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 #define VIRTIO_RING_NO_LEGACY 20 #include "virtio_pci_common.h" 21 22 /* 23 * Type-safe wrappers for io accesses. 24 * Use these to enforce at compile time the following spec requirement: 25 * 26 * The driver MUST access each field using the “natural” access 27 * method, i.e. 32-bit accesses for 32-bit fields, 16-bit accesses 28 * for 16-bit fields and 8-bit accesses for 8-bit fields. 29 */ 30 static inline u8 vp_ioread8(const u8 __iomem *addr) 31 { 32 return ioread8(addr); 33 } 34 static inline u16 vp_ioread16 (const __le16 __iomem *addr) 35 { 36 return ioread16(addr); 37 } 38 39 static inline u32 vp_ioread32(const __le32 __iomem *addr) 40 { 41 return ioread32(addr); 42 } 43 44 static inline void vp_iowrite8(u8 value, u8 __iomem *addr) 45 { 46 iowrite8(value, addr); 47 } 48 49 static inline void vp_iowrite16(u16 value, __le16 __iomem *addr) 50 { 51 iowrite16(value, addr); 52 } 53 54 static inline void vp_iowrite32(u32 value, __le32 __iomem *addr) 55 { 56 iowrite32(value, addr); 57 } 58 59 static void vp_iowrite64_twopart(u64 val, 60 __le32 __iomem *lo, __le32 __iomem *hi) 61 { 62 vp_iowrite32((u32)val, lo); 63 vp_iowrite32(val >> 32, hi); 64 } 65 66 static void __iomem *map_capability(struct pci_dev *dev, int off, 67 size_t minlen, 68 u32 align, 69 u32 start, u32 size, 70 size_t *len) 71 { 72 u8 bar; 73 u32 offset, length; 74 void __iomem *p; 75 76 pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap, 77 bar), 78 &bar); 79 pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset), 80 &offset); 81 pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length), 82 &length); 83 84 if (length <= start) { 85 dev_err(&dev->dev, 86 "virtio_pci: bad capability len %u (>%u expected)\n", 87 length, start); 88 return NULL; 89 } 90 91 if (length - start < minlen) { 92 dev_err(&dev->dev, 93 "virtio_pci: bad capability len %u (>=%zu expected)\n", 94 length, minlen); 95 return NULL; 96 } 97 98 length -= start; 99 100 if (start + offset < offset) { 101 dev_err(&dev->dev, 102 "virtio_pci: map wrap-around %u+%u\n", 103 start, offset); 104 return NULL; 105 } 106 107 offset += start; 108 109 if (offset & (align - 1)) { 110 dev_err(&dev->dev, 111 "virtio_pci: offset %u not aligned to %u\n", 112 offset, align); 113 return NULL; 114 } 115 116 if (length > size) 117 length = size; 118 119 if (len) 120 *len = length; 121 122 if (minlen + offset < minlen || 123 minlen + offset > pci_resource_len(dev, bar)) { 124 dev_err(&dev->dev, 125 "virtio_pci: map virtio %zu@%u " 126 "out of range on bar %i length %lu\n", 127 minlen, offset, 128 bar, (unsigned long)pci_resource_len(dev, bar)); 129 return NULL; 130 } 131 132 p = pci_iomap_range(dev, bar, offset, length); 133 if (!p) 134 dev_err(&dev->dev, 135 "virtio_pci: unable to map virtio %u@%u on bar %i\n", 136 length, offset, bar); 137 return p; 138 } 139 140 /* virtio config->get_features() implementation */ 141 static u64 vp_get_features(struct virtio_device *vdev) 142 { 143 struct virtio_pci_device *vp_dev = to_vp_device(vdev); 144 u64 features; 145 146 vp_iowrite32(0, &vp_dev->common->device_feature_select); 147 features = vp_ioread32(&vp_dev->common->device_feature); 148 vp_iowrite32(1, &vp_dev->common->device_feature_select); 149 features |= ((u64)vp_ioread32(&vp_dev->common->device_feature) << 32); 150 151 return features; 152 } 153 154 static void vp_transport_features(struct virtio_device *vdev, u64 features) 155 { 156 struct virtio_pci_device *vp_dev = to_vp_device(vdev); 157 struct pci_dev *pci_dev = vp_dev->pci_dev; 158 159 if ((features & BIT_ULL(VIRTIO_F_SR_IOV)) && 160 pci_find_ext_capability(pci_dev, PCI_EXT_CAP_ID_SRIOV)) 161 __virtio_set_bit(vdev, VIRTIO_F_SR_IOV); 162 } 163 164 /* virtio config->finalize_features() implementation */ 165 static int vp_finalize_features(struct virtio_device *vdev) 166 { 167 struct virtio_pci_device *vp_dev = to_vp_device(vdev); 168 u64 features = vdev->features; 169 170 /* Give virtio_ring a chance to accept features. */ 171 vring_transport_features(vdev); 172 173 /* Give virtio_pci a chance to accept features. */ 174 vp_transport_features(vdev, features); 175 176 if (!__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) { 177 dev_err(&vdev->dev, "virtio: device uses modern interface " 178 "but does not have VIRTIO_F_VERSION_1\n"); 179 return -EINVAL; 180 } 181 182 vp_iowrite32(0, &vp_dev->common->guest_feature_select); 183 vp_iowrite32((u32)vdev->features, &vp_dev->common->guest_feature); 184 vp_iowrite32(1, &vp_dev->common->guest_feature_select); 185 vp_iowrite32(vdev->features >> 32, &vp_dev->common->guest_feature); 186 187 return 0; 188 } 189 190 /* virtio config->get() implementation */ 191 static void vp_get(struct virtio_device *vdev, unsigned offset, 192 void *buf, unsigned len) 193 { 194 struct virtio_pci_device *vp_dev = to_vp_device(vdev); 195 u8 b; 196 __le16 w; 197 __le32 l; 198 199 BUG_ON(offset + len > vp_dev->device_len); 200 201 switch (len) { 202 case 1: 203 b = ioread8(vp_dev->device + offset); 204 memcpy(buf, &b, sizeof b); 205 break; 206 case 2: 207 w = cpu_to_le16(ioread16(vp_dev->device + offset)); 208 memcpy(buf, &w, sizeof w); 209 break; 210 case 4: 211 l = cpu_to_le32(ioread32(vp_dev->device + offset)); 212 memcpy(buf, &l, sizeof l); 213 break; 214 case 8: 215 l = cpu_to_le32(ioread32(vp_dev->device + offset)); 216 memcpy(buf, &l, sizeof l); 217 l = cpu_to_le32(ioread32(vp_dev->device + offset + sizeof l)); 218 memcpy(buf + sizeof l, &l, sizeof l); 219 break; 220 default: 221 BUG(); 222 } 223 } 224 225 /* the config->set() implementation. it's symmetric to the config->get() 226 * implementation */ 227 static void vp_set(struct virtio_device *vdev, unsigned offset, 228 const void *buf, unsigned len) 229 { 230 struct virtio_pci_device *vp_dev = to_vp_device(vdev); 231 u8 b; 232 __le16 w; 233 __le32 l; 234 235 BUG_ON(offset + len > vp_dev->device_len); 236 237 switch (len) { 238 case 1: 239 memcpy(&b, buf, sizeof b); 240 iowrite8(b, vp_dev->device + offset); 241 break; 242 case 2: 243 memcpy(&w, buf, sizeof w); 244 iowrite16(le16_to_cpu(w), vp_dev->device + offset); 245 break; 246 case 4: 247 memcpy(&l, buf, sizeof l); 248 iowrite32(le32_to_cpu(l), vp_dev->device + offset); 249 break; 250 case 8: 251 memcpy(&l, buf, sizeof l); 252 iowrite32(le32_to_cpu(l), vp_dev->device + offset); 253 memcpy(&l, buf + sizeof l, sizeof l); 254 iowrite32(le32_to_cpu(l), vp_dev->device + offset + sizeof l); 255 break; 256 default: 257 BUG(); 258 } 259 } 260 261 static u32 vp_generation(struct virtio_device *vdev) 262 { 263 struct virtio_pci_device *vp_dev = to_vp_device(vdev); 264 return vp_ioread8(&vp_dev->common->config_generation); 265 } 266 267 /* config->{get,set}_status() implementations */ 268 static u8 vp_get_status(struct virtio_device *vdev) 269 { 270 struct virtio_pci_device *vp_dev = to_vp_device(vdev); 271 return vp_ioread8(&vp_dev->common->device_status); 272 } 273 274 static void vp_set_status(struct virtio_device *vdev, u8 status) 275 { 276 struct virtio_pci_device *vp_dev = to_vp_device(vdev); 277 /* We should never be setting status to 0. */ 278 BUG_ON(status == 0); 279 vp_iowrite8(status, &vp_dev->common->device_status); 280 } 281 282 static void vp_reset(struct virtio_device *vdev) 283 { 284 struct virtio_pci_device *vp_dev = to_vp_device(vdev); 285 /* 0 status means a reset. */ 286 vp_iowrite8(0, &vp_dev->common->device_status); 287 /* After writing 0 to device_status, the driver MUST wait for a read of 288 * device_status to return 0 before reinitializing the device. 289 * This will flush out the status write, and flush in device writes, 290 * including MSI-X interrupts, if any. 291 */ 292 while (vp_ioread8(&vp_dev->common->device_status)) 293 msleep(1); 294 /* Flush pending VQ/configuration callbacks. */ 295 vp_synchronize_vectors(vdev); 296 } 297 298 static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector) 299 { 300 /* Setup the vector used for configuration events */ 301 vp_iowrite16(vector, &vp_dev->common->msix_config); 302 /* Verify we had enough resources to assign the vector */ 303 /* Will also flush the write out to device */ 304 return vp_ioread16(&vp_dev->common->msix_config); 305 } 306 307 static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, 308 struct virtio_pci_vq_info *info, 309 unsigned index, 310 void (*callback)(struct virtqueue *vq), 311 const char *name, 312 bool ctx, 313 u16 msix_vec) 314 { 315 struct virtio_pci_common_cfg __iomem *cfg = vp_dev->common; 316 struct virtqueue *vq; 317 u16 num, off; 318 int err; 319 320 if (index >= vp_ioread16(&cfg->num_queues)) 321 return ERR_PTR(-ENOENT); 322 323 /* Select the queue we're interested in */ 324 vp_iowrite16(index, &cfg->queue_select); 325 326 /* Check if queue is either not available or already active. */ 327 num = vp_ioread16(&cfg->queue_size); 328 if (!num || vp_ioread16(&cfg->queue_enable)) 329 return ERR_PTR(-ENOENT); 330 331 if (num & (num - 1)) { 332 dev_warn(&vp_dev->pci_dev->dev, "bad queue size %u", num); 333 return ERR_PTR(-EINVAL); 334 } 335 336 /* get offset of notification word for this vq */ 337 off = vp_ioread16(&cfg->queue_notify_off); 338 339 info->msix_vector = msix_vec; 340 341 /* create the vring */ 342 vq = vring_create_virtqueue(index, num, 343 SMP_CACHE_BYTES, &vp_dev->vdev, 344 true, true, ctx, 345 vp_notify, callback, name); 346 if (!vq) 347 return ERR_PTR(-ENOMEM); 348 349 /* activate the queue */ 350 vp_iowrite16(virtqueue_get_vring_size(vq), &cfg->queue_size); 351 vp_iowrite64_twopart(virtqueue_get_desc_addr(vq), 352 &cfg->queue_desc_lo, &cfg->queue_desc_hi); 353 vp_iowrite64_twopart(virtqueue_get_avail_addr(vq), 354 &cfg->queue_avail_lo, &cfg->queue_avail_hi); 355 vp_iowrite64_twopart(virtqueue_get_used_addr(vq), 356 &cfg->queue_used_lo, &cfg->queue_used_hi); 357 358 if (vp_dev->notify_base) { 359 /* offset should not wrap */ 360 if ((u64)off * vp_dev->notify_offset_multiplier + 2 361 > vp_dev->notify_len) { 362 dev_warn(&vp_dev->pci_dev->dev, 363 "bad notification offset %u (x %u) " 364 "for queue %u > %zd", 365 off, vp_dev->notify_offset_multiplier, 366 index, vp_dev->notify_len); 367 err = -EINVAL; 368 goto err_map_notify; 369 } 370 vq->priv = (void __force *)vp_dev->notify_base + 371 off * vp_dev->notify_offset_multiplier; 372 } else { 373 vq->priv = (void __force *)map_capability(vp_dev->pci_dev, 374 vp_dev->notify_map_cap, 2, 2, 375 off * vp_dev->notify_offset_multiplier, 2, 376 NULL); 377 } 378 379 if (!vq->priv) { 380 err = -ENOMEM; 381 goto err_map_notify; 382 } 383 384 if (msix_vec != VIRTIO_MSI_NO_VECTOR) { 385 vp_iowrite16(msix_vec, &cfg->queue_msix_vector); 386 msix_vec = vp_ioread16(&cfg->queue_msix_vector); 387 if (msix_vec == VIRTIO_MSI_NO_VECTOR) { 388 err = -EBUSY; 389 goto err_assign_vector; 390 } 391 } 392 393 return vq; 394 395 err_assign_vector: 396 if (!vp_dev->notify_base) 397 pci_iounmap(vp_dev->pci_dev, (void __iomem __force *)vq->priv); 398 err_map_notify: 399 vring_del_virtqueue(vq); 400 return ERR_PTR(err); 401 } 402 403 static int vp_modern_find_vqs(struct virtio_device *vdev, unsigned nvqs, 404 struct virtqueue *vqs[], 405 vq_callback_t *callbacks[], 406 const char * const names[], const bool *ctx, 407 struct irq_affinity *desc) 408 { 409 struct virtio_pci_device *vp_dev = to_vp_device(vdev); 410 struct virtqueue *vq; 411 int rc = vp_find_vqs(vdev, nvqs, vqs, callbacks, names, ctx, desc); 412 413 if (rc) 414 return rc; 415 416 /* Select and activate all queues. Has to be done last: once we do 417 * this, there's no way to go back except reset. 418 */ 419 list_for_each_entry(vq, &vdev->vqs, list) { 420 vp_iowrite16(vq->index, &vp_dev->common->queue_select); 421 vp_iowrite16(1, &vp_dev->common->queue_enable); 422 } 423 424 return 0; 425 } 426 427 static void del_vq(struct virtio_pci_vq_info *info) 428 { 429 struct virtqueue *vq = info->vq; 430 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev); 431 432 vp_iowrite16(vq->index, &vp_dev->common->queue_select); 433 434 if (vp_dev->msix_enabled) { 435 vp_iowrite16(VIRTIO_MSI_NO_VECTOR, 436 &vp_dev->common->queue_msix_vector); 437 /* Flush the write out to device */ 438 vp_ioread16(&vp_dev->common->queue_msix_vector); 439 } 440 441 if (!vp_dev->notify_base) 442 pci_iounmap(vp_dev->pci_dev, (void __force __iomem *)vq->priv); 443 444 vring_del_virtqueue(vq); 445 } 446 447 static int virtio_pci_find_shm_cap(struct pci_dev *dev, u8 required_id, 448 u8 *bar, u64 *offset, u64 *len) 449 { 450 int pos; 451 452 for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR); pos > 0; 453 pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) { 454 u8 type, cap_len, id; 455 u32 tmp32; 456 u64 res_offset, res_length; 457 458 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, 459 cfg_type), &type); 460 if (type != VIRTIO_PCI_CAP_SHARED_MEMORY_CFG) 461 continue; 462 463 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, 464 cap_len), &cap_len); 465 if (cap_len != sizeof(struct virtio_pci_cap64)) { 466 dev_err(&dev->dev, "%s: shm cap with bad size offset:" 467 " %d size: %d\n", __func__, pos, cap_len); 468 continue; 469 } 470 471 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, 472 id), &id); 473 if (id != required_id) 474 continue; 475 476 /* Type, and ID match, looks good */ 477 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, 478 bar), bar); 479 480 /* Read the lower 32bit of length and offset */ 481 pci_read_config_dword(dev, pos + offsetof(struct virtio_pci_cap, 482 offset), &tmp32); 483 res_offset = tmp32; 484 pci_read_config_dword(dev, pos + offsetof(struct virtio_pci_cap, 485 length), &tmp32); 486 res_length = tmp32; 487 488 /* and now the top half */ 489 pci_read_config_dword(dev, 490 pos + offsetof(struct virtio_pci_cap64, 491 offset_hi), &tmp32); 492 res_offset |= ((u64)tmp32) << 32; 493 pci_read_config_dword(dev, 494 pos + offsetof(struct virtio_pci_cap64, 495 length_hi), &tmp32); 496 res_length |= ((u64)tmp32) << 32; 497 498 *offset = res_offset; 499 *len = res_length; 500 501 return pos; 502 } 503 return 0; 504 } 505 506 static bool vp_get_shm_region(struct virtio_device *vdev, 507 struct virtio_shm_region *region, u8 id) 508 { 509 struct virtio_pci_device *vp_dev = to_vp_device(vdev); 510 struct pci_dev *pci_dev = vp_dev->pci_dev; 511 u8 bar; 512 u64 offset, len; 513 phys_addr_t phys_addr; 514 size_t bar_len; 515 516 if (!virtio_pci_find_shm_cap(pci_dev, id, &bar, &offset, &len)) 517 return false; 518 519 phys_addr = pci_resource_start(pci_dev, bar); 520 bar_len = pci_resource_len(pci_dev, bar); 521 522 if ((offset + len) < offset) { 523 dev_err(&pci_dev->dev, "%s: cap offset+len overflow detected\n", 524 __func__); 525 return false; 526 } 527 528 if (offset + len > bar_len) { 529 dev_err(&pci_dev->dev, "%s: bar shorter than cap offset+len\n", 530 __func__); 531 return false; 532 } 533 534 region->len = len; 535 region->addr = (u64) phys_addr + offset; 536 537 return true; 538 } 539 540 static const struct virtio_config_ops virtio_pci_config_nodev_ops = { 541 .get = NULL, 542 .set = NULL, 543 .generation = vp_generation, 544 .get_status = vp_get_status, 545 .set_status = vp_set_status, 546 .reset = vp_reset, 547 .find_vqs = vp_modern_find_vqs, 548 .del_vqs = vp_del_vqs, 549 .get_features = vp_get_features, 550 .finalize_features = vp_finalize_features, 551 .bus_name = vp_bus_name, 552 .set_vq_affinity = vp_set_vq_affinity, 553 .get_vq_affinity = vp_get_vq_affinity, 554 .get_shm_region = vp_get_shm_region, 555 }; 556 557 static const struct virtio_config_ops virtio_pci_config_ops = { 558 .get = vp_get, 559 .set = vp_set, 560 .generation = vp_generation, 561 .get_status = vp_get_status, 562 .set_status = vp_set_status, 563 .reset = vp_reset, 564 .find_vqs = vp_modern_find_vqs, 565 .del_vqs = vp_del_vqs, 566 .get_features = vp_get_features, 567 .finalize_features = vp_finalize_features, 568 .bus_name = vp_bus_name, 569 .set_vq_affinity = vp_set_vq_affinity, 570 .get_vq_affinity = vp_get_vq_affinity, 571 .get_shm_region = vp_get_shm_region, 572 }; 573 574 /** 575 * virtio_pci_find_capability - walk capabilities to find device info. 576 * @dev: the pci device 577 * @cfg_type: the VIRTIO_PCI_CAP_* value we seek 578 * @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO. 579 * @bars: the bitmask of BARs 580 * 581 * Returns offset of the capability, or 0. 582 */ 583 static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type, 584 u32 ioresource_types, int *bars) 585 { 586 int pos; 587 588 for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR); 589 pos > 0; 590 pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) { 591 u8 type, bar; 592 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, 593 cfg_type), 594 &type); 595 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, 596 bar), 597 &bar); 598 599 /* Ignore structures with reserved BAR values */ 600 if (bar > 0x5) 601 continue; 602 603 if (type == cfg_type) { 604 if (pci_resource_len(dev, bar) && 605 pci_resource_flags(dev, bar) & ioresource_types) { 606 *bars |= (1 << bar); 607 return pos; 608 } 609 } 610 } 611 return 0; 612 } 613 614 /* This is part of the ABI. Don't screw with it. */ 615 static inline void check_offsets(void) 616 { 617 /* Note: disk space was harmed in compilation of this function. */ 618 BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR != 619 offsetof(struct virtio_pci_cap, cap_vndr)); 620 BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT != 621 offsetof(struct virtio_pci_cap, cap_next)); 622 BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN != 623 offsetof(struct virtio_pci_cap, cap_len)); 624 BUILD_BUG_ON(VIRTIO_PCI_CAP_CFG_TYPE != 625 offsetof(struct virtio_pci_cap, cfg_type)); 626 BUILD_BUG_ON(VIRTIO_PCI_CAP_BAR != 627 offsetof(struct virtio_pci_cap, bar)); 628 BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET != 629 offsetof(struct virtio_pci_cap, offset)); 630 BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH != 631 offsetof(struct virtio_pci_cap, length)); 632 BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT != 633 offsetof(struct virtio_pci_notify_cap, 634 notify_off_multiplier)); 635 BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT != 636 offsetof(struct virtio_pci_common_cfg, 637 device_feature_select)); 638 BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF != 639 offsetof(struct virtio_pci_common_cfg, device_feature)); 640 BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT != 641 offsetof(struct virtio_pci_common_cfg, 642 guest_feature_select)); 643 BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF != 644 offsetof(struct virtio_pci_common_cfg, guest_feature)); 645 BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX != 646 offsetof(struct virtio_pci_common_cfg, msix_config)); 647 BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ != 648 offsetof(struct virtio_pci_common_cfg, num_queues)); 649 BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS != 650 offsetof(struct virtio_pci_common_cfg, device_status)); 651 BUILD_BUG_ON(VIRTIO_PCI_COMMON_CFGGENERATION != 652 offsetof(struct virtio_pci_common_cfg, config_generation)); 653 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT != 654 offsetof(struct virtio_pci_common_cfg, queue_select)); 655 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE != 656 offsetof(struct virtio_pci_common_cfg, queue_size)); 657 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX != 658 offsetof(struct virtio_pci_common_cfg, queue_msix_vector)); 659 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE != 660 offsetof(struct virtio_pci_common_cfg, queue_enable)); 661 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF != 662 offsetof(struct virtio_pci_common_cfg, queue_notify_off)); 663 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO != 664 offsetof(struct virtio_pci_common_cfg, queue_desc_lo)); 665 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI != 666 offsetof(struct virtio_pci_common_cfg, queue_desc_hi)); 667 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO != 668 offsetof(struct virtio_pci_common_cfg, queue_avail_lo)); 669 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI != 670 offsetof(struct virtio_pci_common_cfg, queue_avail_hi)); 671 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO != 672 offsetof(struct virtio_pci_common_cfg, queue_used_lo)); 673 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI != 674 offsetof(struct virtio_pci_common_cfg, queue_used_hi)); 675 } 676 677 /* the PCI probing function */ 678 int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev) 679 { 680 struct pci_dev *pci_dev = vp_dev->pci_dev; 681 int err, common, isr, notify, device; 682 u32 notify_length; 683 u32 notify_offset; 684 685 check_offsets(); 686 687 /* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */ 688 if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f) 689 return -ENODEV; 690 691 if (pci_dev->device < 0x1040) { 692 /* Transitional devices: use the PCI subsystem device id as 693 * virtio device id, same as legacy driver always did. 694 */ 695 vp_dev->vdev.id.device = pci_dev->subsystem_device; 696 } else { 697 /* Modern devices: simply use PCI device id, but start from 0x1040. */ 698 vp_dev->vdev.id.device = pci_dev->device - 0x1040; 699 } 700 vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor; 701 702 /* check for a common config: if not, use legacy mode (bar 0). */ 703 common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG, 704 IORESOURCE_IO | IORESOURCE_MEM, 705 &vp_dev->modern_bars); 706 if (!common) { 707 dev_info(&pci_dev->dev, 708 "virtio_pci: leaving for legacy driver\n"); 709 return -ENODEV; 710 } 711 712 /* If common is there, these should be too... */ 713 isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG, 714 IORESOURCE_IO | IORESOURCE_MEM, 715 &vp_dev->modern_bars); 716 notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG, 717 IORESOURCE_IO | IORESOURCE_MEM, 718 &vp_dev->modern_bars); 719 if (!isr || !notify) { 720 dev_err(&pci_dev->dev, 721 "virtio_pci: missing capabilities %i/%i/%i\n", 722 common, isr, notify); 723 return -EINVAL; 724 } 725 726 err = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(64)); 727 if (err) 728 err = dma_set_mask_and_coherent(&pci_dev->dev, 729 DMA_BIT_MASK(32)); 730 if (err) 731 dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n"); 732 733 /* Device capability is only mandatory for devices that have 734 * device-specific configuration. 735 */ 736 device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG, 737 IORESOURCE_IO | IORESOURCE_MEM, 738 &vp_dev->modern_bars); 739 740 err = pci_request_selected_regions(pci_dev, vp_dev->modern_bars, 741 "virtio-pci-modern"); 742 if (err) 743 return err; 744 745 err = -EINVAL; 746 vp_dev->common = map_capability(pci_dev, common, 747 sizeof(struct virtio_pci_common_cfg), 4, 748 0, sizeof(struct virtio_pci_common_cfg), 749 NULL); 750 if (!vp_dev->common) 751 goto err_map_common; 752 vp_dev->isr = map_capability(pci_dev, isr, sizeof(u8), 1, 753 0, 1, 754 NULL); 755 if (!vp_dev->isr) 756 goto err_map_isr; 757 758 /* Read notify_off_multiplier from config space. */ 759 pci_read_config_dword(pci_dev, 760 notify + offsetof(struct virtio_pci_notify_cap, 761 notify_off_multiplier), 762 &vp_dev->notify_offset_multiplier); 763 /* Read notify length and offset from config space. */ 764 pci_read_config_dword(pci_dev, 765 notify + offsetof(struct virtio_pci_notify_cap, 766 cap.length), 767 ¬ify_length); 768 769 pci_read_config_dword(pci_dev, 770 notify + offsetof(struct virtio_pci_notify_cap, 771 cap.offset), 772 ¬ify_offset); 773 774 /* We don't know how many VQs we'll map, ahead of the time. 775 * If notify length is small, map it all now. 776 * Otherwise, map each VQ individually later. 777 */ 778 if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) { 779 vp_dev->notify_base = map_capability(pci_dev, notify, 2, 2, 780 0, notify_length, 781 &vp_dev->notify_len); 782 if (!vp_dev->notify_base) 783 goto err_map_notify; 784 } else { 785 vp_dev->notify_map_cap = notify; 786 } 787 788 /* Again, we don't know how much we should map, but PAGE_SIZE 789 * is more than enough for all existing devices. 790 */ 791 if (device) { 792 vp_dev->device = map_capability(pci_dev, device, 0, 4, 793 0, PAGE_SIZE, 794 &vp_dev->device_len); 795 if (!vp_dev->device) 796 goto err_map_device; 797 798 vp_dev->vdev.config = &virtio_pci_config_ops; 799 } else { 800 vp_dev->vdev.config = &virtio_pci_config_nodev_ops; 801 } 802 803 vp_dev->config_vector = vp_config_vector; 804 vp_dev->setup_vq = setup_vq; 805 vp_dev->del_vq = del_vq; 806 807 return 0; 808 809 err_map_device: 810 if (vp_dev->notify_base) 811 pci_iounmap(pci_dev, vp_dev->notify_base); 812 err_map_notify: 813 pci_iounmap(pci_dev, vp_dev->isr); 814 err_map_isr: 815 pci_iounmap(pci_dev, vp_dev->common); 816 err_map_common: 817 return err; 818 } 819 820 void virtio_pci_modern_remove(struct virtio_pci_device *vp_dev) 821 { 822 struct pci_dev *pci_dev = vp_dev->pci_dev; 823 824 if (vp_dev->device) 825 pci_iounmap(pci_dev, vp_dev->device); 826 if (vp_dev->notify_base) 827 pci_iounmap(pci_dev, vp_dev->notify_base); 828 pci_iounmap(pci_dev, vp_dev->isr); 829 pci_iounmap(pci_dev, vp_dev->common); 830 pci_release_selected_regions(pci_dev, vp_dev->modern_bars); 831 } 832