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        cpumask_var_t *msix_affinity_masks;
  52        /* Name strings for interrupts. This size should be enough,
  53         * and I'm too lazy to allocate each name separately. */
  54        char (*msix_names)[256];
  55        /* Number of available vectors */
  56        unsigned msix_vectors;
  57        /* Vectors allocated, excluding per-vq vectors if any */
  58        unsigned msix_used_vectors;
  59
  60        /* Status saved during hibernate/restore */
  61        u8 saved_status;
  62
  63        /* Whether we have vector per vq */
  64        bool per_vq_vectors;
  65};
  66
  67/* Constants for MSI-X */
  68/* Use first vector for configuration changes, second and the rest for
  69 * virtqueues Thus, we need at least 2 vectors for MSI. */
  70enum {
  71        VP_MSIX_CONFIG_VECTOR = 0,
  72        VP_MSIX_VQ_VECTOR = 1,
  73};
  74
  75struct virtio_pci_vq_info
  76{
  77        /* the actual virtqueue */
  78        struct virtqueue *vq;
  79
  80        /* the number of entries in the queue */
  81        int num;
  82
  83        /* the virtual address of the ring queue */
  84        void *queue;
  85
  86        /* the list node for the virtqueues list */
  87        struct list_head node;
  88
  89        /* MSI-X vector (or none) */
  90        unsigned msix_vector;
  91};
  92
  93/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
  94static struct pci_device_id virtio_pci_id_table[] = {
  95        { 0x1af4, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
  96        { 0 },
  97};
  98
  99MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
 100
 101/* Convert a generic virtio device to our structure */
 102static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
 103{
 104        return container_of(vdev, struct virtio_pci_device, vdev);
 105}
 106
 107/* virtio config->get_features() implementation */
 108static u32 vp_get_features(struct virtio_device *vdev)
 109{
 110        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 111
 112        /* When someone needs more than 32 feature bits, we'll need to
 113         * steal a bit to indicate that the rest are somewhere else. */
 114        return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
 115}
 116
 117/* virtio config->finalize_features() implementation */
 118static void vp_finalize_features(struct virtio_device *vdev)
 119{
 120        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 121
 122        /* Give virtio_ring a chance to accept features. */
 123        vring_transport_features(vdev);
 124
 125        /* We only support 32 feature bits. */
 126        BUILD_BUG_ON(ARRAY_SIZE(vdev->features) != 1);
 127        iowrite32(vdev->features[0], vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES);
 128}
 129
 130/* virtio config->get() implementation */
 131static void vp_get(struct virtio_device *vdev, unsigned offset,
 132                   void *buf, unsigned len)
 133{
 134        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 135        void __iomem *ioaddr = vp_dev->ioaddr +
 136                                VIRTIO_PCI_CONFIG(vp_dev) + offset;
 137        u8 *ptr = buf;
 138        int i;
 139
 140        for (i = 0; i < len; i++)
 141                ptr[i] = ioread8(ioaddr + i);
 142}
 143
 144/* the config->set() implementation.  it's symmetric to the config->get()
 145 * implementation */
 146static void vp_set(struct virtio_device *vdev, unsigned offset,
 147                   const void *buf, unsigned len)
 148{
 149        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 150        void __iomem *ioaddr = vp_dev->ioaddr +
 151                                VIRTIO_PCI_CONFIG(vp_dev) + offset;
 152        const u8 *ptr = buf;
 153        int i;
 154
 155        for (i = 0; i < len; i++)
 156                iowrite8(ptr[i], ioaddr + i);
 157}
 158
 159/* config->{get,set}_status() implementations */
 160static u8 vp_get_status(struct virtio_device *vdev)
 161{
 162        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 163        return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
 164}
 165
 166static void vp_set_status(struct virtio_device *vdev, u8 status)
 167{
 168        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 169        /* We should never be setting status to 0. */
 170        BUG_ON(status == 0);
 171        iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
 172}
 173
 174/* wait for pending irq handlers */
 175static void vp_synchronize_vectors(struct virtio_device *vdev)
 176{
 177        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 178        int i;
 179
 180        if (vp_dev->intx_enabled)
 181                synchronize_irq(vp_dev->pci_dev->irq);
 182
 183        for (i = 0; i < vp_dev->msix_vectors; ++i)
 184                synchronize_irq(vp_dev->msix_entries[i].vector);
 185}
 186
 187static void vp_reset(struct virtio_device *vdev)
 188{
 189        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 190        /* 0 status means a reset. */
 191        iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
 192        /* Flush out the status write, and flush in device writes,
 193         * including MSi-X interrupts, if any. */
 194        ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
 195        /* Flush pending VQ/configuration callbacks. */
 196        vp_synchronize_vectors(vdev);
 197}
 198
 199/* the notify function used when creating a virt queue */
 200static void vp_notify(struct virtqueue *vq)
 201{
 202        struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
 203
 204        /* we write the queue's selector into the notification register to
 205         * signal the other end */
 206        iowrite16(virtqueue_get_queue_index(vq),
 207                  vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
 208}
 209
 210/* Handle a configuration change: Tell driver if it wants to know. */
 211static irqreturn_t vp_config_changed(int irq, void *opaque)
 212{
 213        struct virtio_pci_device *vp_dev = opaque;
 214        struct virtio_driver *drv;
 215        drv = container_of(vp_dev->vdev.dev.driver,
 216                           struct virtio_driver, driver);
 217
 218        if (drv && drv->config_changed)
 219                drv->config_changed(&vp_dev->vdev);
 220        return IRQ_HANDLED;
 221}
 222
 223/* Notify all virtqueues on an interrupt. */
 224static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
 225{
 226        struct virtio_pci_device *vp_dev = opaque;
 227        struct virtio_pci_vq_info *info;
 228        irqreturn_t ret = IRQ_NONE;
 229        unsigned long flags;
 230
 231        spin_lock_irqsave(&vp_dev->lock, flags);
 232        list_for_each_entry(info, &vp_dev->virtqueues, node) {
 233                if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
 234                        ret = IRQ_HANDLED;
 235        }
 236        spin_unlock_irqrestore(&vp_dev->lock, flags);
 237
 238        return ret;
 239}
 240
 241/* A small wrapper to also acknowledge the interrupt when it's handled.
 242 * I really need an EIO hook for the vring so I can ack the interrupt once we
 243 * know that we'll be handling the IRQ but before we invoke the callback since
 244 * the callback may notify the host which results in the host attempting to
 245 * raise an interrupt that we would then mask once we acknowledged the
 246 * interrupt. */
 247static irqreturn_t vp_interrupt(int irq, void *opaque)
 248{
 249        struct virtio_pci_device *vp_dev = opaque;
 250        u8 isr;
 251
 252        /* reading the ISR has the effect of also clearing it so it's very
 253         * important to save off the value. */
 254        isr = ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
 255
 256        /* It's definitely not us if the ISR was not high */
 257        if (!isr)
 258                return IRQ_NONE;
 259
 260        /* Configuration change?  Tell driver if it wants to know. */
 261        if (isr & VIRTIO_PCI_ISR_CONFIG)
 262                vp_config_changed(irq, opaque);
 263
 264        return vp_vring_interrupt(irq, opaque);
 265}
 266
 267static void vp_free_vectors(struct virtio_device *vdev)
 268{
 269        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 270        int i;
 271
 272        if (vp_dev->intx_enabled) {
 273                free_irq(vp_dev->pci_dev->irq, vp_dev);
 274                vp_dev->intx_enabled = 0;
 275        }
 276
 277        for (i = 0; i < vp_dev->msix_used_vectors; ++i)
 278                free_irq(vp_dev->msix_entries[i].vector, vp_dev);
 279
 280        for (i = 0; i < vp_dev->msix_vectors; i++)
 281                if (vp_dev->msix_affinity_masks[i])
 282                        free_cpumask_var(vp_dev->msix_affinity_masks[i]);
 283
 284        if (vp_dev->msix_enabled) {
 285                /* Disable the vector used for configuration */
 286                iowrite16(VIRTIO_MSI_NO_VECTOR,
 287                          vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
 288                /* Flush the write out to device */
 289                ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
 290
 291                pci_disable_msix(vp_dev->pci_dev);
 292                vp_dev->msix_enabled = 0;
 293                vp_dev->msix_vectors = 0;
 294        }
 295
 296        vp_dev->msix_used_vectors = 0;
 297        kfree(vp_dev->msix_names);
 298        vp_dev->msix_names = NULL;
 299        kfree(vp_dev->msix_entries);
 300        vp_dev->msix_entries = NULL;
 301        kfree(vp_dev->msix_affinity_masks);
 302        vp_dev->msix_affinity_masks = NULL;
 303}
 304
 305static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
 306                                   bool per_vq_vectors)
 307{
 308        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 309        const char *name = dev_name(&vp_dev->vdev.dev);
 310        unsigned i, v;
 311        int err = -ENOMEM;
 312
 313        vp_dev->msix_entries = kmalloc(nvectors * sizeof *vp_dev->msix_entries,
 314                                       GFP_KERNEL);
 315        if (!vp_dev->msix_entries)
 316                goto error;
 317        vp_dev->msix_names = kmalloc(nvectors * sizeof *vp_dev->msix_names,
 318                                     GFP_KERNEL);
 319        if (!vp_dev->msix_names)
 320                goto error;
 321        vp_dev->msix_affinity_masks
 322                = kzalloc(nvectors * sizeof *vp_dev->msix_affinity_masks,
 323                          GFP_KERNEL);
 324        if (!vp_dev->msix_affinity_masks)
 325                goto error;
 326        for (i = 0; i < nvectors; ++i)
 327                if (!alloc_cpumask_var(&vp_dev->msix_affinity_masks[i],
 328                                        GFP_KERNEL))
 329                        goto error;
 330
 331        for (i = 0; i < nvectors; ++i)
 332                vp_dev->msix_entries[i].entry = i;
 333
 334        /* pci_enable_msix returns positive if we can't get this many. */
 335        err = pci_enable_msix(vp_dev->pci_dev, vp_dev->msix_entries, nvectors);
 336        if (err > 0)
 337                err = -ENOSPC;
 338        if (err)
 339                goto error;
 340        vp_dev->msix_vectors = nvectors;
 341        vp_dev->msix_enabled = 1;
 342
 343        /* Set the vector used for configuration */
 344        v = vp_dev->msix_used_vectors;
 345        snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
 346                 "%s-config", name);
 347        err = request_irq(vp_dev->msix_entries[v].vector,
 348                          vp_config_changed, 0, vp_dev->msix_names[v],
 349                          vp_dev);
 350        if (err)
 351                goto error;
 352        ++vp_dev->msix_used_vectors;
 353
 354        iowrite16(v, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
 355        /* Verify we had enough resources to assign the vector */
 356        v = ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
 357        if (v == VIRTIO_MSI_NO_VECTOR) {
 358                err = -EBUSY;
 359                goto error;
 360        }
 361
 362        if (!per_vq_vectors) {
 363                /* Shared vector for all VQs */
 364                v = vp_dev->msix_used_vectors;
 365                snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
 366                         "%s-virtqueues", name);
 367                err = request_irq(vp_dev->msix_entries[v].vector,
 368                                  vp_vring_interrupt, 0, vp_dev->msix_names[v],
 369                                  vp_dev);
 370                if (err)
 371                        goto error;
 372                ++vp_dev->msix_used_vectors;
 373        }
 374        return 0;
 375error:
 376        vp_free_vectors(vdev);
 377        return err;
 378}
 379
 380static int vp_request_intx(struct virtio_device *vdev)
 381{
 382        int err;
 383        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 384
 385        err = request_irq(vp_dev->pci_dev->irq, vp_interrupt,
 386                          IRQF_SHARED, dev_name(&vdev->dev), vp_dev);
 387        if (!err)
 388                vp_dev->intx_enabled = 1;
 389        return err;
 390}
 391
 392static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
 393                                  void (*callback)(struct virtqueue *vq),
 394                                  const char *name,
 395                                  u16 msix_vec)
 396{
 397        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 398        struct virtio_pci_vq_info *info;
 399        struct virtqueue *vq;
 400        unsigned long flags, size;
 401        u16 num;
 402        int err;
 403
 404        /* Select the queue we're interested in */
 405        iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
 406
 407        /* Check if queue is either not available or already active. */
 408        num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
 409        if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
 410                return ERR_PTR(-ENOENT);
 411
 412        /* allocate and fill out our structure the represents an active
 413         * queue */
 414        info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
 415        if (!info)
 416                return ERR_PTR(-ENOMEM);
 417
 418        info->num = num;
 419        info->msix_vector = msix_vec;
 420
 421        size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN));
 422        info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO);
 423        if (info->queue == NULL) {
 424                err = -ENOMEM;
 425                goto out_info;
 426        }
 427
 428        /* activate the queue */
 429        iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT,
 430                  vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
 431
 432        /* create the vring */
 433        vq = vring_new_virtqueue(index, info->num, VIRTIO_PCI_VRING_ALIGN, vdev,
 434                                 true, info->queue, vp_notify, callback, name);
 435        if (!vq) {
 436                err = -ENOMEM;
 437                goto out_activate_queue;
 438        }
 439
 440        vq->priv = info;
 441        info->vq = vq;
 442
 443        if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
 444                iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
 445                msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
 446                if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
 447                        err = -EBUSY;
 448                        goto out_assign;
 449                }
 450        }
 451
 452        if (callback) {
 453                spin_lock_irqsave(&vp_dev->lock, flags);
 454                list_add(&info->node, &vp_dev->virtqueues);
 455                spin_unlock_irqrestore(&vp_dev->lock, flags);
 456        } else {
 457                INIT_LIST_HEAD(&info->node);
 458        }
 459
 460        return vq;
 461
 462out_assign:
 463        vring_del_virtqueue(vq);
 464out_activate_queue:
 465        iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
 466        free_pages_exact(info->queue, size);
 467out_info:
 468        kfree(info);
 469        return ERR_PTR(err);
 470}
 471
 472static void vp_del_vq(struct virtqueue *vq)
 473{
 474        struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
 475        struct virtio_pci_vq_info *info = vq->priv;
 476        unsigned long flags, size;
 477
 478        spin_lock_irqsave(&vp_dev->lock, flags);
 479        list_del(&info->node);
 480        spin_unlock_irqrestore(&vp_dev->lock, flags);
 481
 482        iowrite16(virtqueue_get_queue_index(vq),
 483                vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
 484
 485        if (vp_dev->msix_enabled) {
 486                iowrite16(VIRTIO_MSI_NO_VECTOR,
 487                          vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
 488                /* Flush the write out to device */
 489                ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
 490        }
 491
 492        vring_del_virtqueue(vq);
 493
 494        /* Select and deactivate the queue */
 495        iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
 496
 497        size = PAGE_ALIGN(vring_size(info->num, VIRTIO_PCI_VRING_ALIGN));
 498        free_pages_exact(info->queue, size);
 499        kfree(info);
 500}
 501
 502/* the config->del_vqs() implementation */
 503static void vp_del_vqs(struct virtio_device *vdev)
 504{
 505        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 506        struct virtqueue *vq, *n;
 507        struct virtio_pci_vq_info *info;
 508
 509        list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
 510                info = vq->priv;
 511                if (vp_dev->per_vq_vectors &&
 512                        info->msix_vector != VIRTIO_MSI_NO_VECTOR)
 513                        free_irq(vp_dev->msix_entries[info->msix_vector].vector,
 514                                 vq);
 515                vp_del_vq(vq);
 516        }
 517        vp_dev->per_vq_vectors = false;
 518
 519        vp_free_vectors(vdev);
 520}
 521
 522static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 523                              struct virtqueue *vqs[],
 524                              vq_callback_t *callbacks[],
 525                              const char *names[],
 526                              bool use_msix,
 527                              bool per_vq_vectors)
 528{
 529        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 530        u16 msix_vec;
 531        int i, err, nvectors, allocated_vectors;
 532
 533        if (!use_msix) {
 534                /* Old style: one normal interrupt for change and all vqs. */
 535                err = vp_request_intx(vdev);
 536                if (err)
 537                        goto error_request;
 538        } else {
 539                if (per_vq_vectors) {
 540                        /* Best option: one for change interrupt, one per vq. */
 541                        nvectors = 1;
 542                        for (i = 0; i < nvqs; ++i)
 543                                if (callbacks[i])
 544                                        ++nvectors;
 545                } else {
 546                        /* Second best: one for change, shared for all vqs. */
 547                        nvectors = 2;
 548                }
 549
 550                err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors);
 551                if (err)
 552                        goto error_request;
 553        }
 554
 555        vp_dev->per_vq_vectors = per_vq_vectors;
 556        allocated_vectors = vp_dev->msix_used_vectors;
 557        for (i = 0; i < nvqs; ++i) {
 558                if (!names[i]) {
 559                        vqs[i] = NULL;
 560                        continue;
 561                } else if (!callbacks[i] || !vp_dev->msix_enabled)
 562                        msix_vec = VIRTIO_MSI_NO_VECTOR;
 563                else if (vp_dev->per_vq_vectors)
 564                        msix_vec = allocated_vectors++;
 565                else
 566                        msix_vec = VP_MSIX_VQ_VECTOR;
 567                vqs[i] = setup_vq(vdev, i, callbacks[i], names[i], msix_vec);
 568                if (IS_ERR(vqs[i])) {
 569                        err = PTR_ERR(vqs[i]);
 570                        goto error_find;
 571                }
 572
 573                if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR)
 574                        continue;
 575
 576                /* allocate per-vq irq if available and necessary */
 577                snprintf(vp_dev->msix_names[msix_vec],
 578                         sizeof *vp_dev->msix_names,
 579                         "%s-%s",
 580                         dev_name(&vp_dev->vdev.dev), names[i]);
 581                err = request_irq(vp_dev->msix_entries[msix_vec].vector,
 582                                  vring_interrupt, 0,
 583                                  vp_dev->msix_names[msix_vec],
 584                                  vqs[i]);
 585                if (err) {
 586                        vp_del_vq(vqs[i]);
 587                        goto error_find;
 588                }
 589        }
 590        return 0;
 591
 592error_find:
 593        vp_del_vqs(vdev);
 594
 595error_request:
 596        return err;
 597}
 598
 599/* the config->find_vqs() implementation */
 600static int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 601                       struct virtqueue *vqs[],
 602                       vq_callback_t *callbacks[],
 603                       const char *names[])
 604{
 605        int err;
 606
 607        /* Try MSI-X with one vector per queue. */
 608        err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names, true, true);
 609        if (!err)
 610                return 0;
 611        /* Fallback: MSI-X with one vector for config, one shared for queues. */
 612        err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
 613                                 true, false);
 614        if (!err)
 615                return 0;
 616        /* Finally fall back to regular interrupts. */
 617        return vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
 618                                  false, false);
 619}
 620
 621static const char *vp_bus_name(struct virtio_device *vdev)
 622{
 623        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 624
 625        return pci_name(vp_dev->pci_dev);
 626}
 627
 628/* Setup the affinity for a virtqueue:
 629 * - force the affinity for per vq vector
 630 * - OR over all affinities for shared MSI
 631 * - ignore the affinity request if we're using INTX
 632 */
 633static int vp_set_vq_affinity(struct virtqueue *vq, int cpu)
 634{
 635        struct virtio_device *vdev = vq->vdev;
 636        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 637        struct virtio_pci_vq_info *info = vq->priv;
 638        struct cpumask *mask;
 639        unsigned int irq;
 640
 641        if (!vq->callback)
 642                return -EINVAL;
 643
 644        if (vp_dev->msix_enabled) {
 645                mask = vp_dev->msix_affinity_masks[info->msix_vector];
 646                irq = vp_dev->msix_entries[info->msix_vector].vector;
 647                if (cpu == -1)
 648                        irq_set_affinity_hint(irq, NULL);
 649                else {
 650                        cpumask_set_cpu(cpu, mask);
 651                        irq_set_affinity_hint(irq, mask);
 652                }
 653        }
 654        return 0;
 655}
 656
 657static struct virtio_config_ops virtio_pci_config_ops = {
 658        .get            = vp_get,
 659        .set            = vp_set,
 660        .get_status     = vp_get_status,
 661        .set_status     = vp_set_status,
 662        .reset          = vp_reset,
 663        .find_vqs       = vp_find_vqs,
 664        .del_vqs        = vp_del_vqs,
 665        .get_features   = vp_get_features,
 666        .finalize_features = vp_finalize_features,
 667        .bus_name       = vp_bus_name,
 668        .set_vq_affinity = vp_set_vq_affinity,
 669};
 670
 671static void virtio_pci_release_dev(struct device *_d)
 672{
 673        /*
 674         * No need for a release method as we allocate/free
 675         * all devices together with the pci devices.
 676         * Provide an empty one to avoid getting a warning from core.
 677         */
 678}
 679
 680/* the PCI probing function */
 681static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
 682                                      const struct pci_device_id *id)
 683{
 684        struct virtio_pci_device *vp_dev;
 685        int err;
 686
 687        /* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
 688        if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
 689                return -ENODEV;
 690
 691        if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
 692                printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
 693                       VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
 694                return -ENODEV;
 695        }
 696
 697        /* allocate our structure and fill it out */
 698        vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
 699        if (vp_dev == NULL)
 700                return -ENOMEM;
 701
 702        vp_dev->vdev.dev.parent = &pci_dev->dev;
 703        vp_dev->vdev.dev.release = virtio_pci_release_dev;
 704        vp_dev->vdev.config = &virtio_pci_config_ops;
 705        vp_dev->pci_dev = pci_dev;
 706        INIT_LIST_HEAD(&vp_dev->virtqueues);
 707        spin_lock_init(&vp_dev->lock);
 708
 709        /* Disable MSI/MSIX to bring device to a known good state. */
 710        pci_msi_off(pci_dev);
 711
 712        /* enable the device */
 713        err = pci_enable_device(pci_dev);
 714        if (err)
 715                goto out;
 716
 717        err = pci_request_regions(pci_dev, "virtio-pci");
 718        if (err)
 719                goto out_enable_device;
 720
 721        vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
 722        if (vp_dev->ioaddr == NULL) {
 723                err = -ENOMEM;
 724                goto out_req_regions;
 725        }
 726
 727        pci_set_drvdata(pci_dev, vp_dev);
 728        pci_set_master(pci_dev);
 729
 730        /* we use the subsystem vendor/device id as the virtio vendor/device
 731         * id.  this allows us to use the same PCI vendor/device id for all
 732         * virtio devices and to identify the particular virtio driver by
 733         * the subsystem ids */
 734        vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
 735        vp_dev->vdev.id.device = pci_dev->subsystem_device;
 736
 737        /* finally register the virtio device */
 738        err = register_virtio_device(&vp_dev->vdev);
 739        if (err)
 740                goto out_set_drvdata;
 741
 742        return 0;
 743
 744out_set_drvdata:
 745        pci_set_drvdata(pci_dev, NULL);
 746        pci_iounmap(pci_dev, vp_dev->ioaddr);
 747out_req_regions:
 748        pci_release_regions(pci_dev);
 749out_enable_device:
 750        pci_disable_device(pci_dev);
 751out:
 752        kfree(vp_dev);
 753        return err;
 754}
 755
 756static void __devexit virtio_pci_remove(struct pci_dev *pci_dev)
 757{
 758        struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
 759
 760        unregister_virtio_device(&vp_dev->vdev);
 761
 762        vp_del_vqs(&vp_dev->vdev);
 763        pci_set_drvdata(pci_dev, NULL);
 764        pci_iounmap(pci_dev, vp_dev->ioaddr);
 765        pci_release_regions(pci_dev);
 766        pci_disable_device(pci_dev);
 767        kfree(vp_dev);
 768}
 769
 770#ifdef CONFIG_PM
 771static int virtio_pci_freeze(struct device *dev)
 772{
 773        struct pci_dev *pci_dev = to_pci_dev(dev);
 774        struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
 775        struct virtio_driver *drv;
 776        int ret;
 777
 778        drv = container_of(vp_dev->vdev.dev.driver,
 779                           struct virtio_driver, driver);
 780
 781        ret = 0;
 782        vp_dev->saved_status = vp_get_status(&vp_dev->vdev);
 783        if (drv && drv->freeze)
 784                ret = drv->freeze(&vp_dev->vdev);
 785
 786        if (!ret)
 787                pci_disable_device(pci_dev);
 788        return ret;
 789}
 790
 791static int virtio_pci_restore(struct device *dev)
 792{
 793        struct pci_dev *pci_dev = to_pci_dev(dev);
 794        struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
 795        struct virtio_driver *drv;
 796        int ret;
 797
 798        drv = container_of(vp_dev->vdev.dev.driver,
 799                           struct virtio_driver, driver);
 800
 801        ret = pci_enable_device(pci_dev);
 802        if (ret)
 803                return ret;
 804
 805        pci_set_master(pci_dev);
 806        vp_finalize_features(&vp_dev->vdev);
 807
 808        if (drv && drv->restore)
 809                ret = drv->restore(&vp_dev->vdev);
 810
 811        /* Finally, tell the device we're all set */
 812        if (!ret)
 813                vp_set_status(&vp_dev->vdev, vp_dev->saved_status);
 814
 815        return ret;
 816}
 817
 818static const struct dev_pm_ops virtio_pci_pm_ops = {
 819        SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore)
 820};
 821#endif
 822
 823static struct pci_driver virtio_pci_driver = {
 824        .name           = "virtio-pci",
 825        .id_table       = virtio_pci_id_table,
 826        .probe          = virtio_pci_probe,
 827        .remove         = __devexit_p(virtio_pci_remove),
 828#ifdef CONFIG_PM
 829        .driver.pm      = &virtio_pci_pm_ops,
 830#endif
 831};
 832
 833static int __init virtio_pci_init(void)
 834{
 835        return pci_register_driver(&virtio_pci_driver);
 836}
 837
 838module_init(virtio_pci_init);
 839
 840static void __exit virtio_pci_exit(void)
 841{
 842        pci_unregister_driver(&virtio_pci_driver);
 843}
 844
 845module_exit(virtio_pci_exit);
 846
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