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_close_device(struct vfio_device *core_vdev) 222 { 223 struct vfio_platform_device *vdev = 224 container_of(core_vdev, struct vfio_platform_device, vdev); 225 const char *extra_dbg = NULL; 226 int ret; 227 228 ret = vfio_platform_call_reset(vdev, &extra_dbg); 229 if (WARN_ON(ret && vdev->reset_required)) { 230 dev_warn( 231 vdev->device, 232 "reset driver is required and reset call failed in release (%d) %s\n", 233 ret, extra_dbg ? extra_dbg : ""); 234 } 235 pm_runtime_put(vdev->device); 236 vfio_platform_regions_cleanup(vdev); 237 vfio_platform_irq_cleanup(vdev); 238 } 239 240 static int vfio_platform_open_device(struct vfio_device *core_vdev) 241 { 242 struct vfio_platform_device *vdev = 243 container_of(core_vdev, struct vfio_platform_device, vdev); 244 const char *extra_dbg = NULL; 245 int ret; 246 247 ret = vfio_platform_regions_init(vdev); 248 if (ret) 249 return ret; 250 251 ret = vfio_platform_irq_init(vdev); 252 if (ret) 253 goto err_irq; 254 255 ret = pm_runtime_get_sync(vdev->device); 256 if (ret < 0) 257 goto err_rst; 258 259 ret = vfio_platform_call_reset(vdev, &extra_dbg); 260 if (ret && vdev->reset_required) { 261 dev_warn( 262 vdev->device, 263 "reset driver is required and reset call failed in open (%d) %s\n", 264 ret, extra_dbg ? extra_dbg : ""); 265 goto err_rst; 266 } 267 return 0; 268 269 err_rst: 270 pm_runtime_put(vdev->device); 271 vfio_platform_irq_cleanup(vdev); 272 err_irq: 273 vfio_platform_regions_cleanup(vdev); 274 return ret; 275 } 276 277 static long vfio_platform_ioctl(struct vfio_device *core_vdev, 278 unsigned int cmd, unsigned long arg) 279 { 280 struct vfio_platform_device *vdev = 281 container_of(core_vdev, struct vfio_platform_device, vdev); 282 283 unsigned long minsz; 284 285 if (cmd == VFIO_DEVICE_GET_INFO) { 286 struct vfio_device_info info; 287 288 minsz = offsetofend(struct vfio_device_info, num_irqs); 289 290 if (copy_from_user(&info, (void __user *)arg, minsz)) 291 return -EFAULT; 292 293 if (info.argsz < minsz) 294 return -EINVAL; 295 296 if (vfio_platform_has_reset(vdev)) 297 vdev->flags |= VFIO_DEVICE_FLAGS_RESET; 298 info.flags = vdev->flags; 299 info.num_regions = vdev->num_regions; 300 info.num_irqs = vdev->num_irqs; 301 302 return copy_to_user((void __user *)arg, &info, minsz) ? 303 -EFAULT : 0; 304 305 } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) { 306 struct vfio_region_info info; 307 308 minsz = offsetofend(struct vfio_region_info, offset); 309 310 if (copy_from_user(&info, (void __user *)arg, minsz)) 311 return -EFAULT; 312 313 if (info.argsz < minsz) 314 return -EINVAL; 315 316 if (info.index >= vdev->num_regions) 317 return -EINVAL; 318 319 /* map offset to the physical address */ 320 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index); 321 info.size = vdev->regions[info.index].size; 322 info.flags = vdev->regions[info.index].flags; 323 324 return copy_to_user((void __user *)arg, &info, minsz) ? 325 -EFAULT : 0; 326 327 } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) { 328 struct vfio_irq_info info; 329 330 minsz = offsetofend(struct vfio_irq_info, count); 331 332 if (copy_from_user(&info, (void __user *)arg, minsz)) 333 return -EFAULT; 334 335 if (info.argsz < minsz) 336 return -EINVAL; 337 338 if (info.index >= vdev->num_irqs) 339 return -EINVAL; 340 341 info.flags = vdev->irqs[info.index].flags; 342 info.count = vdev->irqs[info.index].count; 343 344 return copy_to_user((void __user *)arg, &info, minsz) ? 345 -EFAULT : 0; 346 347 } else if (cmd == VFIO_DEVICE_SET_IRQS) { 348 struct vfio_irq_set hdr; 349 u8 *data = NULL; 350 int ret = 0; 351 size_t data_size = 0; 352 353 minsz = offsetofend(struct vfio_irq_set, count); 354 355 if (copy_from_user(&hdr, (void __user *)arg, minsz)) 356 return -EFAULT; 357 358 ret = vfio_set_irqs_validate_and_prepare(&hdr, vdev->num_irqs, 359 vdev->num_irqs, &data_size); 360 if (ret) 361 return ret; 362 363 if (data_size) { 364 data = memdup_user((void __user *)(arg + minsz), 365 data_size); 366 if (IS_ERR(data)) 367 return PTR_ERR(data); 368 } 369 370 mutex_lock(&vdev->igate); 371 372 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index, 373 hdr.start, hdr.count, data); 374 mutex_unlock(&vdev->igate); 375 kfree(data); 376 377 return ret; 378 379 } else if (cmd == VFIO_DEVICE_RESET) { 380 return vfio_platform_call_reset(vdev, NULL); 381 } 382 383 return -ENOTTY; 384 } 385 386 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg, 387 char __user *buf, size_t count, 388 loff_t off) 389 { 390 unsigned int done = 0; 391 392 if (!reg->ioaddr) { 393 reg->ioaddr = 394 ioremap(reg->addr, reg->size); 395 396 if (!reg->ioaddr) 397 return -ENOMEM; 398 } 399 400 while (count) { 401 size_t filled; 402 403 if (count >= 4 && !(off % 4)) { 404 u32 val; 405 406 val = ioread32(reg->ioaddr + off); 407 if (copy_to_user(buf, &val, 4)) 408 goto err; 409 410 filled = 4; 411 } else if (count >= 2 && !(off % 2)) { 412 u16 val; 413 414 val = ioread16(reg->ioaddr + off); 415 if (copy_to_user(buf, &val, 2)) 416 goto err; 417 418 filled = 2; 419 } else { 420 u8 val; 421 422 val = ioread8(reg->ioaddr + off); 423 if (copy_to_user(buf, &val, 1)) 424 goto err; 425 426 filled = 1; 427 } 428 429 430 count -= filled; 431 done += filled; 432 off += filled; 433 buf += filled; 434 } 435 436 return done; 437 err: 438 return -EFAULT; 439 } 440 441 static ssize_t vfio_platform_read(struct vfio_device *core_vdev, 442 char __user *buf, size_t count, loff_t *ppos) 443 { 444 struct vfio_platform_device *vdev = 445 container_of(core_vdev, struct vfio_platform_device, vdev); 446 unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos); 447 loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK; 448 449 if (index >= vdev->num_regions) 450 return -EINVAL; 451 452 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)) 453 return -EINVAL; 454 455 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) 456 return vfio_platform_read_mmio(&vdev->regions[index], 457 buf, count, off); 458 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) 459 return -EINVAL; /* not implemented */ 460 461 return -EINVAL; 462 } 463 464 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg, 465 const char __user *buf, size_t count, 466 loff_t off) 467 { 468 unsigned int done = 0; 469 470 if (!reg->ioaddr) { 471 reg->ioaddr = 472 ioremap(reg->addr, reg->size); 473 474 if (!reg->ioaddr) 475 return -ENOMEM; 476 } 477 478 while (count) { 479 size_t filled; 480 481 if (count >= 4 && !(off % 4)) { 482 u32 val; 483 484 if (copy_from_user(&val, buf, 4)) 485 goto err; 486 iowrite32(val, reg->ioaddr + off); 487 488 filled = 4; 489 } else if (count >= 2 && !(off % 2)) { 490 u16 val; 491 492 if (copy_from_user(&val, buf, 2)) 493 goto err; 494 iowrite16(val, reg->ioaddr + off); 495 496 filled = 2; 497 } else { 498 u8 val; 499 500 if (copy_from_user(&val, buf, 1)) 501 goto err; 502 iowrite8(val, reg->ioaddr + off); 503 504 filled = 1; 505 } 506 507 count -= filled; 508 done += filled; 509 off += filled; 510 buf += filled; 511 } 512 513 return done; 514 err: 515 return -EFAULT; 516 } 517 518 static ssize_t vfio_platform_write(struct vfio_device *core_vdev, const char __user *buf, 519 size_t count, loff_t *ppos) 520 { 521 struct vfio_platform_device *vdev = 522 container_of(core_vdev, struct vfio_platform_device, vdev); 523 unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos); 524 loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK; 525 526 if (index >= vdev->num_regions) 527 return -EINVAL; 528 529 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)) 530 return -EINVAL; 531 532 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) 533 return vfio_platform_write_mmio(&vdev->regions[index], 534 buf, count, off); 535 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) 536 return -EINVAL; /* not implemented */ 537 538 return -EINVAL; 539 } 540 541 static int vfio_platform_mmap_mmio(struct vfio_platform_region region, 542 struct vm_area_struct *vma) 543 { 544 u64 req_len, pgoff, req_start; 545 546 req_len = vma->vm_end - vma->vm_start; 547 pgoff = vma->vm_pgoff & 548 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1); 549 req_start = pgoff << PAGE_SHIFT; 550 551 if (region.size < PAGE_SIZE || req_start + req_len > region.size) 552 return -EINVAL; 553 554 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 555 vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff; 556 557 return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, 558 req_len, vma->vm_page_prot); 559 } 560 561 static int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma) 562 { 563 struct vfio_platform_device *vdev = 564 container_of(core_vdev, struct vfio_platform_device, vdev); 565 unsigned int index; 566 567 index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT); 568 569 if (vma->vm_end < vma->vm_start) 570 return -EINVAL; 571 if (!(vma->vm_flags & VM_SHARED)) 572 return -EINVAL; 573 if (index >= vdev->num_regions) 574 return -EINVAL; 575 if (vma->vm_start & ~PAGE_MASK) 576 return -EINVAL; 577 if (vma->vm_end & ~PAGE_MASK) 578 return -EINVAL; 579 580 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP)) 581 return -EINVAL; 582 583 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ) 584 && (vma->vm_flags & VM_READ)) 585 return -EINVAL; 586 587 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE) 588 && (vma->vm_flags & VM_WRITE)) 589 return -EINVAL; 590 591 vma->vm_private_data = vdev; 592 593 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) 594 return vfio_platform_mmap_mmio(vdev->regions[index], vma); 595 596 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) 597 return -EINVAL; /* not implemented */ 598 599 return -EINVAL; 600 } 601 602 static const struct vfio_device_ops vfio_platform_ops = { 603 .name = "vfio-platform", 604 .open_device = vfio_platform_open_device, 605 .close_device = vfio_platform_close_device, 606 .ioctl = vfio_platform_ioctl, 607 .read = vfio_platform_read, 608 .write = vfio_platform_write, 609 .mmap = vfio_platform_mmap, 610 }; 611 612 static int vfio_platform_of_probe(struct vfio_platform_device *vdev, 613 struct device *dev) 614 { 615 int ret; 616 617 ret = device_property_read_string(dev, "compatible", 618 &vdev->compat); 619 if (ret) 620 dev_err(dev, "Cannot retrieve compat for %s\n", vdev->name); 621 622 return ret; 623 } 624 625 /* 626 * There can be two kernel build combinations. One build where 627 * ACPI is not selected in Kconfig and another one with the ACPI Kconfig. 628 * 629 * In the first case, vfio_platform_acpi_probe will return since 630 * acpi_disabled is 1. DT user will not see any kind of messages from 631 * ACPI. 632 * 633 * In the second case, both DT and ACPI is compiled in but the system is 634 * booting with any of these combinations. 635 * 636 * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine 637 * terminates immediately without any messages. 638 * 639 * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are 640 * valid checks. We cannot claim that this system is DT. 641 */ 642 int vfio_platform_probe_common(struct vfio_platform_device *vdev, 643 struct device *dev) 644 { 645 int ret; 646 647 vfio_init_group_dev(&vdev->vdev, dev, &vfio_platform_ops); 648 649 ret = vfio_platform_acpi_probe(vdev, dev); 650 if (ret) 651 ret = vfio_platform_of_probe(vdev, dev); 652 653 if (ret) 654 goto out_uninit; 655 656 vdev->device = dev; 657 658 ret = vfio_platform_get_reset(vdev); 659 if (ret && vdev->reset_required) { 660 dev_err(dev, "No reset function found for device %s\n", 661 vdev->name); 662 goto out_uninit; 663 } 664 665 ret = vfio_register_group_dev(&vdev->vdev); 666 if (ret) 667 goto put_reset; 668 669 mutex_init(&vdev->igate); 670 671 pm_runtime_enable(dev); 672 return 0; 673 674 put_reset: 675 vfio_platform_put_reset(vdev); 676 out_uninit: 677 vfio_uninit_group_dev(&vdev->vdev); 678 return ret; 679 } 680 EXPORT_SYMBOL_GPL(vfio_platform_probe_common); 681 682 void vfio_platform_remove_common(struct vfio_platform_device *vdev) 683 { 684 vfio_unregister_group_dev(&vdev->vdev); 685 686 pm_runtime_disable(vdev->device); 687 vfio_platform_put_reset(vdev); 688 vfio_uninit_group_dev(&vdev->vdev); 689 } 690 EXPORT_SYMBOL_GPL(vfio_platform_remove_common); 691 692 void __vfio_platform_register_reset(struct vfio_platform_reset_node *node) 693 { 694 mutex_lock(&driver_lock); 695 list_add(&node->link, &reset_list); 696 mutex_unlock(&driver_lock); 697 } 698 EXPORT_SYMBOL_GPL(__vfio_platform_register_reset); 699 700 void vfio_platform_unregister_reset(const char *compat, 701 vfio_platform_reset_fn_t fn) 702 { 703 struct vfio_platform_reset_node *iter, *temp; 704 705 mutex_lock(&driver_lock); 706 list_for_each_entry_safe(iter, temp, &reset_list, link) { 707 if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) { 708 list_del(&iter->link); 709 break; 710 } 711 } 712 713 mutex_unlock(&driver_lock); 714 715 } 716 EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset); 717 718 MODULE_VERSION(DRIVER_VERSION); 719 MODULE_LICENSE("GPL v2"); 720 MODULE_AUTHOR(DRIVER_AUTHOR); 721 MODULE_DESCRIPTION(DRIVER_DESC); 722