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         pci_bus_insert_busn_res(child, busnr, 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_VFs);
 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_stop_and_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         /*
 177          * pci_stop_dev() could have been called for this virtfn already,
 178          * so the directory for the virtfn may have been removed before.
 179          * Double check to avoid spurious sysfs warnings.
 180          */
 181         if (virtfn->dev.kobj.sd)
 182                 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
 183
 184         mutex_lock(&iov->dev->sriov->lock);
 185         pci_stop_and_remove_bus_device(virtfn);
 186         virtfn_remove_bus(dev->bus, virtfn_bus(dev, id));
 187         mutex_unlock(&iov->dev->sriov->lock);
 188
 189         pci_dev_put(dev);
 190 }
 191
 192 static int sriov_migration(struct pci_dev *dev)
 193 {
 194         u16 status;
 195         struct pci_sriov *iov = dev->sriov;
 196
 197         if (!iov->num_VFs)
 198                 return 0;
 199
 200         if (!(iov->cap & PCI_SRIOV_CAP_VFM))
 201                 return 0;
 202
 203         pci_read_config_word(dev, iov->pos + PCI_SRIOV_STATUS, &status);
 204         if (!(status & PCI_SRIOV_STATUS_VFM))
 205                 return 0;
 206
 207         schedule_work(&iov->mtask);
 208
 209         return 1;
 210 }
 211
 212 static void sriov_migration_task(struct work_struct *work)
 213 {
 214         int i;
 215         u8 state;
 216         u16 status;
 217         struct pci_sriov *iov = container_of(work, struct pci_sriov, mtask);
 218
 219         for (i = iov->initial_VFs; i < iov->num_VFs; i++) {
 220                 state = readb(iov->mstate + i);
 221                 if (state == PCI_SRIOV_VFM_MI) {
 222                         writeb(PCI_SRIOV_VFM_AV, iov->mstate + i);
 223                         state = readb(iov->mstate + i);
 224                         if (state == PCI_SRIOV_VFM_AV)
 225                                 virtfn_add(iov->self, i, 1);
 226                 } else if (state == PCI_SRIOV_VFM_MO) {
 227                         virtfn_remove(iov->self, i, 1);
 228                         writeb(PCI_SRIOV_VFM_UA, iov->mstate + i);
 229                         state = readb(iov->mstate + i);
 230                         if (state == PCI_SRIOV_VFM_AV)
 231                                 virtfn_add(iov->self, i, 0);
 232                 }
 233         }
 234
 235         pci_read_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, &status);
 236         status &= ~PCI_SRIOV_STATUS_VFM;
 237         pci_write_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, status);
 238 }
 239
 240 static int sriov_enable_migration(struct pci_dev *dev, int nr_virtfn)
 241 {
 242         int bir;
 243         u32 table;
 244         resource_size_t pa;
 245         struct pci_sriov *iov = dev->sriov;
 246
 247         if (nr_virtfn <= iov->initial_VFs)
 248                 return 0;
 249
 250         pci_read_config_dword(dev, iov->pos + PCI_SRIOV_VFM, &table);
 251         bir = PCI_SRIOV_VFM_BIR(table);
 252         if (bir > PCI_STD_RESOURCE_END)
 253                 return -EIO;
 254
 255         table = PCI_SRIOV_VFM_OFFSET(table);
 256         if (table + nr_virtfn > pci_resource_len(dev, bir))
 257                 return -EIO;
 258
 259         pa = pci_resource_start(dev, bir) + table;
 260         iov->mstate = ioremap(pa, nr_virtfn);
 261         if (!iov->mstate)
 262                 return -ENOMEM;
 263
 264         INIT_WORK(&iov->mtask, sriov_migration_task);
 265
 266         iov->ctrl |= PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR;
 267         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 268
 269         return 0;
 270 }
 271
 272 static void sriov_disable_migration(struct pci_dev *dev)
 273 {
 274         struct pci_sriov *iov = dev->sriov;
 275
 276         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR);
 277         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 278
 279         cancel_work_sync(&iov->mtask);
 280         iounmap(iov->mstate);
 281 }
 282
 283 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 284 {
 285         int rc;
 286         int i, j;
 287         int nres;
 288         u16 offset, stride, initial;
 289         struct resource *res;
 290         struct pci_dev *pdev;
 291         struct pci_sriov *iov = dev->sriov;
 292         int bars = 0;
 293
 294         if (!nr_virtfn)
 295                 return 0;
 296
 297         if (iov->num_VFs)
 298                 return -EINVAL;
 299
 300         pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
 301         if (initial > iov->total_VFs ||
 302             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
 303                 return -EIO;
 304
 305         if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
 306             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 307                 return -EINVAL;
 308
 309         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
 310         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &offset);
 311         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &stride);
 312         if (!offset || (nr_virtfn > 1 && !stride))
 313                 return -EIO;
 314
 315         nres = 0;
 316         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 317                 bars |= (1 << (i + PCI_IOV_RESOURCES));
 318                 res = dev->resource + PCI_IOV_RESOURCES + i;
 319                 if (res->parent)
 320                         nres++;
 321         }
 322         if (nres != iov->nres) {
 323                 dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
 324                 return -ENOMEM;
 325         }
 326
 327         iov->offset = offset;
 328         iov->stride = stride;
 329
 330         if (virtfn_bus(dev, nr_virtfn - 1) > dev->bus->busn_res.end) {
 331                 dev_err(&dev->dev, "SR-IOV: bus number out of range\n");
 332                 return -ENOMEM;
 333         }
 334
 335         if (pci_enable_resources(dev, bars)) {
 336                 dev_err(&dev->dev, "SR-IOV: IOV BARS not allocated\n");
 337                 return -ENOMEM;
 338         }
 339
 340         if (iov->link != dev->devfn) {
 341                 pdev = pci_get_slot(dev->bus, iov->link);
 342                 if (!pdev)
 343                         return -ENODEV;
 344
 345                 pci_dev_put(pdev);
 346
 347                 if (!pdev->is_physfn)
 348                         return -ENODEV;
 349
 350                 rc = sysfs_create_link(&dev->dev.kobj,
 351                                         &pdev->dev.kobj, "dep_link");
 352                 if (rc)
 353                         return rc;
 354         }
 355
 356         iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 357         pci_cfg_access_lock(dev);
 358         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 359         msleep(100);
 360         pci_cfg_access_unlock(dev);
 361
 362         iov->initial_VFs = initial;
 363         if (nr_virtfn < initial)
 364                 initial = nr_virtfn;
 365
 366         for (i = 0; i < initial; i++) {
 367                 rc = virtfn_add(dev, i, 0);
 368                 if (rc)
 369                         goto failed;
 370         }
 371
 372         if (iov->cap & PCI_SRIOV_CAP_VFM) {
 373                 rc = sriov_enable_migration(dev, nr_virtfn);
 374                 if (rc)
 375                         goto failed;
 376         }
 377
 378         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 379         iov->num_VFs = nr_virtfn;
 380
 381         return 0;
 382
 383 failed:
 384         for (j = 0; j < i; j++)
 385                 virtfn_remove(dev, j, 0);
 386
 387         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 388         pci_cfg_access_lock(dev);
 389         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 390         ssleep(1);
 391         pci_cfg_access_unlock(dev);
 392
 393         if (iov->link != dev->devfn)
 394                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 395
 396         return rc;
 397 }
 398
 399 static void sriov_disable(struct pci_dev *dev)
 400 {
 401         int i;
 402         struct pci_sriov *iov = dev->sriov;
 403
 404         if (!iov->num_VFs)
 405                 return;
 406
 407         if (iov->cap & PCI_SRIOV_CAP_VFM)
 408                 sriov_disable_migration(dev);
 409
 410         for (i = 0; i < iov->num_VFs; i++)
 411                 virtfn_remove(dev, i, 0);
 412
 413         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 414         pci_cfg_access_lock(dev);
 415         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 416         ssleep(1);
 417         pci_cfg_access_unlock(dev);
 418
 419         if (iov->link != dev->devfn)
 420                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 421
 422         iov->num_VFs = 0;
 423 }
 424
 425 static int sriov_init(struct pci_dev *dev, int pos)
 426 {
 427         int i;
 428         int rc;
 429         int nres;
 430         u32 pgsz;
 431         u16 ctrl, total, offset, stride;
 432         struct pci_sriov *iov;
 433         struct resource *res;
 434         struct pci_dev *pdev;
 435
 436         if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END &&
 437             pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT)
 438                 return -ENODEV;
 439
 440         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 441         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 442                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 443                 ssleep(1);
 444         }
 445
 446         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 447         if (!total)
 448                 return 0;
 449
 450         ctrl = 0;
 451         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 452                 if (pdev->is_physfn)
 453                         goto found;
 454
 455         pdev = NULL;
 456         if (pci_ari_enabled(dev->bus))
 457                 ctrl |= PCI_SRIOV_CTRL_ARI;
 458
 459 found:
 460         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 461         pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
 462         pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
 463         if (!offset || (total > 1 && !stride))
 464                 return -EIO;
 465
 466         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 467         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 468         pgsz &= ~((1 << i) - 1);
 469         if (!pgsz)
 470                 return -EIO;
 471
 472         pgsz &= ~(pgsz - 1);
 473         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 474
 475         nres = 0;
 476         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 477                 res = dev->resource + PCI_IOV_RESOURCES + i;
 478                 i += __pci_read_base(dev, pci_bar_unknown, res,
 479                                      pos + PCI_SRIOV_BAR + i * 4);
 480                 if (!res->flags)
 481                         continue;
 482                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 483                         rc = -EIO;
 484                         goto failed;
 485                 }
 486                 res->end = res->start + resource_size(res) * total - 1;
 487                 nres++;
 488         }
 489
 490         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 491         if (!iov) {
 492                 rc = -ENOMEM;
 493                 goto failed;
 494         }
 495
 496         iov->pos = pos;
 497         iov->nres = nres;
 498         iov->ctrl = ctrl;
 499         iov->total_VFs = total;
 500         iov->offset = offset;
 501         iov->stride = stride;
 502         iov->pgsz = pgsz;
 503         iov->self = dev;
 504         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 505         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 506         if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
 507                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 508
 509         if (pdev)
 510                 iov->dev = pci_dev_get(pdev);
 511         else
 512                 iov->dev = dev;
 513
 514         mutex_init(&iov->lock);
 515
 516         dev->sriov = iov;
 517         dev->is_physfn = 1;
 518
 519         return 0;
 520
 521 failed:
 522         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 523                 res = dev->resource + PCI_IOV_RESOURCES + i;
 524                 res->flags = 0;
 525         }
 526
 527         return rc;
 528 }
 529
 530 static void sriov_release(struct pci_dev *dev)
 531 {
 532         BUG_ON(dev->sriov->num_VFs);
 533
 534         if (dev != dev->sriov->dev)
 535                 pci_dev_put(dev->sriov->dev);
 536
 537         mutex_destroy(&dev->sriov->lock);
 538
 539         kfree(dev->sriov);
 540         dev->sriov = NULL;
 541 }
 542
 543 static void sriov_restore_state(struct pci_dev *dev)
 544 {
 545         int i;
 546         u16 ctrl;
 547         struct pci_sriov *iov = dev->sriov;
 548
 549         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 550         if (ctrl & PCI_SRIOV_CTRL_VFE)
 551                 return;
 552
 553         for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
 554                 pci_update_resource(dev, i);
 555
 556         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 557         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, iov->num_VFs);
 558         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 559         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 560                 msleep(100);
 561 }
 562
 563 /**
 564  * pci_iov_init - initialize the IOV capability
 565  * @dev: the PCI device
 566  *
 567  * Returns 0 on success, or negative on failure.
 568  */
 569 int pci_iov_init(struct pci_dev *dev)
 570 {
 571         int pos;
 572
 573         if (!pci_is_pcie(dev))
 574                 return -ENODEV;
 575
 576         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 577         if (pos)
 578                 return sriov_init(dev, pos);
 579
 580         return -ENODEV;
 581 }
 582
 583 /**
 584  * pci_iov_release - release resources used by the IOV capability
 585  * @dev: the PCI device
 586  */
 587 void pci_iov_release(struct pci_dev *dev)
 588 {
 589         if (dev->is_physfn)
 590                 sriov_release(dev);
 591 }
 592
 593 /**
 594  * pci_iov_resource_bar - get position of the SR-IOV BAR
 595  * @dev: the PCI device
 596  * @resno: the resource number
 597  * @type: the BAR type to be filled in
 598  *
 599  * Returns position of the BAR encapsulated in the SR-IOV capability.
 600  */
 601 int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 602                          enum pci_bar_type *type)
 603 {
 604         if (resno < PCI_IOV_RESOURCES || resno > PCI_IOV_RESOURCE_END)
 605                 return 0;
 606
 607         BUG_ON(!dev->is_physfn);
 608
 609         *type = pci_bar_unknown;
 610
 611         return dev->sriov->pos + PCI_SRIOV_BAR +
 612                 4 * (resno - PCI_IOV_RESOURCES);
 613 }
 614
 615 /**
 616  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 617  * @dev: the PCI device
 618  * @resno: the resource number
 619  *
 620  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 621  * This is not the same as the resource size which is defined as
 622  * the VF BAR size multiplied by the number of VFs.  The alignment
 623  * is just the VF BAR size.
 624  */
 625 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 626 {
 627         struct resource tmp;
 628         enum pci_bar_type type;
 629         int reg = pci_iov_resource_bar(dev, resno, &type);
 630
 631         if (!reg)
 632                 return 0;
 633
 634          __pci_read_base(dev, type, &tmp, reg);
 635         return resource_alignment(&tmp);
 636 }
 637
 638 /**
 639  * pci_restore_iov_state - restore the state of the IOV capability
 640  * @dev: the PCI device
 641  */
 642 void pci_restore_iov_state(struct pci_dev *dev)
 643 {
 644         if (dev->is_physfn)
 645                 sriov_restore_state(dev);
 646 }
 647
 648 /**
 649  * pci_iov_bus_range - find bus range used by Virtual Function
 650  * @bus: the PCI bus
 651  *
 652  * Returns max number of buses (exclude current one) used by Virtual
 653  * Functions.
 654  */
 655 int pci_iov_bus_range(struct pci_bus *bus)
 656 {
 657         int max = 0;
 658         u8 busnr;
 659         struct pci_dev *dev;
 660
 661         list_for_each_entry(dev, &bus->devices, bus_list) {
 662                 if (!dev->is_physfn)
 663                         continue;
 664                 busnr = virtfn_bus(dev, dev->sriov->total_VFs - 1);
 665                 if (busnr > max)
 666                         max = busnr;
 667         }
 668
 669         return max ? max - bus->number : 0;
 670 }
 671
 672 /**
 673  * pci_enable_sriov - enable the SR-IOV capability
 674  * @dev: the PCI device
 675  * @nr_virtfn: number of virtual functions to enable
 676  *
 677  * Returns 0 on success, or negative on failure.
 678  */
 679 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 680 {
 681         might_sleep();
 682
 683         if (!dev->is_physfn)
 684                 return -ENODEV;
 685
 686         return sriov_enable(dev, nr_virtfn);
 687 }
 688 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 689
 690 /**
 691  * pci_disable_sriov - disable the SR-IOV capability
 692  * @dev: the PCI device
 693  */
 694 void pci_disable_sriov(struct pci_dev *dev)
 695 {
 696         might_sleep();
 697
 698         if (!dev->is_physfn)
 699                 return;
 700
 701         sriov_disable(dev);
 702 }
 703 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 704
 705 /**
 706  * pci_sriov_migration - notify SR-IOV core of Virtual Function Migration
 707  * @dev: the PCI device
 708  *
 709  * Returns IRQ_HANDLED if the IRQ is handled, or IRQ_NONE if not.
 710  *
 711  * Physical Function driver is responsible to register IRQ handler using
 712  * VF Migration Interrupt Message Number, and call this function when the
 713  * interrupt is generated by the hardware.
 714  */
 715 irqreturn_t pci_sriov_migration(struct pci_dev *dev)
 716 {
 717         if (!dev->is_physfn)
 718                 return IRQ_NONE;
 719
 720         return sriov_migration(dev) ? IRQ_HANDLED : IRQ_NONE;
 721 }
 722 EXPORT_SYMBOL_GPL(pci_sriov_migration);
 723
 724 /**
 725  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 726  * @dev: the PCI device
 727  *
 728  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 729  */
 730 int pci_num_vf(struct pci_dev *dev)
 731 {
 732         if (!dev->is_physfn)
 733                 return 0;
 734
 735         return dev->sriov->num_VFs;
 736 }
 737 EXPORT_SYMBOL_GPL(pci_num_vf);
 738
 739 /**
 740  * pci_sriov_set_totalvfs -- reduce the TotalVFs available
 741  * @dev: the PCI PF device
 742  * @numvfs: number that should be used for TotalVFs supported
 743  *
 744  * Should be called from PF driver's probe routine with
 745  * device's mutex held.
 746  *
 747  * Returns 0 if PF is an SRIOV-capable device and
 748  * value of numvfs valid. If not a PF with VFS, return -EINVAL;
 749  * if VFs already enabled, return -EBUSY.
 750  */
 751 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
 752 {
 753         if (!dev->is_physfn || (numvfs > dev->sriov->total_VFs))
 754                 return -EINVAL;
 755
 756         /* Shouldn't change if VFs already enabled */
 757         if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
 758                 return -EBUSY;
 759         else
 760                 dev->sriov->driver_max_VFs = numvfs;
 761
 762         return 0;
 763 }
 764 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
 765
 766 /**
 767  * pci_sriov_get_totalvfs -- get total VFs supported on this devic3
 768  * @dev: the PCI PF device
 769  *
 770  * For a PCIe device with SRIOV support, return the PCIe
 771  * SRIOV capability value of TotalVFs or the value of driver_max_VFs
 772  * if the driver reduced it.  Otherwise, -EINVAL.
 773  */
 774 int pci_sriov_get_totalvfs(struct pci_dev *dev)
 775 {
 776         if (!dev->is_physfn)
 777                 return -EINVAL;
 778
 779         if (dev->sriov->driver_max_VFs)
 780                 return dev->sriov->driver_max_VFs;
 781
 782         return dev->sriov->total_VFs;
 783 }
 784 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);