drivers/virtio/virtio_pci_modern_dev.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2
   3 #include <linux/virtio_pci_modern.h>
   4 #include <linux/module.h>
   5 #include <linux/pci.h>
   6 #include <linux/delay.h>
   7
   8 /*
   9  * vp_modern_map_capability - map a part of virtio pci capability
  10  * @mdev: the modern virtio-pci device
  11  * @off: offset of the capability
  12  * @minlen: minimal length of the capability
  13  * @align: align requirement
  14  * @start: start from the capability
  15  * @size: map size
  16  * @len: the length that is actually mapped
  17  * @pa: physical address of the capability
  18  *
  19  * Returns the io address of for the part of the capability
  20  */
  21 static void __iomem *
  22 vp_modern_map_capability(struct virtio_pci_modern_device *mdev, int off,
  23                          size_t minlen, u32 align, u32 start, u32 size,
  24                          size_t *len, resource_size_t *pa)
  25 {
  26         struct pci_dev *dev = mdev->pci_dev;
  27         u8 bar;
  28         u32 offset, length;
  29         void __iomem *p;
  30
  31         pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap,
  32                                                  bar),
  33                              &bar);
  34         pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset),
  35                              &offset);
  36         pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length),
  37                               &length);
  38
  39         /* Check if the BAR may have changed since we requested the region. */
  40         if (bar >= PCI_STD_NUM_BARS || !(mdev->modern_bars & (1 << bar))) {
  41                 dev_err(&dev->dev,
  42                         "virtio_pci: bar unexpectedly changed to %u\n", bar);
  43                 return NULL;
  44         }
  45
  46         if (length <= start) {
  47                 dev_err(&dev->dev,
  48                         "virtio_pci: bad capability len %u (>%u expected)\n",
  49                         length, start);
  50                 return NULL;
  51         }
  52
  53         if (length - start < minlen) {
  54                 dev_err(&dev->dev,
  55                         "virtio_pci: bad capability len %u (>=%zu expected)\n",
  56                         length, minlen);
  57                 return NULL;
  58         }
  59
  60         length -= start;
  61
  62         if (start + offset < offset) {
  63                 dev_err(&dev->dev,
  64                         "virtio_pci: map wrap-around %u+%u\n",
  65                         start, offset);
  66                 return NULL;
  67         }
  68
  69         offset += start;
  70
  71         if (offset & (align - 1)) {
  72                 dev_err(&dev->dev,
  73                         "virtio_pci: offset %u not aligned to %u\n",
  74                         offset, align);
  75                 return NULL;
  76         }
  77
  78         if (length > size)
  79                 length = size;
  80
  81         if (len)
  82                 *len = length;
  83
  84         if (minlen + offset < minlen ||
  85             minlen + offset > pci_resource_len(dev, bar)) {
  86                 dev_err(&dev->dev,
  87                         "virtio_pci: map virtio %zu@%u "
  88                         "out of range on bar %i length %lu\n",
  89                         minlen, offset,
  90                         bar, (unsigned long)pci_resource_len(dev, bar));
  91                 return NULL;
  92         }
  93
  94         p = pci_iomap_range(dev, bar, offset, length);
  95         if (!p)
  96                 dev_err(&dev->dev,
  97                         "virtio_pci: unable to map virtio %u@%u on bar %i\n",
  98                         length, offset, bar);
  99         else if (pa)
 100                 *pa = pci_resource_start(dev, bar) + offset;
 101
 102         return p;
 103 }
 104
 105 /**
 106  * virtio_pci_find_capability - walk capabilities to find device info.
 107  * @dev: the pci device
 108  * @cfg_type: the VIRTIO_PCI_CAP_* value we seek
 109  * @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO.
 110  * @bars: the bitmask of BARs
 111  *
 112  * Returns offset of the capability, or 0.
 113  */
 114 static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type,
 115                                              u32 ioresource_types, int *bars)
 116 {
 117         int pos;
 118
 119         for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
 120              pos > 0;
 121              pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
 122                 u8 type, bar;
 123                 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
 124                                                          cfg_type),
 125                                      &type);
 126                 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
 127                                                          bar),
 128                                      &bar);
 129
 130                 /* Ignore structures with reserved BAR values */
 131                 if (bar >= PCI_STD_NUM_BARS)
 132                         continue;
 133
 134                 if (type == cfg_type) {
 135                         if (pci_resource_len(dev, bar) &&
 136                             pci_resource_flags(dev, bar) & ioresource_types) {
 137                                 *bars |= (1 << bar);
 138                                 return pos;
 139                         }
 140                 }
 141         }
 142         return 0;
 143 }
 144
 145 /* This is part of the ABI.  Don't screw with it. */
 146 static inline void check_offsets(void)
 147 {
 148         /* Note: disk space was harmed in compilation of this function. */
 149         BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR !=
 150                      offsetof(struct virtio_pci_cap, cap_vndr));
 151         BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT !=
 152                      offsetof(struct virtio_pci_cap, cap_next));
 153         BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN !=
 154                      offsetof(struct virtio_pci_cap, cap_len));
 155         BUILD_BUG_ON(VIRTIO_PCI_CAP_CFG_TYPE !=
 156                      offsetof(struct virtio_pci_cap, cfg_type));
 157         BUILD_BUG_ON(VIRTIO_PCI_CAP_BAR !=
 158                      offsetof(struct virtio_pci_cap, bar));
 159         BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET !=
 160                      offsetof(struct virtio_pci_cap, offset));
 161         BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH !=
 162                      offsetof(struct virtio_pci_cap, length));
 163         BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT !=
 164                      offsetof(struct virtio_pci_notify_cap,
 165                               notify_off_multiplier));
 166         BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT !=
 167                      offsetof(struct virtio_pci_common_cfg,
 168                               device_feature_select));
 169         BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF !=
 170                      offsetof(struct virtio_pci_common_cfg, device_feature));
 171         BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT !=
 172                      offsetof(struct virtio_pci_common_cfg,
 173                               guest_feature_select));
 174         BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF !=
 175                      offsetof(struct virtio_pci_common_cfg, guest_feature));
 176         BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX !=
 177                      offsetof(struct virtio_pci_common_cfg, msix_config));
 178         BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ !=
 179                      offsetof(struct virtio_pci_common_cfg, num_queues));
 180         BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS !=
 181                      offsetof(struct virtio_pci_common_cfg, device_status));
 182         BUILD_BUG_ON(VIRTIO_PCI_COMMON_CFGGENERATION !=
 183                      offsetof(struct virtio_pci_common_cfg, config_generation));
 184         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT !=
 185                      offsetof(struct virtio_pci_common_cfg, queue_select));
 186         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE !=
 187                      offsetof(struct virtio_pci_common_cfg, queue_size));
 188         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX !=
 189                      offsetof(struct virtio_pci_common_cfg, queue_msix_vector));
 190         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE !=
 191                      offsetof(struct virtio_pci_common_cfg, queue_enable));
 192         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF !=
 193                      offsetof(struct virtio_pci_common_cfg, queue_notify_off));
 194         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO !=
 195                      offsetof(struct virtio_pci_common_cfg, queue_desc_lo));
 196         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI !=
 197                      offsetof(struct virtio_pci_common_cfg, queue_desc_hi));
 198         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO !=
 199                      offsetof(struct virtio_pci_common_cfg, queue_avail_lo));
 200         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI !=
 201                      offsetof(struct virtio_pci_common_cfg, queue_avail_hi));
 202         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO !=
 203                      offsetof(struct virtio_pci_common_cfg, queue_used_lo));
 204         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI !=
 205                      offsetof(struct virtio_pci_common_cfg, queue_used_hi));
 206 }
 207
 208 /*
 209  * vp_modern_probe: probe the modern virtio pci device, note that the
 210  * caller is required to enable PCI device before calling this function.
 211  * @mdev: the modern virtio-pci device
 212  *
 213  * Return 0 on succeed otherwise fail
 214  */
 215 int vp_modern_probe(struct virtio_pci_modern_device *mdev)
 216 {
 217         struct pci_dev *pci_dev = mdev->pci_dev;
 218         int err, common, isr, notify, device;
 219         u32 notify_length;
 220         u32 notify_offset;
 221         int devid;
 222
 223         check_offsets();
 224
 225         if (mdev->device_id_check) {
 226                 devid = mdev->device_id_check(pci_dev);
 227                 if (devid < 0)
 228                         return devid;
 229                 mdev->id.device = devid;
 230         } else {
 231                 /* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
 232                 if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f)
 233                         return -ENODEV;
 234
 235                 if (pci_dev->device < 0x1040) {
 236                         /* Transitional devices: use the PCI subsystem device id as
 237                          * virtio device id, same as legacy driver always did.
 238                          */
 239                         mdev->id.device = pci_dev->subsystem_device;
 240                 } else {
 241                         /* Modern devices: simply use PCI device id, but start from 0x1040. */
 242                         mdev->id.device = pci_dev->device - 0x1040;
 243                 }
 244         }
 245         mdev->id.vendor = pci_dev->subsystem_vendor;
 246
 247         /* check for a common config: if not, use legacy mode (bar 0). */
 248         common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
 249                                             IORESOURCE_IO | IORESOURCE_MEM,
 250                                             &mdev->modern_bars);
 251         if (!common) {
 252                 dev_info(&pci_dev->dev,
 253                          "virtio_pci: leaving for legacy driver\n");
 254                 return -ENODEV;
 255         }
 256
 257         /* If common is there, these should be too... */
 258         isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
 259                                          IORESOURCE_IO | IORESOURCE_MEM,
 260                                          &mdev->modern_bars);
 261         notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
 262                                             IORESOURCE_IO | IORESOURCE_MEM,
 263                                             &mdev->modern_bars);
 264         if (!isr || !notify) {
 265                 dev_err(&pci_dev->dev,
 266                         "virtio_pci: missing capabilities %i/%i/%i\n",
 267                         common, isr, notify);
 268                 return -EINVAL;
 269         }
 270
 271         err = dma_set_mask_and_coherent(&pci_dev->dev,
 272                                         mdev->dma_mask ? : DMA_BIT_MASK(64));
 273         if (err)
 274                 err = dma_set_mask_and_coherent(&pci_dev->dev,
 275                                                 DMA_BIT_MASK(32));
 276         if (err)
 277                 dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA.  Trying to continue, but this might not work.\n");
 278
 279         /* Device capability is only mandatory for devices that have
 280          * device-specific configuration.
 281          */
 282         device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
 283                                             IORESOURCE_IO | IORESOURCE_MEM,
 284                                             &mdev->modern_bars);
 285
 286         err = pci_request_selected_regions(pci_dev, mdev->modern_bars,
 287                                            "virtio-pci-modern");
 288         if (err)
 289                 return err;
 290
 291         err = -EINVAL;
 292         mdev->common = vp_modern_map_capability(mdev, common,
 293                                       sizeof(struct virtio_pci_common_cfg), 4,
 294                                       0, sizeof(struct virtio_pci_modern_common_cfg),
 295                                       NULL, NULL);
 296         if (!mdev->common)
 297                 goto err_map_common;
 298         mdev->isr = vp_modern_map_capability(mdev, isr, sizeof(u8), 1,
 299                                              0, 1,
 300                                              NULL, NULL);
 301         if (!mdev->isr)
 302                 goto err_map_isr;
 303
 304         /* Read notify_off_multiplier from config space. */
 305         pci_read_config_dword(pci_dev,
 306                               notify + offsetof(struct virtio_pci_notify_cap,
 307                                                 notify_off_multiplier),
 308                               &mdev->notify_offset_multiplier);
 309         /* Read notify length and offset from config space. */
 310         pci_read_config_dword(pci_dev,
 311                               notify + offsetof(struct virtio_pci_notify_cap,
 312                                                 cap.length),
 313                               &notify_length);
 314
 315         pci_read_config_dword(pci_dev,
 316                               notify + offsetof(struct virtio_pci_notify_cap,
 317                                                 cap.offset),
 318                               &notify_offset);
 319
 320         /* We don't know how many VQs we'll map, ahead of the time.
 321          * If notify length is small, map it all now.
 322          * Otherwise, map each VQ individually later.
 323          */
 324         if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) {
 325                 mdev->notify_base = vp_modern_map_capability(mdev, notify,
 326                                                              2, 2,
 327                                                              0, notify_length,
 328                                                              &mdev->notify_len,
 329                                                              &mdev->notify_pa);
 330                 if (!mdev->notify_base)
 331                         goto err_map_notify;
 332         } else {
 333                 mdev->notify_map_cap = notify;
 334         }
 335
 336         /* Again, we don't know how much we should map, but PAGE_SIZE
 337          * is more than enough for all existing devices.
 338          */
 339         if (device) {
 340                 mdev->device = vp_modern_map_capability(mdev, device, 0, 4,
 341                                                         0, PAGE_SIZE,
 342                                                         &mdev->device_len,
 343                                                         NULL);
 344                 if (!mdev->device)
 345                         goto err_map_device;
 346         }
 347
 348         return 0;
 349
 350 err_map_device:
 351         if (mdev->notify_base)
 352                 pci_iounmap(pci_dev, mdev->notify_base);
 353 err_map_notify:
 354         pci_iounmap(pci_dev, mdev->isr);
 355 err_map_isr:
 356         pci_iounmap(pci_dev, mdev->common);
 357 err_map_common:
 358         pci_release_selected_regions(pci_dev, mdev->modern_bars);
 359         return err;
 360 }
 361 EXPORT_SYMBOL_GPL(vp_modern_probe);
 362
 363 /*
 364  * vp_modern_remove: remove and cleanup the modern virtio pci device
 365  * @mdev: the modern virtio-pci device
 366  */
 367 void vp_modern_remove(struct virtio_pci_modern_device *mdev)
 368 {
 369         struct pci_dev *pci_dev = mdev->pci_dev;
 370
 371         if (mdev->device)
 372                 pci_iounmap(pci_dev, mdev->device);
 373         if (mdev->notify_base)
 374                 pci_iounmap(pci_dev, mdev->notify_base);
 375         pci_iounmap(pci_dev, mdev->isr);
 376         pci_iounmap(pci_dev, mdev->common);
 377         pci_release_selected_regions(pci_dev, mdev->modern_bars);
 378 }
 379 EXPORT_SYMBOL_GPL(vp_modern_remove);
 380
 381 /*
 382  * vp_modern_get_features - get features from device
 383  * @mdev: the modern virtio-pci device
 384  *
 385  * Returns the features read from the device
 386  */
 387 u64 vp_modern_get_features(struct virtio_pci_modern_device *mdev)
 388 {
 389         struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
 390
 391         u64 features;
 392
 393         vp_iowrite32(0, &cfg->device_feature_select);
 394         features = vp_ioread32(&cfg->device_feature);
 395         vp_iowrite32(1, &cfg->device_feature_select);
 396         features |= ((u64)vp_ioread32(&cfg->device_feature) << 32);
 397
 398         return features;
 399 }
 400 EXPORT_SYMBOL_GPL(vp_modern_get_features);
 401
 402 /*
 403  * vp_modern_get_driver_features - get driver features from device
 404  * @mdev: the modern virtio-pci device
 405  *
 406  * Returns the driver features read from the device
 407  */
 408 u64 vp_modern_get_driver_features(struct virtio_pci_modern_device *mdev)
 409 {
 410         struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
 411
 412         u64 features;
 413
 414         vp_iowrite32(0, &cfg->guest_feature_select);
 415         features = vp_ioread32(&cfg->guest_feature);
 416         vp_iowrite32(1, &cfg->guest_feature_select);
 417         features |= ((u64)vp_ioread32(&cfg->guest_feature) << 32);
 418
 419         return features;
 420 }
 421 EXPORT_SYMBOL_GPL(vp_modern_get_driver_features);
 422
 423 /*
 424  * vp_modern_set_features - set features to device
 425  * @mdev: the modern virtio-pci device
 426  * @features: the features set to device
 427  */
 428 void vp_modern_set_features(struct virtio_pci_modern_device *mdev,
 429                             u64 features)
 430 {
 431         struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
 432
 433         vp_iowrite32(0, &cfg->guest_feature_select);
 434         vp_iowrite32((u32)features, &cfg->guest_feature);
 435         vp_iowrite32(1, &cfg->guest_feature_select);
 436         vp_iowrite32(features >> 32, &cfg->guest_feature);
 437 }
 438 EXPORT_SYMBOL_GPL(vp_modern_set_features);
 439
 440 /*
 441  * vp_modern_generation - get the device genreation
 442  * @mdev: the modern virtio-pci device
 443  *
 444  * Returns the genreation read from device
 445  */
 446 u32 vp_modern_generation(struct virtio_pci_modern_device *mdev)
 447 {
 448         struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
 449
 450         return vp_ioread8(&cfg->config_generation);
 451 }
 452 EXPORT_SYMBOL_GPL(vp_modern_generation);
 453
 454 /*
 455  * vp_modern_get_status - get the device status
 456  * @mdev: the modern virtio-pci device
 457  *
 458  * Returns the status read from device
 459  */
 460 u8 vp_modern_get_status(struct virtio_pci_modern_device *mdev)
 461 {
 462         struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
 463
 464         return vp_ioread8(&cfg->device_status);
 465 }
 466 EXPORT_SYMBOL_GPL(vp_modern_get_status);
 467
 468 /*
 469  * vp_modern_set_status - set status to device
 470  * @mdev: the modern virtio-pci device
 471  * @status: the status set to device
 472  */
 473 void vp_modern_set_status(struct virtio_pci_modern_device *mdev,
 474                                  u8 status)
 475 {
 476         struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
 477
 478         /*
 479          * Per memory-barriers.txt, wmb() is not needed to guarantee
 480          * that the cache coherent memory writes have completed
 481          * before writing to the MMIO region.
 482          */
 483         vp_iowrite8(status, &cfg->device_status);
 484 }
 485 EXPORT_SYMBOL_GPL(vp_modern_set_status);
 486
 487 /*
 488  * vp_modern_get_queue_reset - get the queue reset status
 489  * @mdev: the modern virtio-pci device
 490  * @index: queue index
 491  */
 492 int vp_modern_get_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
 493 {
 494         struct virtio_pci_modern_common_cfg __iomem *cfg;
 495
 496         cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
 497
 498         vp_iowrite16(index, &cfg->cfg.queue_select);
 499         return vp_ioread16(&cfg->queue_reset);
 500 }
 501 EXPORT_SYMBOL_GPL(vp_modern_get_queue_reset);
 502
 503 /*
 504  * vp_modern_set_queue_reset - reset the queue
 505  * @mdev: the modern virtio-pci device
 506  * @index: queue index
 507  */
 508 void vp_modern_set_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
 509 {
 510         struct virtio_pci_modern_common_cfg __iomem *cfg;
 511
 512         cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
 513
 514         vp_iowrite16(index, &cfg->cfg.queue_select);
 515         vp_iowrite16(1, &cfg->queue_reset);
 516
 517         while (vp_ioread16(&cfg->queue_reset))
 518                 msleep(1);
 519
 520         while (vp_ioread16(&cfg->cfg.queue_enable))
 521                 msleep(1);
 522 }
 523 EXPORT_SYMBOL_GPL(vp_modern_set_queue_reset);
 524
 525 /*
 526  * vp_modern_queue_vector - set the MSIX vector for a specific virtqueue
 527  * @mdev: the modern virtio-pci device
 528  * @index: queue index
 529  * @vector: the config vector
 530  *
 531  * Returns the config vector read from the device
 532  */
 533 u16 vp_modern_queue_vector(struct virtio_pci_modern_device *mdev,
 534                            u16 index, u16 vector)
 535 {
 536         struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
 537
 538         vp_iowrite16(index, &cfg->queue_select);
 539         vp_iowrite16(vector, &cfg->queue_msix_vector);
 540         /* Flush the write out to device */
 541         return vp_ioread16(&cfg->queue_msix_vector);
 542 }
 543 EXPORT_SYMBOL_GPL(vp_modern_queue_vector);
 544
 545 /*
 546  * vp_modern_config_vector - set the vector for config interrupt
 547  * @mdev: the modern virtio-pci device
 548  * @vector: the config vector
 549  *
 550  * Returns the config vector read from the device
 551  */
 552 u16 vp_modern_config_vector(struct virtio_pci_modern_device *mdev,
 553                             u16 vector)
 554 {
 555         struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
 556
 557         /* Setup the vector used for configuration events */
 558         vp_iowrite16(vector, &cfg->msix_config);
 559         /* Verify we had enough resources to assign the vector */
 560         /* Will also flush the write out to device */
 561         return vp_ioread16(&cfg->msix_config);
 562 }
 563 EXPORT_SYMBOL_GPL(vp_modern_config_vector);
 564
 565 /*
 566  * vp_modern_queue_address - set the virtqueue address
 567  * @mdev: the modern virtio-pci device
 568  * @index: the queue index
 569  * @desc_addr: address of the descriptor area
 570  * @driver_addr: address of the driver area
 571  * @device_addr: address of the device area
 572  */
 573 void vp_modern_queue_address(struct virtio_pci_modern_device *mdev,
 574                              u16 index, u64 desc_addr, u64 driver_addr,
 575                              u64 device_addr)
 576 {
 577         struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
 578
 579         vp_iowrite16(index, &cfg->queue_select);
 580
 581         vp_iowrite64_twopart(desc_addr, &cfg->queue_desc_lo,
 582                              &cfg->queue_desc_hi);
 583         vp_iowrite64_twopart(driver_addr, &cfg->queue_avail_lo,
 584                              &cfg->queue_avail_hi);
 585         vp_iowrite64_twopart(device_addr, &cfg->queue_used_lo,
 586                              &cfg->queue_used_hi);
 587 }
 588 EXPORT_SYMBOL_GPL(vp_modern_queue_address);
 589
 590 /*
 591  * vp_modern_set_queue_enable - enable a virtqueue
 592  * @mdev: the modern virtio-pci device
 593  * @index: the queue index
 594  * @enable: whether the virtqueue is enable or not
 595  */
 596 void vp_modern_set_queue_enable(struct virtio_pci_modern_device *mdev,
 597                                 u16 index, bool enable)
 598 {
 599         vp_iowrite16(index, &mdev->common->queue_select);
 600         vp_iowrite16(enable, &mdev->common->queue_enable);
 601 }
 602 EXPORT_SYMBOL_GPL(vp_modern_set_queue_enable);
 603
 604 /*
 605  * vp_modern_get_queue_enable - enable a virtqueue
 606  * @mdev: the modern virtio-pci device
 607  * @index: the queue index
 608  *
 609  * Returns whether a virtqueue is enabled or not
 610  */
 611 bool vp_modern_get_queue_enable(struct virtio_pci_modern_device *mdev,
 612                                 u16 index)
 613 {
 614         vp_iowrite16(index, &mdev->common->queue_select);
 615
 616         return vp_ioread16(&mdev->common->queue_enable);
 617 }
 618 EXPORT_SYMBOL_GPL(vp_modern_get_queue_enable);
 619
 620 /*
 621  * vp_modern_set_queue_size - set size for a virtqueue
 622  * @mdev: the modern virtio-pci device
 623  * @index: the queue index
 624  * @size: the size of the virtqueue
 625  */
 626 void vp_modern_set_queue_size(struct virtio_pci_modern_device *mdev,
 627                               u16 index, u16 size)
 628 {
 629         vp_iowrite16(index, &mdev->common->queue_select);
 630         vp_iowrite16(size, &mdev->common->queue_size);
 631
 632 }
 633 EXPORT_SYMBOL_GPL(vp_modern_set_queue_size);
 634
 635 /*
 636  * vp_modern_get_queue_size - get size for a virtqueue
 637  * @mdev: the modern virtio-pci device
 638  * @index: the queue index
 639  *
 640  * Returns the size of the virtqueue
 641  */
 642 u16 vp_modern_get_queue_size(struct virtio_pci_modern_device *mdev,
 643                              u16 index)
 644 {
 645         vp_iowrite16(index, &mdev->common->queue_select);
 646
 647         return vp_ioread16(&mdev->common->queue_size);
 648
 649 }
 650 EXPORT_SYMBOL_GPL(vp_modern_get_queue_size);
 651
 652 /*
 653  * vp_modern_get_num_queues - get the number of virtqueues
 654  * @mdev: the modern virtio-pci device
 655  *
 656  * Returns the number of virtqueues
 657  */
 658 u16 vp_modern_get_num_queues(struct virtio_pci_modern_device *mdev)
 659 {
 660         return vp_ioread16(&mdev->common->num_queues);
 661 }
 662 EXPORT_SYMBOL_GPL(vp_modern_get_num_queues);
 663
 664 /*
 665  * vp_modern_get_queue_notify_off - get notification offset for a virtqueue
 666  * @mdev: the modern virtio-pci device
 667  * @index: the queue index
 668  *
 669  * Returns the notification offset for a virtqueue
 670  */
 671 static u16 vp_modern_get_queue_notify_off(struct virtio_pci_modern_device *mdev,
 672                                           u16 index)
 673 {
 674         vp_iowrite16(index, &mdev->common->queue_select);
 675
 676         return vp_ioread16(&mdev->common->queue_notify_off);
 677 }
 678
 679 /*
 680  * vp_modern_map_vq_notify - map notification area for a
 681  * specific virtqueue
 682  * @mdev: the modern virtio-pci device
 683  * @index: the queue index
 684  * @pa: the pointer to the physical address of the nofity area
 685  *
 686  * Returns the address of the notification area
 687  */
 688 void __iomem *vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev,
 689                                       u16 index, resource_size_t *pa)
 690 {
 691         u16 off = vp_modern_get_queue_notify_off(mdev, index);
 692
 693         if (mdev->notify_base) {
 694                 /* offset should not wrap */
 695                 if ((u64)off * mdev->notify_offset_multiplier + 2
 696                         > mdev->notify_len) {
 697                         dev_warn(&mdev->pci_dev->dev,
 698                                  "bad notification offset %u (x %u) "
 699                                  "for queue %u > %zd",
 700                                  off, mdev->notify_offset_multiplier,
 701                                  index, mdev->notify_len);
 702                         return NULL;
 703                 }
 704                 if (pa)
 705                         *pa = mdev->notify_pa +
 706                               off * mdev->notify_offset_multiplier;
 707                 return mdev->notify_base + off * mdev->notify_offset_multiplier;
 708         } else {
 709                 return vp_modern_map_capability(mdev,
 710                                        mdev->notify_map_cap, 2, 2,
 711                                        off * mdev->notify_offset_multiplier, 2,
 712                                        NULL, pa);
 713         }
 714 }
 715 EXPORT_SYMBOL_GPL(vp_modern_map_vq_notify);
 716
 717 MODULE_VERSION("0.1");
 718 MODULE_DESCRIPTION("Modern Virtio PCI Device");
 719 MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>");
 720 MODULE_LICENSE("GPL");