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 * @pa: physical address of the capability 17 * 18 * Returns the io address of for the part of the capability 19 */ 20 static void __iomem * 21 vp_modern_map_capability(struct virtio_pci_modern_device *mdev, int off, 22 size_t minlen, u32 align, u32 start, u32 size, 23 size_t *len, resource_size_t *pa) 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 /* Check if the BAR may have changed since we requested the region. */ 39 if (bar >= PCI_STD_NUM_BARS || !(mdev->modern_bars & (1 << bar))) { 40 dev_err(&dev->dev, 41 "virtio_pci: bar unexpectedly changed to %u\n", bar); 42 return NULL; 43 } 44 45 if (length <= start) { 46 dev_err(&dev->dev, 47 "virtio_pci: bad capability len %u (>%u expected)\n", 48 length, start); 49 return NULL; 50 } 51 52 if (length - start < minlen) { 53 dev_err(&dev->dev, 54 "virtio_pci: bad capability len %u (>=%zu expected)\n", 55 length, minlen); 56 return NULL; 57 } 58 59 length -= start; 60 61 if (start + offset < offset) { 62 dev_err(&dev->dev, 63 "virtio_pci: map wrap-around %u+%u\n", 64 start, offset); 65 return NULL; 66 } 67 68 offset += start; 69 70 if (offset & (align - 1)) { 71 dev_err(&dev->dev, 72 "virtio_pci: offset %u not aligned to %u\n", 73 offset, align); 74 return NULL; 75 } 76 77 if (length > size) 78 length = size; 79 80 if (len) 81 *len = length; 82 83 if (minlen + offset < minlen || 84 minlen + offset > pci_resource_len(dev, bar)) { 85 dev_err(&dev->dev, 86 "virtio_pci: map virtio %zu@%u " 87 "out of range on bar %i length %lu\n", 88 minlen, offset, 89 bar, (unsigned long)pci_resource_len(dev, bar)); 90 return NULL; 91 } 92 93 p = pci_iomap_range(dev, bar, offset, length); 94 if (!p) 95 dev_err(&dev->dev, 96 "virtio_pci: unable to map virtio %u@%u on bar %i\n", 97 length, offset, bar); 98 else if (pa) 99 *pa = pci_resource_start(dev, bar) + offset; 100 101 return p; 102 } 103 104 /** 105 * virtio_pci_find_capability - walk capabilities to find device info. 106 * @dev: the pci device 107 * @cfg_type: the VIRTIO_PCI_CAP_* value we seek 108 * @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO. 109 * @bars: the bitmask of BARs 110 * 111 * Returns offset of the capability, or 0. 112 */ 113 static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type, 114 u32 ioresource_types, int *bars) 115 { 116 int pos; 117 118 for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR); 119 pos > 0; 120 pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) { 121 u8 type, bar; 122 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, 123 cfg_type), 124 &type); 125 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, 126 bar), 127 &bar); 128 129 /* Ignore structures with reserved BAR values */ 130 if (bar >= PCI_STD_NUM_BARS) 131 continue; 132 133 if (type == cfg_type) { 134 if (pci_resource_len(dev, bar) && 135 pci_resource_flags(dev, bar) & ioresource_types) { 136 *bars |= (1 << bar); 137 return pos; 138 } 139 } 140 } 141 return 0; 142 } 143 144 /* This is part of the ABI. Don't screw with it. */ 145 static inline void check_offsets(void) 146 { 147 /* Note: disk space was harmed in compilation of this function. */ 148 BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR != 149 offsetof(struct virtio_pci_cap, cap_vndr)); 150 BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT != 151 offsetof(struct virtio_pci_cap, cap_next)); 152 BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN != 153 offsetof(struct virtio_pci_cap, cap_len)); 154 BUILD_BUG_ON(VIRTIO_PCI_CAP_CFG_TYPE != 155 offsetof(struct virtio_pci_cap, cfg_type)); 156 BUILD_BUG_ON(VIRTIO_PCI_CAP_BAR != 157 offsetof(struct virtio_pci_cap, bar)); 158 BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET != 159 offsetof(struct virtio_pci_cap, offset)); 160 BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH != 161 offsetof(struct virtio_pci_cap, length)); 162 BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT != 163 offsetof(struct virtio_pci_notify_cap, 164 notify_off_multiplier)); 165 BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT != 166 offsetof(struct virtio_pci_common_cfg, 167 device_feature_select)); 168 BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF != 169 offsetof(struct virtio_pci_common_cfg, device_feature)); 170 BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT != 171 offsetof(struct virtio_pci_common_cfg, 172 guest_feature_select)); 173 BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF != 174 offsetof(struct virtio_pci_common_cfg, guest_feature)); 175 BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX != 176 offsetof(struct virtio_pci_common_cfg, msix_config)); 177 BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ != 178 offsetof(struct virtio_pci_common_cfg, num_queues)); 179 BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS != 180 offsetof(struct virtio_pci_common_cfg, device_status)); 181 BUILD_BUG_ON(VIRTIO_PCI_COMMON_CFGGENERATION != 182 offsetof(struct virtio_pci_common_cfg, config_generation)); 183 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT != 184 offsetof(struct virtio_pci_common_cfg, queue_select)); 185 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE != 186 offsetof(struct virtio_pci_common_cfg, queue_size)); 187 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX != 188 offsetof(struct virtio_pci_common_cfg, queue_msix_vector)); 189 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE != 190 offsetof(struct virtio_pci_common_cfg, queue_enable)); 191 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF != 192 offsetof(struct virtio_pci_common_cfg, queue_notify_off)); 193 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO != 194 offsetof(struct virtio_pci_common_cfg, queue_desc_lo)); 195 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI != 196 offsetof(struct virtio_pci_common_cfg, queue_desc_hi)); 197 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO != 198 offsetof(struct virtio_pci_common_cfg, queue_avail_lo)); 199 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI != 200 offsetof(struct virtio_pci_common_cfg, queue_avail_hi)); 201 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO != 202 offsetof(struct virtio_pci_common_cfg, queue_used_lo)); 203 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI != 204 offsetof(struct virtio_pci_common_cfg, queue_used_hi)); 205 } 206 207 /* 208 * vp_modern_probe: probe the modern virtio pci device, note that the 209 * caller is required to enable PCI device before calling this function. 210 * @mdev: the modern virtio-pci device 211 * 212 * Return 0 on succeed otherwise fail 213 */ 214 int vp_modern_probe(struct virtio_pci_modern_device *mdev) 215 { 216 struct pci_dev *pci_dev = mdev->pci_dev; 217 int err, common, isr, notify, device; 218 u32 notify_length; 219 u32 notify_offset; 220 221 check_offsets(); 222 223 mdev->pci_dev = pci_dev; 224 225 /* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */ 226 if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f) 227 return -ENODEV; 228 229 if (pci_dev->device < 0x1040) { 230 /* Transitional devices: use the PCI subsystem device id as 231 * virtio device id, same as legacy driver always did. 232 */ 233 mdev->id.device = pci_dev->subsystem_device; 234 } else { 235 /* Modern devices: simply use PCI device id, but start from 0x1040. */ 236 mdev->id.device = pci_dev->device - 0x1040; 237 } 238 mdev->id.vendor = pci_dev->subsystem_vendor; 239 240 /* check for a common config: if not, use legacy mode (bar 0). */ 241 common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG, 242 IORESOURCE_IO | IORESOURCE_MEM, 243 &mdev->modern_bars); 244 if (!common) { 245 dev_info(&pci_dev->dev, 246 "virtio_pci: leaving for legacy driver\n"); 247 return -ENODEV; 248 } 249 250 /* If common is there, these should be too... */ 251 isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG, 252 IORESOURCE_IO | IORESOURCE_MEM, 253 &mdev->modern_bars); 254 notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG, 255 IORESOURCE_IO | IORESOURCE_MEM, 256 &mdev->modern_bars); 257 if (!isr || !notify) { 258 dev_err(&pci_dev->dev, 259 "virtio_pci: missing capabilities %i/%i/%i\n", 260 common, isr, notify); 261 return -EINVAL; 262 } 263 264 err = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(64)); 265 if (err) 266 err = dma_set_mask_and_coherent(&pci_dev->dev, 267 DMA_BIT_MASK(32)); 268 if (err) 269 dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n"); 270 271 /* Device capability is only mandatory for devices that have 272 * device-specific configuration. 273 */ 274 device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG, 275 IORESOURCE_IO | IORESOURCE_MEM, 276 &mdev->modern_bars); 277 278 err = pci_request_selected_regions(pci_dev, mdev->modern_bars, 279 "virtio-pci-modern"); 280 if (err) 281 return err; 282 283 err = -EINVAL; 284 mdev->common = vp_modern_map_capability(mdev, common, 285 sizeof(struct virtio_pci_common_cfg), 4, 286 0, sizeof(struct virtio_pci_common_cfg), 287 NULL, NULL); 288 if (!mdev->common) 289 goto err_map_common; 290 mdev->isr = vp_modern_map_capability(mdev, isr, sizeof(u8), 1, 291 0, 1, 292 NULL, NULL); 293 if (!mdev->isr) 294 goto err_map_isr; 295 296 /* Read notify_off_multiplier from config space. */ 297 pci_read_config_dword(pci_dev, 298 notify + offsetof(struct virtio_pci_notify_cap, 299 notify_off_multiplier), 300 &mdev->notify_offset_multiplier); 301 /* Read notify length and offset from config space. */ 302 pci_read_config_dword(pci_dev, 303 notify + offsetof(struct virtio_pci_notify_cap, 304 cap.length), 305 ¬ify_length); 306 307 pci_read_config_dword(pci_dev, 308 notify + offsetof(struct virtio_pci_notify_cap, 309 cap.offset), 310 ¬ify_offset); 311 312 /* We don't know how many VQs we'll map, ahead of the time. 313 * If notify length is small, map it all now. 314 * Otherwise, map each VQ individually later. 315 */ 316 if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) { 317 mdev->notify_base = vp_modern_map_capability(mdev, notify, 318 2, 2, 319 0, notify_length, 320 &mdev->notify_len, 321 &mdev->notify_pa); 322 if (!mdev->notify_base) 323 goto err_map_notify; 324 } else { 325 mdev->notify_map_cap = notify; 326 } 327 328 /* Again, we don't know how much we should map, but PAGE_SIZE 329 * is more than enough for all existing devices. 330 */ 331 if (device) { 332 mdev->device = vp_modern_map_capability(mdev, device, 0, 4, 333 0, PAGE_SIZE, 334 &mdev->device_len, 335 NULL); 336 if (!mdev->device) 337 goto err_map_device; 338 } 339 340 return 0; 341 342 err_map_device: 343 if (mdev->notify_base) 344 pci_iounmap(pci_dev, mdev->notify_base); 345 err_map_notify: 346 pci_iounmap(pci_dev, mdev->isr); 347 err_map_isr: 348 pci_iounmap(pci_dev, mdev->common); 349 err_map_common: 350 pci_release_selected_regions(pci_dev, mdev->modern_bars); 351 return err; 352 } 353 EXPORT_SYMBOL_GPL(vp_modern_probe); 354 355 /* 356 * vp_modern_remove: remove and cleanup the modern virtio pci device 357 * @mdev: the modern virtio-pci device 358 */ 359 void vp_modern_remove(struct virtio_pci_modern_device *mdev) 360 { 361 struct pci_dev *pci_dev = mdev->pci_dev; 362 363 if (mdev->device) 364 pci_iounmap(pci_dev, mdev->device); 365 if (mdev->notify_base) 366 pci_iounmap(pci_dev, mdev->notify_base); 367 pci_iounmap(pci_dev, mdev->isr); 368 pci_iounmap(pci_dev, mdev->common); 369 pci_release_selected_regions(pci_dev, mdev->modern_bars); 370 } 371 EXPORT_SYMBOL_GPL(vp_modern_remove); 372 373 /* 374 * vp_modern_get_features - get features from device 375 * @mdev: the modern virtio-pci device 376 * 377 * Returns the features read from the device 378 */ 379 u64 vp_modern_get_features(struct virtio_pci_modern_device *mdev) 380 { 381 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 382 383 u64 features; 384 385 vp_iowrite32(0, &cfg->device_feature_select); 386 features = vp_ioread32(&cfg->device_feature); 387 vp_iowrite32(1, &cfg->device_feature_select); 388 features |= ((u64)vp_ioread32(&cfg->device_feature) << 32); 389 390 return features; 391 } 392 EXPORT_SYMBOL_GPL(vp_modern_get_features); 393 394 /* 395 * vp_modern_get_driver_features - get driver features from device 396 * @mdev: the modern virtio-pci device 397 * 398 * Returns the driver features read from the device 399 */ 400 u64 vp_modern_get_driver_features(struct virtio_pci_modern_device *mdev) 401 { 402 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 403 404 u64 features; 405 406 vp_iowrite32(0, &cfg->guest_feature_select); 407 features = vp_ioread32(&cfg->guest_feature); 408 vp_iowrite32(1, &cfg->guest_feature_select); 409 features |= ((u64)vp_ioread32(&cfg->guest_feature) << 32); 410 411 return features; 412 } 413 EXPORT_SYMBOL_GPL(vp_modern_get_driver_features); 414 415 /* 416 * vp_modern_set_features - set features to device 417 * @mdev: the modern virtio-pci device 418 * @features: the features set to device 419 */ 420 void vp_modern_set_features(struct virtio_pci_modern_device *mdev, 421 u64 features) 422 { 423 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 424 425 vp_iowrite32(0, &cfg->guest_feature_select); 426 vp_iowrite32((u32)features, &cfg->guest_feature); 427 vp_iowrite32(1, &cfg->guest_feature_select); 428 vp_iowrite32(features >> 32, &cfg->guest_feature); 429 } 430 EXPORT_SYMBOL_GPL(vp_modern_set_features); 431 432 /* 433 * vp_modern_generation - get the device genreation 434 * @mdev: the modern virtio-pci device 435 * 436 * Returns the genreation read from device 437 */ 438 u32 vp_modern_generation(struct virtio_pci_modern_device *mdev) 439 { 440 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 441 442 return vp_ioread8(&cfg->config_generation); 443 } 444 EXPORT_SYMBOL_GPL(vp_modern_generation); 445 446 /* 447 * vp_modern_get_status - get the device status 448 * @mdev: the modern virtio-pci device 449 * 450 * Returns the status read from device 451 */ 452 u8 vp_modern_get_status(struct virtio_pci_modern_device *mdev) 453 { 454 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 455 456 return vp_ioread8(&cfg->device_status); 457 } 458 EXPORT_SYMBOL_GPL(vp_modern_get_status); 459 460 /* 461 * vp_modern_set_status - set status to device 462 * @mdev: the modern virtio-pci device 463 * @status: the status set to device 464 */ 465 void vp_modern_set_status(struct virtio_pci_modern_device *mdev, 466 u8 status) 467 { 468 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 469 470 /* 471 * Per memory-barriers.txt, wmb() is not needed to guarantee 472 * that the the cache coherent memory writes have completed 473 * before writing to the MMIO region. 474 */ 475 vp_iowrite8(status, &cfg->device_status); 476 } 477 EXPORT_SYMBOL_GPL(vp_modern_set_status); 478 479 /* 480 * vp_modern_queue_vector - set the MSIX vector for a specific virtqueue 481 * @mdev: the modern virtio-pci device 482 * @index: queue index 483 * @vector: the config vector 484 * 485 * Returns the config vector read from the device 486 */ 487 u16 vp_modern_queue_vector(struct virtio_pci_modern_device *mdev, 488 u16 index, u16 vector) 489 { 490 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 491 492 vp_iowrite16(index, &cfg->queue_select); 493 vp_iowrite16(vector, &cfg->queue_msix_vector); 494 /* Flush the write out to device */ 495 return vp_ioread16(&cfg->queue_msix_vector); 496 } 497 EXPORT_SYMBOL_GPL(vp_modern_queue_vector); 498 499 /* 500 * vp_modern_config_vector - set the vector for config interrupt 501 * @mdev: the modern virtio-pci device 502 * @vector: the config vector 503 * 504 * Returns the config vector read from the device 505 */ 506 u16 vp_modern_config_vector(struct virtio_pci_modern_device *mdev, 507 u16 vector) 508 { 509 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 510 511 /* Setup the vector used for configuration events */ 512 vp_iowrite16(vector, &cfg->msix_config); 513 /* Verify we had enough resources to assign the vector */ 514 /* Will also flush the write out to device */ 515 return vp_ioread16(&cfg->msix_config); 516 } 517 EXPORT_SYMBOL_GPL(vp_modern_config_vector); 518 519 /* 520 * vp_modern_queue_address - set the virtqueue address 521 * @mdev: the modern virtio-pci device 522 * @index: the queue index 523 * @desc_addr: address of the descriptor area 524 * @driver_addr: address of the driver area 525 * @device_addr: address of the device area 526 */ 527 void vp_modern_queue_address(struct virtio_pci_modern_device *mdev, 528 u16 index, u64 desc_addr, u64 driver_addr, 529 u64 device_addr) 530 { 531 struct virtio_pci_common_cfg __iomem *cfg = mdev->common; 532 533 vp_iowrite16(index, &cfg->queue_select); 534 535 vp_iowrite64_twopart(desc_addr, &cfg->queue_desc_lo, 536 &cfg->queue_desc_hi); 537 vp_iowrite64_twopart(driver_addr, &cfg->queue_avail_lo, 538 &cfg->queue_avail_hi); 539 vp_iowrite64_twopart(device_addr, &cfg->queue_used_lo, 540 &cfg->queue_used_hi); 541 } 542 EXPORT_SYMBOL_GPL(vp_modern_queue_address); 543 544 /* 545 * vp_modern_set_queue_enable - enable a virtqueue 546 * @mdev: the modern virtio-pci device 547 * @index: the queue index 548 * @enable: whether the virtqueue is enable or not 549 */ 550 void vp_modern_set_queue_enable(struct virtio_pci_modern_device *mdev, 551 u16 index, bool enable) 552 { 553 vp_iowrite16(index, &mdev->common->queue_select); 554 vp_iowrite16(enable, &mdev->common->queue_enable); 555 } 556 EXPORT_SYMBOL_GPL(vp_modern_set_queue_enable); 557 558 /* 559 * vp_modern_get_queue_enable - enable a virtqueue 560 * @mdev: the modern virtio-pci device 561 * @index: the queue index 562 * 563 * Returns whether a virtqueue is enabled or not 564 */ 565 bool vp_modern_get_queue_enable(struct virtio_pci_modern_device *mdev, 566 u16 index) 567 { 568 vp_iowrite16(index, &mdev->common->queue_select); 569 570 return vp_ioread16(&mdev->common->queue_enable); 571 } 572 EXPORT_SYMBOL_GPL(vp_modern_get_queue_enable); 573 574 /* 575 * vp_modern_set_queue_size - set size for a virtqueue 576 * @mdev: the modern virtio-pci device 577 * @index: the queue index 578 * @size: the size of the virtqueue 579 */ 580 void vp_modern_set_queue_size(struct virtio_pci_modern_device *mdev, 581 u16 index, u16 size) 582 { 583 vp_iowrite16(index, &mdev->common->queue_select); 584 vp_iowrite16(size, &mdev->common->queue_size); 585 586 } 587 EXPORT_SYMBOL_GPL(vp_modern_set_queue_size); 588 589 /* 590 * vp_modern_get_queue_size - get size for a virtqueue 591 * @mdev: the modern virtio-pci device 592 * @index: the queue index 593 * 594 * Returns the size of the virtqueue 595 */ 596 u16 vp_modern_get_queue_size(struct virtio_pci_modern_device *mdev, 597 u16 index) 598 { 599 vp_iowrite16(index, &mdev->common->queue_select); 600 601 return vp_ioread16(&mdev->common->queue_size); 602 603 } 604 EXPORT_SYMBOL_GPL(vp_modern_get_queue_size); 605 606 /* 607 * vp_modern_get_num_queues - get the number of virtqueues 608 * @mdev: the modern virtio-pci device 609 * 610 * Returns the number of virtqueues 611 */ 612 u16 vp_modern_get_num_queues(struct virtio_pci_modern_device *mdev) 613 { 614 return vp_ioread16(&mdev->common->num_queues); 615 } 616 EXPORT_SYMBOL_GPL(vp_modern_get_num_queues); 617 618 /* 619 * vp_modern_get_queue_notify_off - get notification offset for a virtqueue 620 * @mdev: the modern virtio-pci device 621 * @index: the queue index 622 * 623 * Returns the notification offset for a virtqueue 624 */ 625 static u16 vp_modern_get_queue_notify_off(struct virtio_pci_modern_device *mdev, 626 u16 index) 627 { 628 vp_iowrite16(index, &mdev->common->queue_select); 629 630 return vp_ioread16(&mdev->common->queue_notify_off); 631 } 632 633 /* 634 * vp_modern_map_vq_notify - map notification area for a 635 * specific virtqueue 636 * @mdev: the modern virtio-pci device 637 * @index: the queue index 638 * @pa: the pointer to the physical address of the nofity area 639 * 640 * Returns the address of the notification area 641 */ 642 void __iomem *vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev, 643 u16 index, resource_size_t *pa) 644 { 645 u16 off = vp_modern_get_queue_notify_off(mdev, index); 646 647 if (mdev->notify_base) { 648 /* offset should not wrap */ 649 if ((u64)off * mdev->notify_offset_multiplier + 2 650 > mdev->notify_len) { 651 dev_warn(&mdev->pci_dev->dev, 652 "bad notification offset %u (x %u) " 653 "for queue %u > %zd", 654 off, mdev->notify_offset_multiplier, 655 index, mdev->notify_len); 656 return NULL; 657 } 658 if (pa) 659 *pa = mdev->notify_pa + 660 off * mdev->notify_offset_multiplier; 661 return mdev->notify_base + off * mdev->notify_offset_multiplier; 662 } else { 663 return vp_modern_map_capability(mdev, 664 mdev->notify_map_cap, 2, 2, 665 off * mdev->notify_offset_multiplier, 2, 666 NULL, pa); 667 } 668 } 669 EXPORT_SYMBOL_GPL(vp_modern_map_vq_notify); 670 671 MODULE_VERSION("0.1"); 672 MODULE_DESCRIPTION("Modern Virtio PCI Device"); 673 MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>"); 674 MODULE_LICENSE("GPL"); 675