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         bus->is_added = 1;
  51
  52         return child;
  53 }
  54
  55 static void virtfn_remove_bus(struct pci_bus *bus, int busnr)
  56 {
  57         struct pci_bus *child;
  58
  59         if (bus->number == busnr)
  60                 return;
  61
  62         child = pci_find_bus(pci_domain_nr(bus), busnr);
  63         BUG_ON(!child);
  64
  65         if (list_empty(&child->devices))
  66                 pci_remove_bus(child);
  67 }
  68
  69 static int virtfn_add(struct pci_dev *dev, int id, int reset)
  70 {
  71         int i;
  72         int rc;
  73         u64 size;
  74         char buf[VIRTFN_ID_LEN];
  75         struct pci_dev *virtfn;
  76         struct resource *res;
  77         struct pci_sriov *iov = dev->sriov;
  78
  79         virtfn = alloc_pci_dev();
  80         if (!virtfn)
  81                 return -ENOMEM;
  82
  83         mutex_lock(&iov->dev->sriov->lock);
  84         virtfn->bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id));
  85         if (!virtfn->bus) {
  86                 kfree(virtfn);
  87                 mutex_unlock(&iov->dev->sriov->lock);
  88                 return -ENOMEM;
  89         }
  90         virtfn->devfn = virtfn_devfn(dev, id);
  91         virtfn->vendor = dev->vendor;
  92         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
  93         pci_setup_device(virtfn);
  94         virtfn->dev.parent = dev->dev.parent;
  95
  96         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
  97                 res = dev->resource + PCI_IOV_RESOURCES + i;
  98                 if (!res->parent)
  99                         continue;
 100                 virtfn->resource[i].name = pci_name(virtfn);
 101                 virtfn->resource[i].flags = res->flags;
 102                 size = resource_size(res);
 103                 do_div(size, iov->total_VFs);
 104                 virtfn->resource[i].start = res->start + size * id;
 105                 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
 106                 rc = request_resource(res, &virtfn->resource[i]);
 107                 BUG_ON(rc);
 108         }
 109
 110         if (reset)
 111                 __pci_reset_function(virtfn);
 112
 113         pci_device_add(virtfn, virtfn->bus);
 114         mutex_unlock(&iov->dev->sriov->lock);
 115
 116         virtfn->physfn = pci_dev_get(dev);
 117         virtfn->is_virtfn = 1;
 118
 119         rc = pci_bus_add_device(virtfn);
 120         sprintf(buf, "virtfn%u", id);
 121         rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
 122         if (rc)
 123                 goto failed1;
 124         rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
 125         if (rc)
 126                 goto failed2;
 127
 128         kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
 129
 130         return 0;
 131
 132 failed2:
 133         sysfs_remove_link(&dev->dev.kobj, buf);
 134 failed1:
 135         pci_dev_put(dev);
 136         mutex_lock(&iov->dev->sriov->lock);
 137         pci_stop_and_remove_bus_device(virtfn);
 138         virtfn_remove_bus(dev->bus, virtfn_bus(dev, id));
 139         mutex_unlock(&iov->dev->sriov->lock);
 140
 141         return rc;
 142 }
 143
 144 static void virtfn_remove(struct pci_dev *dev, int id, int reset)
 145 {
 146         char buf[VIRTFN_ID_LEN];
 147         struct pci_bus *bus;
 148         struct pci_dev *virtfn;
 149         struct pci_sriov *iov = dev->sriov;
 150
 151         bus = pci_find_bus(pci_domain_nr(dev->bus), virtfn_bus(dev, id));
 152         if (!bus)
 153                 return;
 154
 155         virtfn = pci_get_slot(bus, virtfn_devfn(dev, id));
 156         if (!virtfn)
 157                 return;
 158
 159         pci_dev_put(virtfn);
 160
 161         if (reset) {
 162                 device_release_driver(&virtfn->dev);
 163                 __pci_reset_function(virtfn);
 164         }
 165
 166         sprintf(buf, "virtfn%u", id);
 167         sysfs_remove_link(&dev->dev.kobj, buf);
 168         /*
 169          * pci_stop_dev() could have been called for this virtfn already,
 170          * so the directory for the virtfn may have been removed before.
 171          * Double check to avoid spurious sysfs warnings.
 172          */
 173         if (virtfn->dev.kobj.sd)
 174                 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
 175
 176         mutex_lock(&iov->dev->sriov->lock);
 177         pci_stop_and_remove_bus_device(virtfn);
 178         virtfn_remove_bus(dev->bus, virtfn_bus(dev, id));
 179         mutex_unlock(&iov->dev->sriov->lock);
 180
 181         pci_dev_put(dev);
 182 }
 183
 184 static int sriov_migration(struct pci_dev *dev)
 185 {
 186         u16 status;
 187         struct pci_sriov *iov = dev->sriov;
 188
 189         if (!iov->num_VFs)
 190                 return 0;
 191
 192         if (!(iov->cap & PCI_SRIOV_CAP_VFM))
 193                 return 0;
 194
 195         pci_read_config_word(dev, iov->pos + PCI_SRIOV_STATUS, &status);
 196         if (!(status & PCI_SRIOV_STATUS_VFM))
 197                 return 0;
 198
 199         schedule_work(&iov->mtask);
 200
 201         return 1;
 202 }
 203
 204 static void sriov_migration_task(struct work_struct *work)
 205 {
 206         int i;
 207         u8 state;
 208         u16 status;
 209         struct pci_sriov *iov = container_of(work, struct pci_sriov, mtask);
 210
 211         for (i = iov->initial_VFs; i < iov->num_VFs; i++) {
 212                 state = readb(iov->mstate + i);
 213                 if (state == PCI_SRIOV_VFM_MI) {
 214                         writeb(PCI_SRIOV_VFM_AV, iov->mstate + i);
 215                         state = readb(iov->mstate + i);
 216                         if (state == PCI_SRIOV_VFM_AV)
 217                                 virtfn_add(iov->self, i, 1);
 218                 } else if (state == PCI_SRIOV_VFM_MO) {
 219                         virtfn_remove(iov->self, i, 1);
 220                         writeb(PCI_SRIOV_VFM_UA, iov->mstate + i);
 221                         state = readb(iov->mstate + i);
 222                         if (state == PCI_SRIOV_VFM_AV)
 223                                 virtfn_add(iov->self, i, 0);
 224                 }
 225         }
 226
 227         pci_read_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, &status);
 228         status &= ~PCI_SRIOV_STATUS_VFM;
 229         pci_write_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, status);
 230 }
 231
 232 static int sriov_enable_migration(struct pci_dev *dev, int nr_virtfn)
 233 {
 234         int bir;
 235         u32 table;
 236         resource_size_t pa;
 237         struct pci_sriov *iov = dev->sriov;
 238
 239         if (nr_virtfn <= iov->initial_VFs)
 240                 return 0;
 241
 242         pci_read_config_dword(dev, iov->pos + PCI_SRIOV_VFM, &table);
 243         bir = PCI_SRIOV_VFM_BIR(table);
 244         if (bir > PCI_STD_RESOURCE_END)
 245                 return -EIO;
 246
 247         table = PCI_SRIOV_VFM_OFFSET(table);
 248         if (table + nr_virtfn > pci_resource_len(dev, bir))
 249                 return -EIO;
 250
 251         pa = pci_resource_start(dev, bir) + table;
 252         iov->mstate = ioremap(pa, nr_virtfn);
 253         if (!iov->mstate)
 254                 return -ENOMEM;
 255
 256         INIT_WORK(&iov->mtask, sriov_migration_task);
 257
 258         iov->ctrl |= PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR;
 259         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 260
 261         return 0;
 262 }
 263
 264 static void sriov_disable_migration(struct pci_dev *dev)
 265 {
 266         struct pci_sriov *iov = dev->sriov;
 267
 268         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR);
 269         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 270
 271         cancel_work_sync(&iov->mtask);
 272         iounmap(iov->mstate);
 273 }
 274
 275 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 276 {
 277         int rc;
 278         int i, j;
 279         int nres;
 280         u16 offset, stride, initial;
 281         struct resource *res;
 282         struct pci_dev *pdev;
 283         struct pci_sriov *iov = dev->sriov;
 284         int bars = 0;
 285
 286         if (!nr_virtfn)
 287                 return 0;
 288
 289         if (iov->num_VFs)
 290                 return -EINVAL;
 291
 292         pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
 293         if (initial > iov->total_VFs ||
 294             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
 295                 return -EIO;
 296
 297         if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
 298             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 299                 return -EINVAL;
 300
 301         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
 302         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &offset);
 303         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &stride);
 304         if (!offset || (nr_virtfn > 1 && !stride))
 305                 return -EIO;
 306
 307         nres = 0;
 308         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 309                 bars |= (1 << (i + PCI_IOV_RESOURCES));
 310                 res = dev->resource + PCI_IOV_RESOURCES + i;
 311                 if (res->parent)
 312                         nres++;
 313         }
 314         if (nres != iov->nres) {
 315                 dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
 316                 return -ENOMEM;
 317         }
 318
 319         iov->offset = offset;
 320         iov->stride = stride;
 321
 322         if (virtfn_bus(dev, nr_virtfn - 1) > dev->bus->busn_res.end) {
 323                 dev_err(&dev->dev, "SR-IOV: bus number out of range\n");
 324                 return -ENOMEM;
 325         }
 326
 327         if (pci_enable_resources(dev, bars)) {
 328                 dev_err(&dev->dev, "SR-IOV: IOV BARS not allocated\n");
 329                 return -ENOMEM;
 330         }
 331
 332         if (iov->link != dev->devfn) {
 333                 pdev = pci_get_slot(dev->bus, iov->link);
 334                 if (!pdev)
 335                         return -ENODEV;
 336
 337                 pci_dev_put(pdev);
 338
 339                 if (!pdev->is_physfn)
 340                         return -ENODEV;
 341
 342                 rc = sysfs_create_link(&dev->dev.kobj,
 343                                         &pdev->dev.kobj, "dep_link");
 344                 if (rc)
 345                         return rc;
 346         }
 347
 348         iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 349         pci_cfg_access_lock(dev);
 350         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 351         msleep(100);
 352         pci_cfg_access_unlock(dev);
 353
 354         iov->initial_VFs = initial;
 355         if (nr_virtfn < initial)
 356                 initial = nr_virtfn;
 357
 358         for (i = 0; i < initial; i++) {
 359                 rc = virtfn_add(dev, i, 0);
 360                 if (rc)
 361                         goto failed;
 362         }
 363
 364         if (iov->cap & PCI_SRIOV_CAP_VFM) {
 365                 rc = sriov_enable_migration(dev, nr_virtfn);
 366                 if (rc)
 367                         goto failed;
 368         }
 369
 370         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 371         iov->num_VFs = nr_virtfn;
 372
 373         return 0;
 374
 375 failed:
 376         for (j = 0; j < i; j++)
 377                 virtfn_remove(dev, j, 0);
 378
 379         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 380         pci_cfg_access_lock(dev);
 381         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 382         ssleep(1);
 383         pci_cfg_access_unlock(dev);
 384
 385         if (iov->link != dev->devfn)
 386                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 387
 388         return rc;
 389 }
 390
 391 static void sriov_disable(struct pci_dev *dev)
 392 {
 393         int i;
 394         struct pci_sriov *iov = dev->sriov;
 395
 396         if (!iov->num_VFs)
 397                 return;
 398
 399         if (iov->cap & PCI_SRIOV_CAP_VFM)
 400                 sriov_disable_migration(dev);
 401
 402         for (i = 0; i < iov->num_VFs; i++)
 403                 virtfn_remove(dev, i, 0);
 404
 405         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 406         pci_cfg_access_lock(dev);
 407         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 408         ssleep(1);
 409         pci_cfg_access_unlock(dev);
 410
 411         if (iov->link != dev->devfn)
 412                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 413
 414         iov->num_VFs = 0;
 415 }
 416
 417 static int sriov_init(struct pci_dev *dev, int pos)
 418 {
 419         int i;
 420         int rc;
 421         int nres;
 422         u32 pgsz;
 423         u16 ctrl, total, offset, stride;
 424         struct pci_sriov *iov;
 425         struct resource *res;
 426         struct pci_dev *pdev;
 427
 428         if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END &&
 429             pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT)
 430                 return -ENODEV;
 431
 432         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 433         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 434                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 435                 ssleep(1);
 436         }
 437
 438         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 439         if (!total)
 440                 return 0;
 441
 442         ctrl = 0;
 443         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 444                 if (pdev->is_physfn)
 445                         goto found;
 446
 447         pdev = NULL;
 448         if (pci_ari_enabled(dev->bus))
 449                 ctrl |= PCI_SRIOV_CTRL_ARI;
 450
 451 found:
 452         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 453         pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
 454         pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
 455         if (!offset || (total > 1 && !stride))
 456                 return -EIO;
 457
 458         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 459         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 460         pgsz &= ~((1 << i) - 1);
 461         if (!pgsz)
 462                 return -EIO;
 463
 464         pgsz &= ~(pgsz - 1);
 465         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 466
 467         nres = 0;
 468         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 469                 res = dev->resource + PCI_IOV_RESOURCES + i;
 470                 i += __pci_read_base(dev, pci_bar_unknown, res,
 471                                      pos + PCI_SRIOV_BAR + i * 4);
 472                 if (!res->flags)
 473                         continue;
 474                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 475                         rc = -EIO;
 476                         goto failed;
 477                 }
 478                 res->end = res->start + resource_size(res) * total - 1;
 479                 nres++;
 480         }
 481
 482         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 483         if (!iov) {
 484                 rc = -ENOMEM;
 485                 goto failed;
 486         }
 487
 488         iov->pos = pos;
 489         iov->nres = nres;
 490         iov->ctrl = ctrl;
 491         iov->total_VFs = total;
 492         iov->offset = offset;
 493         iov->stride = stride;
 494         iov->pgsz = pgsz;
 495         iov->self = dev;
 496         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 497         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 498         if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
 499                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 500
 501         if (pdev)
 502                 iov->dev = pci_dev_get(pdev);
 503         else
 504                 iov->dev = dev;
 505
 506         mutex_init(&iov->lock);
 507
 508         dev->sriov = iov;
 509         dev->is_physfn = 1;
 510
 511         return 0;
 512
 513 failed:
 514         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 515                 res = dev->resource + PCI_IOV_RESOURCES + i;
 516                 res->flags = 0;
 517         }
 518
 519         return rc;
 520 }
 521
 522 static void sriov_release(struct pci_dev *dev)
 523 {
 524         BUG_ON(dev->sriov->num_VFs);
 525
 526         if (dev != dev->sriov->dev)
 527                 pci_dev_put(dev->sriov->dev);
 528
 529         mutex_destroy(&dev->sriov->lock);
 530
 531         kfree(dev->sriov);
 532         dev->sriov = NULL;
 533 }
 534
 535 static void sriov_restore_state(struct pci_dev *dev)
 536 {
 537         int i;
 538         u16 ctrl;
 539         struct pci_sriov *iov = dev->sriov;
 540
 541         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 542         if (ctrl & PCI_SRIOV_CTRL_VFE)
 543                 return;
 544
 545         for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
 546                 pci_update_resource(dev, i);
 547
 548         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 549         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, iov->num_VFs);
 550         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 551         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 552                 msleep(100);
 553 }
 554
 555 /**
 556  * pci_iov_init - initialize the IOV capability
 557  * @dev: the PCI device
 558  *
 559  * Returns 0 on success, or negative on failure.
 560  */
 561 int pci_iov_init(struct pci_dev *dev)
 562 {
 563         int pos;
 564
 565         if (!pci_is_pcie(dev))
 566                 return -ENODEV;
 567
 568         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 569         if (pos)
 570                 return sriov_init(dev, pos);
 571
 572         return -ENODEV;
 573 }
 574
 575 /**
 576  * pci_iov_release - release resources used by the IOV capability
 577  * @dev: the PCI device
 578  */
 579 void pci_iov_release(struct pci_dev *dev)
 580 {
 581         if (dev->is_physfn)
 582                 sriov_release(dev);
 583 }
 584
 585 /**
 586  * pci_iov_resource_bar - get position of the SR-IOV BAR
 587  * @dev: the PCI device
 588  * @resno: the resource number
 589  * @type: the BAR type to be filled in
 590  *
 591  * Returns position of the BAR encapsulated in the SR-IOV capability.
 592  */
 593 int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 594                          enum pci_bar_type *type)
 595 {
 596         if (resno < PCI_IOV_RESOURCES || resno > PCI_IOV_RESOURCE_END)
 597                 return 0;
 598
 599         BUG_ON(!dev->is_physfn);
 600
 601         *type = pci_bar_unknown;
 602
 603         return dev->sriov->pos + PCI_SRIOV_BAR +
 604                 4 * (resno - PCI_IOV_RESOURCES);
 605 }
 606
 607 /**
 608  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 609  * @dev: the PCI device
 610  * @resno: the resource number
 611  *
 612  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 613  * This is not the same as the resource size which is defined as
 614  * the VF BAR size multiplied by the number of VFs.  The alignment
 615  * is just the VF BAR size.
 616  */
 617 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 618 {
 619         struct resource tmp;
 620         enum pci_bar_type type;
 621         int reg = pci_iov_resource_bar(dev, resno, &type);
 622
 623         if (!reg)
 624                 return 0;
 625
 626          __pci_read_base(dev, type, &tmp, reg);
 627         return resource_alignment(&tmp);
 628 }
 629
 630 /**
 631  * pci_restore_iov_state - restore the state of the IOV capability
 632  * @dev: the PCI device
 633  */
 634 void pci_restore_iov_state(struct pci_dev *dev)
 635 {
 636         if (dev->is_physfn)
 637                 sriov_restore_state(dev);
 638 }
 639
 640 /**
 641  * pci_iov_bus_range - find bus range used by Virtual Function
 642  * @bus: the PCI bus
 643  *
 644  * Returns max number of buses (exclude current one) used by Virtual
 645  * Functions.
 646  */
 647 int pci_iov_bus_range(struct pci_bus *bus)
 648 {
 649         int max = 0;
 650         u8 busnr;
 651         struct pci_dev *dev;
 652
 653         list_for_each_entry(dev, &bus->devices, bus_list) {
 654                 if (!dev->is_physfn)
 655                         continue;
 656                 busnr = virtfn_bus(dev, dev->sriov->total_VFs - 1);
 657                 if (busnr > max)
 658                         max = busnr;
 659         }
 660
 661         return max ? max - bus->number : 0;
 662 }
 663
 664 /**
 665  * pci_enable_sriov - enable the SR-IOV capability
 666  * @dev: the PCI device
 667  * @nr_virtfn: number of virtual functions to enable
 668  *
 669  * Returns 0 on success, or negative on failure.
 670  */
 671 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 672 {
 673         might_sleep();
 674
 675         if (!dev->is_physfn)
 676                 return -ENODEV;
 677
 678         return sriov_enable(dev, nr_virtfn);
 679 }
 680 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 681
 682 /**
 683  * pci_disable_sriov - disable the SR-IOV capability
 684  * @dev: the PCI device
 685  */
 686 void pci_disable_sriov(struct pci_dev *dev)
 687 {
 688         might_sleep();
 689
 690         if (!dev->is_physfn)
 691                 return;
 692
 693         sriov_disable(dev);
 694 }
 695 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 696
 697 /**
 698  * pci_sriov_migration - notify SR-IOV core of Virtual Function Migration
 699  * @dev: the PCI device
 700  *
 701  * Returns IRQ_HANDLED if the IRQ is handled, or IRQ_NONE if not.
 702  *
 703  * Physical Function driver is responsible to register IRQ handler using
 704  * VF Migration Interrupt Message Number, and call this function when the
 705  * interrupt is generated by the hardware.
 706  */
 707 irqreturn_t pci_sriov_migration(struct pci_dev *dev)
 708 {
 709         if (!dev->is_physfn)
 710                 return IRQ_NONE;
 711
 712         return sriov_migration(dev) ? IRQ_HANDLED : IRQ_NONE;
 713 }
 714 EXPORT_SYMBOL_GPL(pci_sriov_migration);
 715
 716 /**
 717  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 718  * @dev: the PCI device
 719  *
 720  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 721  */
 722 int pci_num_vf(struct pci_dev *dev)
 723 {
 724         if (!dev->is_physfn)
 725                 return 0;
 726
 727         return dev->sriov->num_VFs;
 728 }
 729 EXPORT_SYMBOL_GPL(pci_num_vf);
 730
 731 /**
 732  * pci_vfs_assigned - returns number of VFs are assigned to a guest
 733  * @dev: the PCI device
 734  *
 735  * Returns number of VFs belonging to this device that are assigned to a guest.
 736  * If device is not a physical function returns -ENODEV.
 737  */
 738 int pci_vfs_assigned(struct pci_dev *dev)
 739 {
 740         struct pci_dev *vfdev;
 741         unsigned int vfs_assigned = 0;
 742         unsigned short dev_id;
 743
 744         /* only search if we are a PF */
 745         if (!dev->is_physfn)
 746                 return 0;
 747
 748         /*
 749          * determine the device ID for the VFs, the vendor ID will be the
 750          * same as the PF so there is no need to check for that one
 751          */
 752         pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_VF_DID, &dev_id);
 753
 754         /* loop through all the VFs to see if we own any that are assigned */
 755         vfdev = pci_get_device(dev->vendor, dev_id, NULL);
 756         while (vfdev) {
 757                 /*
 758                  * It is considered assigned if it is a virtual function with
 759                  * our dev as the physical function and the assigned bit is set
 760                  */
 761                 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
 762                     (vfdev->dev_flags & PCI_DEV_FLAGS_ASSIGNED))
 763                         vfs_assigned++;
 764
 765                 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
 766         }
 767
 768         return vfs_assigned;
 769 }
 770 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
 771
 772 /**
 773  * pci_sriov_set_totalvfs -- reduce the TotalVFs available
 774  * @dev: the PCI PF device
 775  * @numvfs: number that should be used for TotalVFs supported
 776  *
 777  * Should be called from PF driver's probe routine with
 778  * device's mutex held.
 779  *
 780  * Returns 0 if PF is an SRIOV-capable device and
 781  * value of numvfs valid. If not a PF with VFS, return -EINVAL;
 782  * if VFs already enabled, return -EBUSY.
 783  */
 784 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
 785 {
 786         if (!dev->is_physfn || (numvfs > dev->sriov->total_VFs))
 787                 return -EINVAL;
 788
 789         /* Shouldn't change if VFs already enabled */
 790         if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
 791                 return -EBUSY;
 792         else
 793                 dev->sriov->driver_max_VFs = numvfs;
 794
 795         return 0;
 796 }
 797 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
 798
 799 /**
 800  * pci_sriov_get_totalvfs -- get total VFs supported on this devic3
 801  * @dev: the PCI PF device
 802  *
 803  * For a PCIe device with SRIOV support, return the PCIe
 804  * SRIOV capability value of TotalVFs or the value of driver_max_VFs
 805  * if the driver reduced it.  Otherwise, -EINVAL.
 806  */
 807 int pci_sriov_get_totalvfs(struct pci_dev *dev)
 808 {
 809         if (!dev->is_physfn)
 810                 return -EINVAL;
 811
 812         if (dev->sriov->driver_max_VFs)
 813                 return dev->sriov->driver_max_VFs;
 814
 815         return dev->sriov->total_VFs;
 816 }
 817 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);