux/delay.h>
  17 #include <linux/pci-ats.h>
  18 #include "pci.h"
  19
  20 #define VIRTFN_ID_LEN   16
  21
  22 static inline u8 virtfn_bus(struct pci_dev *dev, int id)
  23 {
  24         return dev->bus->number + ((dev->devfn + dev->sriov->offset +
  25                                     dev->sriov->stride * id) >> 8);
  26 }
  27
  28 static inline u8 virtfn_devfn(struct pci_dev *dev, int id)
  29 {
  30         return (dev->devfn + dev->sriov->offset +
  31                 dev->sriov->stride * id) & 0xff;
  32 }
  33
  34 static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
  35 {
  36         struct pci_bus *child;
  37
  38         if (bus->number == busnr)
  39                 return bus;
  40
  41         child = pci_find_bus(pci_domain_nr(bus), busnr);
  42         if (child)
  43                 return child;
  44
  45         child = pci_add_new_bus(bus, NULL, busnr);
  46         if (!child)
  47                 return NULL;
  48
  49         pci_bus_insert_busn_res(child, busnr, busnr);
  50
  51         return child;
  52 }
  53
  54 static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus)
  55 {
  56         if (physbus != virtbus && list_empty(&virtbus->devices))
  57                 pci_remove_bus(virtbus);
  58 }
  59
  60 static int virtfn_add(struct pci_dev *dev, int id, int reset)
  61 {
  62         int i;
  63         int rc = -ENOMEM;
  64         u64 size;
  65         char buf[VIRTFN_ID_LEN];
  66         struct pci_dev *virtfn;
  67         struct resource *res;
  68         struct pci_sriov *iov = dev->sriov;
  69         struct pci_bus *bus;
  70
  71         mutex_lock(&iov->dev->sriov->lock);
  72         bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id));
  73         if (!bus)
  74                 goto failed;
  75
  76         virtfn = pci_alloc_dev(bus);
  77         if (!virtfn)
  78                 goto failed0;
  79
  80         virtfn->devfn = virtfn_devfn(dev, id);
  81         virtfn->vendor = dev->vendor;
  82         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
  83         pci_setup_device(virtfn);
  84         virtfn->dev.parent = dev->dev.parent;
  85         virtfn->physfn = pci_dev_get(dev);
  86         virtfn->is_virtfn = 1;
  87
  88         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
  89                 res = dev->resource + PCI_IOV_RESOURCES + i;
  90                 if (!res->parent)
  91                         continue;
  92                 virtfn->resource[i].name = pci_name(virtfn);
  93                 virtfn->resource[i].flags = res->flags;
  94                 size = resource_size(res);
  95                 do_div(size, iov->total_VFs);
  96                 virtfn->resource[i].start = res->start + size * id;
  97                 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
  98                 rc = request_resource(res, &virtfn->resource[i]);
  99                 BUG_ON(rc);
 100         }
 101
 102         if (reset)
 103                 __pci_reset_function(virtfn);
 104
 105         pci_device_add(virtfn, virtfn->bus);
 106         mutex_unlock(&iov->dev->sriov->lock);
 107
 108         rc = pci_bus_add_device(virtfn);
 109         sprintf(buf, "virtfn%u", id);
 110         rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
 111         if (rc)
 112                 goto failed1;
 113         rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
 114         if (rc)
 115                 goto failed2;
 116
 117         kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
 118
 119         return 0;
 120
 121 failed2:
 122         sysfs_remove_link(&dev->dev.kobj, buf);
 123 failed1:
 124         pci_dev_put(dev);
 125         mutex_lock(&iov->dev->sriov->lock);
 126         pci_stop_and_remove_bus_device(virtfn);
 127 failed0:
 128         virtfn_remove_bus(dev->bus, bus);
 129 failed:
 130         mutex_unlock(&iov->dev->sriov->lock);
 131
 132         return rc;
 133 }
 134
 135 static void virtfn_remove(struct pci_dev *dev, int id, int reset)
 136 {
 137         char buf[VIRTFN_ID_LEN];
 138         struct pci_dev *virtfn;
 139         struct pci_sriov *iov = dev->sriov;
 140
 141         virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
 142                                              virtfn_bus(dev, id),
 143                                              virtfn_devfn(dev, id));
 144         if (!virtfn)
 145                 return;
 146
 147         if (reset) {
 148                 device_release_driver(&virtfn->dev);
 149                 __pci_reset_function(virtfn);
 150         }
 151
 152         sprintf(buf, "virtfn%u", id);
 153         sysfs_remove_link(&dev->dev.kobj, buf);
 154         /*
 155          * pci_stop_dev() could have been called for this virtfn already,
 156          * so the directory for the virtfn may have been removed before.
 157          * Double check to avoid spurious sysfs warnings.
 158          */
 159         if (virtfn->dev.kobj.sd)
 160                 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
 161
 162         mutex_lock(&iov->dev->sriov->lock);
 163         pci_stop_and_remove_bus_device(virtfn);
 164         virtfn_remove_bus(dev->bus, virtfn->bus);
 165         mutex_unlock(&iov->dev->sriov->lock);
 166
 167         /* balance pci_get_domain_bus_and_slot() */
 168         pci_dev_put(virtfn);
 169         pci_dev_put(dev);
 170 }
 171
 172 static int sriov_migration(struct pci_dev *dev)
 173 {
 174         u16 status;
 175         struct pci_sriov *iov = dev->sriov;
 176
 177         if (!iov->num_VFs)
 178                 return 0;
 179
 180         if (!(iov->cap & PCI_SRIOV_CAP_VFM))
 181                 return 0;
 182
 183         pci_read_config_word(dev, iov->pos + PCI_SRIOV_STATUS, &status);
 184         if (!(status & PCI_SRIOV_STATUS_VFM))
 185                 return 0;
 186
 187         schedule_work(&iov->mtask);
 188
 189         return 1;
 190 }
 191
 192 static void sriov_migration_task(struct work_struct *work)
 193 {
 194         int i;
 195         u8 state;
 196         u16 status;
 197         struct pci_sriov *iov = container_of(work, struct pci_sriov, mtask);
 198
 199         for (i = iov->initial_VFs; i < iov->num_VFs; i++) {
 200                 state = readb(iov->mstate + i);
 201                 if (state == PCI_SRIOV_VFM_MI) {
 202                         writeb(PCI_SRIOV_VFM_AV, iov->mstate + i);
 203                         state = readb(iov->mstate + i);
 204                         if (state == PCI_SRIOV_VFM_AV)
 205                                 virtfn_add(iov->self, i, 1);
 206                 } else if (state == PCI_SRIOV_VFM_MO) {
 207                         virtfn_remove(iov->self, i, 1);
 208                         writeb(PCI_SRIOV_VFM_UA, iov->mstate + i);
 209                         state = readb(iov->mstate + i);
 210                         if (state == PCI_SRIOV_VFM_AV)
 211                                 virtfn_add(iov->self, i, 0);
 212                 }
 213         }
 214
 215         pci_read_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, &status);
 216         status &= ~PCI_SRIOV_STATUS_VFM;
 217         pci_write_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, status);
 218 }
 219
 220 static int sriov_enable_migration(struct pci_dev *dev, int nr_virtfn)
 221 {
 222         int bir;
 223         u32 table;
 224         resource_size_t pa;
 225         struct pci_sriov *iov = dev->sriov;
 226
 227         if (nr_virtfn <= iov->initial_VFs)
 228                 return 0;
 229
 230         pci_read_config_dword(dev, iov->pos + PCI_SRIOV_VFM, &table);
 231         bir = PCI_SRIOV_VFM_BIR(table);
 232         if (bir > PCI_STD_RESOURCE_END)
 233                 return -EIO;
 234
 235         table = PCI_SRIOV_VFM_OFFSET(table);
 236         if (table + nr_virtfn > pci_resource_len(dev, bir))
 237                 return -EIO;
 238
 239         pa = pci_resource_start(dev, bir) + table;
 240         iov->mstate = ioremap(pa, nr_virtfn);
 241         if (!iov->mstate)
 242                 return -ENOMEM;
 243
 244         INIT_WORK(&iov->mtask, sriov_migration_task);
 245
 246         iov->ctrl |= PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR;
 247         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 248
 249         return 0;
 250 }
 251
 252 static void sriov_disable_migration(struct pci_dev *dev)
 253 {
 254         struct pci_sriov *iov = dev->sriov;
 255
 256         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR);
 257         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 258
 259         cancel_work_sync(&iov->mtask);
 260         iounmap(iov->mstate);
 261 }
 262
 263 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 264 {
 265         int rc;
 266         int i, j;
 267         int nres;
 268         u16 offset, stride, initial;
 269         struct resource *res;
 270         struct pci_dev *pdev;
 271         struct pci_sriov *iov = dev->sriov;
 272         int bars = 0;
 273
 274         if (!nr_virtfn)
 275                 return 0;
 276
 277         if (iov->num_VFs)
 278                 return -EINVAL;
 279
 280         pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
 281         if (initial > iov->total_VFs ||
 282             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
 283                 return -EIO;
 284
 285         if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
 286             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 287                 return -EINVAL;
 288
 289         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &offset);
 290         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &stride);
 291         if (!offset || (nr_virtfn > 1 && !stride))
 292                 return -EIO;
 293
 294         nres = 0;
 295         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 296                 bars |= (1 << (i + PCI_IOV_RESOURCES));
 297                 res = dev->resource + PCI_IOV_RESOURCES + i;
 298                 if (res->parent)
 299                         nres++;
 300         }
 301         if (nres != iov->nres) {
 302                 dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
 303                 return -ENOMEM;
 304         }
 305
 306         iov->offset = offset;
 307         iov->stride = stride;
 308
 309         if (virtfn_bus(dev, nr_virtfn - 1) > dev->bus->busn_res.end) {
 310                 dev_err(&dev->dev, "SR-IOV: bus number out of range\n");
 311                 return -ENOMEM;
 312         }
 313
 314         if (pci_enable_resources(dev, bars)) {
 315                 dev_err(&dev->dev, "SR-IOV: IOV BARS not allocated\n");
 316                 return -ENOMEM;
 317         }
 318
 319         if (iov->link != dev->devfn) {
 320                 pdev = pci_get_slot(dev->bus, iov->link);
 321                 if (!pdev)
 322                         return -ENODEV;
 323
 324                 if (!pdev->is_physfn) {
 325                         pci_dev_put(pdev);
 326                         return -ENOSYS;
 327                 }
 328
 329                 rc = sysfs_create_link(&dev->dev.kobj,
 330                                         &pdev->dev.kobj, "dep_link");
 331                 pci_dev_put(pdev);
 332                 if (rc)
 333                         return rc;
 334         }
 335
 336         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
 337         iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 338         pci_cfg_access_lock(dev);
 339         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 340         msleep(100);
 341         pci_cfg_access_unlock(dev);
 342
 343         iov->initial_VFs = initial;
 344         if (nr_virtfn < initial)
 345                 initial = nr_virtfn;
 346
 347         for (i = 0; i < initial; i++) {
 348                 rc = virtfn_add(dev, i, 0);
 349                 if (rc)
 350                         goto failed;
 351         }
 352
 353         if (iov->cap & PCI_SRIOV_CAP_VFM) {
 354                 rc = sriov_enable_migration(dev, nr_virtfn);
 355                 if (rc)
 356                         goto failed;
 357         }
 358
 359         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 360         iov->num_VFs = nr_virtfn;
 361
 362         return 0;
 363
 364 failed:
 365         for (j = 0; j < i; j++)
 366                 virtfn_remove(dev, j, 0);
 367
 368         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 369         pci_cfg_access_lock(dev);
 370         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 371         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, 0);
 372         ssleep(1);
 373         pci_cfg_access_unlock(dev);
 374
 375         if (iov->link != dev->devfn)
 376                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 377
 378         return rc;
 379 }
 380
 381 static void sriov_disable(struct pci_dev *dev)
 382 {
 383         int i;
 384         struct pci_sriov *iov = dev->sriov;
 385
 386         if (!iov->num_VFs)
 387                 return;
 388
 389         if (iov->cap & PCI_SRIOV_CAP_VFM)
 390                 sriov_disable_migration(dev);
 391
 392         for (i = 0; i < iov->num_VFs; i++)
 393                 virtfn_remove(dev, i, 0);
 394
 395         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 396         pci_cfg_access_lock(dev);
 397         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 398         ssleep(1);
 399         pci_cfg_access_unlock(dev);
 400
 401         if (iov->link != dev->devfn)
 402                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 403
 404         iov->num_VFs = 0;
 405         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, 0);
 406 }
 407
 408 static int sriov_init(struct pci_dev *dev, int pos)
 409 {
 410         int i;
 411         int rc;
 412         int nres;
 413         u32 pgsz;
 414         u16 ctrl, total, offset, stride;
 415         struct pci_sriov *iov;
 416         struct resource *res;
 417         struct pci_dev *pdev;
 418
 419         if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END &&
 420             pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT)
 421                 return -ENODEV;
 422
 423         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 424         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 425                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 426                 ssleep(1);
 427         }
 428
 429         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 430         if (!total)
 431                 return 0;
 432
 433         ctrl = 0;
 434         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 435                 if (pdev->is_physfn)
 436                         goto found;
 437
 438         pdev = NULL;
 439         if (pci_ari_enabled(dev->bus))
 440                 ctrl |= PCI_SRIOV_CTRL_ARI;
 441
 442 found:
 443         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 444         pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
 445         pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
 446         if (!offset || (total > 1 && !stride))
 447                 return -EIO;
 448
 449         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 450         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 451         pgsz &= ~((1 << i) - 1);
 452         if (!pgsz)
 453                 return -EIO;
 454
 455         pgsz &= ~(pgsz - 1);
 456         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 457
 458         nres = 0;
 459         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 460                 res = dev->resource + PCI_IOV_RESOURCES + i;
 461                 i += __pci_read_base(dev, pci_bar_unknown, res,
 462                                      pos + PCI_SRIOV_BAR + i * 4);
 463                 if (!res->flags)
 464                         continue;
 465                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 466                         rc = -EIO;
 467                         goto failed;
 468                 }
 469                 res->end = res->start + resource_size(res) * total - 1;
 470                 nres++;
 471         }
 472
 473         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 474         if (!iov) {
 475                 rc = -ENOMEM;
 476                 goto failed;
 477         }
 478
 479         iov->pos = pos;
 480         iov->nres = nres;
 481         iov->ctrl = ctrl;
 482         iov->total_VFs = total;
 483         iov->offset = offset;
 484         iov->stride = stride;
 485         iov->pgsz = pgsz;
 486         iov->self = dev;
 487         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 488         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 489         if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
 490                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 491
 492         if (pdev)
 493                 iov->dev = pci_dev_get(pdev);
 494         else
 495                 iov->dev = dev;
 496
 497         mutex_init(&iov->lock);
 498
 499         dev->sriov = iov;
 500         dev->is_physfn = 1;
 501
 502         return 0;
 503
 504 failed:
 505         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 506                 res = dev->resource + PCI_IOV_RESOURCES + i;
 507                 res->flags = 0;
 508         }
 509
 510         return rc;
 511 }
 512
 513 static void sriov_release(struct pci_dev *dev)
 514 {
 515         BUG_ON(dev->sriov->num_VFs);
 516
 517         if (dev != dev->sriov->dev)
 518                 pci_dev_put(dev->sriov->dev);
 519
 520         mutex_destroy(&dev->sriov->lock);
 521
 522         kfree(dev->sriov);
 523         dev->sriov = NULL;
 524 }
 525
 526 static void sriov_restore_state(struct pci_dev *dev)
 527 {
 528         int i;
 529         u16 ctrl;
 530         struct pci_sriov *iov = dev->sriov;
 531
 532         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 533         if (ctrl & PCI_SRIOV_CTRL_VFE)
 534                 return;
 535
 536         for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
 537                 pci_update_resource(dev, i);
 538
 539         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 540         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, iov->num_VFs);
 541         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 542         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 543                 msleep(100);
 544 }
 545
 546 /**
 547  * pci_iov_init - initialize the IOV capability
 548  * @dev: the PCI device
 549  *
 550  * Returns 0 on success, or negative on failure.
 551  */
 552 int pci_iov_init(struct pci_dev *dev)
 553 {
 554         int pos;
 555
 556         if (!pci_is_pcie(dev))
 557                 return -ENODEV;
 558
 559         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 560         if (pos)
 561                 return sriov_init(dev, pos);
 562
 563         return -ENODEV;
 564 }
 565
 566 /**
 567  * pci_iov_release - release resources used by the IOV capability
 568  * @dev: the PCI device
 569  */
 570 void pci_iov_release(struct pci_dev *dev)
 571 {
 572         if (dev->is_physfn)
 573                 sriov_release(dev);
 574 }
 575
 576 /**
 577  * pci_iov_resource_bar - get position of the SR-IOV BAR
 578  * @dev: the PCI device
 579  * @resno: the resource number
 580  * @type: the BAR type to be filled in
 581  *
 582  * Returns position of the BAR encapsulated in the SR-IOV capability.
 583  */
 584 int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 585                          enum pci_bar_type *type)
 586 {
 587         if (resno < PCI_IOV_RESOURCES || resno > PCI_IOV_RESOURCE_END)
 588                 return 0;
 589
 590         BUG_ON(!dev->is_physfn);
 591
 592         *type = pci_bar_unknown;
 593
 594         return dev->sriov->pos + PCI_SRIOV_BAR +
 595                 4 * (resno - PCI_IOV_RESOURCES);
 596 }
 597
 598 /**
 599  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 600  * @dev: the PCI device
 601  * @resno: the resource number
 602  *
 603  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 604  * This is not the same as the resource size which is defined as
 605  * the VF BAR size multiplied by the number of VFs.  The alignment
 606  * is just the VF BAR size.
 607  */
 608 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 609 {
 610         struct resource tmp;
 611         enum pci_bar_type type;
 612         int reg = pci_iov_resource_bar(dev, resno, &type);
 613
 614         if (!reg)
 615                 return 0;
 616
 617          __pci_read_base(dev, type, &tmp, reg);
 618         return resource_alignment(&tmp);
 619 }
 620
 621 /**
 622  * pci_restore_iov_state - restore the state of the IOV capability
 623  * @dev: the PCI device
 624  */
 625 void pci_restore_iov_state(struct pci_dev *dev)
 626 {
 627         if (dev->is_physfn)
 628                 sriov_restore_state(dev);
 629 }
 630
 631 /**
 632  * pci_iov_bus_range - find bus range used by Virtual Function
 633  * @bus: the PCI bus
 634  *
 635  * Returns max number of buses (exclude current one) used by Virtual
 636  * Functions.
 637  */
 638 int pci_iov_bus_range(struct pci_bus *bus)
 639 {
 640         int max = 0;
 641         u8 busnr;
 642         struct pci_dev *dev;
 643
 644         list_for_each_entry(dev, &bus->devices, bus_list) {
 645                 if (!dev->is_physfn)
 646                         continue;
 647                 busnr = virtfn_bus(dev, dev->sriov->total_VFs - 1);
 648                 if (busnr > max)
 649                         max = busnr;
 650         }
 651
 652         return max ? max - bus->number : 0;
 653 }
 654
 655 /**
 656  * pci_enable_sriov - enable the SR-IOV capability
 657  * @dev: the PCI device
 658  * @nr_virtfn: number of virtual functions to enable
 659  *
 660  * Returns 0 on success, or negative on failure.
 661  */
 662 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 663 {
 664         might_sleep();
 665
 666         if (!dev->is_physfn)
 667                 return -ENOSYS;
 668
 669         return sriov_enable(dev, nr_virtfn);
 670 }
 671 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 672
 673 /**
 674  * pci_disable_sriov - disable the SR-IOV capability
 675  * @dev: the PCI device
 676  */
 677 void pci_disable_sriov(struct pci_dev *dev)
 678 {
 679         might_sleep();
 680
 681         if (!dev->is_physfn)
 682                 return;
 683
 684         sriov_disable(dev);
 685 }
 686 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 687
 688 /**
 689  * pci_sriov_migration - notify SR-IOV core of Virtual Function Migration
 690  * @dev: the PCI device
 691  *
 692  * Returns IRQ_HANDLED if the IRQ is handled, or IRQ_NONE if not.
 693  *
 694  * Physical Function driver is responsible to register IRQ handler using
 695  * VF Migration Interrupt Message Number, and call this function when the
 696  * interrupt is generated by the hardware.
 697  */
 698 irqreturn_t pci_sriov_migration(struct pci_dev *dev)
 699 {
 700         if (!dev->is_physfn)
 701                 return IRQ_NONE;
 702
 703         return sriov_migration(dev) ? IRQ_HANDLED : IRQ_NONE;
 704 }
 705 EXPORT_SYMBOL_GPL(pci_sriov_migration);
 706
 707 /**
 708  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 709  * @dev: the PCI device
 710  *
 711  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 712  */
 713 int pci_num_vf(struct pci_dev *dev)
 714 {
 715         if (!dev->is_physfn)
 716                 return 0;
 717
 718         return dev->sriov->num_VFs;
 719 }
 720 EXPORT_SYMBOL_GPL(pci_num_vf);
 721
 722 /**
 723  * pci_vfs_assigned - returns number of VFs are assigned to a guest
 724  * @dev: the PCI device
 725  *
 726  * Returns number of VFs belonging to this device that are assigned to a guest.
 727  * If device is not a physical function returns 0.
 728  */
 729 int pci_vfs_assigned(struct pci_dev *dev)
 730 {
 731         struct pci_dev *vfdev;
 732         unsigned int vfs_assigned = 0;
 733         unsigned short dev_id;
 734
 735         /* only search if we are a PF */
 736         if (!dev->is_physfn)
 737                 return 0;
 738
 739         /*
 740          * determine the device ID for the VFs, the vendor ID will be the
 741          * same as the PF so there is no need to check for that one
 742          */
 743         pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_VF_DID, &dev_id);
 744
 745         /* loop through all the VFs to see if we own any that are assigned */
 746         vfdev = pci_get_device(dev->vendor, dev_id, NULL);
 747         while (vfdev) {
 748                 /*
 749                  * It is considered assigned if it is a virtual function with
 750                  * our dev as the physical function and the assigned bit is set
 751                  */
 752                 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
 753                     (vfdev->dev_flags & PCI_DEV_FLAGS_ASSIGNED))
 754                         vfs_assigned++;
 755
 756                 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
 757         }
 758
 759         return vfs_assigned;
 760 }
 761 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
 762
 763 /**
 764  * pci_sriov_set_totalvfs -- reduce the TotalVFs available
 765  * @dev: the PCI PF device
 766  * @numvfs: number that should be used for TotalVFs supported
 767  *
 768  * Should be called from PF driver's probe routine with
 769  * device's mutex held.
 770  *
 771  * Returns 0 if PF is an SRIOV-capable device and
 772  * value of numvfs valid. If not a PF return -ENOSYS;
 773  * if numvfs is invalid return -EINVAL;
 774  * if VFs already enabled, return -EBUSY.
 775  */
 776 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
 777 {
 778         if (!dev->is_physfn)
 779                 return -ENOSYS;
 780         if (numvfs > dev->sriov->total_VFs)
 781                 return -EINVAL;
 782
 783         /* Shouldn't change if VFs already enabled */
 784         if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
 785                 return -EBUSY;
 786         else
 787                 dev->sriov->driver_max_VFs = numvfs;
 788
 789         return 0;
 790 }
 791 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
 792
 793 /**
 794  * pci_sriov_get_totalvfs -- get total VFs supported on this device
 795  * @dev: the PCI PF device
 796  *
 797  * For a PCIe device with SRIOV support, return the PCIe
 798  * SRIOV capability value of TotalVFs or the value of driver_max_VFs
 799  * if the driver reduced it.  Otherwise 0.
 800  */
 801 int pci_sriov_get_totalvfs(struct pci_dev *dev)
 802 {
 803         if (!dev->is_physfn)
 804                 return 0;
 805
 806         if (dev->sriov->driver_max_VFs)
 807                 return dev->sriov->driver_max_VFs;
 808
 809         return dev->sriov->total_VFs;
 810 }
 811 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);