drivers/virtio/virtio_pci.c

   1 /*
   2  * Virtio PCI driver
   3  *
   4  * This module allows virtio devices to be used over a virtual PCI device.
   5  * This can be used with QEMU based VMMs like KVM or Xen.
   6  *
   7  * Copyright IBM Corp. 2007
   8  *
   9  * Authors:
  10  *  Anthony Liguori  <aliguori@us.ibm.com>
  11  *
  12  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  13  * See the COPYING file in the top-level directory.
  14  *
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/list.h>
  19 #include <linux/pci.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/virtio.h>
  22 #include <linux/virtio_config.h>
  23 #include <linux/virtio_ring.h>
  24 #include <linux/virtio_pci.h>
  25 #include <linux/highmem.h>
  26 #include <linux/spinlock.h>
  27
  28 MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
  29 MODULE_DESCRIPTION("virtio-pci");
  30 MODULE_LICENSE("GPL");
  31 MODULE_VERSION("1");
  32
  33 /* Our device structure */
  34 struct virtio_pci_device
  35 {
  36         struct virtio_device vdev;
  37         struct pci_dev *pci_dev;
  38
  39         /* the IO mapping for the PCI config space */
  40         void __iomem *ioaddr;
  41
  42         /* a list of queues so we can dispatch IRQs */
  43         spinlock_t lock;
  44         struct list_head virtqueues;
  45
  46         /* MSI-X support */
  47         int msix_enabled;
  48         int intx_enabled;
  49         struct msix_entry *msix_entries;
  50         /* Name strings for interrupts. This size should be enough,
  51          * and I'm too lazy to allocate each name separately. */
  52         char (*msix_names)[256];
  53         /* Number of available vectors */
  54         unsigned msix_vectors;
  55         /* Vectors allocated, excluding per-vq vectors if any */
  56         unsigned msix_used_vectors;
  57         /* Whether we have vector per vq */
  58         bool per_vq_vectors;
  59 };
  60
  61 /* Constants for MSI-X */
  62 /* Use first vector for configuration changes, second and the rest for
  63  * virtqueues Thus, we need at least 2 vectors for MSI. */
  64 enum {
  65         VP_MSIX_CONFIG_VECTOR = 0,
  66         VP_MSIX_VQ_VECTOR = 1,
  67 };
  68
  69 struct virtio_pci_vq_info
  70 {
  71         /* the actual virtqueue */
  72         struct virtqueue *vq;
  73
  74         /* the number of entries in the queue */
  75         int num;
  76
  77         /* the index of the queue */
  78         int queue_index;
  79
  80         /* the virtual address of the ring queue */
  81         void *queue;
  82
  83         /* the list node for the virtqueues list */
  84         struct list_head node;
  85
  86         /* MSI-X vector (or none) */
  87         unsigned msix_vector;
  88 };
  89
  90 /* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
  91 static struct pci_device_id virtio_pci_id_table[] = {
  92         { 0x1af4, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
  93         { 0 },
  94 };
  95
  96 MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
  97
  98 /* Convert a generic virtio device to our structure */
  99 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
 100 {
 101         return container_of(vdev, struct virtio_pci_device, vdev);
 102 }
 103
 104 /* virtio config->get_features() implementation */
 105 static u32 vp_get_features(struct virtio_device *vdev)
 106 {
 107         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 108
 109         /* When someone needs more than 32 feature bits, we'll need to
 110          * steal a bit to indicate that the rest are somewhere else. */
 111         return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
 112 }
 113
 114 /* virtio config->finalize_features() implementation */
 115 static void vp_finalize_features(struct virtio_device *vdev)
 116 {
 117         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 118
 119         /* Give virtio_ring a chance to accept features. */
 120         vring_transport_features(vdev);
 121
 122         /* We only support 32 feature bits. */
 123         BUILD_BUG_ON(ARRAY_SIZE(vdev->features) != 1);
 124         iowrite32(vdev->features[0], vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES);
 125 }
 126
 127 /* virtio config->get() implementation */
 128 static void vp_get(struct virtio_device *vdev, unsigned offset,
 129                    void *buf, unsigned len)
 130 {
 131         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 132         void __iomem *ioaddr = vp_dev->ioaddr +
 133                                 VIRTIO_PCI_CONFIG(vp_dev) + offset;
 134         u8 *ptr = buf;
 135         int i;
 136
 137         for (i = 0; i < len; i++)
 138                 ptr[i] = ioread8(ioaddr + i);
 139 }
 140
 141 /* the config->set() implementation.  it's symmetric to the config->get()
 142  * implementation */
 143 static void vp_set(struct virtio_device *vdev, unsigned offset,
 144                    const void *buf, unsigned len)
 145 {
 146         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 147         void __iomem *ioaddr = vp_dev->ioaddr +
 148                                 VIRTIO_PCI_CONFIG(vp_dev) + offset;
 149         const u8 *ptr = buf;
 150         int i;
 151
 152         for (i = 0; i < len; i++)
 153                 iowrite8(ptr[i], ioaddr + i);
 154 }
 155
 156 /* config->{get,set}_status() implementations */
 157 static u8 vp_get_status(struct virtio_device *vdev)
 158 {
 159         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 160         return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
 161 }
 162
 163 static void vp_set_status(struct virtio_device *vdev, u8 status)
 164 {
 165         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 166         /* We should never be setting status to 0. */
 167         BUG_ON(status == 0);
 168         iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
 169 }
 170
 171 static void vp_reset(struct virtio_device *vdev)
 172 {
 173         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 174         /* 0 status means a reset. */
 175         iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
 176 }
 177
 178 /* the notify function used when creating a virt queue */
 179 static void vp_notify(struct virtqueue *vq)
 180 {
 181         struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
 182         struct virtio_pci_vq_info *info = vq->priv;
 183
 184         /* we write the queue's selector into the notification register to
 185          * signal the other end */
 186         iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
 187 }
 188
 189 /* Handle a configuration change: Tell driver if it wants to know. */
 190 static irqreturn_t vp_config_changed(int irq, void *opaque)
 191 {
 192         struct virtio_pci_device *vp_dev = opaque;
 193         struct virtio_driver *drv;
 194         drv = container_of(vp_dev->vdev.dev.driver,
 195                            struct virtio_driver, driver);
 196
 197         if (drv && drv->config_changed)
 198                 drv->config_changed(&vp_dev->vdev);
 199         return IRQ_HANDLED;
 200 }
 201
 202 /* Notify all virtqueues on an interrupt. */
 203 static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
 204 {
 205         struct virtio_pci_device *vp_dev = opaque;
 206         struct virtio_pci_vq_info *info;
 207         irqreturn_t ret = IRQ_NONE;
 208         unsigned long flags;
 209
 210         spin_lock_irqsave(&vp_dev->lock, flags);
 211         list_for_each_entry(info, &vp_dev->virtqueues, node) {
 212                 if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
 213                         ret = IRQ_HANDLED;
 214         }
 215         spin_unlock_irqrestore(&vp_dev->lock, flags);
 216
 217         return ret;
 218 }
 219
 220 /* A small wrapper to also acknowledge the interrupt when it's handled.
 221  * I really need an EIO hook for the vring so I can ack the interrupt once we
 222  * know that we'll be handling the IRQ but before we invoke the callback since
 223  * the callback may notify the host which results in the host attempting to
 224  * raise an interrupt that we would then mask once we acknowledged the
 225  * interrupt. */
 226 static irqreturn_t vp_interrupt(int irq, void *opaque)
 227 {
 228         struct virtio_pci_device *vp_dev = opaque;
 229         u8 isr;
 230
 231         /* reading the ISR has the effect of also clearing it so it's very
 232          * important to save off the value. */
 233         isr = ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
 234
 235         /* It's definitely not us if the ISR was not high */
 236         if (!isr)
 237                 return IRQ_NONE;
 238
 239         /* Configuration change?  Tell driver if it wants to know. */
 240         if (isr & VIRTIO_PCI_ISR_CONFIG)
 241                 vp_config_changed(irq, opaque);
 242
 243         return vp_vring_interrupt(irq, opaque);
 244 }
 245
 246 static void vp_free_vectors(struct virtio_device *vdev)
 247 {
 248         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 249         int i;
 250
 251         if (vp_dev->intx_enabled) {
 252                 free_irq(vp_dev->pci_dev->irq, vp_dev);
 253                 vp_dev->intx_enabled = 0;
 254         }
 255
 256         for (i = 0; i < vp_dev->msix_used_vectors; ++i)
 257                 free_irq(vp_dev->msix_entries[i].vector, vp_dev);
 258
 259         if (vp_dev->msix_enabled) {
 260                 /* Disable the vector used for configuration */
 261                 iowrite16(VIRTIO_MSI_NO_VECTOR,
 262                           vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
 263                 /* Flush the write out to device */
 264                 ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
 265
 266                 pci_disable_msix(vp_dev->pci_dev);
 267                 vp_dev->msix_enabled = 0;
 268                 vp_dev->msix_vectors = 0;
 269         }
 270
 271         vp_dev->msix_used_vectors = 0;
 272         kfree(vp_dev->msix_names);
 273         vp_dev->msix_names = NULL;
 274         kfree(vp_dev->msix_entries);
 275         vp_dev->msix_entries = NULL;
 276 }
 277
 278 static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
 279                                    bool per_vq_vectors)
 280 {
 281         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 282         const char *name = dev_name(&vp_dev->vdev.dev);
 283         unsigned i, v;
 284         int err = -ENOMEM;
 285
 286         vp_dev->msix_entries = kmalloc(nvectors * sizeof *vp_dev->msix_entries,
 287                                        GFP_KERNEL);
 288         if (!vp_dev->msix_entries)
 289                 goto error;
 290         vp_dev->msix_names = kmalloc(nvectors * sizeof *vp_dev->msix_names,
 291                                      GFP_KERNEL);
 292         if (!vp_dev->msix_names)
 293                 goto error;
 294
 295         for (i = 0; i < nvectors; ++i)
 296                 vp_dev->msix_entries[i].entry = i;
 297
 298         /* pci_enable_msix returns positive if we can't get this many. */
 299         err = pci_enable_msix(vp_dev->pci_dev, vp_dev->msix_entries, nvectors);
 300         if (err > 0)
 301                 err = -ENOSPC;
 302         if (err)
 303                 goto error;
 304         vp_dev->msix_vectors = nvectors;
 305         vp_dev->msix_enabled = 1;
 306
 307         /* Set the vector used for configuration */
 308         v = vp_dev->msix_used_vectors;
 309         snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
 310                  "%s-config", name);
 311         err = request_irq(vp_dev->msix_entries[v].vector,
 312                           vp_config_changed, 0, vp_dev->msix_names[v],
 313                           vp_dev);
 314         if (err)
 315                 goto error;
 316         ++vp_dev->msix_used_vectors;
 317
 318         iowrite16(v, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
 319         /* Verify we had enough resources to assign the vector */
 320         v = ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
 321         if (v == VIRTIO_MSI_NO_VECTOR) {
 322                 err = -EBUSY;
 323                 goto error;
 324         }
 325
 326         if (!per_vq_vectors) {
 327                 /* Shared vector for all VQs */
 328                 v = vp_dev->msix_used_vectors;
 329                 snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
 330                          "%s-virtqueues", name);
 331                 err = request_irq(vp_dev->msix_entries[v].vector,
 332                                   vp_vring_interrupt, 0, vp_dev->msix_names[v],
 333                                   vp_dev);
 334                 if (err)
 335                         goto error;
 336                 ++vp_dev->msix_used_vectors;
 337         }
 338         return 0;
 339 error:
 340         vp_free_vectors(vdev);
 341         return err;
 342 }
 343
 344 static int vp_request_intx(struct virtio_device *vdev)
 345 {
 346         int err;
 347         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 348
 349         err = request_irq(vp_dev->pci_dev->irq, vp_interrupt,
 350                           IRQF_SHARED, dev_name(&vdev->dev), vp_dev);
 351         if (!err)
 352                 vp_dev->intx_enabled = 1;
 353         return err;
 354 }
 355
 356 static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
 357                                   void (*callback)(struct virtqueue *vq),
 358                                   const char *name,
 359                                   u16 msix_vec)
 360 {
 361         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 362         struct virtio_pci_vq_info *info;
 363         struct virtqueue *vq;
 364         unsigned long flags, size;
 365         u16 num;
 366         int err;
 367
 368         /* Select the queue we're interested in */
 369         iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
 370
 371         /* Check if queue is either not available or already active. */
 372         num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
 373         if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
 374                 return ERR_PTR(-ENOENT);
 375
 376         /* allocate and fill out our structure the represents an active
 377          * queue */
 378         info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
 379         if (!info)
 380                 return ERR_PTR(-ENOMEM);
 381
 382         info->queue_index = index;
 383         info->num = num;
 384         info->msix_vector = msix_vec;
 385
 386         size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN));
 387         info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO);
 388         if (info->queue == NULL) {
 389                 err = -ENOMEM;
 390                 goto out_info;
 391         }
 392
 393         /* activate the queue */
 394         iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT,
 395                   vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
 396
 397         /* create the vring */
 398         vq = vring_new_virtqueue(info->num, VIRTIO_PCI_VRING_ALIGN,
 399                                  vdev, info->queue, vp_notify, callback, name);
 400         if (!vq) {
 401                 err = -ENOMEM;
 402                 goto out_activate_queue;
 403         }
 404
 405         vq->priv = info;
 406         info->vq = vq;
 407
 408         if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
 409                 iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
 410                 msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
 411                 if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
 412                         err = -EBUSY;
 413                         goto out_assign;
 414                 }
 415         }
 416
 417         spin_lock_irqsave(&vp_dev->lock, flags);
 418         list_add(&info->node, &vp_dev->virtqueues);
 419         spin_unlock_irqrestore(&vp_dev->lock, flags);
 420
 421         return vq;
 422
 423 out_assign:
 424         vring_del_virtqueue(vq);
 425 out_activate_queue:
 426         iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
 427         free_pages_exact(info->queue, size);
 428 out_info:
 429         kfree(info);
 430         return ERR_PTR(err);
 431 }
 432
 433 static void vp_del_vq(struct virtqueue *vq)
 434 {
 435         struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
 436         struct virtio_pci_vq_info *info = vq->priv;
 437         unsigned long flags, size;
 438
 439         spin_lock_irqsave(&vp_dev->lock, flags);
 440         list_del(&info->node);
 441         spin_unlock_irqrestore(&vp_dev->lock, flags);
 442
 443         iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
 444
 445         if (vp_dev->msix_enabled) {
 446                 iowrite16(VIRTIO_MSI_NO_VECTOR,
 447                           vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
 448                 /* Flush the write out to device */
 449                 ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
 450         }
 451
 452         vring_del_virtqueue(vq);
 453
 454         /* Select and deactivate the queue */
 455         iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
 456
 457         size = PAGE_ALIGN(vring_size(info->num, VIRTIO_PCI_VRING_ALIGN));
 458         free_pages_exact(info->queue, size);
 459         kfree(info);
 460 }
 461
 462 /* the config->del_vqs() implementation */
 463 static void vp_del_vqs(struct virtio_device *vdev)
 464 {
 465         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 466         struct virtqueue *vq, *n;
 467         struct virtio_pci_vq_info *info;
 468
 469         list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
 470                 info = vq->priv;
 471                 if (vp_dev->per_vq_vectors &&
 472                         info->msix_vector != VIRTIO_MSI_NO_VECTOR)
 473                         free_irq(vp_dev->msix_entries[info->msix_vector].vector,
 474                                  vq);
 475                 vp_del_vq(vq);
 476         }
 477         vp_dev->per_vq_vectors = false;
 478
 479         vp_free_vectors(vdev);
 480 }
 481
 482 static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 483                               struct virtqueue *vqs[],
 484                               vq_callback_t *callbacks[],
 485                               const char *names[],
 486                               bool use_msix,
 487                               bool per_vq_vectors)
 488 {
 489         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 490         u16 msix_vec;
 491         int i, err, nvectors, allocated_vectors;
 492
 493         if (!use_msix) {
 494                 /* Old style: one normal interrupt for change and all vqs. */
 495                 err = vp_request_intx(vdev);
 496                 if (err)
 497                         goto error_request;
 498         } else {
 499                 if (per_vq_vectors) {
 500                         /* Best option: one for change interrupt, one per vq. */
 501                         nvectors = 1;
 502                         for (i = 0; i < nvqs; ++i)
 503                                 if (callbacks[i])
 504                                         ++nvectors;
 505                 } else {
 506                         /* Second best: one for change, shared for all vqs. */
 507                         nvectors = 2;
 508                 }
 509
 510                 err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors);
 511                 if (err)
 512                         goto error_request;
 513         }
 514
 515         vp_dev->per_vq_vectors = per_vq_vectors;
 516         allocated_vectors = vp_dev->msix_used_vectors;
 517         for (i = 0; i < nvqs; ++i) {
 518                 if (!callbacks[i] || !vp_dev->msix_enabled)
 519                         msix_vec = VIRTIO_MSI_NO_VECTOR;
 520                 else if (vp_dev->per_vq_vectors)
 521                         msix_vec = allocated_vectors++;
 522                 else
 523                         msix_vec = VP_MSIX_VQ_VECTOR;
 524                 vqs[i] = setup_vq(vdev, i, callbacks[i], names[i], msix_vec);
 525                 if (IS_ERR(vqs[i])) {
 526                         err = PTR_ERR(vqs[i]);
 527                         goto error_find;
 528                 }
 529
 530                 if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR)
 531                         continue;
 532
 533                 /* allocate per-vq irq if available and necessary */
 534                 snprintf(vp_dev->msix_names[msix_vec],
 535                          sizeof *vp_dev->msix_names,
 536                          "%s-%s",
 537                          dev_name(&vp_dev->vdev.dev), names[i]);
 538                 err = request_irq(vp_dev->msix_entries[msix_vec].vector,
 539                                   vring_interrupt, 0,
 540                                   vp_dev->msix_names[msix_vec],
 541                                   vqs[i]);
 542                 if (err) {
 543                         vp_del_vq(vqs[i]);
 544                         goto error_find;
 545                 }
 546         }
 547         return 0;
 548
 549 error_find:
 550         vp_del_vqs(vdev);
 551
 552 error_request:
 553         return err;
 554 }
 555
 556 /* the config->find_vqs() implementation */
 557 static int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 558                        struct virtqueue *vqs[],
 559                        vq_callback_t *callbacks[],
 560                        const char *names[])
 561 {
 562         int err;
 563
 564         /* Try MSI-X with one vector per queue. */
 565         err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names, true, true);
 566         if (!err)
 567                 return 0;
 568         /* Fallback: MSI-X with one vector for config, one shared for queues. */
 569         err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
 570                                  true, false);
 571         if (!err)
 572                 return 0;
 573         /* Finally fall back to regular interrupts. */
 574         return vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
 575                                   false, false);
 576 }
 577
 578 static struct virtio_config_ops virtio_pci_config_ops = {
 579         .get            = vp_get,
 580         .set            = vp_set,
 581         .get_status     = vp_get_status,
 582         .set_status     = vp_set_status,
 583         .reset          = vp_reset,
 584         .find_vqs       = vp_find_vqs,
 585         .del_vqs        = vp_del_vqs,
 586         .get_features   = vp_get_features,
 587         .finalize_features = vp_finalize_features,
 588 };
 589
 590 static void virtio_pci_release_dev(struct device *_d)
 591 {
 592         struct virtio_device *dev = container_of(_d, struct virtio_device, dev);
 593         struct virtio_pci_device *vp_dev = to_vp_device(dev);
 594         struct pci_dev *pci_dev = vp_dev->pci_dev;
 595
 596         vp_del_vqs(dev);
 597         pci_set_drvdata(pci_dev, NULL);
 598         pci_iounmap(pci_dev, vp_dev->ioaddr);
 599         pci_release_regions(pci_dev);
 600         pci_disable_device(pci_dev);
 601         kfree(vp_dev);
 602 }
 603
 604 /* the PCI probing function */
 605 static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
 606                                       const struct pci_device_id *id)
 607 {
 608         struct virtio_pci_device *vp_dev;
 609         int err;
 610
 611         /* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
 612         if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
 613                 return -ENODEV;
 614
 615         if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
 616                 printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
 617                        VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
 618                 return -ENODEV;
 619         }
 620
 621         /* allocate our structure and fill it out */
 622         vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
 623         if (vp_dev == NULL)
 624                 return -ENOMEM;
 625
 626         vp_dev->vdev.dev.parent = &pci_dev->dev;
 627         vp_dev->vdev.dev.release = virtio_pci_release_dev;
 628         vp_dev->vdev.config = &virtio_pci_config_ops;
 629         vp_dev->pci_dev = pci_dev;
 630         INIT_LIST_HEAD(&vp_dev->virtqueues);
 631         spin_lock_init(&vp_dev->lock);
 632
 633         /* enable the device */
 634         err = pci_enable_device(pci_dev);
 635         if (err)
 636                 goto out;
 637
 638         err = pci_request_regions(pci_dev, "virtio-pci");
 639         if (err)
 640                 goto out_enable_device;
 641
 642         vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
 643         if (vp_dev->ioaddr == NULL)
 644                 goto out_req_regions;
 645
 646         pci_set_drvdata(pci_dev, vp_dev);
 647
 648         /* we use the subsystem vendor/device id as the virtio vendor/device
 649          * id.  this allows us to use the same PCI vendor/device id for all
 650          * virtio devices and to identify the particular virtio driver by
 651          * the subsytem ids */
 652         vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
 653         vp_dev->vdev.id.device = pci_dev->subsystem_device;
 654
 655         /* finally register the virtio device */
 656         err = register_virtio_device(&vp_dev->vdev);
 657         if (err)
 658                 goto out_set_drvdata;
 659
 660         return 0;
 661
 662 out_set_drvdata:
 663         pci_set_drvdata(pci_dev, NULL);
 664         pci_iounmap(pci_dev, vp_dev->ioaddr);
 665 out_req_regions:
 666         pci_release_regions(pci_dev);
 667 out_enable_device:
 668         pci_disable_device(pci_dev);
 669 out:
 670         kfree(vp_dev);
 671         return err;
 672 }
 673
 674 static void __devexit virtio_pci_remove(struct pci_dev *pci_dev)
 675 {
 676         struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
 677
 678         unregister_virtio_device(&vp_dev->vdev);
 679 }
 680
 681 #ifdef CONFIG_PM
 682 static int virtio_pci_suspend(struct pci_dev *pci_dev, pm_message_t state)
 683 {
 684         pci_save_state(pci_dev);
 685         pci_set_power_state(pci_dev, PCI_D3hot);
 686         return 0;
 687 }
 688
 689 static int virtio_pci_resume(struct pci_dev *pci_dev)
 690 {
 691         pci_restore_state(pci_dev);
 692         pci_set_power_state(pci_dev, PCI_D0);
 693         return 0;
 694 }
 695 #endif
 696
 697 static struct pci_driver virtio_pci_driver = {
 698         .name           = "virtio-pci",
 699         .id_table       = virtio_pci_id_table,
 700         .probe          = virtio_pci_probe,
 701         .remove         = virtio_pci_remove,
 702 #ifdef CONFIG_PM
 703         .suspend        = virtio_pci_suspend,
 704         .resume         = virtio_pci_resume,
 705 #endif
 706 };
 707
 708 static int __init virtio_pci_init(void)
 709 {
 710         return pci_register_driver(&virtio_pci_driver);
 711 }
 712
 713 module_init(virtio_pci_init);
 714
 715 static void __exit virtio_pci_exit(void)
 716 {
 717         pci_unregister_driver(&virtio_pci_driver);
 718 }
 719
 720 module_exit(virtio_pci_exit);