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/string.h>
  15 #include <linux/delay.h>
  16 #include "pci.h"
  17
  18 #define VIRTFN_ID_LEN   16
  19
  20 static inline u8 virtfn_bus(struct pci_dev *dev, int id)
  21 {
  22         return dev->bus->number + ((dev->devfn + dev->sriov->offset +
  23                                     dev->sriov->stride * id) >> 8);
  24 }
  25
  26 static inline u8 virtfn_devfn(struct pci_dev *dev, int id)
  27 {
  28         return (dev->devfn + dev->sriov->offset +
  29                 dev->sriov->stride * id) & 0xff;
  30 }
  31
  32 static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
  33 {
  34         int rc;
  35         struct pci_bus *child;
  36
  37         if (bus->number == busnr)
  38                 return bus;
  39
  40         child = pci_find_bus(pci_domain_nr(bus), busnr);
  41         if (child)
  42                 return child;
  43
  44         child = pci_add_new_bus(bus, NULL, busnr);
  45         if (!child)
  46                 return NULL;
  47
  48         child->subordinate = busnr;
  49         child->dev.parent = bus->bridge;
  50         rc = pci_bus_add_child(child);
  51         if (rc) {
  52                 pci_remove_bus(child);
  53                 return NULL;
  54         }
  55
  56         return child;
  57 }
  58
  59 static void virtfn_remove_bus(struct pci_bus *bus, int busnr)
  60 {
  61         struct pci_bus *child;
  62
  63         if (bus->number == busnr)
  64                 return;
  65
  66         child = pci_find_bus(pci_domain_nr(bus), busnr);
  67         BUG_ON(!child);
  68
  69         if (list_empty(&child->devices))
  70                 pci_remove_bus(child);
  71 }
  72
  73 static int virtfn_add(struct pci_dev *dev, int id, int reset)
  74 {
  75         int i;
  76         int rc;
  77         u64 size;
  78         char buf[VIRTFN_ID_LEN];
  79         struct pci_dev *virtfn;
  80         struct resource *res;
  81         struct pci_sriov *iov = dev->sriov;
  82
  83         virtfn = alloc_pci_dev();
  84         if (!virtfn)
  85                 return -ENOMEM;
  86
  87         mutex_lock(&iov->dev->sriov->lock);
  88         virtfn->bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id));
  89         if (!virtfn->bus) {
  90                 kfree(virtfn);
  91                 mutex_unlock(&iov->dev->sriov->lock);
  92                 return -ENOMEM;
  93         }
  94         virtfn->devfn = virtfn_devfn(dev, id);
  95         virtfn->vendor = dev->vendor;
  96         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
  97         pci_setup_device(virtfn);
  98         virtfn->dev.parent = dev->dev.parent;
  99
 100         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 101                 res = dev->resource + PCI_IOV_RESOURCES + i;
 102                 if (!res->parent)
 103                         continue;
 104                 virtfn->resource[i].name = pci_name(virtfn);
 105                 virtfn->resource[i].flags = res->flags;
 106                 size = resource_size(res);
 107                 do_div(size, iov->total);
 108                 virtfn->resource[i].start = res->start + size * id;
 109                 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
 110                 rc = request_resource(res, &virtfn->resource[i]);
 111                 BUG_ON(rc);
 112         }
 113
 114         if (reset)
 115                 __pci_reset_function(virtfn);
 116
 117         pci_device_add(virtfn, virtfn->bus);
 118         mutex_unlock(&iov->dev->sriov->lock);
 119
 120         virtfn->physfn = pci_dev_get(dev);
 121         virtfn->is_virtfn = 1;
 122
 123         rc = pci_bus_add_device(virtfn);
 124         if (rc)
 125                 goto failed1;
 126         sprintf(buf, "virtfn%u", id);
 127         rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
 128         if (rc)
 129                 goto failed1;
 130         rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
 131         if (rc)
 132                 goto failed2;
 133
 134         kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
 135
 136         return 0;
 137
 138 failed2:
 139         sysfs_remove_link(&dev->dev.kobj, buf);
 140 failed1:
 141         pci_dev_put(dev);
 142         mutex_lock(&iov->dev->sriov->lock);
 143         pci_remove_bus_device(virtfn);
 144         virtfn_remove_bus(dev->bus, virtfn_bus(dev, id));
 145         mutex_unlock(&iov->dev->sriov->lock);
 146
 147         return rc;
 148 }
 149
 150 static void virtfn_remove(struct pci_dev *dev, int id, int reset)
 151 {
 152         char buf[VIRTFN_ID_LEN];
 153         struct pci_bus *bus;
 154         struct pci_dev *virtfn;
 155         struct pci_sriov *iov = dev->sriov;
 156
 157         bus = pci_find_bus(pci_domain_nr(dev->bus), virtfn_bus(dev, id));
 158         if (!bus)
 159                 return;
 160
 161         virtfn = pci_get_slot(bus, virtfn_devfn(dev, id));
 162         if (!virtfn)
 163                 return;
 164
 165         pci_dev_put(virtfn);
 166
 167         if (reset) {
 168                 device_release_driver(&virtfn->dev);
 169                 __pci_reset_function(virtfn);
 170         }
 171
 172         sprintf(buf, "virtfn%u", id);
 173         sysfs_remove_link(&dev->dev.kobj, buf);
 174         sysfs_remove_link(&virtfn->dev.kobj, "physfn");
 175
 176         mutex_lock(&iov->dev->sriov->lock);
 177         pci_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->nr_virtfn)
 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; i < iov->nr_virtfn; 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)
 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
 285         if (!nr_virtfn)
 286                 return 0;
 287
 288         if (iov->nr_virtfn)
 289                 return -EINVAL;
 290
 291         pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
 292         if (initial > iov->total ||
 293             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total)))
 294                 return -EIO;
 295
 296         if (nr_virtfn < 0 || nr_virtfn > iov->total ||
 297             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 298                 return -EINVAL;
 299
 300         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
 301         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &offset);
 302         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &stride);
 303         if (!offset || (nr_virtfn > 1 && !stride))
 304                 return -EIO;
 305
 306         nres = 0;
 307         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 308                 res = dev->resource + PCI_IOV_RESOURCES + i;
 309                 if (res->parent)
 310                         nres++;
 311         }
 312         if (nres != iov->nres) {
 313                 dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
 314                 return -ENOMEM;
 315         }
 316
 317         iov->offset = offset;
 318         iov->stride = stride;
 319
 320         if (virtfn_bus(dev, nr_virtfn - 1) > dev->bus->subordinate) {
 321                 dev_err(&dev->dev, "SR-IOV: bus number out of range\n");
 322                 return -ENOMEM;
 323         }
 324
 325         if (iov->link != dev->devfn) {
 326                 pdev = pci_get_slot(dev->bus, iov->link);
 327                 if (!pdev)
 328                         return -ENODEV;
 329
 330                 pci_dev_put(pdev);
 331
 332                 if (!pdev->is_physfn)
 333                         return -ENODEV;
 334
 335                 rc = sysfs_create_link(&dev->dev.kobj,
 336                                         &pdev->dev.kobj, "dep_link");
 337                 if (rc)
 338                         return rc;
 339         }
 340
 341         iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 342         pci_block_user_cfg_access(dev);
 343         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 344         msleep(100);
 345         pci_unblock_user_cfg_access(dev);
 346
 347         iov->initial = initial;
 348         if (nr_virtfn < initial)
 349                 initial = nr_virtfn;
 350
 351         for (i = 0; i < initial; i++) {
 352                 rc = virtfn_add(dev, i, 0);
 353                 if (rc)
 354                         goto failed;
 355         }
 356
 357         if (iov->cap & PCI_SRIOV_CAP_VFM) {
 358                 rc = sriov_enable_migration(dev, nr_virtfn);
 359                 if (rc)
 360                         goto failed;
 361         }
 362
 363         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 364         iov->nr_virtfn = nr_virtfn;
 365
 366         return 0;
 367
 368 failed:
 369         for (j = 0; j < i; j++)
 370                 virtfn_remove(dev, j, 0);
 371
 372         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 373         pci_block_user_cfg_access(dev);
 374         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 375         ssleep(1);
 376         pci_unblock_user_cfg_access(dev);
 377
 378         if (iov->link != dev->devfn)
 379                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 380
 381         return rc;
 382 }
 383
 384 static void sriov_disable(struct pci_dev *dev)
 385 {
 386         int i;
 387         struct pci_sriov *iov = dev->sriov;
 388
 389         if (!iov->nr_virtfn)
 390                 return;
 391
 392         if (iov->cap & PCI_SRIOV_CAP_VFM)
 393                 sriov_disable_migration(dev);
 394
 395         for (i = 0; i < iov->nr_virtfn; i++)
 396                 virtfn_remove(dev, i, 0);
 397
 398         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 399         pci_block_user_cfg_access(dev);
 400         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 401         ssleep(1);
 402         pci_unblock_user_cfg_access(dev);
 403
 404         if (iov->link != dev->devfn)
 405                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 406
 407         iov->nr_virtfn = 0;
 408 }
 409
 410 static int sriov_init(struct pci_dev *dev, int pos)
 411 {
 412         int i;
 413         int rc;
 414         int nres;
 415         u32 pgsz;
 416         u16 ctrl, total, offset, stride;
 417         struct pci_sriov *iov;
 418         struct resource *res;
 419         struct pci_dev *pdev;
 420
 421         if (dev->pcie_type != PCI_EXP_TYPE_RC_END &&
 422             dev->pcie_type != PCI_EXP_TYPE_ENDPOINT)
 423                 return -ENODEV;
 424
 425         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 426         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 427                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 428                 ssleep(1);
 429         }
 430
 431         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 432         if (!total)
 433                 return 0;
 434
 435         ctrl = 0;
 436         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 437                 if (pdev->is_physfn)
 438                         goto found;
 439
 440         pdev = NULL;
 441         if (pci_ari_enabled(dev->bus))
 442                 ctrl |= PCI_SRIOV_CTRL_ARI;
 443
 444 found:
 445         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 446         pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, total);
 447         pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
 448         pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
 449         if (!offset || (total > 1 && !stride))
 450                 return -EIO;
 451
 452         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 453         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 454         pgsz &= ~((1 << i) - 1);
 455         if (!pgsz)
 456                 return -EIO;
 457
 458         pgsz &= ~(pgsz - 1);
 459         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 460
 461         nres = 0;
 462         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 463                 res = dev->resource + PCI_IOV_RESOURCES + i;
 464                 i += __pci_read_base(dev, pci_bar_unknown, res,
 465                                      pos + PCI_SRIOV_BAR + i * 4);
 466                 if (!res->flags)
 467                         continue;
 468                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 469                         rc = -EIO;
 470                         goto failed;
 471                 }
 472                 res->end = res->start + resource_size(res) * total - 1;
 473                 nres++;
 474         }
 475
 476         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 477         if (!iov) {
 478                 rc = -ENOMEM;
 479                 goto failed;
 480         }
 481
 482         iov->pos = pos;
 483         iov->nres = nres;
 484         iov->ctrl = ctrl;
 485         iov->total = total;
 486         iov->offset = offset;
 487         iov->stride = stride;
 488         iov->pgsz = pgsz;
 489         iov->self = dev;
 490         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 491         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 492         if (dev->pcie_type == PCI_EXP_TYPE_RC_END)
 493                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 494
 495         if (pdev)
 496                 iov->dev = pci_dev_get(pdev);
 497         else
 498                 iov->dev = dev;
 499
 500         mutex_init(&iov->lock);
 501
 502         dev->sriov = iov;
 503         dev->is_physfn = 1;
 504
 505         return 0;
 506
 507 failed:
 508         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 509                 res = dev->resource + PCI_IOV_RESOURCES + i;
 510                 res->flags = 0;
 511         }
 512
 513         return rc;
 514 }
 515
 516 static void sriov_release(struct pci_dev *dev)
 517 {
 518         BUG_ON(dev->sriov->nr_virtfn);
 519
 520         if (dev != dev->sriov->dev)
 521                 pci_dev_put(dev->sriov->dev);
 522
 523         mutex_destroy(&dev->sriov->lock);
 524
 525         kfree(dev->sriov);
 526         dev->sriov = NULL;
 527 }
 528
 529 static void sriov_restore_state(struct pci_dev *dev)
 530 {
 531         int i;
 532         u16 ctrl;
 533         struct pci_sriov *iov = dev->sriov;
 534
 535         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 536         if (ctrl & PCI_SRIOV_CTRL_VFE)
 537                 return;
 538
 539         for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
 540                 pci_update_resource(dev, i);
 541
 542         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 543         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, iov->nr_virtfn);
 544         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 545         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 546                 msleep(100);
 547 }
 548
 549 /**
 550  * pci_iov_init - initialize the IOV capability
 551  * @dev: the PCI device
 552  *
 553  * Returns 0 on success, or negative on failure.
 554  */
 555 int pci_iov_init(struct pci_dev *dev)
 556 {
 557         int pos;
 558
 559         if (!pci_is_pcie(dev))
 560                 return -ENODEV;
 561
 562         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 563         if (pos)
 564                 return sriov_init(dev, pos);
 565
 566         return -ENODEV;
 567 }
 568
 569 /**
 570  * pci_iov_release - release resources used by the IOV capability
 571  * @dev: the PCI device
 572  */
 573 void pci_iov_release(struct pci_dev *dev)
 574 {
 575         if (dev->is_physfn)
 576                 sriov_release(dev);
 577 }
 578
 579 /**
 580  * pci_iov_resource_bar - get position of the SR-IOV BAR
 581  * @dev: the PCI device
 582  * @resno: the resource number
 583  * @type: the BAR type to be filled in
 584  *
 585  * Returns position of the BAR encapsulated in the SR-IOV capability.
 586  */
 587 int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 588                          enum pci_bar_type *type)
 589 {
 590         if (resno < PCI_IOV_RESOURCES || resno > PCI_IOV_RESOURCE_END)
 591                 return 0;
 592
 593         BUG_ON(!dev->is_physfn);
 594
 595         *type = pci_bar_unknown;
 596
 597         return dev->sriov->pos + PCI_SRIOV_BAR +
 598                 4 * (resno - PCI_IOV_RESOURCES);
 599 }
 600
 601 /**
 602  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 603  * @dev: the PCI device
 604  * @resno: the resource number
 605  *
 606  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 607  * This is not the same as the resource size which is defined as
 608  * the VF BAR size multiplied by the number of VFs.  The alignment
 609  * is just the VF BAR size.
 610  */
 611 int pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 612 {
 613         struct resource tmp;
 614         enum pci_bar_type type;
 615         int reg = pci_iov_resource_bar(dev, resno, &type);
 616
 617         if (!reg)
 618                 return 0;
 619
 620          __pci_read_base(dev, type, &tmp, reg);
 621         return resource_alignment(&tmp);
 622 }
 623
 624 /**
 625  * pci_restore_iov_state - restore the state of the IOV capability
 626  * @dev: the PCI device
 627  */
 628 void pci_restore_iov_state(struct pci_dev *dev)
 629 {
 630         if (dev->is_physfn)
 631                 sriov_restore_state(dev);
 632 }
 633
 634 /**
 635  * pci_iov_bus_range - find bus range used by Virtual Function
 636  * @bus: the PCI bus
 637  *
 638  * Returns max number of buses (exclude current one) used by Virtual
 639  * Functions.
 640  */
 641 int pci_iov_bus_range(struct pci_bus *bus)
 642 {
 643         int max = 0;
 644         u8 busnr;
 645         struct pci_dev *dev;
 646
 647         list_for_each_entry(dev, &bus->devices, bus_list) {
 648                 if (!dev->is_physfn)
 649                         continue;
 650                 busnr = virtfn_bus(dev, dev->sriov->total - 1);
 651                 if (busnr > max)
 652                         max = busnr;
 653         }
 654
 655         return max ? max - bus->number : 0;
 656 }
 657
 658 /**
 659  * pci_enable_sriov - enable the SR-IOV capability
 660  * @dev: the PCI device
 661  * @nr_virtfn: number of virtual functions to enable
 662  *
 663  * Returns 0 on success, or negative on failure.
 664  */
 665 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 666 {
 667         might_sleep();
 668
 669         if (!dev->is_physfn)
 670                 return -ENODEV;
 671
 672         return sriov_enable(dev, nr_virtfn);
 673 }
 674 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 675
 676 /**
 677  * pci_disable_sriov - disable the SR-IOV capability
 678  * @dev: the PCI device
 679  */
 680 void pci_disable_sriov(struct pci_dev *dev)
 681 {
 682         might_sleep();
 683
 684         if (!dev->is_physfn)
 685                 return;
 686
 687         sriov_disable(dev);
 688 }
 689 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 690
 691 /**
 692  * pci_sriov_migration - notify SR-IOV core of Virtual Function Migration
 693  * @dev: the PCI device
 694  *
 695  * Returns IRQ_HANDLED if the IRQ is handled, or IRQ_NONE if not.
 696  *
 697  * Physical Function driver is responsible to register IRQ handler using
 698  * VF Migration Interrupt Message Number, and call this function when the
 699  * interrupt is generated by the hardware.
 700  */
 701 irqreturn_t pci_sriov_migration(struct pci_dev *dev)
 702 {
 703         if (!dev->is_physfn)
 704                 return IRQ_NONE;
 705
 706         return sriov_migration(dev) ? IRQ_HANDLED : IRQ_NONE;
 707 }
 708 EXPORT_SYMBOL_GPL(pci_sriov_migration);
 709
 710 /**
 711  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 712  * @dev: the PCI device
 713  *
 714  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 715  */
 716 int pci_num_vf(struct pci_dev *dev)
 717 {
 718         if (!dev || !dev->is_physfn)
 719                 return 0;
 720         else
 721                 return dev->sriov->nr_virtfn;
 722 }
 723 EXPORT_SYMBOL_GPL(pci_num_vf);
 724
 725 static int ats_alloc_one(struct pci_dev *dev, int ps)
 726 {
 727         int pos;
 728         u16 cap;
 729         struct pci_ats *ats;
 730
 731         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
 732         if (!pos)
 733                 return -ENODEV;
 734
 735         ats = kzalloc(sizeof(*ats), GFP_KERNEL);
 736         if (!ats)
 737                 return -ENOMEM;
 738
 739         ats->pos = pos;
 740         ats->stu = ps;
 741         pci_read_config_word(dev, pos + PCI_ATS_CAP, &cap);
 742         ats->qdep = PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) :
 743                                             PCI_ATS_MAX_QDEP;
 744         dev->ats = ats;
 745
 746         return 0;
 747 }
 748
 749 static void ats_free_one(struct pci_dev *dev)
 750 {
 751         kfree(dev->ats);
 752         dev->ats = NULL;
 753 }
 754
 755 /**
 756  * pci_enable_ats - enable the ATS capability
 757  * @dev: the PCI device
 758  * @ps: the IOMMU page shift
 759  *
 760  * Returns 0 on success, or negative on failure.
 761  */
 762 int pci_enable_ats(struct pci_dev *dev, int ps)
 763 {
 764         int rc;
 765         u16 ctrl;
 766
 767         BUG_ON(dev->ats && dev->ats->is_enabled);
 768
 769         if (ps < PCI_ATS_MIN_STU)
 770                 return -EINVAL;
 771
 772         if (dev->is_physfn || dev->is_virtfn) {
 773                 struct pci_dev *pdev = dev->is_physfn ? dev : dev->physfn;
 774
 775                 mutex_lock(&pdev->sriov->lock);
 776                 if (pdev->ats)
 777                         rc = pdev->ats->stu == ps ? 0 : -EINVAL;
 778                 else
 779                         rc = ats_alloc_one(pdev, ps);
 780
 781                 if (!rc)
 782                         pdev->ats->ref_cnt++;
 783                 mutex_unlock(&pdev->sriov->lock);
 784                 if (rc)
 785                         return rc;
 786         }
 787
 788         if (!dev->is_physfn) {
 789                 rc = ats_alloc_one(dev, ps);
 790                 if (rc)
 791                         return rc;
 792         }
 793
 794         ctrl = PCI_ATS_CTRL_ENABLE;
 795         if (!dev->is_virtfn)
 796                 ctrl |= PCI_ATS_CTRL_STU(ps - PCI_ATS_MIN_STU);
 797         pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
 798
 799         dev->ats->is_enabled = 1;
 800
 801         return 0;
 802 }
 803
 804 /**
 805  * pci_disable_ats - disable the ATS capability
 806  * @dev: the PCI device
 807  */
 808 void pci_disable_ats(struct pci_dev *dev)
 809 {
 810         u16 ctrl;
 811
 812         BUG_ON(!dev->ats || !dev->ats->is_enabled);
 813
 814         pci_read_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, &ctrl);
 815         ctrl &= ~PCI_ATS_CTRL_ENABLE;
 816         pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
 817
 818         dev->ats->is_enabled = 0;
 819
 820         if (dev->is_physfn || dev->is_virtfn) {
 821                 struct pci_dev *pdev = dev->is_physfn ? dev : dev->physfn;
 822
 823                 mutex_lock(&pdev->sriov->lock);
 824                 pdev->ats->ref_cnt--;
 825                 if (!pdev->ats->ref_cnt)
 826                         ats_free_one(pdev);
 827                 mutex_unlock(&pdev->sriov->lock);
 828         }
 829
 830         if (!dev->is_physfn)
 831                 ats_free_one(dev);
 832 }
 833
 834 /**
 835  * pci_ats_queue_depth - query the ATS Invalidate Queue Depth
 836  * @dev: the PCI device
 837  *
 838  * Returns the queue depth on success, or negative on failure.
 839  *
 840  * The ATS spec uses 0 in the Invalidate Queue Depth field to
 841  * indicate that the function can accept 32 Invalidate Request.
 842  * But here we use the `real' values (i.e. 1~32) for the Queue
 843  * Depth; and 0 indicates the function shares the Queue with
 844  * other functions (doesn't exclusively own a Queue).
 845  */
 846 int pci_ats_queue_depth(struct pci_dev *dev)
 847 {
 848         int pos;
 849         u16 cap;
 850
 851         if (dev->is_virtfn)
 852                 return 0;
 853
 854         if (dev->ats)
 855                 return dev->ats->qdep;
 856
 857         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
 858         if (!pos)
 859                 return -ENODEV;
 860
 861         pci_read_config_word(dev, pos + PCI_ATS_CAP, &cap);
 862
 863         return PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) :
 864                                        PCI_ATS_MAX_QDEP;
 865 }