linux/drivers/virtio/virtio_pci.c
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   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
  29MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
  30MODULE_DESCRIPTION("virtio-pci");
  31MODULE_LICENSE("GPL");
  32MODULE_VERSION("1");
  33
  34/* Our device structure */
  35struct 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
  59        /* Status saved during hibernate/restore */
  60        u8 saved_status;
  61
  62        /* Whether we have vector per vq */
  63        bool per_vq_vectors;
  64};
  65
  66/* Constants for MSI-X */
  67/* Use first vector for configuration changes, second and the rest for
  68 * virtqueues Thus, we need at least 2 vectors for MSI. */
  69enum {
  70        VP_MSIX_CONFIG_VECTOR = 0,
  71        VP_MSIX_VQ_VECTOR = 1,
  72};
  73
  74struct virtio_pci_vq_info
  75{
  76        /* the actual virtqueue */
  77        struct virtqueue *vq;
  78
  79        /* the number of entries in the queue */
  80        int num;
  81
  82        /* the index of the queue */
  83        int queue_index;
  84
  85        /* the virtual address of the ring queue */
  86        void *queue;
  87
  88        /* the list node for the virtqueues list */
  89        struct list_head node;
  90
  91        /* MSI-X vector (or none) */
  92        unsigned msix_vector;
  93};
  94
  95/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
  96static struct pci_device_id virtio_pci_id_table[] = {
  97        { 0x1af4, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
  98        { 0 },
  99};
 100
 101MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
 102
 103/* Convert a generic virtio device to our structure */
 104static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
 105{
 106        return container_of(vdev, struct virtio_pci_device, vdev);
 107}
 108
 109/* virtio config->get_features() implementation */
 110static u32 vp_get_features(struct virtio_device *vdev)
 111{
 112        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 113
 114        /* When someone needs more than 32 feature bits, we'll need to
 115         * steal a bit to indicate that the rest are somewhere else. */
 116        return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
 117}
 118
 119/* virtio config->finalize_features() implementation */
 120static void vp_finalize_features(struct virtio_device *vdev)
 121{
 122        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 123
 124        /* Give virtio_ring a chance to accept features. */
 125        vring_transport_features(vdev);
 126
 127        /* We only support 32 feature bits. */
 128        BUILD_BUG_ON(ARRAY_SIZE(vdev->features) != 1);
 129        iowrite32(vdev->features[0], vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES);
 130}
 131
 132/* virtio config->get() implementation */
 133static void vp_get(struct virtio_device *vdev, unsigned offset,
 134                   void *buf, unsigned len)
 135{
 136        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 137        void __iomem *ioaddr = vp_dev->ioaddr +
 138                                VIRTIO_PCI_CONFIG(vp_dev) + offset;
 139        u8 *ptr = buf;
 140        int i;
 141
 142        for (i = 0; i < len; i++)
 143                ptr[i] = ioread8(ioaddr + i);
 144}
 145
 146/* the config->set() implementation.  it's symmetric to the config->get()
 147 * implementation */
 148static void vp_set(struct virtio_device *vdev, unsigned offset,
 149                   const void *buf, unsigned len)
 150{
 151        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 152        void __iomem *ioaddr = vp_dev->ioaddr +
 153                                VIRTIO_PCI_CONFIG(vp_dev) + offset;
 154        const u8 *ptr = buf;
 155        int i;
 156
 157        for (i = 0; i < len; i++)
 158                iowrite8(ptr[i], ioaddr + i);
 159}
 160
 161/* config->{get,set}_status() implementations */
 162static u8 vp_get_status(struct virtio_device *vdev)
 163{
 164        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 165        return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
 166}
 167
 168static void vp_set_status(struct virtio_device *vdev, u8 status)
 169{
 170        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 171        /* We should never be setting status to 0. */
 172        BUG_ON(status == 0);
 173        iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
 174}
 175
 176/* wait for pending irq handlers */
 177static void vp_synchronize_vectors(struct virtio_device *vdev)
 178{
 179        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 180        int i;
 181
 182        if (vp_dev->intx_enabled)
 183                synchronize_irq(vp_dev->pci_dev->irq);
 184
 185        for (i = 0; i < vp_dev->msix_vectors; ++i)
 186                synchronize_irq(vp_dev->msix_entries[i].vector);
 187}
 188
 189static void vp_reset(struct virtio_device *vdev)
 190{
 191        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 192        /* 0 status means a reset. */
 193        iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
 194        /* Flush out the status write, and flush in device writes,
 195         * including MSi-X interrupts, if any. */
 196        ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
 197        /* Flush pending VQ/configuration callbacks. */
 198        vp_synchronize_vectors(vdev);
 199}
 200
 201/* the notify function used when creating a virt queue */
 202static void vp_notify(struct virtqueue *vq)
 203{
 204        struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
 205        struct virtio_pci_vq_info *info = vq->priv;
 206
 207        /* we write the queue's selector into the notification register to
 208         * signal the other end */
 209        iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
 210}
 211
 212/* Handle a configuration change: Tell driver if it wants to know. */
 213static irqreturn_t vp_config_changed(int irq, void *opaque)
 214{
 215        struct virtio_pci_device *vp_dev = opaque;
 216        struct virtio_driver *drv;
 217        drv = container_of(vp_dev->vdev.dev.driver,
 218                           struct virtio_driver, driver);
 219
 220        if (drv && drv->config_changed)
 221                drv->config_changed(&vp_dev->vdev);
 222        return IRQ_HANDLED;
 223}
 224
 225/* Notify all virtqueues on an interrupt. */
 226static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
 227{
 228        struct virtio_pci_device *vp_dev = opaque;
 229        struct virtio_pci_vq_info *info;
 230        irqreturn_t ret = IRQ_NONE;
 231        unsigned long flags;
 232
 233        spin_lock_irqsave(&vp_dev->lock, flags);
 234        list_for_each_entry(info, &vp_dev->virtqueues, node) {
 235                if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
 236                        ret = IRQ_HANDLED;
 237        }
 238        spin_unlock_irqrestore(&vp_dev->lock, flags);
 239
 240        return ret;
 241}
 242
 243/* A small wrapper to also acknowledge the interrupt when it's handled.
 244 * I really need an EIO hook for the vring so I can ack the interrupt once we
 245 * know that we'll be handling the IRQ but before we invoke the callback since
 246 * the callback may notify the host which results in the host attempting to
 247 * raise an interrupt that we would then mask once we acknowledged the
 248 * interrupt. */
 249static irqreturn_t vp_interrupt(int irq, void *opaque)
 250{
 251        struct virtio_pci_device *vp_dev = opaque;
 252        u8 isr;
 253
 254        /* reading the ISR has the effect of also clearing it so it's very
 255         * important to save off the value. */
 256        isr = ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
 257
 258        /* It's definitely not us if the ISR was not high */
 259        if (!isr)
 260                return IRQ_NONE;
 261
 262        /* Configuration change?  Tell driver if it wants to know. */
 263        if (isr & VIRTIO_PCI_ISR_CONFIG)
 264                vp_config_changed(irq, opaque);
 265
 266        return vp_vring_interrupt(irq, opaque);
 267}
 268
 269static void vp_free_vectors(struct virtio_device *vdev)
 270{
 271        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 272        int i;
 273
 274        if (vp_dev->intx_enabled) {
 275                free_irq(vp_dev->pci_dev->irq, vp_dev);
 276                vp_dev->intx_enabled = 0;
 277        }
 278
 279        for (i = 0; i < vp_dev->msix_used_vectors; ++i)
 280                free_irq(vp_dev->msix_entries[i].vector, vp_dev);
 281
 282        if (vp_dev->msix_enabled) {
 283                /* Disable the vector used for configuration */
 284                iowrite16(VIRTIO_MSI_NO_VECTOR,
 285                          vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
 286                /* Flush the write out to device */
 287                ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
 288
 289                pci_disable_msix(vp_dev->pci_dev);
 290                vp_dev->msix_enabled = 0;
 291                vp_dev->msix_vectors = 0;
 292        }
 293
 294        vp_dev->msix_used_vectors = 0;
 295        kfree(vp_dev->msix_names);
 296        vp_dev->msix_names = NULL;
 297        kfree(vp_dev->msix_entries);
 298        vp_dev->msix_entries = NULL;
 299}
 300
 301static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
 302                                   bool per_vq_vectors)
 303{
 304        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 305        const char *name = dev_name(&vp_dev->vdev.dev);
 306        unsigned i, v;
 307        int err = -ENOMEM;
 308
 309        vp_dev->msix_entries = kmalloc(nvectors * sizeof *vp_dev->msix_entries,
 310                                       GFP_KERNEL);
 311        if (!vp_dev->msix_entries)
 312                goto error;
 313        vp_dev->msix_names = kmalloc(nvectors * sizeof *vp_dev->msix_names,
 314                                     GFP_KERNEL);
 315        if (!vp_dev->msix_names)
 316                goto error;
 317
 318        for (i = 0; i < nvectors; ++i)
 319                vp_dev->msix_entries[i].entry = i;
 320
 321        /* pci_enable_msix returns positive if we can't get this many. */
 322        err = pci_enable_msix(vp_dev->pci_dev, vp_dev->msix_entries, nvectors);
 323        if (err > 0)
 324                err = -ENOSPC;
 325        if (err)
 326                goto error;
 327        vp_dev->msix_vectors = nvectors;
 328        vp_dev->msix_enabled = 1;
 329
 330        /* Set the vector used for configuration */
 331        v = vp_dev->msix_used_vectors;
 332        snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
 333                 "%s-config", name);
 334        err = request_irq(vp_dev->msix_entries[v].vector,
 335                          vp_config_changed, 0, vp_dev->msix_names[v],
 336                          vp_dev);
 337        if (err)
 338                goto error;
 339        ++vp_dev->msix_used_vectors;
 340
 341        iowrite16(v, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
 342        /* Verify we had enough resources to assign the vector */
 343        v = ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
 344        if (v == VIRTIO_MSI_NO_VECTOR) {
 345                err = -EBUSY;
 346                goto error;
 347        }
 348
 349        if (!per_vq_vectors) {
 350                /* Shared vector for all VQs */
 351                v = vp_dev->msix_used_vectors;
 352                snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
 353                         "%s-virtqueues", name);
 354                err = request_irq(vp_dev->msix_entries[v].vector,
 355                                  vp_vring_interrupt, 0, vp_dev->msix_names[v],
 356                                  vp_dev);
 357                if (err)
 358                        goto error;
 359                ++vp_dev->msix_used_vectors;
 360        }
 361        return 0;
 362error:
 363        vp_free_vectors(vdev);
 364        return err;
 365}
 366
 367static int vp_request_intx(struct virtio_device *vdev)
 368{
 369        int err;
 370        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 371
 372        err = request_irq(vp_dev->pci_dev->irq, vp_interrupt,
 373                          IRQF_SHARED, dev_name(&vdev->dev), vp_dev);
 374        if (!err)
 375                vp_dev->intx_enabled = 1;
 376        return err;
 377}
 378
 379static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
 380                                  void (*callback)(struct virtqueue *vq),
 381                                  const char *name,
 382                                  u16 msix_vec)
 383{
 384        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 385        struct virtio_pci_vq_info *info;
 386        struct virtqueue *vq;
 387        unsigned long flags, size;
 388        u16 num;
 389        int err;
 390
 391        /* Select the queue we're interested in */
 392        iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
 393
 394        /* Check if queue is either not available or already active. */
 395        num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
 396        if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
 397                return ERR_PTR(-ENOENT);
 398
 399        /* allocate and fill out our structure the represents an active
 400         * queue */
 401        info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
 402        if (!info)
 403                return ERR_PTR(-ENOMEM);
 404
 405        info->queue_index = index;
 406        info->num = num;
 407        info->msix_vector = msix_vec;
 408
 409        size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN));
 410        info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO);
 411        if (info->queue == NULL) {
 412                err = -ENOMEM;
 413                goto out_info;
 414        }
 415
 416        /* activate the queue */
 417        iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT,
 418                  vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
 419
 420        /* create the vring */
 421        vq = vring_new_virtqueue(info->num, VIRTIO_PCI_VRING_ALIGN, vdev,
 422                                 true, info->queue, vp_notify, callback, name);
 423        if (!vq) {
 424                err = -ENOMEM;
 425                goto out_activate_queue;
 426        }
 427
 428        vq->priv = info;
 429        info->vq = vq;
 430
 431        if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
 432                iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
 433                msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
 434                if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
 435                        err = -EBUSY;
 436                        goto out_assign;
 437                }
 438        }
 439
 440        if (callback) {
 441                spin_lock_irqsave(&vp_dev->lock, flags);
 442                list_add(&info->node, &vp_dev->virtqueues);
 443                spin_unlock_irqrestore(&vp_dev->lock, flags);
 444        } else {
 445                INIT_LIST_HEAD(&info->node);
 446        }
 447
 448        return vq;
 449
 450out_assign:
 451        vring_del_virtqueue(vq);
 452out_activate_queue:
 453        iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
 454        free_pages_exact(info->queue, size);
 455out_info:
 456        kfree(info);
 457        return ERR_PTR(err);
 458}
 459
 460static void vp_del_vq(struct virtqueue *vq)
 461{
 462        struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
 463        struct virtio_pci_vq_info *info = vq->priv;
 464        unsigned long flags, size;
 465
 466        spin_lock_irqsave(&vp_dev->lock, flags);
 467        list_del(&info->node);
 468        spin_unlock_irqrestore(&vp_dev->lock, flags);
 469
 470        iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
 471
 472        if (vp_dev->msix_enabled) {
 473                iowrite16(VIRTIO_MSI_NO_VECTOR,
 474                          vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
 475                /* Flush the write out to device */
 476                ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
 477        }
 478
 479        vring_del_virtqueue(vq);
 480
 481        /* Select and deactivate the queue */
 482        iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
 483
 484        size = PAGE_ALIGN(vring_size(info->num, VIRTIO_PCI_VRING_ALIGN));
 485        free_pages_exact(info->queue, size);
 486        kfree(info);
 487}
 488
 489/* the config->del_vqs() implementation */
 490static void vp_del_vqs(struct virtio_device *vdev)
 491{
 492        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 493        struct virtqueue *vq, *n;
 494        struct virtio_pci_vq_info *info;
 495
 496        list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
 497                info = vq->priv;
 498                if (vp_dev->per_vq_vectors &&
 499                        info->msix_vector != VIRTIO_MSI_NO_VECTOR)
 500                        free_irq(vp_dev->msix_entries[info->msix_vector].vector,
 501                                 vq);
 502                vp_del_vq(vq);
 503        }
 504        vp_dev->per_vq_vectors = false;
 505
 506        vp_free_vectors(vdev);
 507}
 508
 509static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 510                              struct virtqueue *vqs[],
 511                              vq_callback_t *callbacks[],
 512                              const char *names[],
 513                              bool use_msix,
 514                              bool per_vq_vectors)
 515{
 516        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 517        u16 msix_vec;
 518        int i, err, nvectors, allocated_vectors;
 519
 520        if (!use_msix) {
 521                /* Old style: one normal interrupt for change and all vqs. */
 522                err = vp_request_intx(vdev);
 523                if (err)
 524                        goto error_request;
 525        } else {
 526                if (per_vq_vectors) {
 527                        /* Best option: one for change interrupt, one per vq. */
 528                        nvectors = 1;
 529                        for (i = 0; i < nvqs; ++i)
 530                                if (callbacks[i])
 531                                        ++nvectors;
 532                } else {
 533                        /* Second best: one for change, shared for all vqs. */
 534                        nvectors = 2;
 535                }
 536
 537                err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors);
 538                if (err)
 539                        goto error_request;
 540        }
 541
 542        vp_dev->per_vq_vectors = per_vq_vectors;
 543        allocated_vectors = vp_dev->msix_used_vectors;
 544        for (i = 0; i < nvqs; ++i) {
 545                if (!callbacks[i] || !vp_dev->msix_enabled)
 546                        msix_vec = VIRTIO_MSI_NO_VECTOR;
 547                else if (vp_dev->per_vq_vectors)
 548                        msix_vec = allocated_vectors++;
 549                else
 550                        msix_vec = VP_MSIX_VQ_VECTOR;
 551                vqs[i] = setup_vq(vdev, i, callbacks[i], names[i], msix_vec);
 552                if (IS_ERR(vqs[i])) {
 553                        err = PTR_ERR(vqs[i]);
 554                        goto error_find;
 555                }
 556
 557                if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR)
 558                        continue;
 559
 560                /* allocate per-vq irq if available and necessary */
 561                snprintf(vp_dev->msix_names[msix_vec],
 562                         sizeof *vp_dev->msix_names,
 563                         "%s-%s",
 564                         dev_name(&vp_dev->vdev.dev), names[i]);
 565                err = request_irq(vp_dev->msix_entries[msix_vec].vector,
 566                                  vring_interrupt, 0,
 567                                  vp_dev->msix_names[msix_vec],
 568                                  vqs[i]);
 569                if (err) {
 570                        vp_del_vq(vqs[i]);
 571                        goto error_find;
 572                }
 573        }
 574        return 0;
 575
 576error_find:
 577        vp_del_vqs(vdev);
 578
 579error_request:
 580        return err;
 581}
 582
 583/* the config->find_vqs() implementation */
 584static int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 585                       struct virtqueue *vqs[],
 586                       vq_callback_t *callbacks[],
 587                       const char *names[])
 588{
 589        int err;
 590
 591        /* Try MSI-X with one vector per queue. */
 592        err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names, true, true);
 593        if (!err)
 594                return 0;
 595        /* Fallback: MSI-X with one vector for config, one shared for queues. */
 596        err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
 597                                 true, false);
 598        if (!err)
 599                return 0;
 600        /* Finally fall back to regular interrupts. */
 601        return vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
 602                                  false, false);
 603}
 604
 605static const char *vp_bus_name(struct virtio_device *vdev)
 606{
 607        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 608
 609        return pci_name(vp_dev->pci_dev);
 610}
 611
 612static struct virtio_config_ops virtio_pci_config_ops = {
 613        .get            = vp_get,
 614        .set            = vp_set,
 615        .get_status     = vp_get_status,
 616        .set_status     = vp_set_status,
 617        .reset          = vp_reset,
 618        .find_vqs       = vp_find_vqs,
 619        .del_vqs        = vp_del_vqs,
 620        .get_features   = vp_get_features,
 621        .finalize_features = vp_finalize_features,
 622        .bus_name       = vp_bus_name,
 623};
 624
 625static void virtio_pci_release_dev(struct device *_d)
 626{
 627        /*
 628         * No need for a release method as we allocate/free
 629         * all devices together with the pci devices.
 630         * Provide an empty one to avoid getting a warning from core.
 631         */
 632}
 633
 634/* the PCI probing function */
 635static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
 636                                      const struct pci_device_id *id)
 637{
 638        struct virtio_pci_device *vp_dev;
 639        int err;
 640
 641        /* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
 642        if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
 643                return -ENODEV;
 644
 645        if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
 646                printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
 647                       VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
 648                return -ENODEV;
 649        }
 650
 651        /* allocate our structure and fill it out */
 652        vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
 653        if (vp_dev == NULL)
 654                return -ENOMEM;
 655
 656        vp_dev->vdev.dev.parent = &pci_dev->dev;
 657        vp_dev->vdev.dev.release = virtio_pci_release_dev;
 658        vp_dev->vdev.config = &virtio_pci_config_ops;
 659        vp_dev->pci_dev = pci_dev;
 660        INIT_LIST_HEAD(&vp_dev->virtqueues);
 661        spin_lock_init(&vp_dev->lock);
 662
 663        /* Disable MSI/MSIX to bring device to a known good state. */
 664        pci_msi_off(pci_dev);
 665
 666        /* enable the device */
 667        err = pci_enable_device(pci_dev);
 668        if (err)
 669                goto out;
 670
 671        err = pci_request_regions(pci_dev, "virtio-pci");
 672        if (err)
 673                goto out_enable_device;
 674
 675        vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
 676        if (vp_dev->ioaddr == NULL)
 677                goto out_req_regions;
 678
 679        pci_set_drvdata(pci_dev, vp_dev);
 680        pci_set_master(pci_dev);
 681
 682        /* we use the subsystem vendor/device id as the virtio vendor/device
 683         * id.  this allows us to use the same PCI vendor/device id for all
 684         * virtio devices and to identify the particular virtio driver by
 685         * the subsystem ids */
 686        vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
 687        vp_dev->vdev.id.device = pci_dev->subsystem_device;
 688
 689        /* finally register the virtio device */
 690        err = register_virtio_device(&vp_dev->vdev);
 691        if (err)
 692                goto out_set_drvdata;
 693
 694        return 0;
 695
 696out_set_drvdata:
 697        pci_set_drvdata(pci_dev, NULL);
 698        pci_iounmap(pci_dev, vp_dev->ioaddr);
 699out_req_regions:
 700        pci_release_regions(pci_dev);
 701out_enable_device:
 702        pci_disable_device(pci_dev);
 703out:
 704        kfree(vp_dev);
 705        return err;
 706}
 707
 708static void __devexit virtio_pci_remove(struct pci_dev *pci_dev)
 709{
 710        struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
 711
 712        unregister_virtio_device(&vp_dev->vdev);
 713
 714        vp_del_vqs(&vp_dev->vdev);
 715        pci_set_drvdata(pci_dev, NULL);
 716        pci_iounmap(pci_dev, vp_dev->ioaddr);
 717        pci_release_regions(pci_dev);
 718        pci_disable_device(pci_dev);
 719        kfree(vp_dev);
 720}
 721
 722#ifdef CONFIG_PM
 723static int virtio_pci_freeze(struct device *dev)
 724{
 725        struct pci_dev *pci_dev = to_pci_dev(dev);
 726        struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
 727        struct virtio_driver *drv;
 728        int ret;
 729
 730        drv = container_of(vp_dev->vdev.dev.driver,
 731                           struct virtio_driver, driver);
 732
 733        ret = 0;
 734        vp_dev->saved_status = vp_get_status(&vp_dev->vdev);
 735        if (drv && drv->freeze)
 736                ret = drv->freeze(&vp_dev->vdev);
 737
 738        if (!ret)
 739                pci_disable_device(pci_dev);
 740        return ret;
 741}
 742
 743static int virtio_pci_restore(struct device *dev)
 744{
 745        struct pci_dev *pci_dev = to_pci_dev(dev);
 746        struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
 747        struct virtio_driver *drv;
 748        int ret;
 749
 750        drv = container_of(vp_dev->vdev.dev.driver,
 751                           struct virtio_driver, driver);
 752
 753        ret = pci_enable_device(pci_dev);
 754        if (ret)
 755                return ret;
 756
 757        pci_set_master(pci_dev);
 758        vp_finalize_features(&vp_dev->vdev);
 759
 760        if (drv && drv->restore)
 761                ret = drv->restore(&vp_dev->vdev);
 762
 763        /* Finally, tell the device we're all set */
 764        if (!ret)
 765                vp_set_status(&vp_dev->vdev, vp_dev->saved_status);
 766
 767        return ret;
 768}
 769
 770static const struct dev_pm_ops virtio_pci_pm_ops = {
 771        SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore)
 772};
 773#endif
 774
 775static struct pci_driver virtio_pci_driver = {
 776        .name           = "virtio-pci",
 777        .id_table       = virtio_pci_id_table,
 778        .probe          = virtio_pci_probe,
 779        .remove         = __devexit_p(virtio_pci_remove),
 780#ifdef CONFIG_PM
 781        .driver.pm      = &virtio_pci_pm_ops,
 782#endif
 783};
 784
 785static int __init virtio_pci_init(void)
 786{
 787        return pci_register_driver(&virtio_pci_driver);
 788}
 789
 790module_init(virtio_pci_init);
 791
 792static void __exit virtio_pci_exit(void)
 793{
 794        pci_unregister_driver(&virtio_pci_driver);
 795}
 796
 797module_exit(virtio_pci_exit);
 798
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