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_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
 290         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &offset);
 291         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &stride);
 292         if (!offset || (nr_virtfn > 1 && !stride))
 293                 return -EIO;
 294
 295         nres = 0;
 296         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 297                 bars |= (1 << (i + PCI_IOV_RESOURCES));
 298                 res = dev->resource + PCI_IOV_RESOURCES + i;
 299                 if (res->parent)
 300                         nres++;
 301         }
 302         if (nres != iov->nres) {
 303                 dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
 304                 return -ENOMEM;
 305         }
 306
 307         iov->offset = offset;
 308         iov->stride = stride;
 309
 310         if (virtfn_bus(dev, nr_virtfn - 1) > dev->bus->busn_res.end) {
 311                 dev_err(&dev->dev, "SR-IOV: bus number out of range\n");
 312                 return -ENOMEM;
 313         }
 314
 315         if (pci_enable_resources(dev, bars)) {
 316                 dev_err(&dev->dev, "SR-IOV: IOV BARS not allocated\n");
 317                 return -ENOMEM;
 318         }
 319
 320         if (iov->link != dev->devfn) {
 321                 pdev = pci_get_slot(dev->bus, iov->link);
 322                 if (!pdev)
 323                         return -ENODEV;
 324
 325                 if (!pdev->is_physfn) {
 326                         pci_dev_put(pdev);
 327                         return -ENODEV;
 328                 }
 329
 330                 rc = sysfs_create_link(&dev->dev.kobj,
 331                                         &pdev->dev.kobj, "dep_link");
 332                 pci_dev_put(pdev);
 333                 if (rc)
 334                         return rc;
 335         }
 336
 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         ssleep(1);
 372         pci_cfg_access_unlock(dev);
 373
 374         if (iov->link != dev->devfn)
 375                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 376
 377         return rc;
 378 }
 379
 380 static void sriov_disable(struct pci_dev *dev)
 381 {
 382         int i;
 383         struct pci_sriov *iov = dev->sriov;
 384
 385         if (!iov->num_VFs)
 386                 return;
 387
 388         if (iov->cap & PCI_SRIOV_CAP_VFM)
 389                 sriov_disable_migration(dev);
 390
 391         for (i = 0; i < iov->num_VFs; i++)
 392                 virtfn_remove(dev, i, 0);
 393
 394         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 395         pci_cfg_access_lock(dev);
 396         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 397         ssleep(1);
 398         pci_cfg_access_unlock(dev);
 399
 400         if (iov->link != dev->devfn)
 401                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 402
 403         iov->num_VFs = 0;
 404 }
 405
 406 static int sriov_init(struct pci_dev *dev, int pos)
 407 {
 408         int i;
 409         int rc;
 410         int nres;
 411         u32 pgsz;
 412         u16 ctrl, total, offset, stride;
 413         struct pci_sriov *iov;
 414         struct resource *res;
 415         struct pci_dev *pdev;
 416
 417         if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END &&
 418             pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT)
 419                 return -ENODEV;
 420
 421         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 422         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 423                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 424                 ssleep(1);
 425         }
 426
 427         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 428         if (!total)
 429                 return 0;
 430
 431         ctrl = 0;
 432         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 433                 if (pdev->is_physfn)
 434                         goto found;
 435
 436         pdev = NULL;
 437         if (pci_ari_enabled(dev->bus))
 438                 ctrl |= PCI_SRIOV_CTRL_ARI;
 439
 440 found:
 441         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 442         pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
 443         pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
 444         if (!offset || (total > 1 && !stride))
 445                 return -EIO;
 446
 447         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 448         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 449         pgsz &= ~((1 << i) - 1);
 450         if (!pgsz)
 451                 return -EIO;
 452
 453         pgsz &= ~(pgsz - 1);
 454         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 455
 456         nres = 0;
 457         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 458                 res = dev->resource + PCI_IOV_RESOURCES + i;
 459                 i += __pci_read_base(dev, pci_bar_unknown, res,
 460                                      pos + PCI_SRIOV_BAR + i * 4);
 461                 if (!res->flags)
 462                         continue;
 463                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 464                         rc = -EIO;
 465                         goto failed;
 466                 }
 467                 res->end = res->start + resource_size(res) * total - 1;
 468                 nres++;
 469         }
 470
 471         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 472         if (!iov) {
 473                 rc = -ENOMEM;
 474                 goto failed;
 475         }
 476
 477         iov->pos = pos;
 478         iov->nres = nres;
 479         iov->ctrl = ctrl;
 480         iov->total_VFs = total;
 481         iov->offset = offset;
 482         iov->stride = stride;
 483         iov->pgsz = pgsz;
 484         iov->self = dev;
 485         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 486         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 487         if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
 488                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 489
 490         if (pdev)
 491                 iov->dev = pci_dev_get(pdev);
 492         else
 493                 iov->dev = dev;
 494
 495         mutex_init(&iov->lock);
 496
 497         dev->sriov = iov;
 498         dev->is_physfn = 1;
 499
 500         return 0;
 501
 502 failed:
 503         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 504                 res = dev->resource + PCI_IOV_RESOURCES + i;
 505                 res->flags = 0;
 506         }
 507
 508         return rc;
 509 }
 510
 511 static void sriov_release(struct pci_dev *dev)
 512 {
 513         BUG_ON(dev->sriov->num_VFs);
 514
 515         if (dev != dev->sriov->dev)
 516                 pci_dev_put(dev->sriov->dev);
 517
 518         mutex_destroy(&dev->sriov->lock);
 519
 520         kfree(dev->sriov);
 521         dev->sriov = NULL;
 522 }
 523
 524 static void sriov_restore_state(struct pci_dev *dev)
 525 {
 526         int i;
 527         u16 ctrl;
 528         struct pci_sriov *iov = dev->sriov;
 529
 530         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 531         if (ctrl & PCI_SRIOV_CTRL_VFE)
 532                 return;
 533
 534         for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
 535                 pci_update_resource(dev, i);
 536
 537         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 538         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, iov->num_VFs);
 539         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 540         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 541                 msleep(100);
 542 }
 543
 544 /**
 545  * pci_iov_init - initialize the IOV capability
 546  * @dev: the PCI device
 547  *
 548  * Returns 0 on success, or negative on failure.
 549  */
 550 int pci_iov_init(struct pci_dev *dev)
 551 {
 552         int pos;
 553
 554         if (!pci_is_pcie(dev))
 555                 return -ENODEV;
 556
 557         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 558         if (pos)
 559                 return sriov_init(dev, pos);
 560
 561         return -ENODEV;
 562 }
 563
 564 /**
 565  * pci_iov_release - release resources used by the IOV capability
 566  * @dev: the PCI device
 567  */
 568 void pci_iov_release(struct pci_dev *dev)
 569 {
 570         if (dev->is_physfn)
 571                 sriov_release(dev);
 572 }
 573
 574 /**
 575  * pci_iov_resource_bar - get position of the SR-IOV BAR
 576  * @dev: the PCI device
 577  * @resno: the resource number
 578  * @type: the BAR type to be filled in
 579  *
 580  * Returns position of the BAR encapsulated in the SR-IOV capability.
 581  */
 582 int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 583                          enum pci_bar_type *type)
 584 {
 585         if (resno < PCI_IOV_RESOURCES || resno > PCI_IOV_RESOURCE_END)
 586                 return 0;
 587
 588         BUG_ON(!dev->is_physfn);
 589
 590         *type = pci_bar_unknown;
 591
 592         return dev->sriov->pos + PCI_SRIOV_BAR +
 593                 4 * (resno - PCI_IOV_RESOURCES);
 594 }
 595
 596 /**
 597  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 598  * @dev: the PCI device
 599  * @resno: the resource number
 600  *
 601  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 602  * This is not the same as the resource size which is defined as
 603  * the VF BAR size multiplied by the number of VFs.  The alignment
 604  * is just the VF BAR size.
 605  */
 606 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 607 {
 608         struct resource tmp;
 609         enum pci_bar_type type;
 610         int reg = pci_iov_resource_bar(dev, resno, &type);
 611
 612         if (!reg)
 613                 return 0;
 614
 615          __pci_read_base(dev, type, &tmp, reg);
 616         return resource_alignment(&tmp);
 617 }
 618
 619 /**
 620  * pci_restore_iov_state - restore the state of the IOV capability
 621  * @dev: the PCI device
 622  */
 623 void pci_restore_iov_state(struct pci_dev *dev)
 624 {
 625         if (dev->is_physfn)
 626                 sriov_restore_state(dev);
 627 }
 628
 629 /**
 630  * pci_iov_bus_range - find bus range used by Virtual Function
 631  * @bus: the PCI bus
 632  *
 633  * Returns max number of buses (exclude current one) used by Virtual
 634  * Functions.
 635  */
 636 int pci_iov_bus_range(struct pci_bus *bus)
 637 {
 638         int max = 0;
 639         u8 busnr;
 640         struct pci_dev *dev;
 641
 642         list_for_each_entry(dev, &bus->devices, bus_list) {
 643                 if (!dev->is_physfn)
 644                         continue;
 645                 busnr = virtfn_bus(dev, dev->sriov->total_VFs - 1);
 646                 if (busnr > max)
 647                         max = busnr;
 648         }
 649
 650         return max ? max - bus->number : 0;
 651 }
 652
 653 /**
 654  * pci_enable_sriov - enable the SR-IOV capability
 655  * @dev: the PCI device
 656  * @nr_virtfn: number of virtual functions to enable
 657  *
 658  * Returns 0 on success, or negative on failure.
 659  */
 660 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 661 {
 662         might_sleep();
 663
 664         if (!dev->is_physfn)
 665                 return -ENODEV;
 666
 667         return sriov_enable(dev, nr_virtfn);
 668 }
 669 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 670
 671 /**
 672  * pci_disable_sriov - disable the SR-IOV capability
 673  * @dev: the PCI device
 674  */
 675 void pci_disable_sriov(struct pci_dev *dev)
 676 {
 677         might_sleep();
 678
 679         if (!dev->is_physfn)
 680                 return;
 681
 682         sriov_disable(dev);
 683 }
 684 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 685
 686 /**
 687  * pci_sriov_migration - notify SR-IOV core of Virtual Function Migration
 688  * @dev: the PCI device
 689  *
 690  * Returns IRQ_HANDLED if the IRQ is handled, or IRQ_NONE if not.
 691  *
 692  * Physical Function driver is responsible to register IRQ handler using
 693  * VF Migration Interrupt Message Number, and call this function when the
 694  * interrupt is generated by the hardware.
 695  */
 696 irqreturn_t pci_sriov_migration(struct pci_dev *dev)
 697 {
 698         if (!dev->is_physfn)
 699                 return IRQ_NONE;
 700
 701         return sriov_migration(dev) ? IRQ_HANDLED : IRQ_NONE;
 702 }
 703 EXPORT_SYMBOL_GPL(pci_sriov_migration);
 704
 705 /**
 706  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 707  * @dev: the PCI device
 708  *
 709  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 710  */
 711 int pci_num_vf(struct pci_dev *dev)
 712 {
 713         if (!dev->is_physfn)
 714                 return 0;
 715
 716         return dev->sriov->num_VFs;
 717 }
 718 EXPORT_SYMBOL_GPL(pci_num_vf);
 719
 720 /**
 721  * pci_vfs_assigned - returns number of VFs are assigned to a guest
 722  * @dev: the PCI device
 723  *
 724  * Returns number of VFs belonging to this device that are assigned to a guest.
 725  * If device is not a physical function returns -ENODEV.
 726  */
 727 int pci_vfs_assigned(struct pci_dev *dev)
 728 {
 729         struct pci_dev *vfdev;
 730         unsigned int vfs_assigned = 0;
 731         unsigned short dev_id;
 732
 733         /* only search if we are a PF */
 734         if (!dev->is_physfn)
 735                 return 0;
 736
 737         /*
 738          * determine the device ID for the VFs, the vendor ID will be the
 739          * same as the PF so there is no need to check for that one
 740          */
 741         pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_VF_DID, &dev_id);
 742
 743         /* loop through all the VFs to see if we own any that are assigned */
 744         vfdev = pci_get_device(dev->vendor, dev_id, NULL);
 745         while (vfdev) {
 746                 /*
 747                  * It is considered assigned if it is a virtual function with
 748                  * our dev as the physical function and the assigned bit is set
 749                  */
 750                 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
 751                     (vfdev->dev_flags & PCI_DEV_FLAGS_ASSIGNED))
 752                         vfs_assigned++;
 753
 754                 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
 755         }
 756
 757         return vfs_assigned;
 758 }
 759 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
 760
 761 /**
 762  * pci_sriov_set_totalvfs -- reduce the TotalVFs available
 763  * @dev: the PCI PF device
 764  * @numvfs: number that should be used for TotalVFs supported
 765  *
 766  * Should be called from PF driver's probe routine with
 767  * device's mutex held.
 768  *
 769  * Returns 0 if PF is an SRIOV-capable device and
 770  * value of numvfs valid. If not a PF with VFS, return -EINVAL;
 771  * if VFs already enabled, return -EBUSY.
 772  */
 773 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
 774 {
 775         if (!dev->is_physfn || (numvfs > dev->sriov->total_VFs))
 776                 return -EINVAL;
 777
 778         /* Shouldn't change if VFs already enabled */
 779         if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
 780                 return -EBUSY;
 781         else
 782                 dev->sriov->driver_max_VFs = numvfs;
 783
 784         return 0;
 785 }
 786 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
 787
 788 /**
 789  * pci_sriov_get_totalvfs -- get total VFs supported on this devic3
 790  * @dev: the PCI PF device
 791  *
 792  * For a PCIe device with SRIOV support, return the PCIe
 793  * SRIOV capability value of TotalVFs or the value of driver_max_VFs
 794  * if the driver reduced it.  Otherwise, -EINVAL.
 795  */
 796 int pci_sriov_get_totalvfs(struct pci_dev *dev)
 797 {
 798         if (!dev->is_physfn)
 799                 return -EINVAL;
 800
 801         if (dev->sriov->driver_max_VFs)
 802                 return dev->sriov->driver_max_VFs;
 803
 804         return dev->sriov->total_VFs;
 805 }
 806 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);