drivers/virtio/virtio_pci

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This source file includes following definitions.
vp_ioread8
vp_ioread16
vp_ioread32
vp_iowrite8
vp_iowrite16
vp_iowrite32
vp_iowrite64_twopart
map_capability
vp_get_features
vp_transport_features
vp_finalize_features
vp_get
vp_set
vp_generation
vp_get_status
vp_set_status
vp_reset
vp_config_vector
setup_vq
vp_modern_find_vqs
del_vq
virtio_pci_find_capability
check_offsets
virtio_pci_modern_probe
virtio_pci_modern_remove
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Virtio PCI driver - modern (virtio 1.0) device support
   4  *
   5  * This module allows virtio devices to be used over a virtual PCI device.
   6  * This can be used with QEMU based VMMs like KVM or Xen.
   7  *
   8  * Copyright IBM Corp. 2007
   9  * Copyright Red Hat, Inc. 2014
  10  *
  11  * Authors:
  12  *  Anthony Liguori  <aliguori@us.ibm.com>
  13  *  Rusty Russell <rusty@rustcorp.com.au>
  14  *  Michael S. Tsirkin <mst@redhat.com>
  15  */
  16 
  17 #include <linux/delay.h>
  18 #define VIRTIO_PCI_NO_LEGACY
  19 #include "virtio_pci_common.h"
  20 
  21 /*
  22  * Type-safe wrappers for io accesses.
  23  * Use these to enforce at compile time the following spec requirement:
  24  *
  25  * The driver MUST access each field using the “natural” access
  26  * method, i.e. 32-bit accesses for 32-bit fields, 16-bit accesses
  27  * for 16-bit fields and 8-bit accesses for 8-bit fields.
  28  */
  29 static inline u8 vp_ioread8(u8 __iomem *addr)
  30 {
  31         return ioread8(addr);
  32 }
  33 static inline u16 vp_ioread16 (__le16 __iomem *addr)
  34 {
  35         return ioread16(addr);
  36 }
  37 
  38 static inline u32 vp_ioread32(__le32 __iomem *addr)
  39 {
  40         return ioread32(addr);
  41 }
  42 
  43 static inline void vp_iowrite8(u8 value, u8 __iomem *addr)
  44 {
  45         iowrite8(value, addr);
  46 }
  47 
  48 static inline void vp_iowrite16(u16 value, __le16 __iomem *addr)
  49 {
  50         iowrite16(value, addr);
  51 }
  52 
  53 static inline void vp_iowrite32(u32 value, __le32 __iomem *addr)
  54 {
  55         iowrite32(value, addr);
  56 }
  57 
  58 static void vp_iowrite64_twopart(u64 val,
  59                                  __le32 __iomem *lo, __le32 __iomem *hi)
  60 {
  61         vp_iowrite32((u32)val, lo);
  62         vp_iowrite32(val >> 32, hi);
  63 }
  64 
  65 static void __iomem *map_capability(struct pci_dev *dev, int off,
  66                                     size_t minlen,
  67                                     u32 align,
  68                                     u32 start, u32 size,
  69                                     size_t *len)
  70 {
  71         u8 bar;
  72         u32 offset, length;
  73         void __iomem *p;
  74 
  75         pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap,
  76                                                  bar),
  77                              &bar);
  78         pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset),
  79                              &offset);
  80         pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length),
  81                               &length);
  82 
  83         if (length <= start) {
  84                 dev_err(&dev->dev,
  85                         "virtio_pci: bad capability len %u (>%u expected)\n",
  86                         length, start);
  87                 return NULL;
  88         }
  89 
  90         if (length - start < minlen) {
  91                 dev_err(&dev->dev,
  92                         "virtio_pci: bad capability len %u (>=%zu expected)\n",
  93                         length, minlen);
  94                 return NULL;
  95         }
  96 
  97         length -= start;
  98 
  99         if (start + offset < offset) {
 100                 dev_err(&dev->dev,
 101                         "virtio_pci: map wrap-around %u+%u\n",
 102                         start, offset);
 103                 return NULL;
 104         }
 105 
 106         offset += start;
 107 
 108         if (offset & (align - 1)) {
 109                 dev_err(&dev->dev,
 110                         "virtio_pci: offset %u not aligned to %u\n",
 111                         offset, align);
 112                 return NULL;
 113         }
 114 
 115         if (length > size)
 116                 length = size;
 117 
 118         if (len)
 119                 *len = length;
 120 
 121         if (minlen + offset < minlen ||
 122             minlen + offset > pci_resource_len(dev, bar)) {
 123                 dev_err(&dev->dev,
 124                         "virtio_pci: map virtio %zu@%u "
 125                         "out of range on bar %i length %lu\n",
 126                         minlen, offset,
 127                         bar, (unsigned long)pci_resource_len(dev, bar));
 128                 return NULL;
 129         }
 130 
 131         p = pci_iomap_range(dev, bar, offset, length);
 132         if (!p)
 133                 dev_err(&dev->dev,
 134                         "virtio_pci: unable to map virtio %u@%u on bar %i\n",
 135                         length, offset, bar);
 136         return p;
 137 }
 138 
 139 /* virtio config->get_features() implementation */
 140 static u64 vp_get_features(struct virtio_device *vdev)
 141 {
 142         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 143         u64 features;
 144 
 145         vp_iowrite32(0, &vp_dev->common->device_feature_select);
 146         features = vp_ioread32(&vp_dev->common->device_feature);
 147         vp_iowrite32(1, &vp_dev->common->device_feature_select);
 148         features |= ((u64)vp_ioread32(&vp_dev->common->device_feature) << 32);
 149 
 150         return features;
 151 }
 152 
 153 static void vp_transport_features(struct virtio_device *vdev, u64 features)
 154 {
 155         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 156         struct pci_dev *pci_dev = vp_dev->pci_dev;
 157 
 158         if ((features & BIT_ULL(VIRTIO_F_SR_IOV)) &&
 159                         pci_find_ext_capability(pci_dev, PCI_EXT_CAP_ID_SRIOV))
 160                 __virtio_set_bit(vdev, VIRTIO_F_SR_IOV);
 161 }
 162 
 163 /* virtio config->finalize_features() implementation */
 164 static int vp_finalize_features(struct virtio_device *vdev)
 165 {
 166         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 167         u64 features = vdev->features;
 168 
 169         /* Give virtio_ring a chance to accept features. */
 170         vring_transport_features(vdev);
 171 
 172         /* Give virtio_pci a chance to accept features. */
 173         vp_transport_features(vdev, features);
 174 
 175         if (!__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
 176                 dev_err(&vdev->dev, "virtio: device uses modern interface "
 177                         "but does not have VIRTIO_F_VERSION_1\n");
 178                 return -EINVAL;
 179         }
 180 
 181         vp_iowrite32(0, &vp_dev->common->guest_feature_select);
 182         vp_iowrite32((u32)vdev->features, &vp_dev->common->guest_feature);
 183         vp_iowrite32(1, &vp_dev->common->guest_feature_select);
 184         vp_iowrite32(vdev->features >> 32, &vp_dev->common->guest_feature);
 185 
 186         return 0;
 187 }
 188 
 189 /* virtio config->get() implementation */
 190 static void vp_get(struct virtio_device *vdev, unsigned offset,
 191                    void *buf, unsigned len)
 192 {
 193         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 194         u8 b;
 195         __le16 w;
 196         __le32 l;
 197 
 198         BUG_ON(offset + len > vp_dev->device_len);
 199 
 200         switch (len) {
 201         case 1:
 202                 b = ioread8(vp_dev->device + offset);
 203                 memcpy(buf, &b, sizeof b);
 204                 break;
 205         case 2:
 206                 w = cpu_to_le16(ioread16(vp_dev->device + offset));
 207                 memcpy(buf, &w, sizeof w);
 208                 break;
 209         case 4:
 210                 l = cpu_to_le32(ioread32(vp_dev->device + offset));
 211                 memcpy(buf, &l, sizeof l);
 212                 break;
 213         case 8:
 214                 l = cpu_to_le32(ioread32(vp_dev->device + offset));
 215                 memcpy(buf, &l, sizeof l);
 216                 l = cpu_to_le32(ioread32(vp_dev->device + offset + sizeof l));
 217                 memcpy(buf + sizeof l, &l, sizeof l);
 218                 break;
 219         default:
 220                 BUG();
 221         }
 222 }
 223 
 224 /* the config->set() implementation.  it's symmetric to the config->get()
 225  * implementation */
 226 static void vp_set(struct virtio_device *vdev, unsigned offset,
 227                    const void *buf, unsigned len)
 228 {
 229         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 230         u8 b;
 231         __le16 w;
 232         __le32 l;
 233 
 234         BUG_ON(offset + len > vp_dev->device_len);
 235 
 236         switch (len) {
 237         case 1:
 238                 memcpy(&b, buf, sizeof b);
 239                 iowrite8(b, vp_dev->device + offset);
 240                 break;
 241         case 2:
 242                 memcpy(&w, buf, sizeof w);
 243                 iowrite16(le16_to_cpu(w), vp_dev->device + offset);
 244                 break;
 245         case 4:
 246                 memcpy(&l, buf, sizeof l);
 247                 iowrite32(le32_to_cpu(l), vp_dev->device + offset);
 248                 break;
 249         case 8:
 250                 memcpy(&l, buf, sizeof l);
 251                 iowrite32(le32_to_cpu(l), vp_dev->device + offset);
 252                 memcpy(&l, buf + sizeof l, sizeof l);
 253                 iowrite32(le32_to_cpu(l), vp_dev->device + offset + sizeof l);
 254                 break;
 255         default:
 256                 BUG();
 257         }
 258 }
 259 
 260 static u32 vp_generation(struct virtio_device *vdev)
 261 {
 262         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 263         return vp_ioread8(&vp_dev->common->config_generation);
 264 }
 265 
 266 /* config->{get,set}_status() implementations */
 267 static u8 vp_get_status(struct virtio_device *vdev)
 268 {
 269         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 270         return vp_ioread8(&vp_dev->common->device_status);
 271 }
 272 
 273 static void vp_set_status(struct virtio_device *vdev, u8 status)
 274 {
 275         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 276         /* We should never be setting status to 0. */
 277         BUG_ON(status == 0);
 278         vp_iowrite8(status, &vp_dev->common->device_status);
 279 }
 280 
 281 static void vp_reset(struct virtio_device *vdev)
 282 {
 283         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 284         /* 0 status means a reset. */
 285         vp_iowrite8(0, &vp_dev->common->device_status);
 286         /* After writing 0 to device_status, the driver MUST wait for a read of
 287          * device_status to return 0 before reinitializing the device.
 288          * This will flush out the status write, and flush in device writes,
 289          * including MSI-X interrupts, if any.
 290          */
 291         while (vp_ioread8(&vp_dev->common->device_status))
 292                 msleep(1);
 293         /* Flush pending VQ/configuration callbacks. */
 294         vp_synchronize_vectors(vdev);
 295 }
 296 
 297 static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
 298 {
 299         /* Setup the vector used for configuration events */
 300         vp_iowrite16(vector, &vp_dev->common->msix_config);
 301         /* Verify we had enough resources to assign the vector */
 302         /* Will also flush the write out to device */
 303         return vp_ioread16(&vp_dev->common->msix_config);
 304 }
 305 
 306 static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
 307                                   struct virtio_pci_vq_info *info,
 308                                   unsigned index,
 309                                   void (*callback)(struct virtqueue *vq),
 310                                   const char *name,
 311                                   bool ctx,
 312                                   u16 msix_vec)
 313 {
 314         struct virtio_pci_common_cfg __iomem *cfg = vp_dev->common;
 315         struct virtqueue *vq;
 316         u16 num, off;
 317         int err;
 318 
 319         if (index >= vp_ioread16(&cfg->num_queues))
 320                 return ERR_PTR(-ENOENT);
 321 
 322         /* Select the queue we're interested in */
 323         vp_iowrite16(index, &cfg->queue_select);
 324 
 325         /* Check if queue is either not available or already active. */
 326         num = vp_ioread16(&cfg->queue_size);
 327         if (!num || vp_ioread16(&cfg->queue_enable))
 328                 return ERR_PTR(-ENOENT);
 329 
 330         if (num & (num - 1)) {
 331                 dev_warn(&vp_dev->pci_dev->dev, "bad queue size %u", num);
 332                 return ERR_PTR(-EINVAL);
 333         }
 334 
 335         /* get offset of notification word for this vq */
 336         off = vp_ioread16(&cfg->queue_notify_off);
 337 
 338         info->msix_vector = msix_vec;
 339 
 340         /* create the vring */
 341         vq = vring_create_virtqueue(index, num,
 342                                     SMP_CACHE_BYTES, &vp_dev->vdev,
 343                                     true, true, ctx,
 344                                     vp_notify, callback, name);
 345         if (!vq)
 346                 return ERR_PTR(-ENOMEM);
 347 
 348         /* activate the queue */
 349         vp_iowrite16(virtqueue_get_vring_size(vq), &cfg->queue_size);
 350         vp_iowrite64_twopart(virtqueue_get_desc_addr(vq),
 351                              &cfg->queue_desc_lo, &cfg->queue_desc_hi);
 352         vp_iowrite64_twopart(virtqueue_get_avail_addr(vq),
 353                              &cfg->queue_avail_lo, &cfg->queue_avail_hi);
 354         vp_iowrite64_twopart(virtqueue_get_used_addr(vq),
 355                              &cfg->queue_used_lo, &cfg->queue_used_hi);
 356 
 357         if (vp_dev->notify_base) {
 358                 /* offset should not wrap */
 359                 if ((u64)off * vp_dev->notify_offset_multiplier + 2
 360                     > vp_dev->notify_len) {
 361                         dev_warn(&vp_dev->pci_dev->dev,
 362                                  "bad notification offset %u (x %u) "
 363                                  "for queue %u > %zd",
 364                                  off, vp_dev->notify_offset_multiplier,
 365                                  index, vp_dev->notify_len);
 366                         err = -EINVAL;
 367                         goto err_map_notify;
 368                 }
 369                 vq->priv = (void __force *)vp_dev->notify_base +
 370                         off * vp_dev->notify_offset_multiplier;
 371         } else {
 372                 vq->priv = (void __force *)map_capability(vp_dev->pci_dev,
 373                                           vp_dev->notify_map_cap, 2, 2,
 374                                           off * vp_dev->notify_offset_multiplier, 2,
 375                                           NULL);
 376         }
 377 
 378         if (!vq->priv) {
 379                 err = -ENOMEM;
 380                 goto err_map_notify;
 381         }
 382 
 383         if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
 384                 vp_iowrite16(msix_vec, &cfg->queue_msix_vector);
 385                 msix_vec = vp_ioread16(&cfg->queue_msix_vector);
 386                 if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
 387                         err = -EBUSY;
 388                         goto err_assign_vector;
 389                 }
 390         }
 391 
 392         return vq;
 393 
 394 err_assign_vector:
 395         if (!vp_dev->notify_base)
 396                 pci_iounmap(vp_dev->pci_dev, (void __iomem __force *)vq->priv);
 397 err_map_notify:
 398         vring_del_virtqueue(vq);
 399         return ERR_PTR(err);
 400 }
 401 
 402 static int vp_modern_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 403                               struct virtqueue *vqs[],
 404                               vq_callback_t *callbacks[],
 405                               const char * const names[], const bool *ctx,
 406                               struct irq_affinity *desc)
 407 {
 408         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 409         struct virtqueue *vq;
 410         int rc = vp_find_vqs(vdev, nvqs, vqs, callbacks, names, ctx, desc);
 411 
 412         if (rc)
 413                 return rc;
 414 
 415         /* Select and activate all queues. Has to be done last: once we do
 416          * this, there's no way to go back except reset.
 417          */
 418         list_for_each_entry(vq, &vdev->vqs, list) {
 419                 vp_iowrite16(vq->index, &vp_dev->common->queue_select);
 420                 vp_iowrite16(1, &vp_dev->common->queue_enable);
 421         }
 422 
 423         return 0;
 424 }
 425 
 426 static void del_vq(struct virtio_pci_vq_info *info)
 427 {
 428         struct virtqueue *vq = info->vq;
 429         struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
 430 
 431         vp_iowrite16(vq->index, &vp_dev->common->queue_select);
 432 
 433         if (vp_dev->msix_enabled) {
 434                 vp_iowrite16(VIRTIO_MSI_NO_VECTOR,
 435                              &vp_dev->common->queue_msix_vector);
 436                 /* Flush the write out to device */
 437                 vp_ioread16(&vp_dev->common->queue_msix_vector);
 438         }
 439 
 440         if (!vp_dev->notify_base)
 441                 pci_iounmap(vp_dev->pci_dev, (void __force __iomem *)vq->priv);
 442 
 443         vring_del_virtqueue(vq);
 444 }
 445 
 446 static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
 447         .get            = NULL,
 448         .set            = NULL,
 449         .generation     = vp_generation,
 450         .get_status     = vp_get_status,
 451         .set_status     = vp_set_status,
 452         .reset          = vp_reset,
 453         .find_vqs       = vp_modern_find_vqs,
 454         .del_vqs        = vp_del_vqs,
 455         .get_features   = vp_get_features,
 456         .finalize_features = vp_finalize_features,
 457         .bus_name       = vp_bus_name,
 458         .set_vq_affinity = vp_set_vq_affinity,
 459         .get_vq_affinity = vp_get_vq_affinity,
 460 };
 461 
 462 static const struct virtio_config_ops virtio_pci_config_ops = {
 463         .get            = vp_get,
 464         .set            = vp_set,
 465         .generation     = vp_generation,
 466         .get_status     = vp_get_status,
 467         .set_status     = vp_set_status,
 468         .reset          = vp_reset,
 469         .find_vqs       = vp_modern_find_vqs,
 470         .del_vqs        = vp_del_vqs,
 471         .get_features   = vp_get_features,
 472         .finalize_features = vp_finalize_features,
 473         .bus_name       = vp_bus_name,
 474         .set_vq_affinity = vp_set_vq_affinity,
 475         .get_vq_affinity = vp_get_vq_affinity,
 476 };
 477 
 478 /**
 479  * virtio_pci_find_capability - walk capabilities to find device info.
 480  * @dev: the pci device
 481  * @cfg_type: the VIRTIO_PCI_CAP_* value we seek
 482  * @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO.
 483  *
 484  * Returns offset of the capability, or 0.
 485  */
 486 static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type,
 487                                              u32 ioresource_types, int *bars)
 488 {
 489         int pos;
 490 
 491         for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
 492              pos > 0;
 493              pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
 494                 u8 type, bar;
 495                 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
 496                                                          cfg_type),
 497                                      &type);
 498                 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
 499                                                          bar),
 500                                      &bar);
 501 
 502                 /* Ignore structures with reserved BAR values */
 503                 if (bar > 0x5)
 504                         continue;
 505 
 506                 if (type == cfg_type) {
 507                         if (pci_resource_len(dev, bar) &&
 508                             pci_resource_flags(dev, bar) & ioresource_types) {
 509                                 *bars |= (1 << bar);
 510                                 return pos;
 511                         }
 512                 }
 513         }
 514         return 0;
 515 }
 516 
 517 /* This is part of the ABI.  Don't screw with it. */
 518 static inline void check_offsets(void)
 519 {
 520         /* Note: disk space was harmed in compilation of this function. */
 521         BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR !=
 522                      offsetof(struct virtio_pci_cap, cap_vndr));
 523         BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT !=
 524                      offsetof(struct virtio_pci_cap, cap_next));
 525         BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN !=
 526                      offsetof(struct virtio_pci_cap, cap_len));
 527         BUILD_BUG_ON(VIRTIO_PCI_CAP_CFG_TYPE !=
 528                      offsetof(struct virtio_pci_cap, cfg_type));
 529         BUILD_BUG_ON(VIRTIO_PCI_CAP_BAR !=
 530                      offsetof(struct virtio_pci_cap, bar));
 531         BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET !=
 532                      offsetof(struct virtio_pci_cap, offset));
 533         BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH !=
 534                      offsetof(struct virtio_pci_cap, length));
 535         BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT !=
 536                      offsetof(struct virtio_pci_notify_cap,
 537                               notify_off_multiplier));
 538         BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT !=
 539                      offsetof(struct virtio_pci_common_cfg,
 540                               device_feature_select));
 541         BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF !=
 542                      offsetof(struct virtio_pci_common_cfg, device_feature));
 543         BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT !=
 544                      offsetof(struct virtio_pci_common_cfg,
 545                               guest_feature_select));
 546         BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF !=
 547                      offsetof(struct virtio_pci_common_cfg, guest_feature));
 548         BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX !=
 549                      offsetof(struct virtio_pci_common_cfg, msix_config));
 550         BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ !=
 551                      offsetof(struct virtio_pci_common_cfg, num_queues));
 552         BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS !=
 553                      offsetof(struct virtio_pci_common_cfg, device_status));
 554         BUILD_BUG_ON(VIRTIO_PCI_COMMON_CFGGENERATION !=
 555                      offsetof(struct virtio_pci_common_cfg, config_generation));
 556         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT !=
 557                      offsetof(struct virtio_pci_common_cfg, queue_select));
 558         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE !=
 559                      offsetof(struct virtio_pci_common_cfg, queue_size));
 560         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX !=
 561                      offsetof(struct virtio_pci_common_cfg, queue_msix_vector));
 562         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE !=
 563                      offsetof(struct virtio_pci_common_cfg, queue_enable));
 564         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF !=
 565                      offsetof(struct virtio_pci_common_cfg, queue_notify_off));
 566         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO !=
 567                      offsetof(struct virtio_pci_common_cfg, queue_desc_lo));
 568         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI !=
 569                      offsetof(struct virtio_pci_common_cfg, queue_desc_hi));
 570         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO !=
 571                      offsetof(struct virtio_pci_common_cfg, queue_avail_lo));
 572         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI !=
 573                      offsetof(struct virtio_pci_common_cfg, queue_avail_hi));
 574         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO !=
 575                      offsetof(struct virtio_pci_common_cfg, queue_used_lo));
 576         BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI !=
 577                      offsetof(struct virtio_pci_common_cfg, queue_used_hi));
 578 }
 579 
 580 /* the PCI probing function */
 581 int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev)
 582 {
 583         struct pci_dev *pci_dev = vp_dev->pci_dev;
 584         int err, common, isr, notify, device;
 585         u32 notify_length;
 586         u32 notify_offset;
 587 
 588         check_offsets();
 589 
 590         /* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
 591         if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f)
 592                 return -ENODEV;
 593 
 594         if (pci_dev->device < 0x1040) {
 595                 /* Transitional devices: use the PCI subsystem device id as
 596                  * virtio device id, same as legacy driver always did.
 597                  */
 598                 vp_dev->vdev.id.device = pci_dev->subsystem_device;
 599         } else {
 600                 /* Modern devices: simply use PCI device id, but start from 0x1040. */
 601                 vp_dev->vdev.id.device = pci_dev->device - 0x1040;
 602         }
 603         vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
 604 
 605         /* check for a common config: if not, use legacy mode (bar 0). */
 606         common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
 607                                             IORESOURCE_IO | IORESOURCE_MEM,
 608                                             &vp_dev->modern_bars);
 609         if (!common) {
 610                 dev_info(&pci_dev->dev,
 611                          "virtio_pci: leaving for legacy driver\n");
 612                 return -ENODEV;
 613         }
 614 
 615         /* If common is there, these should be too... */
 616         isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
 617                                          IORESOURCE_IO | IORESOURCE_MEM,
 618                                          &vp_dev->modern_bars);
 619         notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
 620                                             IORESOURCE_IO | IORESOURCE_MEM,
 621                                             &vp_dev->modern_bars);
 622         if (!isr || !notify) {
 623                 dev_err(&pci_dev->dev,
 624                         "virtio_pci: missing capabilities %i/%i/%i\n",
 625                         common, isr, notify);
 626                 return -EINVAL;
 627         }
 628 
 629         err = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(64));
 630         if (err)
 631                 err = dma_set_mask_and_coherent(&pci_dev->dev,
 632                                                 DMA_BIT_MASK(32));
 633         if (err)
 634                 dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA.  Trying to continue, but this might not work.\n");
 635 
 636         /* Device capability is only mandatory for devices that have
 637          * device-specific configuration.
 638          */
 639         device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
 640                                             IORESOURCE_IO | IORESOURCE_MEM,
 641                                             &vp_dev->modern_bars);
 642 
 643         err = pci_request_selected_regions(pci_dev, vp_dev->modern_bars,
 644                                            "virtio-pci-modern");
 645         if (err)
 646                 return err;
 647 
 648         err = -EINVAL;
 649         vp_dev->common = map_capability(pci_dev, common,
 650                                         sizeof(struct virtio_pci_common_cfg), 4,
 651                                         0, sizeof(struct virtio_pci_common_cfg),
 652                                         NULL);
 653         if (!vp_dev->common)
 654                 goto err_map_common;
 655         vp_dev->isr = map_capability(pci_dev, isr, sizeof(u8), 1,
 656                                      0, 1,
 657                                      NULL);
 658         if (!vp_dev->isr)
 659                 goto err_map_isr;
 660 
 661         /* Read notify_off_multiplier from config space. */
 662         pci_read_config_dword(pci_dev,
 663                               notify + offsetof(struct virtio_pci_notify_cap,
 664                                                 notify_off_multiplier),
 665                               &vp_dev->notify_offset_multiplier);
 666         /* Read notify length and offset from config space. */
 667         pci_read_config_dword(pci_dev,
 668                               notify + offsetof(struct virtio_pci_notify_cap,
 669                                                 cap.length),
 670                               &notify_length);
 671 
 672         pci_read_config_dword(pci_dev,
 673                               notify + offsetof(struct virtio_pci_notify_cap,
 674                                                 cap.offset),
 675                               &notify_offset);
 676 
 677         /* We don't know how many VQs we'll map, ahead of the time.
 678          * If notify length is small, map it all now.
 679          * Otherwise, map each VQ individually later.
 680          */
 681         if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) {
 682                 vp_dev->notify_base = map_capability(pci_dev, notify, 2, 2,
 683                                                      0, notify_length,
 684                                                      &vp_dev->notify_len);
 685                 if (!vp_dev->notify_base)
 686                         goto err_map_notify;
 687         } else {
 688                 vp_dev->notify_map_cap = notify;
 689         }
 690 
 691         /* Again, we don't know how much we should map, but PAGE_SIZE
 692          * is more than enough for all existing devices.
 693          */
 694         if (device) {
 695                 vp_dev->device = map_capability(pci_dev, device, 0, 4,
 696                                                 0, PAGE_SIZE,
 697                                                 &vp_dev->device_len);
 698                 if (!vp_dev->device)
 699                         goto err_map_device;
 700 
 701                 vp_dev->vdev.config = &virtio_pci_config_ops;
 702         } else {
 703                 vp_dev->vdev.config = &virtio_pci_config_nodev_ops;
 704         }
 705 
 706         vp_dev->config_vector = vp_config_vector;
 707         vp_dev->setup_vq = setup_vq;
 708         vp_dev->del_vq = del_vq;
 709 
 710         return 0;
 711 
 712 err_map_device:
 713         if (vp_dev->notify_base)
 714                 pci_iounmap(pci_dev, vp_dev->notify_base);
 715 err_map_notify:
 716         pci_iounmap(pci_dev, vp_dev->isr);
 717 err_map_isr:
 718         pci_iounmap(pci_dev, vp_dev->common);
 719 err_map_common:
 720         return err;
 721 }
 722 
 723 void virtio_pci_modern_remove(struct virtio_pci_device *vp_dev)
 724 {
 725         struct pci_dev *pci_dev = vp_dev->pci_dev;
 726 
 727         if (vp_dev->device)
 728                 pci_iounmap(pci_dev, vp_dev->device);
 729         if (vp_dev->notify_base)
 730                 pci_iounmap(pci_dev, vp_dev->notify_base);
 731         pci_iounmap(pci_dev, vp_dev->isr);
 732         pci_iounmap(pci_dev, vp_dev->common);
 733         pci_release_selected_regions(pci_dev, vp_dev->modern_bars);
 734 }
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/virtio/virtio_pci_modern.c

DEFINITIONS
