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/slab.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/virtio.h>
  23 #include <linux/virtio_config.h>
  24 #include <linux/virtio_ring.h>
  25 #include <linux/virtio_pci.h>
  26 #include <linux/highmem.h>
  27 #include <linux/spinlock.h>
  28
  29 MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
  30 MODULE_DESCRIPTION("virtio-pci");
  31 MODULE_LICENSE("GPL");
  32 MODULE_VERSION("1");
  33
  34 /* Our device structure */
  35 struct virtio_pci_device
  36 {
  37         struct virtio_device vdev;
  38         struct pci_dev *pci_dev;
  39
  40         /* the IO mapping for the PCI config space */
  41         void __iomem *ioaddr;
  42
  43         /* a list of queues so we can dispatch IRQs */
  44         spinlock_t lock;
  45         struct list_head virtqueues;
  46
  47         /* MSI-X support */
  48         int msix_enabled;
  49         int intx_enabled;
  50         struct msix_entry *msix_entries;
  51         /* Name strings for interrupts. This size should be enough,
  52          * and I'm too lazy to allocate each name separately. */
  53         char (*msix_names)[256];
  54         /* Number of available vectors */
  55         unsigned msix_vectors;
  56         /* Vectors allocated, excluding per-vq vectors if any */
  57         unsigned msix_used_vectors;
  58         /* Whether we have vector per vq */
  59         bool per_vq_vectors;
  60 };
  61
  62 /* Constants for MSI-X */
  63 /* Use first vector for configuration changes, second and the rest for
  64  * virtqueues Thus, we need at least 2 vectors for MSI. */
  65 enum {
  66         VP_MSIX_CONFIG_VECTOR = 0,
  67         VP_MSIX_VQ_VECTOR = 1,
  68 };
  69
  70 struct virtio_pci_vq_info
  71 {
  72         /* the actual virtqueue */
  73         struct virtqueue *vq;
  74
  75         /* the number of entries in the queue */
  76         int num;
  77
  78         /* the index of the queue */
  79         int queue_index;
  80
  81         /* the virtual address of the ring queue */
  82         void *queue;
  83
  84         /* the list node for the virtqueues list */
  85         struct list_head node;
  86
  87         /* MSI-X vector (or none) */
  88         unsigned msix_vector;
  89 };
  90
  91 /* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
  92 static struct pci_device_id virtio_pci_id_table[] = {
  93         { 0x1af4, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
  94         { 0 },
  95 };
  96
  97 MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
  98
  99 /* A PCI device has it's own struct device and so does a virtio device so
 100  * we create a place for the virtio devices to show up in sysfs.  I think it
 101  * would make more sense for virtio to not insist on having it's own device. */
 102 static struct device *virtio_pci_root;
 103
 104 /* Convert a generic virtio device to our structure */
 105 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
 106 {
 107         return container_of(vdev, struct virtio_pci_device, vdev);
 108 }
 109
 110 /* virtio config->get_features() implementation */
 111 static u32 vp_get_features(struct virtio_device *vdev)
 112 {
 113         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 114
 115         /* When someone needs more than 32 feature bits, we'll need to
 116          * steal a bit to indicate that the rest are somewhere else. */
 117         return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
 118 }
 119
 120 /* virtio config->finalize_features() implementation */
 121 static void vp_finalize_features(struct virtio_device *vdev)
 122 {
 123         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 124
 125         /* Give virtio_ring a chance to accept features. */
 126         vring_transport_features(vdev);
 127
 128         /* We only support 32 feature bits. */
 129         BUILD_BUG_ON(ARRAY_SIZE(vdev->features) != 1);
 130         iowrite32(vdev->features[0], vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES);
 131 }
 132
 133 /* virtio config->get() implementation */
 134 static void vp_get(struct virtio_device *vdev, unsigned offset,
 135                    void *buf, unsigned len)
 136 {
 137         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 138         void __iomem *ioaddr = vp_dev->ioaddr +
 139                                 VIRTIO_PCI_CONFIG(vp_dev) + offset;
 140         u8 *ptr = buf;
 141         int i;
 142
 143         for (i = 0; i < len; i++)
 144                 ptr[i] = ioread8(ioaddr + i);
 145 }
 146
 147 /* the config->set() implementation.  it's symmetric to the config->get()
 148  * implementation */
 149 static void vp_set(struct virtio_device *vdev, unsigned offset,
 150                    const void *buf, unsigned len)
 151 {
 152         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 153         void __iomem *ioaddr = vp_dev->ioaddr +
 154                                 VIRTIO_PCI_CONFIG(vp_dev) + offset;
 155         const u8 *ptr = buf;
 156         int i;
 157
 158         for (i = 0; i < len; i++)
 159                 iowrite8(ptr[i], ioaddr + i);
 160 }
 161
 162 /* config->{get,set}_status() implementations */
 163 static u8 vp_get_status(struct virtio_device *vdev)
 164 {
 165         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 166         return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
 167 }
 168
 169 static void vp_set_status(struct virtio_device *vdev, u8 status)
 170 {
 171         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 172         /* We should never be setting status to 0. */
 173         BUG_ON(status == 0);
 174         iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
 175 }
 176
 177 static void vp_reset(struct virtio_device *vdev)
 178 {
 179         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 180         /* 0 status means a reset. */
 181         iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
 182 }
 183
 184 /* the notify function used when creating a virt queue */
 185 static void vp_notify(struct virtqueue *vq)
 186 {
 187         struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
 188         struct virtio_pci_vq_info *info = vq->priv;
 189
 190         /* we write the queue's selector into the notification register to
 191          * signal the other end */
 192         iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
 193 }
 194
 195 /* Handle a configuration change: Tell driver if it wants to know. */
 196 static irqreturn_t vp_config_changed(int irq, void *opaque)
 197 {
 198         struct virtio_pci_device *vp_dev = opaque;
 199         struct virtio_driver *drv;
 200         drv = container_of(vp_dev->vdev.dev.driver,
 201                            struct virtio_driver, driver);
 202
 203         if (drv && drv->config_changed)
 204                 drv->config_changed(&vp_dev->vdev);
 205         return IRQ_HANDLED;
 206 }
 207
 208 /* Notify all virtqueues on an interrupt. */
 209 static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
 210 {
 211         struct virtio_pci_device *vp_dev = opaque;
 212         struct virtio_pci_vq_info *info;
 213         irqreturn_t ret = IRQ_NONE;
 214         unsigned long flags;
 215
 216         spin_lock_irqsave(&vp_dev->lock, flags);
 217         list_for_each_entry(info, &vp_dev->virtqueues, node) {
 218                 if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
 219                         ret = IRQ_HANDLED;
 220         }
 221         spin_unlock_irqrestore(&vp_dev->lock, flags);
 222
 223         return ret;
 224 }
 225
 226 /* A small wrapper to also acknowledge the interrupt when it's handled.
 227  * I really need an EIO hook for the vring so I can ack the interrupt once we
 228  * know that we'll be handling the IRQ but before we invoke the callback since
 229  * the callback may notify the host which results in the host attempting to
 230  * raise an interrupt that we would then mask once we acknowledged the
 231  * interrupt. */
 232 static irqreturn_t vp_interrupt(int irq, void *opaque)
 233 {
 234         struct virtio_pci_device *vp_dev = opaque;
 235         u8 isr;
 236
 237         /* reading the ISR has the effect of also clearing it so it's very
 238          * important to save off the value. */
 239         isr = ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
 240
 241         /* It's definitely not us if the ISR was not high */
 242         if (!isr)
 243                 return IRQ_NONE;
 244
 245         /* Configuration change?  Tell driver if it wants to know. */
 246         if (isr & VIRTIO_PCI_ISR_CONFIG)
 247                 vp_config_changed(irq, opaque);
 248
 249         return vp_vring_interrupt(irq, opaque);
 250 }
 251
 252 static void vp_free_vectors(struct virtio_device *vdev)
 253 {
 254         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 255         int i;
 256
 257         if (vp_dev->intx_enabled) {
 258                 free_irq(vp_dev->pci_dev->irq, vp_dev);
 259                 vp_dev->intx_enabled = 0;
 260         }
 261
 262         for (i = 0; i < vp_dev->msix_used_vectors; ++i)
 263                 free_irq(vp_dev->msix_entries[i].vector, vp_dev);
 264
 265         if (vp_dev->msix_enabled) {
 266                 /* Disable the vector used for configuration */
 267                 iowrite16(VIRTIO_MSI_NO_VECTOR,
 268                           vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
 269                 /* Flush the write out to device */
 270                 ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
 271
 272                 pci_disable_msix(vp_dev->pci_dev);
 273                 vp_dev->msix_enabled = 0;
 274                 vp_dev->msix_vectors = 0;
 275         }
 276
 277         vp_dev->msix_used_vectors = 0;
 278         kfree(vp_dev->msix_names);
 279         vp_dev->msix_names = NULL;
 280         kfree(vp_dev->msix_entries);
 281         vp_dev->msix_entries = NULL;
 282 }
 283
 284 static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
 285                                    bool per_vq_vectors)
 286 {
 287         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 288         const char *name = dev_name(&vp_dev->vdev.dev);
 289         unsigned i, v;
 290         int err = -ENOMEM;
 291
 292         vp_dev->msix_entries = kmalloc(nvectors * sizeof *vp_dev->msix_entries,
 293                                        GFP_KERNEL);
 294         if (!vp_dev->msix_entries)
 295                 goto error;
 296         vp_dev->msix_names = kmalloc(nvectors * sizeof *vp_dev->msix_names,
 297                                      GFP_KERNEL);
 298         if (!vp_dev->msix_names)
 299                 goto error;
 300
 301         for (i = 0; i < nvectors; ++i)
 302                 vp_dev->msix_entries[i].entry = i;
 303
 304         /* pci_enable_msix returns positive if we can't get this many. */
 305         err = pci_enable_msix(vp_dev->pci_dev, vp_dev->msix_entries, nvectors);
 306         if (err > 0)
 307                 err = -ENOSPC;
 308         if (err)
 309                 goto error;
 310         vp_dev->msix_vectors = nvectors;
 311         vp_dev->msix_enabled = 1;
 312
 313         /* Set the vector used for configuration */
 314         v = vp_dev->msix_used_vectors;
 315         snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
 316                  "%s-config", name);
 317         err = request_irq(vp_dev->msix_entries[v].vector,
 318                           vp_config_changed, 0, vp_dev->msix_names[v],
 319                           vp_dev);
 320         if (err)
 321                 goto error;
 322         ++vp_dev->msix_used_vectors;
 323
 324         iowrite16(v, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
 325         /* Verify we had enough resources to assign the vector */
 326         v = ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
 327         if (v == VIRTIO_MSI_NO_VECTOR) {
 328                 err = -EBUSY;
 329                 goto error;
 330         }
 331
 332         if (!per_vq_vectors) {
 333                 /* Shared vector for all VQs */
 334                 v = vp_dev->msix_used_vectors;
 335                 snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
 336                          "%s-virtqueues", name);
 337                 err = request_irq(vp_dev->msix_entries[v].vector,
 338                                   vp_vring_interrupt, 0, vp_dev->msix_names[v],
 339                                   vp_dev);
 340                 if (err)
 341                         goto error;
 342                 ++vp_dev->msix_used_vectors;
 343         }
 344         return 0;
 345 error:
 346         vp_free_vectors(vdev);
 347         return err;
 348 }
 349
 350 static int vp_request_intx(struct virtio_device *vdev)
 351 {
 352         int err;
 353         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 354
 355         err = request_irq(vp_dev->pci_dev->irq, vp_interrupt,
 356                           IRQF_SHARED, dev_name(&vdev->dev), vp_dev);
 357         if (!err)
 358                 vp_dev->intx_enabled = 1;
 359         return err;
 360 }
 361
 362 static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
 363                                   void (*callback)(struct virtqueue *vq),
 364                                   const char *name,
 365                                   u16 msix_vec)
 366 {
 367         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 368         struct virtio_pci_vq_info *info;
 369         struct virtqueue *vq;
 370         unsigned long flags, size;
 371         u16 num;
 372         int err;
 373
 374         /* Select the queue we're interested in */
 375         iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
 376
 377         /* Check if queue is either not available or already active. */
 378         num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
 379         if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
 380                 return ERR_PTR(-ENOENT);
 381
 382         /* allocate and fill out our structure the represents an active
 383          * queue */
 384         info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
 385         if (!info)
 386                 return ERR_PTR(-ENOMEM);
 387
 388         info->queue_index = index;
 389         info->num = num;
 390         info->msix_vector = msix_vec;
 391
 392         size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN));
 393         info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO);
 394         if (info->queue == NULL) {
 395                 err = -ENOMEM;
 396                 goto out_info;
 397         }
 398
 399         /* activate the queue */
 400         iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT,
 401                   vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
 402
 403         /* create the vring */
 404         vq = vring_new_virtqueue(info->num, VIRTIO_PCI_VRING_ALIGN,
 405                                  vdev, info->queue, vp_notify, callback, name);
 406         if (!vq) {
 407                 err = -ENOMEM;
 408                 goto out_activate_queue;
 409         }
 410
 411         vq->priv = info;
 412         info->vq = vq;
 413
 414         if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
 415                 iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
 416                 msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
 417                 if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
 418                         err = -EBUSY;
 419                         goto out_assign;
 420                 }
 421         }
 422
 423         spin_lock_irqsave(&vp_dev->lock, flags);
 424         list_add(&info->node, &vp_dev->virtqueues);
 425         spin_unlock_irqrestore(&vp_dev->lock, flags);
 426
 427         return vq;
 428
 429 out_assign:
 430         vring_del_virtqueue(vq);
 431 out_activate_queue:
 432         iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
 433         free_pages_exact(info->queue, size);
 434 out_info:
 435         kfree(info);
 436         return ERR_PTR(err);
 437 }
 438
 439 static void vp_del_vq(struct virtqueue *vq)
 440 {
 441         struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
 442         struct virtio_pci_vq_info *info = vq->priv;
 443         unsigned long flags, size;
 444
 445         spin_lock_irqsave(&vp_dev->lock, flags);
 446         list_del(&info->node);
 447         spin_unlock_irqrestore(&vp_dev->lock, flags);
 448
 449         iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
 450
 451         if (vp_dev->msix_enabled) {
 452                 iowrite16(VIRTIO_MSI_NO_VECTOR,
 453                           vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
 454                 /* Flush the write out to device */
 455                 ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
 456         }
 457
 458         vring_del_virtqueue(vq);
 459
 460         /* Select and deactivate the queue */
 461         iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
 462
 463         size = PAGE_ALIGN(vring_size(info->num, VIRTIO_PCI_VRING_ALIGN));
 464         free_pages_exact(info->queue, size);
 465         kfree(info);
 466 }
 467
 468 /* the config->del_vqs() implementation */
 469 static void vp_del_vqs(struct virtio_device *vdev)
 470 {
 471         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 472         struct virtqueue *vq, *n;
 473         struct virtio_pci_vq_info *info;
 474
 475         list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
 476                 info = vq->priv;
 477                 if (vp_dev->per_vq_vectors &&
 478                         info->msix_vector != VIRTIO_MSI_NO_VECTOR)
 479                         free_irq(vp_dev->msix_entries[info->msix_vector].vector,
 480                                  vq);
 481                 vp_del_vq(vq);
 482         }
 483         vp_dev->per_vq_vectors = false;
 484
 485         vp_free_vectors(vdev);
 486 }
 487
 488 static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 489                               struct virtqueue *vqs[],
 490                               vq_callback_t *callbacks[],
 491                               const char *names[],
 492                               bool use_msix,
 493                               bool per_vq_vectors)
 494 {
 495         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 496         u16 msix_vec;
 497         int i, err, nvectors, allocated_vectors;
 498
 499         if (!use_msix) {
 500                 /* Old style: one normal interrupt for change and all vqs. */
 501                 err = vp_request_intx(vdev);
 502                 if (err)
 503                         goto error_request;
 504         } else {
 505                 if (per_vq_vectors) {
 506                         /* Best option: one for change interrupt, one per vq. */
 507                         nvectors = 1;
 508                         for (i = 0; i < nvqs; ++i)
 509                                 if (callbacks[i])
 510                                         ++nvectors;
 511                 } else {
 512                         /* Second best: one for change, shared for all vqs. */
 513                         nvectors = 2;
 514                 }
 515
 516                 err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors);
 517                 if (err)
 518                         goto error_request;
 519         }
 520
 521         vp_dev->per_vq_vectors = per_vq_vectors;
 522         allocated_vectors = vp_dev->msix_used_vectors;
 523         for (i = 0; i < nvqs; ++i) {
 524                 if (!callbacks[i] || !vp_dev->msix_enabled)
 525                         msix_vec = VIRTIO_MSI_NO_VECTOR;
 526                 else if (vp_dev->per_vq_vectors)
 527                         msix_vec = allocated_vectors++;
 528                 else
 529                         msix_vec = VP_MSIX_VQ_VECTOR;
 530                 vqs[i] = setup_vq(vdev, i, callbacks[i], names[i], msix_vec);
 531                 if (IS_ERR(vqs[i])) {
 532                         err = PTR_ERR(vqs[i]);
 533                         goto error_find;
 534                 }
 535
 536                 if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR)
 537                         continue;
 538
 539                 /* allocate per-vq irq if available and necessary */
 540                 snprintf(vp_dev->msix_names[msix_vec],
 541                          sizeof *vp_dev->msix_names,
 542                          "%s-%s",
 543                          dev_name(&vp_dev->vdev.dev), names[i]);
 544                 err = request_irq(vp_dev->msix_entries[msix_vec].vector,
 545                                   vring_interrupt, 0,
 546                                   vp_dev->msix_names[msix_vec],
 547                                   vqs[i]);
 548                 if (err) {
 549                         vp_del_vq(vqs[i]);
 550                         goto error_find;
 551                 }
 552         }
 553         return 0;
 554
 555 error_find:
 556         vp_del_vqs(vdev);
 557
 558 error_request:
 559         return err;
 560 }
 561
 562 /* the config->find_vqs() implementation */
 563 static int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 564                        struct virtqueue *vqs[],
 565                        vq_callback_t *callbacks[],
 566                        const char *names[])
 567 {
 568         int err;
 569
 570         /* Try MSI-X with one vector per queue. */
 571         err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names, true, true);
 572         if (!err)
 573                 return 0;
 574         /* Fallback: MSI-X with one vector for config, one shared for queues. */
 575         err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
 576                                  true, false);
 577         if (!err)
 578                 return 0;
 579         /* Finally fall back to regular interrupts. */
 580         return vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
 581                                   false, false);
 582 }
 583
 584 static struct virtio_config_ops virtio_pci_config_ops = {
 585         .get            = vp_get,
 586         .set            = vp_set,
 587         .get_status     = vp_get_status,
 588         .set_status     = vp_set_status,
 589         .reset          = vp_reset,
 590         .find_vqs       = vp_find_vqs,
 591         .del_vqs        = vp_del_vqs,
 592         .get_features   = vp_get_features,
 593         .finalize_features = vp_finalize_features,
 594 };
 595
 596 static void virtio_pci_release_dev(struct device *_d)
 597 {
 598         struct virtio_device *dev = container_of(_d, struct virtio_device, dev);
 599         struct virtio_pci_device *vp_dev = to_vp_device(dev);
 600         struct pci_dev *pci_dev = vp_dev->pci_dev;
 601
 602         vp_del_vqs(dev);
 603         pci_set_drvdata(pci_dev, NULL);
 604         pci_iounmap(pci_dev, vp_dev->ioaddr);
 605         pci_release_regions(pci_dev);
 606         pci_disable_device(pci_dev);
 607         kfree(vp_dev);
 608 }
 609
 610 /* the PCI probing function */
 611 static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
 612                                       const struct pci_device_id *id)
 613 {
 614         struct virtio_pci_device *vp_dev;
 615         int err;
 616
 617         /* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
 618         if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
 619                 return -ENODEV;
 620
 621         if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
 622                 printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
 623                        VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
 624                 return -ENODEV;
 625         }
 626
 627         /* allocate our structure and fill it out */
 628         vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
 629         if (vp_dev == NULL)
 630                 return -ENOMEM;
 631
 632         vp_dev->vdev.dev.parent = virtio_pci_root;
 633         vp_dev->vdev.dev.release = virtio_pci_release_dev;
 634         vp_dev->vdev.config = &virtio_pci_config_ops;
 635         vp_dev->pci_dev = pci_dev;
 636         INIT_LIST_HEAD(&vp_dev->virtqueues);
 637         spin_lock_init(&vp_dev->lock);
 638
 639         /* Disable MSI/MSIX to bring device to a known good state. */
 640         pci_msi_off(pci_dev);
 641
 642         /* enable the device */
 643         err = pci_enable_device(pci_dev);
 644         if (err)
 645                 goto out;
 646
 647         err = pci_request_regions(pci_dev, "virtio-pci");
 648         if (err)
 649                 goto out_enable_device;
 650
 651         vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
 652         if (vp_dev->ioaddr == NULL)
 653                 goto out_req_regions;
 654
 655         pci_set_drvdata(pci_dev, vp_dev);
 656         pci_set_master(pci_dev);
 657
 658         /* we use the subsystem vendor/device id as the virtio vendor/device
 659          * id.  this allows us to use the same PCI vendor/device id for all
 660          * virtio devices and to identify the particular virtio driver by
 661          * the subsystem ids */
 662         vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
 663         vp_dev->vdev.id.device = pci_dev->subsystem_device;
 664
 665         /* finally register the virtio device */
 666         err = register_virtio_device(&vp_dev->vdev);
 667         if (err)
 668                 goto out_set_drvdata;
 669
 670         return 0;
 671
 672 out_set_drvdata:
 673         pci_set_drvdata(pci_dev, NULL);
 674         pci_iounmap(pci_dev, vp_dev->ioaddr);
 675 out_req_regions:
 676         pci_release_regions(pci_dev);
 677 out_enable_device:
 678         pci_disable_device(pci_dev);
 679 out:
 680         kfree(vp_dev);
 681         return err;
 682 }
 683
 684 static void __devexit virtio_pci_remove(struct pci_dev *pci_dev)
 685 {
 686         struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
 687
 688         unregister_virtio_device(&vp_dev->vdev);
 689 }
 690
 691 #ifdef CONFIG_PM
 692 static int virtio_pci_suspend(struct pci_dev *pci_dev, pm_message_t state)
 693 {
 694         pci_save_state(pci_dev);
 695         pci_set_power_state(pci_dev, PCI_D3hot);
 696         return 0;
 697 }
 698
 699 static int virtio_pci_resume(struct pci_dev *pci_dev)
 700 {
 701         pci_restore_state(pci_dev);
 702         pci_set_power_state(pci_dev, PCI_D0);
 703         return 0;
 704 }
 705 #endif
 706
 707 static struct pci_driver virtio_pci_driver = {
 708         .name           = "virtio-pci",
 709         .id_table       = virtio_pci_id_table,
 710         .probe          = virtio_pci_probe,
 711         .remove         = __devexit_p(virtio_pci_remove),
 712 #ifdef CONFIG_PM
 713         .suspend        = virtio_pci_suspend,
 714         .resume         = virtio_pci_resume,
 715 #endif
 716 };
 717
 718 static int __init virtio_pci_init(void)
 719 {
 720         int err;
 721
 722         virtio_pci_root = root_device_register("virtio-pci");
 723         if (IS_ERR(virtio_pci_root))
 724                 return PTR_ERR(virtio_pci_root);
 725
 726         err = pci_register_driver(&virtio_pci_driver);
 727         if (err)
 728                 root_device_unregister(virtio_pci_root);
 729
 730         return err;
 731 }
 732
 733 module_init(virtio_pci_init);
 734
 735 static void __exit virtio_pci_exit(void)
 736 {
 737         pci_unregister_driver(&virtio_pci_driver);
 738         root_device_unregister(virtio_pci_root);
 739 }
 740
 741 module_exit(virtio_pci_exit);