drivers/pci/iov.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * PCI Express I/O Virtualization (IOV) support
   4  *   Single Root IOV 1.0
   5  *   Address Translation Service 1.0
   6  *
   7  * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com>
   8  */
   9
  10 #include <linux/pci.h>
  11 #include <linux/slab.h>
  12 #include <linux/mutex.h>
  13 #include <linux/export.h>
  14 #include <linux/string.h>
  15 #include <linux/delay.h>
  16 #include <linux/pci-ats.h>
  17 #include "pci.h"
  18
  19 #define VIRTFN_ID_LEN   16
  20
  21 int pci_iov_virtfn_bus(struct pci_dev *dev, int vf_id)
  22 {
  23         if (!dev->is_physfn)
  24                 return -EINVAL;
  25         return dev->bus->number + ((dev->devfn + dev->sriov->offset +
  26                                     dev->sriov->stride * vf_id) >> 8);
  27 }
  28
  29 int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id)
  30 {
  31         if (!dev->is_physfn)
  32                 return -EINVAL;
  33         return (dev->devfn + dev->sriov->offset +
  34                 dev->sriov->stride * vf_id) & 0xff;
  35 }
  36
  37 /*
  38  * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may
  39  * change when NumVFs changes.
  40  *
  41  * Update iov->offset and iov->stride when NumVFs is written.
  42  */
  43 static inline void pci_iov_set_numvfs(struct pci_dev *dev, int nr_virtfn)
  44 {
  45         struct pci_sriov *iov = dev->sriov;
  46
  47         pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
  48         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &iov->offset);
  49         pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &iov->stride);
  50 }
  51
  52 /*
  53  * The PF consumes one bus number.  NumVFs, First VF Offset, and VF Stride
  54  * determine how many additional bus numbers will be consumed by VFs.
  55  *
  56  * Iterate over all valid NumVFs, validate offset and stride, and calculate
  57  * the maximum number of bus numbers that could ever be required.
  58  */
  59 static int compute_max_vf_buses(struct pci_dev *dev)
  60 {
  61         struct pci_sriov *iov = dev->sriov;
  62         int nr_virtfn, busnr, rc = 0;
  63
  64         for (nr_virtfn = iov->total_VFs; nr_virtfn; nr_virtfn--) {
  65                 pci_iov_set_numvfs(dev, nr_virtfn);
  66                 if (!iov->offset || (nr_virtfn > 1 && !iov->stride)) {
  67                         rc = -EIO;
  68                         goto out;
  69                 }
  70
  71                 busnr = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
  72                 if (busnr > iov->max_VF_buses)
  73                         iov->max_VF_buses = busnr;
  74         }
  75
  76 out:
  77         pci_iov_set_numvfs(dev, 0);
  78         return rc;
  79 }
  80
  81 static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
  82 {
  83         struct pci_bus *child;
  84
  85         if (bus->number == busnr)
  86                 return bus;
  87
  88         child = pci_find_bus(pci_domain_nr(bus), busnr);
  89         if (child)
  90                 return child;
  91
  92         child = pci_add_new_bus(bus, NULL, busnr);
  93         if (!child)
  94                 return NULL;
  95
  96         pci_bus_insert_busn_res(child, busnr, busnr);
  97
  98         return child;
  99 }
 100
 101 static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus)
 102 {
 103         if (physbus != virtbus && list_empty(&virtbus->devices))
 104                 pci_remove_bus(virtbus);
 105 }
 106
 107 resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
 108 {
 109         if (!dev->is_physfn)
 110                 return 0;
 111
 112         return dev->sriov->barsz[resno - PCI_IOV_RESOURCES];
 113 }
 114
 115 static void pci_read_vf_config_common(struct pci_dev *virtfn)
 116 {
 117         struct pci_dev *physfn = virtfn->physfn;
 118
 119         /*
 120          * Some config registers are the same across all associated VFs.
 121          * Read them once from VF0 so we can skip reading them from the
 122          * other VFs.
 123          *
 124          * PCIe r4.0, sec 9.3.4.1, technically doesn't require all VFs to
 125          * have the same Revision ID and Subsystem ID, but we assume they
 126          * do.
 127          */
 128         pci_read_config_dword(virtfn, PCI_CLASS_REVISION,
 129                               &physfn->sriov->class);
 130         pci_read_config_byte(virtfn, PCI_HEADER_TYPE,
 131                              &physfn->sriov->hdr_type);
 132         pci_read_config_word(virtfn, PCI_SUBSYSTEM_VENDOR_ID,
 133                              &physfn->sriov->subsystem_vendor);
 134         pci_read_config_word(virtfn, PCI_SUBSYSTEM_ID,
 135                              &physfn->sriov->subsystem_device);
 136 }
 137
 138 int pci_iov_add_virtfn(struct pci_dev *dev, int id)
 139 {
 140         int i;
 141         int rc = -ENOMEM;
 142         u64 size;
 143         char buf[VIRTFN_ID_LEN];
 144         struct pci_dev *virtfn;
 145         struct resource *res;
 146         struct pci_sriov *iov = dev->sriov;
 147         struct pci_bus *bus;
 148
 149         bus = virtfn_add_bus(dev->bus, pci_iov_virtfn_bus(dev, id));
 150         if (!bus)
 151                 goto failed;
 152
 153         virtfn = pci_alloc_dev(bus);
 154         if (!virtfn)
 155                 goto failed0;
 156
 157         virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
 158         virtfn->vendor = dev->vendor;
 159         virtfn->device = iov->vf_device;
 160         virtfn->is_virtfn = 1;
 161         virtfn->physfn = pci_dev_get(dev);
 162
 163         if (id == 0)
 164                 pci_read_vf_config_common(virtfn);
 165
 166         rc = pci_setup_device(virtfn);
 167         if (rc)
 168                 goto failed1;
 169
 170         virtfn->dev.parent = dev->dev.parent;
 171         virtfn->multifunction = 0;
 172
 173         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 174                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 175                 if (!res->parent)
 176                         continue;
 177                 virtfn->resource[i].name = pci_name(virtfn);
 178                 virtfn->resource[i].flags = res->flags;
 179                 size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
 180                 virtfn->resource[i].start = res->start + size * id;
 181                 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
 182                 rc = request_resource(res, &virtfn->resource[i]);
 183                 BUG_ON(rc);
 184         }
 185
 186         pci_device_add(virtfn, virtfn->bus);
 187
 188         sprintf(buf, "virtfn%u", id);
 189         rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
 190         if (rc)
 191                 goto failed1;
 192         rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
 193         if (rc)
 194                 goto failed2;
 195
 196         kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
 197
 198         pci_bus_add_device(virtfn);
 199
 200         return 0;
 201
 202 failed2:
 203         sysfs_remove_link(&dev->dev.kobj, buf);
 204 failed1:
 205         pci_stop_and_remove_bus_device(virtfn);
 206         pci_dev_put(dev);
 207 failed0:
 208         virtfn_remove_bus(dev->bus, bus);
 209 failed:
 210
 211         return rc;
 212 }
 213
 214 void pci_iov_remove_virtfn(struct pci_dev *dev, int id)
 215 {
 216         char buf[VIRTFN_ID_LEN];
 217         struct pci_dev *virtfn;
 218
 219         virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
 220                                              pci_iov_virtfn_bus(dev, id),
 221                                              pci_iov_virtfn_devfn(dev, id));
 222         if (!virtfn)
 223                 return;
 224
 225         sprintf(buf, "virtfn%u", id);
 226         sysfs_remove_link(&dev->dev.kobj, buf);
 227         /*
 228          * pci_stop_dev() could have been called for this virtfn already,
 229          * so the directory for the virtfn may have been removed before.
 230          * Double check to avoid spurious sysfs warnings.
 231          */
 232         if (virtfn->dev.kobj.sd)
 233                 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
 234
 235         pci_stop_and_remove_bus_device(virtfn);
 236         virtfn_remove_bus(dev->bus, virtfn->bus);
 237
 238         /* balance pci_get_domain_bus_and_slot() */
 239         pci_dev_put(virtfn);
 240         pci_dev_put(dev);
 241 }
 242
 243 int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
 244 {
 245         return 0;
 246 }
 247
 248 int __weak pcibios_sriov_disable(struct pci_dev *pdev)
 249 {
 250         return 0;
 251 }
 252
 253 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 254 {
 255         int rc;
 256         int i;
 257         int nres;
 258         u16 initial;
 259         struct resource *res;
 260         struct pci_dev *pdev;
 261         struct pci_sriov *iov = dev->sriov;
 262         int bars = 0;
 263         int bus;
 264
 265         if (!nr_virtfn)
 266                 return 0;
 267
 268         if (iov->num_VFs)
 269                 return -EINVAL;
 270
 271         pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
 272         if (initial > iov->total_VFs ||
 273             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
 274                 return -EIO;
 275
 276         if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
 277             (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 278                 return -EINVAL;
 279
 280         nres = 0;
 281         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 282                 bars |= (1 << (i + PCI_IOV_RESOURCES));
 283                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 284                 if (res->parent)
 285                         nres++;
 286         }
 287         if (nres != iov->nres) {
 288                 pci_err(dev, "not enough MMIO resources for SR-IOV\n");
 289                 return -ENOMEM;
 290         }
 291
 292         bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
 293         if (bus > dev->bus->busn_res.end) {
 294                 pci_err(dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
 295                         nr_virtfn, bus, &dev->bus->busn_res);
 296                 return -ENOMEM;
 297         }
 298
 299         if (pci_enable_resources(dev, bars)) {
 300                 pci_err(dev, "SR-IOV: IOV BARS not allocated\n");
 301                 return -ENOMEM;
 302         }
 303
 304         if (iov->link != dev->devfn) {
 305                 pdev = pci_get_slot(dev->bus, iov->link);
 306                 if (!pdev)
 307                         return -ENODEV;
 308
 309                 if (!pdev->is_physfn) {
 310                         pci_dev_put(pdev);
 311                         return -ENOSYS;
 312                 }
 313
 314                 rc = sysfs_create_link(&dev->dev.kobj,
 315                                         &pdev->dev.kobj, "dep_link");
 316                 pci_dev_put(pdev);
 317                 if (rc)
 318                         return rc;
 319         }
 320
 321         iov->initial_VFs = initial;
 322         if (nr_virtfn < initial)
 323                 initial = nr_virtfn;
 324
 325         rc = pcibios_sriov_enable(dev, initial);
 326         if (rc) {
 327                 pci_err(dev, "failure %d from pcibios_sriov_enable()\n", rc);
 328                 goto err_pcibios;
 329         }
 330
 331         pci_iov_set_numvfs(dev, nr_virtfn);
 332         iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 333         pci_cfg_access_lock(dev);
 334         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 335         msleep(100);
 336         pci_cfg_access_unlock(dev);
 337
 338         for (i = 0; i < initial; i++) {
 339                 rc = pci_iov_add_virtfn(dev, i);
 340                 if (rc)
 341                         goto failed;
 342         }
 343
 344         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 345         iov->num_VFs = nr_virtfn;
 346
 347         return 0;
 348
 349 failed:
 350         while (i--)
 351                 pci_iov_remove_virtfn(dev, i);
 352
 353 err_pcibios:
 354         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 355         pci_cfg_access_lock(dev);
 356         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 357         ssleep(1);
 358         pci_cfg_access_unlock(dev);
 359
 360         pcibios_sriov_disable(dev);
 361
 362         if (iov->link != dev->devfn)
 363                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 364
 365         pci_iov_set_numvfs(dev, 0);
 366         return rc;
 367 }
 368
 369 static void sriov_disable(struct pci_dev *dev)
 370 {
 371         int i;
 372         struct pci_sriov *iov = dev->sriov;
 373
 374         if (!iov->num_VFs)
 375                 return;
 376
 377         for (i = 0; i < iov->num_VFs; i++)
 378                 pci_iov_remove_virtfn(dev, i);
 379
 380         iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 381         pci_cfg_access_lock(dev);
 382         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 383         ssleep(1);
 384         pci_cfg_access_unlock(dev);
 385
 386         pcibios_sriov_disable(dev);
 387
 388         if (iov->link != dev->devfn)
 389                 sysfs_remove_link(&dev->dev.kobj, "dep_link");
 390
 391         iov->num_VFs = 0;
 392         pci_iov_set_numvfs(dev, 0);
 393 }
 394
 395 static int sriov_init(struct pci_dev *dev, int pos)
 396 {
 397         int i, bar64;
 398         int rc;
 399         int nres;
 400         u32 pgsz;
 401         u16 ctrl, total;
 402         struct pci_sriov *iov;
 403         struct resource *res;
 404         struct pci_dev *pdev;
 405
 406         pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
 407         if (ctrl & PCI_SRIOV_CTRL_VFE) {
 408                 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
 409                 ssleep(1);
 410         }
 411
 412         ctrl = 0;
 413         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
 414                 if (pdev->is_physfn)
 415                         goto found;
 416
 417         pdev = NULL;
 418         if (pci_ari_enabled(dev->bus))
 419                 ctrl |= PCI_SRIOV_CTRL_ARI;
 420
 421 found:
 422         pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 423
 424         pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
 425         if (!total)
 426                 return 0;
 427
 428         pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 429         i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
 430         pgsz &= ~((1 << i) - 1);
 431         if (!pgsz)
 432                 return -EIO;
 433
 434         pgsz &= ~(pgsz - 1);
 435         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 436
 437         iov = kzalloc(sizeof(*iov), GFP_KERNEL);
 438         if (!iov)
 439                 return -ENOMEM;
 440
 441         nres = 0;
 442         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 443                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 444                 /*
 445                  * If it is already FIXED, don't change it, something
 446                  * (perhaps EA or header fixups) wants it this way.
 447                  */
 448                 if (res->flags & IORESOURCE_PCI_FIXED)
 449                         bar64 = (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
 450                 else
 451                         bar64 = __pci_read_base(dev, pci_bar_unknown, res,
 452                                                 pos + PCI_SRIOV_BAR + i * 4);
 453                 if (!res->flags)
 454                         continue;
 455                 if (resource_size(res) & (PAGE_SIZE - 1)) {
 456                         rc = -EIO;
 457                         goto failed;
 458                 }
 459                 iov->barsz[i] = resource_size(res);
 460                 res->end = res->start + resource_size(res) * total - 1;
 461                 pci_info(dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
 462                          i, res, i, total);
 463                 i += bar64;
 464                 nres++;
 465         }
 466
 467         iov->pos = pos;
 468         iov->nres = nres;
 469         iov->ctrl = ctrl;
 470         iov->total_VFs = total;
 471         iov->driver_max_VFs = total;
 472         pci_read_config_word(dev, pos + PCI_SRIOV_VF_DID, &iov->vf_device);
 473         iov->pgsz = pgsz;
 474         iov->self = dev;
 475         iov->drivers_autoprobe = true;
 476         pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
 477         pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
 478         if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
 479                 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
 480
 481         if (pdev)
 482                 iov->dev = pci_dev_get(pdev);
 483         else
 484                 iov->dev = dev;
 485
 486         dev->sriov = iov;
 487         dev->is_physfn = 1;
 488         rc = compute_max_vf_buses(dev);
 489         if (rc)
 490                 goto fail_max_buses;
 491
 492         return 0;
 493
 494 fail_max_buses:
 495         dev->sriov = NULL;
 496         dev->is_physfn = 0;
 497 failed:
 498         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 499                 res = &dev->resource[i + PCI_IOV_RESOURCES];
 500                 res->flags = 0;
 501         }
 502
 503         kfree(iov);
 504         return rc;
 505 }
 506
 507 static void sriov_release(struct pci_dev *dev)
 508 {
 509         BUG_ON(dev->sriov->num_VFs);
 510
 511         if (dev != dev->sriov->dev)
 512                 pci_dev_put(dev->sriov->dev);
 513
 514         kfree(dev->sriov);
 515         dev->sriov = NULL;
 516 }
 517
 518 static void sriov_restore_state(struct pci_dev *dev)
 519 {
 520         int i;
 521         u16 ctrl;
 522         struct pci_sriov *iov = dev->sriov;
 523
 524         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
 525         if (ctrl & PCI_SRIOV_CTRL_VFE)
 526                 return;
 527
 528         /*
 529          * Restore PCI_SRIOV_CTRL_ARI before pci_iov_set_numvfs() because
 530          * it reads offset & stride, which depend on PCI_SRIOV_CTRL_ARI.
 531          */
 532         ctrl &= ~PCI_SRIOV_CTRL_ARI;
 533         ctrl |= iov->ctrl & PCI_SRIOV_CTRL_ARI;
 534         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, ctrl);
 535
 536         for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
 537                 pci_update_resource(dev, i);
 538
 539         pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 540         pci_iov_set_numvfs(dev, iov->num_VFs);
 541         pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 542         if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 543                 msleep(100);
 544 }
 545
 546 /**
 547  * pci_iov_init - initialize the IOV capability
 548  * @dev: the PCI device
 549  *
 550  * Returns 0 on success, or negative on failure.
 551  */
 552 int pci_iov_init(struct pci_dev *dev)
 553 {
 554         int pos;
 555
 556         if (!pci_is_pcie(dev))
 557                 return -ENODEV;
 558
 559         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 560         if (pos)
 561                 return sriov_init(dev, pos);
 562
 563         return -ENODEV;
 564 }
 565
 566 /**
 567  * pci_iov_release - release resources used by the IOV capability
 568  * @dev: the PCI device
 569  */
 570 void pci_iov_release(struct pci_dev *dev)
 571 {
 572         if (dev->is_physfn)
 573                 sriov_release(dev);
 574 }
 575
 576 /**
 577  * pci_iov_remove - clean up SR-IOV state after PF driver is detached
 578  * @dev: the PCI device
 579  */
 580 void pci_iov_remove(struct pci_dev *dev)
 581 {
 582         struct pci_sriov *iov = dev->sriov;
 583
 584         if (!dev->is_physfn)
 585                 return;
 586
 587         iov->driver_max_VFs = iov->total_VFs;
 588         if (iov->num_VFs)
 589                 pci_warn(dev, "driver left SR-IOV enabled after remove\n");
 590 }
 591
 592 /**
 593  * pci_iov_update_resource - update a VF BAR
 594  * @dev: the PCI device
 595  * @resno: the resource number
 596  *
 597  * Update a VF BAR in the SR-IOV capability of a PF.
 598  */
 599 void pci_iov_update_resource(struct pci_dev *dev, int resno)
 600 {
 601         struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL;
 602         struct resource *res = dev->resource + resno;
 603         int vf_bar = resno - PCI_IOV_RESOURCES;
 604         struct pci_bus_region region;
 605         u16 cmd;
 606         u32 new;
 607         int reg;
 608
 609         /*
 610          * The generic pci_restore_bars() path calls this for all devices,
 611          * including VFs and non-SR-IOV devices.  If this is not a PF, we
 612          * have nothing to do.
 613          */
 614         if (!iov)
 615                 return;
 616
 617         pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &cmd);
 618         if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) {
 619                 dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n",
 620                          vf_bar, res);
 621                 return;
 622         }
 623
 624         /*
 625          * Ignore unimplemented BARs, unused resource slots for 64-bit
 626          * BARs, and non-movable resources, e.g., those described via
 627          * Enhanced Allocation.
 628          */
 629         if (!res->flags)
 630                 return;
 631
 632         if (res->flags & IORESOURCE_UNSET)
 633                 return;
 634
 635         if (res->flags & IORESOURCE_PCI_FIXED)
 636                 return;
 637
 638         pcibios_resource_to_bus(dev->bus, &region, res);
 639         new = region.start;
 640         new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
 641
 642         reg = iov->pos + PCI_SRIOV_BAR + 4 * vf_bar;
 643         pci_write_config_dword(dev, reg, new);
 644         if (res->flags & IORESOURCE_MEM_64) {
 645                 new = region.start >> 16 >> 16;
 646                 pci_write_config_dword(dev, reg + 4, new);
 647         }
 648 }
 649
 650 resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
 651                                                       int resno)
 652 {
 653         return pci_iov_resource_size(dev, resno);
 654 }
 655
 656 /**
 657  * pci_sriov_resource_alignment - get resource alignment for VF BAR
 658  * @dev: the PCI device
 659  * @resno: the resource number
 660  *
 661  * Returns the alignment of the VF BAR found in the SR-IOV capability.
 662  * This is not the same as the resource size which is defined as
 663  * the VF BAR size multiplied by the number of VFs.  The alignment
 664  * is just the VF BAR size.
 665  */
 666 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 667 {
 668         return pcibios_iov_resource_alignment(dev, resno);
 669 }
 670
 671 /**
 672  * pci_restore_iov_state - restore the state of the IOV capability
 673  * @dev: the PCI device
 674  */
 675 void pci_restore_iov_state(struct pci_dev *dev)
 676 {
 677         if (dev->is_physfn)
 678                 sriov_restore_state(dev);
 679 }
 680
 681 /**
 682  * pci_vf_drivers_autoprobe - set PF property drivers_autoprobe for VFs
 683  * @dev: the PCI device
 684  * @auto_probe: set VF drivers auto probe flag
 685  */
 686 void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool auto_probe)
 687 {
 688         if (dev->is_physfn)
 689                 dev->sriov->drivers_autoprobe = auto_probe;
 690 }
 691
 692 /**
 693  * pci_iov_bus_range - find bus range used by Virtual Function
 694  * @bus: the PCI bus
 695  *
 696  * Returns max number of buses (exclude current one) used by Virtual
 697  * Functions.
 698  */
 699 int pci_iov_bus_range(struct pci_bus *bus)
 700 {
 701         int max = 0;
 702         struct pci_dev *dev;
 703
 704         list_for_each_entry(dev, &bus->devices, bus_list) {
 705                 if (!dev->is_physfn)
 706                         continue;
 707                 if (dev->sriov->max_VF_buses > max)
 708                         max = dev->sriov->max_VF_buses;
 709         }
 710
 711         return max ? max - bus->number : 0;
 712 }
 713
 714 /**
 715  * pci_enable_sriov - enable the SR-IOV capability
 716  * @dev: the PCI device
 717  * @nr_virtfn: number of virtual functions to enable
 718  *
 719  * Returns 0 on success, or negative on failure.
 720  */
 721 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 722 {
 723         might_sleep();
 724
 725         if (!dev->is_physfn)
 726                 return -ENOSYS;
 727
 728         return sriov_enable(dev, nr_virtfn);
 729 }
 730 EXPORT_SYMBOL_GPL(pci_enable_sriov);
 731
 732 /**
 733  * pci_disable_sriov - disable the SR-IOV capability
 734  * @dev: the PCI device
 735  */
 736 void pci_disable_sriov(struct pci_dev *dev)
 737 {
 738         might_sleep();
 739
 740         if (!dev->is_physfn)
 741                 return;
 742
 743         sriov_disable(dev);
 744 }
 745 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 746
 747 /**
 748  * pci_num_vf - return number of VFs associated with a PF device_release_driver
 749  * @dev: the PCI device
 750  *
 751  * Returns number of VFs, or 0 if SR-IOV is not enabled.
 752  */
 753 int pci_num_vf(struct pci_dev *dev)
 754 {
 755         if (!dev->is_physfn)
 756                 return 0;
 757
 758         return dev->sriov->num_VFs;
 759 }
 760 EXPORT_SYMBOL_GPL(pci_num_vf);
 761
 762 /**
 763  * pci_vfs_assigned - returns number of VFs are assigned to a guest
 764  * @dev: the PCI device
 765  *
 766  * Returns number of VFs belonging to this device that are assigned to a guest.
 767  * If device is not a physical function returns 0.
 768  */
 769 int pci_vfs_assigned(struct pci_dev *dev)
 770 {
 771         struct pci_dev *vfdev;
 772         unsigned int vfs_assigned = 0;
 773         unsigned short dev_id;
 774
 775         /* only search if we are a PF */
 776         if (!dev->is_physfn)
 777                 return 0;
 778
 779         /*
 780          * determine the device ID for the VFs, the vendor ID will be the
 781          * same as the PF so there is no need to check for that one
 782          */
 783         dev_id = dev->sriov->vf_device;
 784
 785         /* loop through all the VFs to see if we own any that are assigned */
 786         vfdev = pci_get_device(dev->vendor, dev_id, NULL);
 787         while (vfdev) {
 788                 /*
 789                  * It is considered assigned if it is a virtual function with
 790                  * our dev as the physical function and the assigned bit is set
 791                  */
 792                 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
 793                         pci_is_dev_assigned(vfdev))
 794                         vfs_assigned++;
 795
 796                 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
 797         }
 798
 799         return vfs_assigned;
 800 }
 801 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
 802
 803 /**
 804  * pci_sriov_set_totalvfs -- reduce the TotalVFs available
 805  * @dev: the PCI PF device
 806  * @numvfs: number that should be used for TotalVFs supported
 807  *
 808  * Should be called from PF driver's probe routine with
 809  * device's mutex held.
 810  *
 811  * Returns 0 if PF is an SRIOV-capable device and
 812  * value of numvfs valid. If not a PF return -ENOSYS;
 813  * if numvfs is invalid return -EINVAL;
 814  * if VFs already enabled, return -EBUSY.
 815  */
 816 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
 817 {
 818         if (!dev->is_physfn)
 819                 return -ENOSYS;
 820
 821         if (numvfs > dev->sriov->total_VFs)
 822                 return -EINVAL;
 823
 824         /* Shouldn't change if VFs already enabled */
 825         if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
 826                 return -EBUSY;
 827
 828         dev->sriov->driver_max_VFs = numvfs;
 829         return 0;
 830 }
 831 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
 832
 833 /**
 834  * pci_sriov_get_totalvfs -- get total VFs supported on this device
 835  * @dev: the PCI PF device
 836  *
 837  * For a PCIe device with SRIOV support, return the PCIe
 838  * SRIOV capability value of TotalVFs or the value of driver_max_VFs
 839  * if the driver reduced it.  Otherwise 0.
 840  */
 841 int pci_sriov_get_totalvfs(struct pci_dev *dev)
 842 {
 843         if (!dev->is_physfn)
 844                 return 0;
 845
 846         return dev->sriov->driver_max_VFs;
 847 }
 848 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);
 849
 850 /**
 851  * pci_sriov_configure_simple - helper to configure SR-IOV
 852  * @dev: the PCI device
 853  * @nr_virtfn: number of virtual functions to enable, 0 to disable
 854  *
 855  * Enable or disable SR-IOV for devices that don't require any PF setup
 856  * before enabling SR-IOV.  Return value is negative on error, or number of
 857  * VFs allocated on success.
 858  */
 859 int pci_sriov_configure_simple(struct pci_dev *dev, int nr_virtfn)
 860 {
 861         int rc;
 862
 863         might_sleep();
 864
 865         if (!dev->is_physfn)
 866                 return -ENODEV;
 867
 868         if (pci_vfs_assigned(dev)) {
 869                 pci_warn(dev, "Cannot modify SR-IOV while VFs are assigned\n");
 870                 return -EPERM;
 871         }
 872
 873         if (nr_virtfn == 0) {
 874                 sriov_disable(dev);
 875                 return 0;
 876         }
 877
 878         rc = sriov_enable(dev, nr_virtfn);
 879         if (rc < 0)
 880                 return rc;
 881
 882         return nr_virtfn;
 883 }
 884 EXPORT_SYMBOL_GPL(pci_sriov_configure_simple);