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_rst; 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 vfio_platform_irq_cleanup(vdev); 288 err_irq: 289 vfio_platform_regions_cleanup(vdev); 290 err_reg: 291 mutex_unlock(&driver_lock); 292 module_put(THIS_MODULE); 293 return ret; 294 } 295 296 static long vfio_platform_ioctl(void *device_data, 297 unsigned int cmd, unsigned long arg) 298 { 299 struct vfio_platform_device *vdev = device_data; 300 unsigned long minsz; 301 302 if (cmd == VFIO_DEVICE_GET_INFO) { 303 struct vfio_device_info info; 304 305 minsz = offsetofend(struct vfio_device_info, num_irqs); 306 307 if (copy_from_user(&info, (void __user *)arg, minsz)) 308 return -EFAULT; 309 310 if (info.argsz < minsz) 311 return -EINVAL; 312 313 if (vfio_platform_has_reset(vdev)) 314 vdev->flags |= VFIO_DEVICE_FLAGS_RESET; 315 info.flags = vdev->flags; 316 info.num_regions = vdev->num_regions; 317 info.num_irqs = vdev->num_irqs; 318 319 return copy_to_user((void __user *)arg, &info, minsz) ? 320 -EFAULT : 0; 321 322 } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) { 323 struct vfio_region_info info; 324 325 minsz = offsetofend(struct vfio_region_info, offset); 326 327 if (copy_from_user(&info, (void __user *)arg, minsz)) 328 return -EFAULT; 329 330 if (info.argsz < minsz) 331 return -EINVAL; 332 333 if (info.index >= vdev->num_regions) 334 return -EINVAL; 335 336 /* map offset to the physical address */ 337 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index); 338 info.size = vdev->regions[info.index].size; 339 info.flags = vdev->regions[info.index].flags; 340 341 return copy_to_user((void __user *)arg, &info, minsz) ? 342 -EFAULT : 0; 343 344 } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) { 345 struct vfio_irq_info info; 346 347 minsz = offsetofend(struct vfio_irq_info, count); 348 349 if (copy_from_user(&info, (void __user *)arg, minsz)) 350 return -EFAULT; 351 352 if (info.argsz < minsz) 353 return -EINVAL; 354 355 if (info.index >= vdev->num_irqs) 356 return -EINVAL; 357 358 info.flags = vdev->irqs[info.index].flags; 359 info.count = vdev->irqs[info.index].count; 360 361 return copy_to_user((void __user *)arg, &info, minsz) ? 362 -EFAULT : 0; 363 364 } else if (cmd == VFIO_DEVICE_SET_IRQS) { 365 struct vfio_irq_set hdr; 366 u8 *data = NULL; 367 int ret = 0; 368 size_t data_size = 0; 369 370 minsz = offsetofend(struct vfio_irq_set, count); 371 372 if (copy_from_user(&hdr, (void __user *)arg, minsz)) 373 return -EFAULT; 374 375 ret = vfio_set_irqs_validate_and_prepare(&hdr, vdev->num_irqs, 376 vdev->num_irqs, &data_size); 377 if (ret) 378 return ret; 379 380 if (data_size) { 381 data = memdup_user((void __user *)(arg + minsz), 382 data_size); 383 if (IS_ERR(data)) 384 return PTR_ERR(data); 385 } 386 387 mutex_lock(&vdev->igate); 388 389 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index, 390 hdr.start, hdr.count, data); 391 mutex_unlock(&vdev->igate); 392 kfree(data); 393 394 return ret; 395 396 } else if (cmd == VFIO_DEVICE_RESET) { 397 return vfio_platform_call_reset(vdev, NULL); 398 } 399 400 return -ENOTTY; 401 } 402 403 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg, 404 char __user *buf, size_t count, 405 loff_t off) 406 { 407 unsigned int done = 0; 408 409 if (!reg->ioaddr) { 410 reg->ioaddr = 411 ioremap(reg->addr, reg->size); 412 413 if (!reg->ioaddr) 414 return -ENOMEM; 415 } 416 417 while (count) { 418 size_t filled; 419 420 if (count >= 4 && !(off % 4)) { 421 u32 val; 422 423 val = ioread32(reg->ioaddr + off); 424 if (copy_to_user(buf, &val, 4)) 425 goto err; 426 427 filled = 4; 428 } else if (count >= 2 && !(off % 2)) { 429 u16 val; 430 431 val = ioread16(reg->ioaddr + off); 432 if (copy_to_user(buf, &val, 2)) 433 goto err; 434 435 filled = 2; 436 } else { 437 u8 val; 438 439 val = ioread8(reg->ioaddr + off); 440 if (copy_to_user(buf, &val, 1)) 441 goto err; 442 443 filled = 1; 444 } 445 446 447 count -= filled; 448 done += filled; 449 off += filled; 450 buf += filled; 451 } 452 453 return done; 454 err: 455 return -EFAULT; 456 } 457 458 static ssize_t vfio_platform_read(void *device_data, char __user *buf, 459 size_t count, loff_t *ppos) 460 { 461 struct vfio_platform_device *vdev = device_data; 462 unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos); 463 loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK; 464 465 if (index >= vdev->num_regions) 466 return -EINVAL; 467 468 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)) 469 return -EINVAL; 470 471 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) 472 return vfio_platform_read_mmio(&vdev->regions[index], 473 buf, count, off); 474 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) 475 return -EINVAL; /* not implemented */ 476 477 return -EINVAL; 478 } 479 480 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg, 481 const char __user *buf, size_t count, 482 loff_t off) 483 { 484 unsigned int done = 0; 485 486 if (!reg->ioaddr) { 487 reg->ioaddr = 488 ioremap(reg->addr, reg->size); 489 490 if (!reg->ioaddr) 491 return -ENOMEM; 492 } 493 494 while (count) { 495 size_t filled; 496 497 if (count >= 4 && !(off % 4)) { 498 u32 val; 499 500 if (copy_from_user(&val, buf, 4)) 501 goto err; 502 iowrite32(val, reg->ioaddr + off); 503 504 filled = 4; 505 } else if (count >= 2 && !(off % 2)) { 506 u16 val; 507 508 if (copy_from_user(&val, buf, 2)) 509 goto err; 510 iowrite16(val, reg->ioaddr + off); 511 512 filled = 2; 513 } else { 514 u8 val; 515 516 if (copy_from_user(&val, buf, 1)) 517 goto err; 518 iowrite8(val, reg->ioaddr + off); 519 520 filled = 1; 521 } 522 523 count -= filled; 524 done += filled; 525 off += filled; 526 buf += filled; 527 } 528 529 return done; 530 err: 531 return -EFAULT; 532 } 533 534 static ssize_t vfio_platform_write(void *device_data, const char __user *buf, 535 size_t count, loff_t *ppos) 536 { 537 struct vfio_platform_device *vdev = device_data; 538 unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos); 539 loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK; 540 541 if (index >= vdev->num_regions) 542 return -EINVAL; 543 544 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)) 545 return -EINVAL; 546 547 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) 548 return vfio_platform_write_mmio(&vdev->regions[index], 549 buf, count, off); 550 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) 551 return -EINVAL; /* not implemented */ 552 553 return -EINVAL; 554 } 555 556 static int vfio_platform_mmap_mmio(struct vfio_platform_region region, 557 struct vm_area_struct *vma) 558 { 559 u64 req_len, pgoff, req_start; 560 561 req_len = vma->vm_end - vma->vm_start; 562 pgoff = vma->vm_pgoff & 563 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1); 564 req_start = pgoff << PAGE_SHIFT; 565 566 if (region.size < PAGE_SIZE || req_start + req_len > region.size) 567 return -EINVAL; 568 569 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 570 vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff; 571 572 return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, 573 req_len, vma->vm_page_prot); 574 } 575 576 static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma) 577 { 578 struct vfio_platform_device *vdev = device_data; 579 unsigned int index; 580 581 index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT); 582 583 if (vma->vm_end < vma->vm_start) 584 return -EINVAL; 585 if (!(vma->vm_flags & VM_SHARED)) 586 return -EINVAL; 587 if (index >= vdev->num_regions) 588 return -EINVAL; 589 if (vma->vm_start & ~PAGE_MASK) 590 return -EINVAL; 591 if (vma->vm_end & ~PAGE_MASK) 592 return -EINVAL; 593 594 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP)) 595 return -EINVAL; 596 597 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ) 598 && (vma->vm_flags & VM_READ)) 599 return -EINVAL; 600 601 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE) 602 && (vma->vm_flags & VM_WRITE)) 603 return -EINVAL; 604 605 vma->vm_private_data = vdev; 606 607 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) 608 return vfio_platform_mmap_mmio(vdev->regions[index], vma); 609 610 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) 611 return -EINVAL; /* not implemented */ 612 613 return -EINVAL; 614 } 615 616 static const struct vfio_device_ops vfio_platform_ops = { 617 .name = "vfio-platform", 618 .open = vfio_platform_open, 619 .release = vfio_platform_release, 620 .ioctl = vfio_platform_ioctl, 621 .read = vfio_platform_read, 622 .write = vfio_platform_write, 623 .mmap = vfio_platform_mmap, 624 }; 625 626 static int vfio_platform_of_probe(struct vfio_platform_device *vdev, 627 struct device *dev) 628 { 629 int ret; 630 631 ret = device_property_read_string(dev, "compatible", 632 &vdev->compat); 633 if (ret) 634 dev_err(dev, "Cannot retrieve compat for %s\n", vdev->name); 635 636 return ret; 637 } 638 639 /* 640 * There can be two kernel build combinations. One build where 641 * ACPI is not selected in Kconfig and another one with the ACPI Kconfig. 642 * 643 * In the first case, vfio_platform_acpi_probe will return since 644 * acpi_disabled is 1. DT user will not see any kind of messages from 645 * ACPI. 646 * 647 * In the second case, both DT and ACPI is compiled in but the system is 648 * booting with any of these combinations. 649 * 650 * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine 651 * terminates immediately without any messages. 652 * 653 * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are 654 * valid checks. We cannot claim that this system is DT. 655 */ 656 int vfio_platform_probe_common(struct vfio_platform_device *vdev, 657 struct device *dev) 658 { 659 struct iommu_group *group; 660 int ret; 661 662 if (!vdev) 663 return -EINVAL; 664 665 ret = vfio_platform_acpi_probe(vdev, dev); 666 if (ret) 667 ret = vfio_platform_of_probe(vdev, dev); 668 669 if (ret) 670 return ret; 671 672 vdev->device = dev; 673 674 ret = vfio_platform_get_reset(vdev); 675 if (ret && vdev->reset_required) { 676 dev_err(dev, "No reset function found for device %s\n", 677 vdev->name); 678 return ret; 679 } 680 681 group = vfio_iommu_group_get(dev); 682 if (!group) { 683 dev_err(dev, "No IOMMU group for device %s\n", vdev->name); 684 ret = -EINVAL; 685 goto put_reset; 686 } 687 688 ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev); 689 if (ret) 690 goto put_iommu; 691 692 mutex_init(&vdev->igate); 693 694 pm_runtime_enable(vdev->device); 695 return 0; 696 697 put_iommu: 698 vfio_iommu_group_put(group, dev); 699 put_reset: 700 vfio_platform_put_reset(vdev); 701 return ret; 702 } 703 EXPORT_SYMBOL_GPL(vfio_platform_probe_common); 704 705 struct vfio_platform_device *vfio_platform_remove_common(struct device *dev) 706 { 707 struct vfio_platform_device *vdev; 708 709 vdev = vfio_del_group_dev(dev); 710 711 if (vdev) { 712 pm_runtime_disable(vdev->device); 713 vfio_platform_put_reset(vdev); 714 vfio_iommu_group_put(dev->iommu_group, dev); 715 } 716 717 return vdev; 718 } 719 EXPORT_SYMBOL_GPL(vfio_platform_remove_common); 720 721 void __vfio_platform_register_reset(struct vfio_platform_reset_node *node) 722 { 723 mutex_lock(&driver_lock); 724 list_add(&node->link, &reset_list); 725 mutex_unlock(&driver_lock); 726 } 727 EXPORT_SYMBOL_GPL(__vfio_platform_register_reset); 728 729 void vfio_platform_unregister_reset(const char *compat, 730 vfio_platform_reset_fn_t fn) 731 { 732 struct vfio_platform_reset_node *iter, *temp; 733 734 mutex_lock(&driver_lock); 735 list_for_each_entry_safe(iter, temp, &reset_list, link) { 736 if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) { 737 list_del(&iter->link); 738 break; 739 } 740 } 741 742 mutex_unlock(&driver_lock); 743 744 } 745 EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset); 746 747 MODULE_VERSION(DRIVER_VERSION); 748 MODULE_LICENSE("GPL v2"); 749 MODULE_AUTHOR(DRIVER_AUTHOR); 750 MODULE_DESCRIPTION(DRIVER_DESC); 751