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         int rc;
  37         struct pci_bus *child;
  38
  39         if (bus->number == busnr)
  40                 return bus;
  41
  42         child = pci_find_bus(pci_domain_nr(bus), busnr);
  43         if (child)
  44                 return child;
  45
  46         child = pci_add_new_bus(bus, NULL, busnr);
  47         if (!child)
  48                 return NULL;
  49
  50         child->subordinate = busnr;
  51         child->dev.parent = bus->bridge;
  52         rc = pci_bus_add_child(child);
  53         if (rc) {
  54                 pci_remove_bus(child);
  55                 return NULL;
  56         }
  57
  58         return child;
  59 }
  60
  61 static void virtfn_remove_bus(struct pci_bus *bus, int busnr)
  62 {
  63         struct pci_bus *child;
  64
  65         if (bus->number == busnr)
  66                 return;
  67
  68         child = pci_find_bus(pci_domain_nr(bus), busnr);
  69         BUG_ON(!child);
  70
  71         if (list_empty(&child->devices))
  72                 pci_remove_bus(child);
  73 }
  74
  75 static int virtfn_add(struct pci_dev *dev, int id, int reset)
  76 {
  77         int i;
  78         int rc;
  79         u64 size;
  80         char buf[VIRTFN_ID_LEN];
  81         struct pci_dev *virtfn;
  82         struct resource *res;
  83         struct pci_sriov *iov = dev->sriov;
  84
  85         virtfn = alloc_pci_dev();
  86         if (!virtfn)
  87                 return -ENOMEM;
  88
  89         mutex_lock(&iov->dev->sriov->lock);
  90         virtfn->bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id));
  91         if (!virtfn->bus) {
  92                 kfree(virtfn);
  93                 mutex_unlock(&iov->dev->sriov->lock);
  94                 return -ENOMEM;
  95         }
  96         virtfn->devfn = virtfn_devfn(dev, id);
  97         virtfn->vendor = dev->vendor;
  98         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
  99         pci_setup_device(virtfn);
 100         virtfn->dev.parent = dev->dev.parent;
 101
 102         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 103                 res = dev->resource + PCI_IOV_RESOURCES + i;
 104                 if (!res->parent)
 105                         continue;
 106                 virtfn->resource[i].name = pci_name(virtfn);
 107                 virtfn->resource[i].flags = res->flags;
 108                 size = resource_size(res);
 109                 do_div(size, iov->total);
 110                 virtfn->resource[i].start = res->start + size * id;
 111                 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
 112                 rc = request_resource(res, &virtfn->resource[i]);
 113                 BUG_ON(rc);
 114         }
 115
 116         if (reset)
 117                 __pci_reset_function(virtfn);
 118
 119         pci_device_add(virtfn, virtfn->bus);
 120         mutex_unlock(&iov->dev->sriov->lock);
 121
 122         virtfn->physfn = pci_dev_get(dev);
 123         virtfn->is_virtfn = 1;
 124
 125         rc = pci_bus_add_device(virtfn);
 126         if (rc)
 127                 goto failed1;
 128         sprintf(buf, "virtfn%u", id);
 129         rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
 130         if (rc)
 131                 goto failed1;
 132         rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
 133         if (rc)
 134                 goto failed2;
 135
 136         kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
 137
 138         return 0;
 139
 140 failed2:
 141         sysfs_remove_link(&dev->dev.kobj, buf);
 142 failed1:
 143         pci_dev_put(dev);
 144         mutex_lock(&iov->dev->sriov->lock);
 145         pci_remove_bus_device(virtfn);
 146         virtfn_remove_bus(dev->bus, virtfn_bus(dev, id));
 147         mutex_unlock(&iov->dev->sriov->lock);
 148
 149         return rc;
 150 }
 151
 152 static void virtfn_remove(struct pci_dev *dev, int id, int reset)
 153 {
 154         char buf[VIRTFN_ID_LEN];
 155         struct pci_bus *bus;
 156         struct pci_dev *virtfn;
 157         struct pci_sriov *iov = dev->sriov;
 158
 159         bus = pci_find_bus(pci_domain_nr(dev->bus), virtfn_bus(dev, id));
 160         if (!bus)
 161                 return;
 162
 163         virtfn = pci_get_slot(bus, virtfn_devfn(dev, id));
 164         if (!virtfn)
 165                 return;
 166
 167         pci_dev_put(virtfn);
 168
 169         if (reset) {
 170                 device_release_driver(&virtfn->dev);
 171                 __pci_reset_function(virtfn);
 172         }
 173
 174         sprintf(buf, "virtfn%u", id);
 175         sysfs_remove_link(&dev->dev.kobj, buf);
 176         sysfs_remove_link(&virtfn->dev.kobj, "physfn");
 177
 178         mutex_lock(&iov->dev->sriov->lock);
 179         pci_remove_bus_device(virtfn);
 180         virtfn_remove_bus(dev->bus, virtfn_bus(dev, id));
 181         mutex_unlock(&iov->dev->sriov->lock);
 182
 183         pci_dev_put(dev);
 184 }
 185
 186 static int sriov_migration(struct pci_dev *dev)
 187 {
 188         u16 status;
 189         struct pci_sriov *iov = dev->sriov;
 190
 191         if (!iov->nr_virtfn)
 192                 return 0;
 193
 194         if (!(iov->cap & PCI_SRIOV_CAP_VFM))
 195                 return 0;
 196
 197         pci_read_config_word(dev, iov->pos + PCI_SRIOV_STATUS, &status);
 198         if (!(status & PCI_SRIOV_STATUS_VFM))
 199                 return 0;
 200
 201         schedule_work(&iov->mtask);
 202
 203         return 1;
 204 }
 205
 206 static void sriov_migration_task(struct work_struct *work)
 207 {
 208         int i;
 209         u8 state;
 210         u16 status;
 211         struct pci_sriov *iov = container_of(work, struct pci_sriov, mtask);
 212
 213         for (i = iov->initial; i < iov->nr_virtfn; i++) {
 214                 state = readb(iov->mstate + i);
 215                 if (state == PCI_SRIOV_VFM_MI) {
 216                         writeb(PCI_SRIOV_VFM_AV, iov->mstate + i);
 217                         state = readb(iov->mstate + i);
 218                         if (state == PCI_SRIOV_VFM_AV)
 219                                 virtfn_add(iov->self, i, 1);
 220                 } else if (state == PCI_SRIOV_VFM_MO) {
 221                         virtfn_remove(iov->self, i, 1);
 222                         writeb(PCI_SRIOV_VFM_UA, iov->mstate + i);
 223                         state = readb(iov->mstate + i);
 224                         if (state == PCI_SRIOV_VFM_AV)
 225                                 virtfn_add(iov->self, i, 0);
 226                 }
 227         }
 228
 229         pci_read_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, &status);
 230         status &= ~PCI_SRIOV_STATUS_VFM;
 231         pci_write_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, status);
 232 }
 233
 234 static int sriov_enable_migration(struct pci_dev *dev, int nr_virtfn)
 235 {
 236         int bir;
 237         u32 table;
 238         resource_size_t pa;
 239         struct pci_sriov *iov = dev->sriov;
 240
 241         if (nr_virtfn <= iov->initial)
 242                 return 0;
 243
 244         pci_read_config_dword(dev, iov->pos + PCI_SRIOV_VFM, &table);
 245         bir = PCI_SRIOV_VFM_BIR(table);
 246         if (bir > PCI_STD_RESOURCE_END)
 247                 return -EIO;
 248
 249         table = PCI_SRIOV_VFM_OFFSET(table);
 250         if (table + nr_virtfn > pci_resource_len(dev, bir))
 251                 return -EIO;
 252
 253         pa = pci_resource_start(dev, bir) + table;
 254         iov->mstate = ioremap(pa, nr_virtfn);
 255         if (!iov->mstate)
 256                 return -ENOMEM;
 257
 258         INIT_WORK(&iov->mtask, sriov_migration_task);
 259
 260         iov->ctrl |= PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR;
 261         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 262
 263         return 0;
 264 }
 265
 266 static void sriov_disable_migration(struct pci_dev *dev)
 267 {
 268         struct pci_sriov *iov = dev->sriov;
 269
 270         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR);
 271         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 272
 273         cancel_work_sync(&iov->mtask);
 274         iounmap(iov->mstate);
 275 }
 276
 277 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 278 {
 279         int rc;
 280         int i, j;
 281         int nres;
 282         u16 offset, stride, initial;
 283         struct resource *res;
 284         struct pci_dev *pdev;
 285         struct pci_sriov *iov = dev->sriov;
 286         int bars = 0;
 287
 288         if (!nr_virtfn)
 289                 return 0;
 290
 291         if (iov->nr_virtfn)
 292                 return -EINVAL;
 293
 294         pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
 295         if (initial > iov->total ||
 296             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total)))
 297                 return -EIO;
 298
 299         if (nr_virtfn < 0 || nr_virtfn > iov->total ||
 300             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 301                 return -EINVAL;
 302
 303         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
 304         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &offset);
 305         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &stride);
 306         if (!offset || (nr_virtfn > 1 && !stride))
 307                 return -EIO;
 308
 309         nres = 0;
 310         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 311                 bars |= (1 << (i + PCI_IOV_RESOURCES));
 312                 res = dev->resource + PCI_IOV_RESOURCES + i;
 313                 if (res->parent)
 314                         nres++;
 315         }
 316         if (nres != iov->nres) {
 317                 dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
 318                 return -ENOMEM;
 319         }
 320
 321         iov->offset = offset;
 322         iov->stride = stride;
 323
 324         if (virtfn_bus(dev, nr_virtfn - 1) > dev->bus->subordinate) {
 325                 dev_err(&dev->dev, "SR-IOV: bus number out of range\n");
 326                 return -ENOMEM;
 327         }
 328
 329         if (pci_enable_resources(dev, bars)) {
 330                 dev_err(&dev->dev, "SR-IOV: IOV BARS not allocated\n");
 331                 return -ENOMEM;
 332         }
 333
 334         if (iov->link != dev->devfn) {
 335                 pdev = pci_get_slot(dev->bus, iov->link);
 336                 if (!pdev)
 337                         return -ENODEV;
 338
 339                 pci_dev_put(pdev);
 340
 341                 if (!pdev->is_physfn)
 342                         return -ENODEV;
 343
 344                 rc = sysfs_create_link(&dev->dev.kobj,
 345                                         &pdev->dev.kobj, "dep_link");
 346                 if (rc)
 347                         return rc;
 348         }
 349
 350         iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 351         pci_cfg_access_lock(dev);
 352         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 353         msleep(100);
 354         pci_cfg_access_unlock(dev);
 355
 356         iov->initial = initial;
 357         if (nr_virtfn < initial)
 358                 initial = nr_virtfn;
 359
 360         for (i = 0; i < initial; i++) {
 361                 rc = virtfn_add(dev, i, 0);
 362                 if (rc)
 363                         goto failed;
 364         }
 365
 366         if (iov->cap & PCI_SRIOV_CAP_VFM) {
 367                 rc = sriov_enable_migration(dev, nr_virtfn);
 368                 if (rc)
 369                         goto failed;
 370         }
 371
 372         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 373         iov->nr_virtfn = nr_virtfn;
 374
 375         return 0;
 376
 377 failed:
 378         for (j = 0; j < i; j++)
 379                 virtfn_remove(dev, j, 0);
 380
 381         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 382         pci_cfg_access_lock(dev);
 383         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 384         ssleep(1);
 385         pci_cfg_access_unlock(dev);
 386
 387         if (iov->link != dev->devfn)
 388                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 389
 390         return rc;
 391 }
 392
 393 static void sriov_disable(struct pci_dev *dev)
 394 {
 395         int i;
 396         struct pci_sriov *iov = dev->sriov;
 397
 398         if (!iov->nr_virtfn)
 399                 return;
 400
 401         if (iov->cap & PCI_SRIOV_CAP_VFM)
 402                 sriov_disable_migration(dev);
 403
 404         for (i = 0; i < iov->nr_virtfn; i++)
 405                 virtfn_remove(dev, i, 0);
 406
 407         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 408         pci_cfg_access_lock(dev);
 409         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 410         ssleep(1);
 411         pci_cfg_access_unlock(dev);
 412
 413         if (iov->link != dev->devfn)
 414                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 415
 416         iov->nr_virtfn = 0;
 417 }
 418
 419 static int sriov_init(struct pci_dev *dev, int pos)
 420 {
 421         int i;
 422         int rc;
 423         int nres;
 424         u32 pgsz;
 425         u16 ctrl, total, offset, stride;
 426         struct pci_sriov *iov;
 427         struct resource *res;
 428         struct pci_dev *pdev;
 429
 430         if (dev->pcie_type != PCI_EXP_TYPE_RC_END &&
 431             dev->pcie_type != PCI_EXP_TYPE_ENDPOINT)
 432                 return -ENODEV;
 433
 434         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 435         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 436                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 437                 ssleep(1);
 438         }
 439
 440         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 441         if (!total)
 442                 return 0;
 443
 444         ctrl = 0;
 445         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 446                 if (pdev->is_physfn)
 447                         goto found;
 448
 449         pdev = NULL;
 450         if (pci_ari_enabled(dev->bus))
 451                 ctrl |= PCI_SRIOV_CTRL_ARI;
 452
 453 found:
 454         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 455         pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
 456         pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
 457         if (!offset || (total > 1 && !stride))
 458                 return -EIO;
 459
 460         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 461         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 462         pgsz &= ~((1 << i) - 1);
 463         if (!pgsz)
 464                 return -EIO;
 465
 466         pgsz &= ~(pgsz - 1);
 467         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 468
 469         nres = 0;
 470         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 471                 res = dev->resource + PCI_IOV_RESOURCES + i;
 472                 i += __pci_read_base(dev, pci_bar_unknown, res,
 473                                      pos + PCI_SRIOV_BAR + i * 4);
 474                 if (!res->flags)
 475                         continue;
 476                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 477                         rc = -EIO;
 478                         goto failed;
 479                 }
 480                 res->end = res->start + resource_size(res) * total - 1;
 481                 nres++;
 482         }
 483
 484         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 485         if (!iov) {
 486                 rc = -ENOMEM;
 487                 goto failed;
 488         }
 489
 490         iov->pos = pos;
 491         iov->nres = nres;
 492         iov->ctrl = ctrl;
 493         iov->total = total;
 494         iov->offset = offset;
 495         iov->stride = stride;
 496         iov->pgsz = pgsz;
 497         iov->self = dev;
 498         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 499         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 500         if (dev->pcie_type == PCI_EXP_TYPE_RC_END)
 501                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 502
 503         if (pdev)
 504                 iov->dev = pci_dev_get(pdev);
 505         else
 506                 iov->dev = dev;
 507
 508         mutex_init(&iov->lock);
 509
 510         dev->sriov = iov;
 511         dev->is_physfn = 1;
 512
 513         return 0;
 514
 515 failed:
 516         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 517                 res = dev->resource + PCI_IOV_RESOURCES + i;
 518                 res->flags = 0;
 519         }
 520
 521         return rc;
 522 }
 523
 524 static void sriov_release(struct pci_dev *dev)
 525 {
 526         BUG_ON(dev->sriov->nr_virtfn);
 527
 528         if (dev != dev->sriov->dev)
 529                 pci_dev_put(dev->sriov->dev);
 530
 531         mutex_destroy(&dev->sriov->lock);
 532
 533         kfree(dev->sriov);
 534         dev->sriov = NULL;
 535 }
 536
 537 static void sriov_restore_state(struct pci_dev *dev)
 538 {
 539         int i;
 540         u16 ctrl;
 541         struct pci_sriov *iov = dev->sriov;
 542
 543         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 544         if (ctrl & PCI_SRIOV_CTRL_VFE)
 545                 return;
 546
 547         for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
 548                 pci_update_resource(dev, i);
 549
 550         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 551         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, iov->nr_virtfn);
 552         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 553         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 554                 msleep(100);
 555 }
 556
 557 /**
 558  * pci_iov_init - initialize the IOV capability
 559  * @dev: the PCI device
 560  *
 561  * Returns 0 on success, or negative on failure.
 562  */
 563 int pci_iov_init(struct pci_dev *dev)
 564 {
 565         int pos;
 566
 567         if (!pci_is_pcie(dev))
 568                 return -ENODEV;
 569
 570         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 571         if (pos)
 572                 return sriov_init(dev, pos);
 573
 574         return -ENODEV;
 575 }
 576
 577 /**
 578  * pci_iov_release - release resources used by the IOV capability
 579  * @dev: the PCI device
 580  */
 581 void pci_iov_release(struct pci_dev *dev)
 582 {
 583         if (dev->is_physfn)
 584                 sriov_release(dev);
 585 }
 586
 587 /**
 588  * pci_iov_resource_bar - get position of the SR-IOV BAR
 589  * @dev: the PCI device
 590  * @resno: the resource number
 591  * @type: the BAR type to be filled in
 592  *
 593  * Returns position of the BAR encapsulated in the SR-IOV capability.
 594  */
 595 int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 596                          enum pci_bar_type *type)
 597 {
 598         if (resno < PCI_IOV_RESOURCES || resno > PCI_IOV_RESOURCE_END)
 599                 return 0;
 600
 601         BUG_ON(!dev->is_physfn);
 602
 603         *type = pci_bar_unknown;
 604
 605         return dev->sriov->pos + PCI_SRIOV_BAR +
 606                 4 * (resno - PCI_IOV_RESOURCES);
 607 }
 608
 609 /**
 610  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 611  * @dev: the PCI device
 612  * @resno: the resource number
 613  *
 614  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 615  * This is not the same as the resource size which is defined as
 616  * the VF BAR size multiplied by the number of VFs.  The alignment
 617  * is just the VF BAR size.
 618  */
 619 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 620 {
 621         struct resource tmp;
 622         enum pci_bar_type type;
 623         int reg = pci_iov_resource_bar(dev, resno, &type);
 624
 625         if (!reg)
 626                 return 0;
 627
 628          __pci_read_base(dev, type, &tmp, reg);
 629         return resource_alignment(&tmp);
 630 }
 631
 632 /**
 633  * pci_restore_iov_state - restore the state of the IOV capability
 634  * @dev: the PCI device
 635  */
 636 void pci_restore_iov_state(struct pci_dev *dev)
 637 {
 638         if (dev->is_physfn)
 639                 sriov_restore_state(dev);
 640 }
 641
 642 /**
 643  * pci_iov_bus_range - find bus range used by Virtual Function
 644  * @bus: the PCI bus
 645  *
 646  * Returns max number of buses (exclude current one) used by Virtual
 647  * Functions.
 648  */
 649 int pci_iov_bus_range(struct pci_bus *bus)
 650 {
 651         int max = 0;
 652         u8 busnr;
 653         struct pci_dev *dev;
 654
 655         list_for_each_entry(dev, &bus->devices, bus_list) {
 656                 if (!dev->is_physfn)
 657                         continue;
 658                 busnr = virtfn_bus(dev, dev->sriov->total - 1);
 659                 if (busnr > max)
 660                         max = busnr;
 661         }
 662
 663         return max ? max - bus->number : 0;
 664 }
 665
 666 /**
 667  * pci_enable_sriov - enable the SR-IOV capability
 668  * @dev: the PCI device
 669  * @nr_virtfn: number of virtual functions to enable
 670  *
 671  * Returns 0 on success, or negative on failure.
 672  */
 673 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 674 {
 675         might_sleep();
 676
 677         if (!dev->is_physfn)
 678                 return -ENODEV;
 679
 680         return sriov_enable(dev, nr_virtfn);
 681 }
 682 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 683
 684 /**
 685  * pci_disable_sriov - disable the SR-IOV capability
 686  * @dev: the PCI device
 687  */
 688 void pci_disable_sriov(struct pci_dev *dev)
 689 {
 690         might_sleep();
 691
 692         if (!dev->is_physfn)
 693                 return;
 694
 695         sriov_disable(dev);
 696 }
 697 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 698
 699 /**
 700  * pci_sriov_migration - notify SR-IOV core of Virtual Function Migration
 701  * @dev: the PCI device
 702  *
 703  * Returns IRQ_HANDLED if the IRQ is handled, or IRQ_NONE if not.
 704  *
 705  * Physical Function driver is responsible to register IRQ handler using
 706  * VF Migration Interrupt Message Number, and call this function when the
 707  * interrupt is generated by the hardware.
 708  */
 709 irqreturn_t pci_sriov_migration(struct pci_dev *dev)
 710 {
 711         if (!dev->is_physfn)
 712                 return IRQ_NONE;
 713
 714         return sriov_migration(dev) ? IRQ_HANDLED : IRQ_NONE;
 715 }
 716 EXPORT_SYMBOL_GPL(pci_sriov_migration);
 717
 718 /**
 719  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 720  * @dev: the PCI device
 721  *
 722  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 723  */
 724 int pci_num_vf(struct pci_dev *dev)
 725 {
 726         if (!dev || !dev->is_physfn)
 727                 return 0;
 728         else
 729                 return dev->sriov->nr_virtfn;
 730 }
 731 EXPORT_SYMBOL_GPL(pci_num_vf);