1 // SPDX-License-Identifier: GPL-2.0-or-later 2 3 #include <linux/virtio_pci_modern.h> 4 #include <linux/module.h> 5 #include <linux/pci.h> 6 7 /* 8 * vp_modern_map_capability - map a part of virtio pci capability 9 * @mdev: the modern virtio-pci device 10 * @off: offset of the capability 11 * @minlen: minimal length of the capability 12 * @align: align requirement 13 * @start: start from the capability 14 * @size: map size 15 * @len: the length that is actually mapped 16 * 17 * Returns the io address of for the part of the capability 18 */ 19 void __iomem *vp_modern_map_capability(struct virtio_pci_modern_device *mdev, int off, 20 size_t minlen, 21 u32 align, 22 u32 start, u32 size, 23 size_t *len) 24 { 25 struct pci_dev *dev = mdev->pci_dev; 26 u8 bar; 27 u32 offset, length; 28 void __iomem *p; 29 30 pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap, 31 bar), 32 &bar); 33 pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset), 34 &offset); 35 pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length), 36 &length); 37 38 if (length <= start) { 39 dev_err(&dev->dev, 40 "virtio_pci: bad capability len %u (>%u expected)\n", 41 length, start); 42 return NULL; 43 } 44 45 if (length - start < minlen) { 46 dev_err(&dev->dev, 47 "virtio_pci: bad capability len %u (>=%zu expected)\n", 48 length, minlen); 49 return NULL; 50 } 51 52 length -= start; 53 54 if (start + offset < offset) { 55 dev_err(&dev->dev, 56 "virtio_pci: map wrap-around %u+%u\n", 57 start, offset); 58 return NULL; 59 } 60 61 offset += start; 62 63 if (offset & (align - 1)) { 64 dev_err(&dev->dev, 65 "virtio_pci: offset %u not aligned to %u\n", 66 offset, align); 67 return NULL; 68 } 69 70 if (length > size) 71 length = size; 72 73 if (len) 74 *len = length; 75 76 if (minlen + offset < minlen || 77 minlen + offset > pci_resource_len(dev, bar)) { 78 dev_err(&dev->dev, 79 "virtio_pci: map virtio %zu@%u " 80 "out of range on bar %i length %lu\n", 81 minlen, offset, 82 bar, (unsigned long)pci_resource_len(dev, bar)); 83 return NULL; 84 } 85 86 p = pci_iomap_range(dev, bar, offset, length); 87 if (!p) 88 dev_err(&dev->dev, 89 "virtio_pci: unable to map virtio %u@%u on bar %i\n", 90 length, offset, bar); 91 return p; 92 } 93 EXPORT_SYMBOL_GPL(vp_modern_map_capability); 94 95 /** 96 * virtio_pci_find_capability - walk capabilities to find device info. 97 * @dev: the pci device 98 * @cfg_type: the VIRTIO_PCI_CAP_* value we seek 99 * @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO. 100 * @bars: the bitmask of BARs 101 * 102 * Returns offset of the capability, or 0. 103 */ 104 static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type, 105 u32 ioresource_types, int *bars) 106 { 107 int pos; 108 109 for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR); 110 pos > 0; 111 pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) { 112 u8 type, bar; 113 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, 114 cfg_type), 115 &type); 116 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, 117 bar), 118 &bar); 119 120 /* Ignore structures with reserved BAR values */ 121 if (bar > 0x5) 122 continue; 123 124 if (type == cfg_type) { 125 if (pci_resource_len(dev, bar) && 126 pci_resource_flags(dev, bar) & ioresource_types) { 127 *bars |= (1 << bar); 128 return pos; 129 } 130 } 131 } 132 return 0; 133 } 134 135 /* This is part of the ABI. Don't screw with it. */ 136 static inline void check_offsets(void) 137 { 138 /* Note: disk space was harmed in compilation of this function. */ 139 BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR != 140 offsetof(struct virtio_pci_cap, cap_vndr)); 141 BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT != 142 offsetof(struct virtio_pci_cap, cap_next)); 143 BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN != 144 offsetof(struct virtio_pci_cap, cap_len)); 145 BUILD_BUG_ON(VIRTIO_PCI_CAP_CFG_TYPE != 146 offsetof(struct virtio_pci_cap, cfg_type)); 147 BUILD_BUG_ON(VIRTIO_PCI_CAP_BAR != 148 offsetof(struct virtio_pci_cap, bar)); 149 BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET != 150 offsetof(struct virtio_pci_cap, offset)); 151 BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH != 152 offsetof(struct virtio_pci_cap, length)); 153 BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT != 154 offsetof(struct virtio_pci_notify_cap, 155 notify_off_multiplier)); 156 BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT != 157 offsetof(struct virtio_pci_common_cfg, 158 device_feature_select)); 159 BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF != 160 offsetof(struct virtio_pci_common_cfg, device_feature)); 161 BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT != 162 offsetof(struct virtio_pci_common_cfg, 163 guest_feature_select)); 164 BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF != 165 offsetof(struct virtio_pci_common_cfg, guest_feature)); 166 BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX != 167 offsetof(struct virtio_pci_common_cfg, msix_config)); 168 BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ != 169 offsetof(struct virtio_pci_common_cfg, num_queues)); 170 BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS != 171 offsetof(struct virtio_pci_common_cfg, device_status)); 172 BUILD_BUG_ON(VIRTIO_PCI_COMMON_CFGGENERATION != 173 offsetof(struct virtio_pci_common_cfg, config_generation)); 174 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT != 175 offsetof(struct virtio_pci_common_cfg, queue_select)); 176 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE != 177 offsetof(struct virtio_pci_common_cfg, queue_size)); 178 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX != 179 offsetof(struct virtio_pci_common_cfg, queue_msix_vector)); 180 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE != 181 offsetof(struct virtio_pci_common_cfg, queue_enable)); 182 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF != 183 offsetof(struct virtio_pci_common_cfg, queue_notify_off)); 184 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO != 185 offsetof(struct virtio_pci_common_cfg, queue_desc_lo)); 186 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI != 187 offsetof(struct virtio_pci_common_cfg, queue_desc_hi)); 188 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO != 189 offsetof(struct virtio_pci_common_cfg, queue_avail_lo)); 190 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI != 191 offsetof(struct virtio_pci_common_cfg, queue_avail_hi)); 192 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO != 193 offsetof(struct virtio_pci_common_cfg, queue_used_lo)); 194 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI != 195 offsetof(struct virtio_pci_common_cfg, queue_used_hi)); 196 } 197 198 /* 199 * vp_modern_probe: probe the modern virtio pci device, note that the 200 * caller is required to enable PCI device before calling this function. 201 * @mdev: the modern virtio-pci device 202 * 203 * Return 0 on succeed otherwise fail 204 */ 205 int vp_modern_probe(struct virtio_pci_modern_device *mdev) 206 { 207 struct pci_dev *pci_dev = mdev->pci_dev; 208 int err, common, isr, notify, device; 209 u32 notify_length; 210 u32 notify_offset; 211 212 check_offsets(); 213 214 mdev->pci_dev = pci_dev; 215 216 /* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */ 217 if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f) 218 return -ENODEV; 219 220 if (pci_dev->device < 0x1040) { 221 /* Transitional devices: use the PCI subsystem device id as 222 * virtio device id, same as legacy driver always did. 223 */ 224 mdev->id.device = pci_dev->subsystem_device; 225 } else { 226 /* Modern devices: simply use PCI device id, but start from 0x1040. */ 227 mdev->id.device = pci_dev->device - 0x1040; 228 } 229 mdev->id.vendor = pci_dev->subsystem_vendor; 230 231 /* check for a common config: if not, use legacy mode (bar 0). */ 232 common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG, 233 IORESOURCE_IO | IORESOURCE_MEM, 234 &mdev->modern_bars); 235 if (!common) { 236 dev_info(&pci_dev->dev, 237 "virtio_pci: leaving for legacy driver\n"); 238 return -ENODEV; 239 } 240 241 /* If common is there, these should be too... */ 242 isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG, 243 IORESOURCE_IO | IORESOURCE_MEM, 244 &mdev->modern_bars); 245 notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG, 246 IORESOURCE_IO | IORESOURCE_MEM, 247 &mdev->modern_bars); 248 if (!isr || !notify) { 249 dev_err(&pci_dev->dev, 250 "virtio_pci: missing capabilities %i/%i/%i\n", 251 common, isr, notify); 252 return -EINVAL; 253 } 254 255 err = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(64)); 256 if (err) 257 err = dma_set_mask_and_coherent(&pci_dev->dev, 258 DMA_BIT_MASK(32)); 259 if (err) 260 dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n"); 261 262 /* Device capability is only mandatory for devices that have 263 * device-specific configuration. 264 */ 265 device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG, 266 IORESOURCE_IO | IORESOURCE_MEM, 267 &mdev->modern_bars); 268 269 err = pci_request_selected_regions(pci_dev, mdev->modern_bars, 270 "virtio-pci-modern"); 271 if (err) 272 return err; 273 274 err = -EINVAL; 275 mdev->common = vp_modern_map_capability(mdev, common, 276 sizeof(struct virtio_pci_common_cfg), 4, 277 0, sizeof(struct virtio_pci_common_cfg), 278 NULL); 279 if (!mdev->common) 280 goto err_map_common; 281 mdev->isr = vp_modern_map_capability(mdev, isr, sizeof(u8), 1, 282 0, 1, 283 NULL); 284 if (!mdev->isr) 285 goto err_map_isr; 286 287 /* Read notify_off_multiplier from config space. */ 288 pci_read_config_dword(pci_dev, 289 notify + offsetof(struct virtio_pci_notify_cap, 290 notify_off_multiplier), 291 &mdev->notify_offset_multiplier); 292 /* Read notify length and offset from config space. */ 293 pci_read_config_dword(pci_dev, 294 notify + offsetof(struct virtio_pci_notify_cap, 295 cap.length), 296 ¬ify_length); 297 298 pci_read_config_dword(pci_dev, 299 notify + offsetof(struct virtio_pci_notify_cap, 300 cap.offset), 301 ¬ify_offset); 302 303 /* We don't know how many VQs we'll map, ahead of the time. 304 * If notify length is small, map it all now. 305 * Otherwise, map each VQ individually later. 306 */ 307 if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) { 308 mdev->notify_base = vp_modern_map_capability(mdev, notify, 309 2, 2, 310 0, notify_length, 311 &mdev->notify_len); 312 if (!mdev->notify_base) 313 goto err_map_notify; 314 } else { 315 mdev->notify_map_cap = notify; 316 } 317 318 /* Again, we don't know how much we should map, but PAGE_SIZE 319 * is more than enough for all existing devices. 320 */ 321 if (device) { 322 mdev->device = vp_modern_map_capability(mdev, device, 0, 4, 323 0, PAGE_SIZE, 324 &mdev->device_len); 325 if (!mdev->device) 326 goto err_map_device; 327 } 328 329 return 0; 330 331 err_map_device: 332 if (mdev->notify_base) 333 pci_iounmap(pci_dev, mdev->notify_base); 334 err_map_notify: 335 pci_iounmap(pci_dev, mdev->isr); 336 err_map_isr: 337 pci_iounmap(pci_dev, mdev->common); 338 err_map_common: 339 return err; 340 } 341 EXPORT_SYMBOL_GPL(vp_modern_probe); 342 343 /* 344 * vp_modern_probe: remove and cleanup the modern virtio pci device 345 * @mdev: the modern virtio-pci device 346 */ 347 void vp_modern_remove(struct virtio_pci_modern_device *mdev) 348 { 349 struct pci_dev *pci_dev = mdev->pci_dev; 350 351 if (mdev->device) 352 pci_iounmap(pci_dev, mdev->device); 353 if (mdev->notify_base) 354 pci_iounmap(pci_dev, mdev->notify_base); 355 pci_iounmap(pci_dev, mdev->isr); 356 pci_iounmap(pci_dev, mdev->common); 357 pci_release_selected_regions(pci_dev, mdev->modern_bars); 358 } 359 EXPORT_SYMBOL_GPL(vp_modern_remove); 360 361 /* 362 * vp_modern_get_features - get features from device 363 * @mdev: the modern virtio-pci device 364 * 365 * Returns the features read from the device 366 */ 367 u64 vp_modern_get_features(struct virtio_pci_modern_device *mdev) 368 { 369 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 370 371 u64 features; 372 373 vp_iowrite32(0, &cfg->device_feature_select); 374 features = vp_ioread32(&cfg->device_feature); 375 vp_iowrite32(1, &cfg->device_feature_select); 376 features |= ((u64)vp_ioread32(&cfg->device_feature) << 32); 377 378 return features; 379 } 380 EXPORT_SYMBOL_GPL(vp_modern_get_features); 381 382 /* 383 * vp_modern_set_features - set features to device 384 * @mdev: the modern virtio-pci device 385 * @features: the features set to device 386 */ 387 void vp_modern_set_features(struct virtio_pci_modern_device *mdev, 388 u64 features) 389 { 390 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 391 392 vp_iowrite32(0, &cfg->guest_feature_select); 393 vp_iowrite32((u32)features, &cfg->guest_feature); 394 vp_iowrite32(1, &cfg->guest_feature_select); 395 vp_iowrite32(features >> 32, &cfg->guest_feature); 396 } 397 EXPORT_SYMBOL_GPL(vp_modern_set_features); 398 399 /* 400 * vp_modern_generation - get the device genreation 401 * @mdev: the modern virtio-pci device 402 * 403 * Returns the genreation read from device 404 */ 405 u32 vp_modern_generation(struct virtio_pci_modern_device *mdev) 406 { 407 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 408 409 return vp_ioread8(&cfg->config_generation); 410 } 411 EXPORT_SYMBOL_GPL(vp_modern_generation); 412 413 /* 414 * vp_modern_get_status - get the device status 415 * @mdev: the modern virtio-pci device 416 * 417 * Returns the status read from device 418 */ 419 u8 vp_modern_get_status(struct virtio_pci_modern_device *mdev) 420 { 421 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 422 423 return vp_ioread8(&cfg->device_status); 424 } 425 EXPORT_SYMBOL_GPL(vp_modern_get_status); 426 427 /* 428 * vp_modern_set_status - set status to device 429 * @mdev: the modern virtio-pci device 430 * @status: the status set to device 431 */ 432 void vp_modern_set_status(struct virtio_pci_modern_device *mdev, 433 u8 status) 434 { 435 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 436 437 vp_iowrite8(status, &cfg->device_status); 438 } 439 EXPORT_SYMBOL_GPL(vp_modern_set_status); 440 441 /* 442 * vp_modern_queue_vector - set the MSIX vector for a specific virtqueue 443 * @mdev: the modern virtio-pci device 444 * @index: queue index 445 * @vector: the config vector 446 * 447 * Returns the config vector read from the device 448 */ 449 u16 vp_modern_queue_vector(struct virtio_pci_modern_device *mdev, 450 u16 index, u16 vector) 451 { 452 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 453 454 vp_iowrite16(index, &cfg->queue_select); 455 vp_iowrite16(vector, &cfg->queue_msix_vector); 456 /* Flush the write out to device */ 457 return vp_ioread16(&cfg->queue_msix_vector); 458 } 459 EXPORT_SYMBOL_GPL(vp_modern_queue_vector); 460 461 /* 462 * vp_modern_config_vector - set the vector for config interrupt 463 * @mdev: the modern virtio-pci device 464 * @vector: the config vector 465 * 466 * Returns the config vector read from the device 467 */ 468 u16 vp_modern_config_vector(struct virtio_pci_modern_device *mdev, 469 u16 vector) 470 { 471 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 472 473 /* Setup the vector used for configuration events */ 474 vp_iowrite16(vector, &cfg->msix_config); 475 /* Verify we had enough resources to assign the vector */ 476 /* Will also flush the write out to device */ 477 return vp_ioread16(&cfg->msix_config); 478 } 479 EXPORT_SYMBOL_GPL(vp_modern_config_vector); 480 481 /* 482 * vp_modern_queue_address - set the virtqueue address 483 * @mdev: the modern virtio-pci device 484 * @index: the queue index 485 * @desc_addr: address of the descriptor area 486 * @driver_addr: address of the driver area 487 * @device_addr: address of the device area 488 */ 489 void vp_modern_queue_address(struct virtio_pci_modern_device *mdev, 490 u16 index, u64 desc_addr, u64 driver_addr, 491 u64 device_addr) 492 { 493 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 494 495 vp_iowrite16(index, &cfg->queue_select); 496 497 vp_iowrite64_twopart(desc_addr, &cfg->queue_desc_lo, 498 &cfg->queue_desc_hi); 499 vp_iowrite64_twopart(driver_addr, &cfg->queue_avail_lo, 500 &cfg->queue_avail_hi); 501 vp_iowrite64_twopart(device_addr, &cfg->queue_used_lo, 502 &cfg->queue_used_hi); 503 } 504 EXPORT_SYMBOL_GPL(vp_modern_queue_address); 505 506 /* 507 * vp_modern_set_queue_enable - enable a virtqueue 508 * @mdev: the modern virtio-pci device 509 * @index: the queue index 510 * @enable: whether the virtqueue is enable or not 511 */ 512 void vp_modern_set_queue_enable(struct virtio_pci_modern_device *mdev, 513 u16 index, bool enable) 514 { 515 vp_iowrite16(index, &mdev->common->queue_select); 516 vp_iowrite16(enable, &mdev->common->queue_enable); 517 } 518 EXPORT_SYMBOL_GPL(vp_modern_set_queue_enable); 519 520 /* 521 * vp_modern_get_queue_enable - enable a virtqueue 522 * @mdev: the modern virtio-pci device 523 * @index: the queue index 524 * 525 * Returns whether a virtqueue is enabled or not 526 */ 527 bool vp_modern_get_queue_enable(struct virtio_pci_modern_device *mdev, 528 u16 index) 529 { 530 vp_iowrite16(index, &mdev->common->queue_select); 531 532 return vp_ioread16(&mdev->common->queue_enable); 533 } 534 EXPORT_SYMBOL_GPL(vp_modern_get_queue_enable); 535 536 /* 537 * vp_modern_set_queue_size - set size for a virtqueue 538 * @mdev: the modern virtio-pci device 539 * @index: the queue index 540 * @size: the size of the virtqueue 541 */ 542 void vp_modern_set_queue_size(struct virtio_pci_modern_device *mdev, 543 u16 index, u16 size) 544 { 545 vp_iowrite16(index, &mdev->common->queue_select); 546 vp_iowrite16(size, &mdev->common->queue_size); 547 548 } 549 EXPORT_SYMBOL_GPL(vp_modern_set_queue_size); 550 551 /* 552 * vp_modern_get_queue_size - get size for a virtqueue 553 * @mdev: the modern virtio-pci device 554 * @index: the queue index 555 * 556 * Returns the size of the virtqueue 557 */ 558 u16 vp_modern_get_queue_size(struct virtio_pci_modern_device *mdev, 559 u16 index) 560 { 561 vp_iowrite16(index, &mdev->common->queue_select); 562 563 return vp_ioread16(&mdev->common->queue_size); 564 565 } 566 EXPORT_SYMBOL_GPL(vp_modern_get_queue_size); 567 568 /* 569 * vp_modern_get_num_queues - get the number of virtqueues 570 * @mdev: the modern virtio-pci device 571 * 572 * Returns the number of virtqueues 573 */ 574 u16 vp_modern_get_num_queues(struct virtio_pci_modern_device *mdev) 575 { 576 return vp_ioread16(&mdev->common->num_queues); 577 } 578 EXPORT_SYMBOL_GPL(vp_modern_get_num_queues); 579 580 /* 581 * vp_modern_get_queue_notify_off - get notification offset for a virtqueue 582 * @mdev: the modern virtio-pci device 583 * @index: the queue index 584 * 585 * Returns the notification offset for a virtqueue 586 */ 587 u16 vp_modern_get_queue_notify_off(struct virtio_pci_modern_device *mdev, 588 u16 index) 589 { 590 vp_iowrite16(index, &mdev->common->queue_select); 591 592 return vp_ioread16(&mdev->common->queue_notify_off); 593 } 594 EXPORT_SYMBOL_GPL(vp_modern_get_queue_notify_off); 595 596 MODULE_VERSION("0.1"); 597 MODULE_DESCRIPTION("Modern Virtio PCI Device"); 598 MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>"); 599 MODULE_LICENSE("GPL"); 600