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