1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2013 - Virtual Open Systems 4 * Author: Antonios Motakis <a.motakis@virtualopensystems.com> 5 */ 6 7 #define dev_fmt(fmt) "VFIO: " fmt 8 9 #include <linux/device.h> 10 #include <linux/acpi.h> 11 #include <linux/iommu.h> 12 #include <linux/module.h> 13 #include <linux/mutex.h> 14 #include <linux/pm_runtime.h> 15 #include <linux/slab.h> 16 #include <linux/types.h> 17 #include <linux/uaccess.h> 18 #include <linux/vfio.h> 19 20 #include "vfio_platform_private.h" 21 22 #define DRIVER_VERSION "0.10" 23 #define DRIVER_AUTHOR "Antonios Motakis <a.motakis@virtualopensystems.com>" 24 #define DRIVER_DESC "VFIO platform base module" 25 26 #define VFIO_PLATFORM_IS_ACPI(vdev) ((vdev)->acpihid != NULL) 27 28 static LIST_HEAD(reset_list); 29 static DEFINE_MUTEX(driver_lock); 30 31 static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat, 32 struct module **module) 33 { 34 struct vfio_platform_reset_node *iter; 35 vfio_platform_reset_fn_t reset_fn = NULL; 36 37 mutex_lock(&driver_lock); 38 list_for_each_entry(iter, &reset_list, link) { 39 if (!strcmp(iter->compat, compat) && 40 try_module_get(iter->owner)) { 41 *module = iter->owner; 42 reset_fn = iter->of_reset; 43 break; 44 } 45 } 46 mutex_unlock(&driver_lock); 47 return reset_fn; 48 } 49 50 static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev, 51 struct device *dev) 52 { 53 struct acpi_device *adev; 54 55 if (acpi_disabled) 56 return -ENOENT; 57 58 adev = ACPI_COMPANION(dev); 59 if (!adev) { 60 dev_err(dev, "ACPI companion device not found for %s\n", 61 vdev->name); 62 return -ENODEV; 63 } 64 65 #ifdef CONFIG_ACPI 66 vdev->acpihid = acpi_device_hid(adev); 67 #endif 68 return WARN_ON(!vdev->acpihid) ? -EINVAL : 0; 69 } 70 71 static int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev, 72 const char **extra_dbg) 73 { 74 #ifdef CONFIG_ACPI 75 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 76 struct device *dev = vdev->device; 77 acpi_handle handle = ACPI_HANDLE(dev); 78 acpi_status acpi_ret; 79 80 acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, &buffer); 81 if (ACPI_FAILURE(acpi_ret)) { 82 if (extra_dbg) 83 *extra_dbg = acpi_format_exception(acpi_ret); 84 return -EINVAL; 85 } 86 87 return 0; 88 #else 89 return -ENOENT; 90 #endif 91 } 92 93 static bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev) 94 { 95 #ifdef CONFIG_ACPI 96 struct device *dev = vdev->device; 97 acpi_handle handle = ACPI_HANDLE(dev); 98 99 return acpi_has_method(handle, "_RST"); 100 #else 101 return false; 102 #endif 103 } 104 105 static bool vfio_platform_has_reset(struct vfio_platform_device *vdev) 106 { 107 if (VFIO_PLATFORM_IS_ACPI(vdev)) 108 return vfio_platform_acpi_has_reset(vdev); 109 110 return vdev->of_reset ? true : false; 111 } 112 113 static int vfio_platform_get_reset(struct vfio_platform_device *vdev) 114 { 115 if (VFIO_PLATFORM_IS_ACPI(vdev)) 116 return vfio_platform_acpi_has_reset(vdev) ? 0 : -ENOENT; 117 118 vdev->of_reset = vfio_platform_lookup_reset(vdev->compat, 119 &vdev->reset_module); 120 if (!vdev->of_reset) { 121 request_module("vfio-reset:%s", vdev->compat); 122 vdev->of_reset = vfio_platform_lookup_reset(vdev->compat, 123 &vdev->reset_module); 124 } 125 126 return vdev->of_reset ? 0 : -ENOENT; 127 } 128 129 static void vfio_platform_put_reset(struct vfio_platform_device *vdev) 130 { 131 if (VFIO_PLATFORM_IS_ACPI(vdev)) 132 return; 133 134 if (vdev->of_reset) 135 module_put(vdev->reset_module); 136 } 137 138 static int vfio_platform_regions_init(struct vfio_platform_device *vdev) 139 { 140 int cnt = 0, i; 141 142 while (vdev->get_resource(vdev, cnt)) 143 cnt++; 144 145 vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region), 146 GFP_KERNEL); 147 if (!vdev->regions) 148 return -ENOMEM; 149 150 for (i = 0; i < cnt; i++) { 151 struct resource *res = 152 vdev->get_resource(vdev, i); 153 154 if (!res) 155 goto err; 156 157 vdev->regions[i].addr = res->start; 158 vdev->regions[i].size = resource_size(res); 159 vdev->regions[i].flags = 0; 160 161 switch (resource_type(res)) { 162 case IORESOURCE_MEM: 163 vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO; 164 vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ; 165 if (!(res->flags & IORESOURCE_READONLY)) 166 vdev->regions[i].flags |= 167 VFIO_REGION_INFO_FLAG_WRITE; 168 169 /* 170 * Only regions addressed with PAGE granularity may be 171 * MMAPed securely. 172 */ 173 if (!(vdev->regions[i].addr & ~PAGE_MASK) && 174 !(vdev->regions[i].size & ~PAGE_MASK)) 175 vdev->regions[i].flags |= 176 VFIO_REGION_INFO_FLAG_MMAP; 177 178 break; 179 case IORESOURCE_IO: 180 vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO; 181 break; 182 default: 183 goto err; 184 } 185 } 186 187 vdev->num_regions = cnt; 188 189 return 0; 190 err: 191 kfree(vdev->regions); 192 return -EINVAL; 193 } 194 195 static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev) 196 { 197 int i; 198 199 for (i = 0; i < vdev->num_regions; i++) 200 iounmap(vdev->regions[i].ioaddr); 201 202 vdev->num_regions = 0; 203 kfree(vdev->regions); 204 } 205 206 static int vfio_platform_call_reset(struct vfio_platform_device *vdev, 207 const char **extra_dbg) 208 { 209 if (VFIO_PLATFORM_IS_ACPI(vdev)) { 210 dev_info(vdev->device, "reset\n"); 211 return vfio_platform_acpi_call_reset(vdev, extra_dbg); 212 } else if (vdev->of_reset) { 213 dev_info(vdev->device, "reset\n"); 214 return vdev->of_reset(vdev); 215 } 216 217 dev_warn(vdev->device, "no reset function found!\n"); 218 return -EINVAL; 219 } 220 221 static void vfio_platform_release(void *device_data) 222 { 223 struct vfio_platform_device *vdev = device_data; 224 225 mutex_lock(&driver_lock); 226 227 if (!(--vdev->refcnt)) { 228 const char *extra_dbg = NULL; 229 int ret; 230 231 ret = vfio_platform_call_reset(vdev, &extra_dbg); 232 if (ret && vdev->reset_required) { 233 dev_warn(vdev->device, "reset driver is required and reset call failed in release (%d) %s\n", 234 ret, extra_dbg ? extra_dbg : ""); 235 WARN_ON(1); 236 } 237 pm_runtime_put(vdev->device); 238 vfio_platform_regions_cleanup(vdev); 239 vfio_platform_irq_cleanup(vdev); 240 } 241 242 mutex_unlock(&driver_lock); 243 244 module_put(vdev->parent_module); 245 } 246 247 static int vfio_platform_open(void *device_data) 248 { 249 struct vfio_platform_device *vdev = device_data; 250 int ret; 251 252 if (!try_module_get(vdev->parent_module)) 253 return -ENODEV; 254 255 mutex_lock(&driver_lock); 256 257 if (!vdev->refcnt) { 258 const char *extra_dbg = NULL; 259 260 ret = vfio_platform_regions_init(vdev); 261 if (ret) 262 goto err_reg; 263 264 ret = vfio_platform_irq_init(vdev); 265 if (ret) 266 goto err_irq; 267 268 ret = pm_runtime_get_sync(vdev->device); 269 if (ret < 0) 270 goto err_pm; 271 272 ret = vfio_platform_call_reset(vdev, &extra_dbg); 273 if (ret && vdev->reset_required) { 274 dev_warn(vdev->device, "reset driver is required and reset call failed in open (%d) %s\n", 275 ret, extra_dbg ? extra_dbg : ""); 276 goto err_rst; 277 } 278 } 279 280 vdev->refcnt++; 281 282 mutex_unlock(&driver_lock); 283 return 0; 284 285 err_rst: 286 pm_runtime_put(vdev->device); 287 err_pm: 288 vfio_platform_irq_cleanup(vdev); 289 err_irq: 290 vfio_platform_regions_cleanup(vdev); 291 err_reg: 292 mutex_unlock(&driver_lock); 293 module_put(THIS_MODULE); 294 return ret; 295 } 296 297 static long vfio_platform_ioctl(void *device_data, 298 unsigned int cmd, unsigned long arg) 299 { 300 struct vfio_platform_device *vdev = device_data; 301 unsigned long minsz; 302 303 if (cmd == VFIO_DEVICE_GET_INFO) { 304 struct vfio_device_info info; 305 306 minsz = offsetofend(struct vfio_device_info, num_irqs); 307 308 if (copy_from_user(&info, (void __user *)arg, minsz)) 309 return -EFAULT; 310 311 if (info.argsz < minsz) 312 return -EINVAL; 313 314 if (vfio_platform_has_reset(vdev)) 315 vdev->flags |= VFIO_DEVICE_FLAGS_RESET; 316 info.flags = vdev->flags; 317 info.num_regions = vdev->num_regions; 318 info.num_irqs = vdev->num_irqs; 319 320 return copy_to_user((void __user *)arg, &info, minsz) ? 321 -EFAULT : 0; 322 323 } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) { 324 struct vfio_region_info info; 325 326 minsz = offsetofend(struct vfio_region_info, offset); 327 328 if (copy_from_user(&info, (void __user *)arg, minsz)) 329 return -EFAULT; 330 331 if (info.argsz < minsz) 332 return -EINVAL; 333 334 if (info.index >= vdev->num_regions) 335 return -EINVAL; 336 337 /* map offset to the physical address */ 338 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index); 339 info.size = vdev->regions[info.index].size; 340 info.flags = vdev->regions[info.index].flags; 341 342 return copy_to_user((void __user *)arg, &info, minsz) ? 343 -EFAULT : 0; 344 345 } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) { 346 struct vfio_irq_info info; 347 348 minsz = offsetofend(struct vfio_irq_info, count); 349 350 if (copy_from_user(&info, (void __user *)arg, minsz)) 351 return -EFAULT; 352 353 if (info.argsz < minsz) 354 return -EINVAL; 355 356 if (info.index >= vdev->num_irqs) 357 return -EINVAL; 358 359 info.flags = vdev->irqs[info.index].flags; 360 info.count = vdev->irqs[info.index].count; 361 362 return copy_to_user((void __user *)arg, &info, minsz) ? 363 -EFAULT : 0; 364 365 } else if (cmd == VFIO_DEVICE_SET_IRQS) { 366 struct vfio_irq_set hdr; 367 u8 *data = NULL; 368 int ret = 0; 369 size_t data_size = 0; 370 371 minsz = offsetofend(struct vfio_irq_set, count); 372 373 if (copy_from_user(&hdr, (void __user *)arg, minsz)) 374 return -EFAULT; 375 376 ret = vfio_set_irqs_validate_and_prepare(&hdr, vdev->num_irqs, 377 vdev->num_irqs, &data_size); 378 if (ret) 379 return ret; 380 381 if (data_size) { 382 data = memdup_user((void __user *)(arg + minsz), 383 data_size); 384 if (IS_ERR(data)) 385 return PTR_ERR(data); 386 } 387 388 mutex_lock(&vdev->igate); 389 390 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index, 391 hdr.start, hdr.count, data); 392 mutex_unlock(&vdev->igate); 393 kfree(data); 394 395 return ret; 396 397 } else if (cmd == VFIO_DEVICE_RESET) { 398 return vfio_platform_call_reset(vdev, NULL); 399 } 400 401 return -ENOTTY; 402 } 403 404 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg, 405 char __user *buf, size_t count, 406 loff_t off) 407 { 408 unsigned int done = 0; 409 410 if (!reg->ioaddr) { 411 reg->ioaddr = 412 ioremap(reg->addr, reg->size); 413 414 if (!reg->ioaddr) 415 return -ENOMEM; 416 } 417 418 while (count) { 419 size_t filled; 420 421 if (count >= 4 && !(off % 4)) { 422 u32 val; 423 424 val = ioread32(reg->ioaddr + off); 425 if (copy_to_user(buf, &val, 4)) 426 goto err; 427 428 filled = 4; 429 } else if (count >= 2 && !(off % 2)) { 430 u16 val; 431 432 val = ioread16(reg->ioaddr + off); 433 if (copy_to_user(buf, &val, 2)) 434 goto err; 435 436 filled = 2; 437 } else { 438 u8 val; 439 440 val = ioread8(reg->ioaddr + off); 441 if (copy_to_user(buf, &val, 1)) 442 goto err; 443 444 filled = 1; 445 } 446 447 448 count -= filled; 449 done += filled; 450 off += filled; 451 buf += filled; 452 } 453 454 return done; 455 err: 456 return -EFAULT; 457 } 458 459 static ssize_t vfio_platform_read(void *device_data, char __user *buf, 460 size_t count, loff_t *ppos) 461 { 462 struct vfio_platform_device *vdev = device_data; 463 unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos); 464 loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK; 465 466 if (index >= vdev->num_regions) 467 return -EINVAL; 468 469 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)) 470 return -EINVAL; 471 472 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) 473 return vfio_platform_read_mmio(&vdev->regions[index], 474 buf, count, off); 475 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) 476 return -EINVAL; /* not implemented */ 477 478 return -EINVAL; 479 } 480 481 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg, 482 const char __user *buf, size_t count, 483 loff_t off) 484 { 485 unsigned int done = 0; 486 487 if (!reg->ioaddr) { 488 reg->ioaddr = 489 ioremap(reg->addr, reg->size); 490 491 if (!reg->ioaddr) 492 return -ENOMEM; 493 } 494 495 while (count) { 496 size_t filled; 497 498 if (count >= 4 && !(off % 4)) { 499 u32 val; 500 501 if (copy_from_user(&val, buf, 4)) 502 goto err; 503 iowrite32(val, reg->ioaddr + off); 504 505 filled = 4; 506 } else if (count >= 2 && !(off % 2)) { 507 u16 val; 508 509 if (copy_from_user(&val, buf, 2)) 510 goto err; 511 iowrite16(val, reg->ioaddr + off); 512 513 filled = 2; 514 } else { 515 u8 val; 516 517 if (copy_from_user(&val, buf, 1)) 518 goto err; 519 iowrite8(val, reg->ioaddr + off); 520 521 filled = 1; 522 } 523 524 count -= filled; 525 done += filled; 526 off += filled; 527 buf += filled; 528 } 529 530 return done; 531 err: 532 return -EFAULT; 533 } 534 535 static ssize_t vfio_platform_write(void *device_data, const char __user *buf, 536 size_t count, loff_t *ppos) 537 { 538 struct vfio_platform_device *vdev = device_data; 539 unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos); 540 loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK; 541 542 if (index >= vdev->num_regions) 543 return -EINVAL; 544 545 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)) 546 return -EINVAL; 547 548 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) 549 return vfio_platform_write_mmio(&vdev->regions[index], 550 buf, count, off); 551 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) 552 return -EINVAL; /* not implemented */ 553 554 return -EINVAL; 555 } 556 557 static int vfio_platform_mmap_mmio(struct vfio_platform_region region, 558 struct vm_area_struct *vma) 559 { 560 u64 req_len, pgoff, req_start; 561 562 req_len = vma->vm_end - vma->vm_start; 563 pgoff = vma->vm_pgoff & 564 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1); 565 req_start = pgoff << PAGE_SHIFT; 566 567 if (region.size < PAGE_SIZE || req_start + req_len > region.size) 568 return -EINVAL; 569 570 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 571 vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff; 572 573 return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, 574 req_len, vma->vm_page_prot); 575 } 576 577 static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma) 578 { 579 struct vfio_platform_device *vdev = device_data; 580 unsigned int index; 581 582 index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT); 583 584 if (vma->vm_end < vma->vm_start) 585 return -EINVAL; 586 if (!(vma->vm_flags & VM_SHARED)) 587 return -EINVAL; 588 if (index >= vdev->num_regions) 589 return -EINVAL; 590 if (vma->vm_start & ~PAGE_MASK) 591 return -EINVAL; 592 if (vma->vm_end & ~PAGE_MASK) 593 return -EINVAL; 594 595 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP)) 596 return -EINVAL; 597 598 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ) 599 && (vma->vm_flags & VM_READ)) 600 return -EINVAL; 601 602 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE) 603 && (vma->vm_flags & VM_WRITE)) 604 return -EINVAL; 605 606 vma->vm_private_data = vdev; 607 608 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) 609 return vfio_platform_mmap_mmio(vdev->regions[index], vma); 610 611 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) 612 return -EINVAL; /* not implemented */ 613 614 return -EINVAL; 615 } 616 617 static const struct vfio_device_ops vfio_platform_ops = { 618 .name = "vfio-platform", 619 .open = vfio_platform_open, 620 .release = vfio_platform_release, 621 .ioctl = vfio_platform_ioctl, 622 .read = vfio_platform_read, 623 .write = vfio_platform_write, 624 .mmap = vfio_platform_mmap, 625 }; 626 627 static int vfio_platform_of_probe(struct vfio_platform_device *vdev, 628 struct device *dev) 629 { 630 int ret; 631 632 ret = device_property_read_string(dev, "compatible", 633 &vdev->compat); 634 if (ret) 635 dev_err(dev, "Cannot retrieve compat for %s\n", vdev->name); 636 637 return ret; 638 } 639 640 /* 641 * There can be two kernel build combinations. One build where 642 * ACPI is not selected in Kconfig and another one with the ACPI Kconfig. 643 * 644 * In the first case, vfio_platform_acpi_probe will return since 645 * acpi_disabled is 1. DT user will not see any kind of messages from 646 * ACPI. 647 * 648 * In the second case, both DT and ACPI is compiled in but the system is 649 * booting with any of these combinations. 650 * 651 * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine 652 * terminates immediately without any messages. 653 * 654 * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are 655 * valid checks. We cannot claim that this system is DT. 656 */ 657 int vfio_platform_probe_common(struct vfio_platform_device *vdev, 658 struct device *dev) 659 { 660 struct iommu_group *group; 661 int ret; 662 663 if (!vdev) 664 return -EINVAL; 665 666 ret = vfio_platform_acpi_probe(vdev, dev); 667 if (ret) 668 ret = vfio_platform_of_probe(vdev, dev); 669 670 if (ret) 671 return ret; 672 673 vdev->device = dev; 674 675 ret = vfio_platform_get_reset(vdev); 676 if (ret && vdev->reset_required) { 677 dev_err(dev, "No reset function found for device %s\n", 678 vdev->name); 679 return ret; 680 } 681 682 group = vfio_iommu_group_get(dev); 683 if (!group) { 684 dev_err(dev, "No IOMMU group for device %s\n", vdev->name); 685 ret = -EINVAL; 686 goto put_reset; 687 } 688 689 ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev); 690 if (ret) 691 goto put_iommu; 692 693 mutex_init(&vdev->igate); 694 695 pm_runtime_enable(vdev->device); 696 return 0; 697 698 put_iommu: 699 vfio_iommu_group_put(group, dev); 700 put_reset: 701 vfio_platform_put_reset(vdev); 702 return ret; 703 } 704 EXPORT_SYMBOL_GPL(vfio_platform_probe_common); 705 706 struct vfio_platform_device *vfio_platform_remove_common(struct device *dev) 707 { 708 struct vfio_platform_device *vdev; 709 710 vdev = vfio_del_group_dev(dev); 711 712 if (vdev) { 713 pm_runtime_disable(vdev->device); 714 vfio_platform_put_reset(vdev); 715 vfio_iommu_group_put(dev->iommu_group, dev); 716 } 717 718 return vdev; 719 } 720 EXPORT_SYMBOL_GPL(vfio_platform_remove_common); 721 722 void __vfio_platform_register_reset(struct vfio_platform_reset_node *node) 723 { 724 mutex_lock(&driver_lock); 725 list_add(&node->link, &reset_list); 726 mutex_unlock(&driver_lock); 727 } 728 EXPORT_SYMBOL_GPL(__vfio_platform_register_reset); 729 730 void vfio_platform_unregister_reset(const char *compat, 731 vfio_platform_reset_fn_t fn) 732 { 733 struct vfio_platform_reset_node *iter, *temp; 734 735 mutex_lock(&driver_lock); 736 list_for_each_entry_safe(iter, temp, &reset_list, link) { 737 if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) { 738 list_del(&iter->link); 739 break; 740 } 741 } 742 743 mutex_unlock(&driver_lock); 744 745 } 746 EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset); 747 748 MODULE_VERSION(DRIVER_VERSION); 749 MODULE_LICENSE("GPL v2"); 750 MODULE_AUTHOR(DRIVER_AUTHOR); 751 MODULE_DESCRIPTION(DRIVER_DESC); 752