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 device *dev = vdev->device; 76 acpi_handle handle = ACPI_HANDLE(dev); 77 acpi_status acpi_ret; 78 79 acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, NULL); 80 if (ACPI_FAILURE(acpi_ret)) { 81 if (extra_dbg) 82 *extra_dbg = acpi_format_exception(acpi_ret); 83 return -EINVAL; 84 } 85 86 return 0; 87 #else 88 return -ENOENT; 89 #endif 90 } 91 92 static bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev) 93 { 94 #ifdef CONFIG_ACPI 95 struct device *dev = vdev->device; 96 acpi_handle handle = ACPI_HANDLE(dev); 97 98 return acpi_has_method(handle, "_RST"); 99 #else 100 return false; 101 #endif 102 } 103 104 static bool vfio_platform_has_reset(struct vfio_platform_device *vdev) 105 { 106 if (VFIO_PLATFORM_IS_ACPI(vdev)) 107 return vfio_platform_acpi_has_reset(vdev); 108 109 return vdev->of_reset ? true : false; 110 } 111 112 static int vfio_platform_get_reset(struct vfio_platform_device *vdev) 113 { 114 if (VFIO_PLATFORM_IS_ACPI(vdev)) 115 return vfio_platform_acpi_has_reset(vdev) ? 0 : -ENOENT; 116 117 vdev->of_reset = vfio_platform_lookup_reset(vdev->compat, 118 &vdev->reset_module); 119 if (!vdev->of_reset) { 120 request_module("vfio-reset:%s", vdev->compat); 121 vdev->of_reset = vfio_platform_lookup_reset(vdev->compat, 122 &vdev->reset_module); 123 } 124 125 return vdev->of_reset ? 0 : -ENOENT; 126 } 127 128 static void vfio_platform_put_reset(struct vfio_platform_device *vdev) 129 { 130 if (VFIO_PLATFORM_IS_ACPI(vdev)) 131 return; 132 133 if (vdev->of_reset) 134 module_put(vdev->reset_module); 135 } 136 137 static int vfio_platform_regions_init(struct vfio_platform_device *vdev) 138 { 139 int cnt = 0, i; 140 141 while (vdev->get_resource(vdev, cnt)) 142 cnt++; 143 144 vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region), 145 GFP_KERNEL_ACCOUNT); 146 if (!vdev->regions) 147 return -ENOMEM; 148 149 for (i = 0; i < cnt; i++) { 150 struct resource *res = 151 vdev->get_resource(vdev, i); 152 153 vdev->regions[i].addr = res->start; 154 vdev->regions[i].size = resource_size(res); 155 vdev->regions[i].flags = 0; 156 157 switch (resource_type(res)) { 158 case IORESOURCE_MEM: 159 vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO; 160 vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ; 161 if (!(res->flags & IORESOURCE_READONLY)) 162 vdev->regions[i].flags |= 163 VFIO_REGION_INFO_FLAG_WRITE; 164 165 /* 166 * Only regions addressed with PAGE granularity may be 167 * MMAPed securely. 168 */ 169 if (!(vdev->regions[i].addr & ~PAGE_MASK) && 170 !(vdev->regions[i].size & ~PAGE_MASK)) 171 vdev->regions[i].flags |= 172 VFIO_REGION_INFO_FLAG_MMAP; 173 174 break; 175 case IORESOURCE_IO: 176 vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO; 177 break; 178 default: 179 goto err; 180 } 181 } 182 183 vdev->num_regions = cnt; 184 185 return 0; 186 err: 187 kfree(vdev->regions); 188 return -EINVAL; 189 } 190 191 static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev) 192 { 193 int i; 194 195 for (i = 0; i < vdev->num_regions; i++) 196 iounmap(vdev->regions[i].ioaddr); 197 198 vdev->num_regions = 0; 199 kfree(vdev->regions); 200 } 201 202 static int vfio_platform_call_reset(struct vfio_platform_device *vdev, 203 const char **extra_dbg) 204 { 205 if (VFIO_PLATFORM_IS_ACPI(vdev)) { 206 dev_info(vdev->device, "reset\n"); 207 return vfio_platform_acpi_call_reset(vdev, extra_dbg); 208 } else if (vdev->of_reset) { 209 dev_info(vdev->device, "reset\n"); 210 return vdev->of_reset(vdev); 211 } 212 213 dev_warn(vdev->device, "no reset function found!\n"); 214 return -EINVAL; 215 } 216 217 void vfio_platform_close_device(struct vfio_device *core_vdev) 218 { 219 struct vfio_platform_device *vdev = 220 container_of(core_vdev, struct vfio_platform_device, vdev); 221 const char *extra_dbg = NULL; 222 int ret; 223 224 ret = vfio_platform_call_reset(vdev, &extra_dbg); 225 if (WARN_ON(ret && vdev->reset_required)) { 226 dev_warn( 227 vdev->device, 228 "reset driver is required and reset call failed in release (%d) %s\n", 229 ret, extra_dbg ? extra_dbg : ""); 230 } 231 pm_runtime_put(vdev->device); 232 vfio_platform_regions_cleanup(vdev); 233 vfio_platform_irq_cleanup(vdev); 234 } 235 EXPORT_SYMBOL_GPL(vfio_platform_close_device); 236 237 int vfio_platform_open_device(struct vfio_device *core_vdev) 238 { 239 struct vfio_platform_device *vdev = 240 container_of(core_vdev, struct vfio_platform_device, vdev); 241 const char *extra_dbg = NULL; 242 int ret; 243 244 ret = vfio_platform_regions_init(vdev); 245 if (ret) 246 return ret; 247 248 ret = vfio_platform_irq_init(vdev); 249 if (ret) 250 goto err_irq; 251 252 ret = pm_runtime_get_sync(vdev->device); 253 if (ret < 0) 254 goto err_rst; 255 256 ret = vfio_platform_call_reset(vdev, &extra_dbg); 257 if (ret && vdev->reset_required) { 258 dev_warn( 259 vdev->device, 260 "reset driver is required and reset call failed in open (%d) %s\n", 261 ret, extra_dbg ? extra_dbg : ""); 262 goto err_rst; 263 } 264 return 0; 265 266 err_rst: 267 pm_runtime_put(vdev->device); 268 vfio_platform_irq_cleanup(vdev); 269 err_irq: 270 vfio_platform_regions_cleanup(vdev); 271 return ret; 272 } 273 EXPORT_SYMBOL_GPL(vfio_platform_open_device); 274 275 int vfio_platform_ioctl_get_region_info(struct vfio_device *core_vdev, 276 struct vfio_region_info __user *arg) 277 { 278 struct vfio_platform_device *vdev = 279 container_of(core_vdev, struct vfio_platform_device, vdev); 280 struct vfio_region_info info; 281 unsigned long minsz; 282 283 minsz = offsetofend(struct vfio_region_info, offset); 284 285 if (copy_from_user(&info, arg, minsz)) 286 return -EFAULT; 287 288 if (info.argsz < minsz) 289 return -EINVAL; 290 291 if (info.index >= vdev->num_regions) 292 return -EINVAL; 293 294 /* map offset to the physical address */ 295 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index); 296 info.size = vdev->regions[info.index].size; 297 info.flags = vdev->regions[info.index].flags; 298 299 return copy_to_user(arg, &info, minsz) ? -EFAULT : 0; 300 } 301 EXPORT_SYMBOL_GPL(vfio_platform_ioctl_get_region_info); 302 303 long vfio_platform_ioctl(struct vfio_device *core_vdev, 304 unsigned int cmd, unsigned long arg) 305 { 306 struct vfio_platform_device *vdev = 307 container_of(core_vdev, struct vfio_platform_device, vdev); 308 309 unsigned long minsz; 310 311 if (cmd == VFIO_DEVICE_GET_INFO) { 312 struct vfio_device_info info; 313 314 minsz = offsetofend(struct vfio_device_info, num_irqs); 315 316 if (copy_from_user(&info, (void __user *)arg, minsz)) 317 return -EFAULT; 318 319 if (info.argsz < minsz) 320 return -EINVAL; 321 322 if (vfio_platform_has_reset(vdev)) 323 vdev->flags |= VFIO_DEVICE_FLAGS_RESET; 324 info.flags = vdev->flags; 325 info.num_regions = vdev->num_regions; 326 info.num_irqs = vdev->num_irqs; 327 328 return copy_to_user((void __user *)arg, &info, minsz) ? 329 -EFAULT : 0; 330 331 } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) { 332 struct vfio_irq_info info; 333 334 minsz = offsetofend(struct vfio_irq_info, count); 335 336 if (copy_from_user(&info, (void __user *)arg, minsz)) 337 return -EFAULT; 338 339 if (info.argsz < minsz) 340 return -EINVAL; 341 342 if (info.index >= vdev->num_irqs) 343 return -EINVAL; 344 345 info.flags = vdev->irqs[info.index].flags; 346 info.count = vdev->irqs[info.index].count; 347 348 return copy_to_user((void __user *)arg, &info, minsz) ? 349 -EFAULT : 0; 350 351 } else if (cmd == VFIO_DEVICE_SET_IRQS) { 352 struct vfio_irq_set hdr; 353 u8 *data = NULL; 354 int ret = 0; 355 size_t data_size = 0; 356 357 minsz = offsetofend(struct vfio_irq_set, count); 358 359 if (copy_from_user(&hdr, (void __user *)arg, minsz)) 360 return -EFAULT; 361 362 ret = vfio_set_irqs_validate_and_prepare(&hdr, vdev->num_irqs, 363 vdev->num_irqs, &data_size); 364 if (ret) 365 return ret; 366 367 if (data_size) { 368 data = memdup_user((void __user *)(arg + minsz), 369 data_size); 370 if (IS_ERR(data)) 371 return PTR_ERR(data); 372 } 373 374 mutex_lock(&vdev->igate); 375 376 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index, 377 hdr.start, hdr.count, data); 378 mutex_unlock(&vdev->igate); 379 kfree(data); 380 381 return ret; 382 383 } else if (cmd == VFIO_DEVICE_RESET) { 384 return vfio_platform_call_reset(vdev, NULL); 385 } 386 387 return -ENOTTY; 388 } 389 EXPORT_SYMBOL_GPL(vfio_platform_ioctl); 390 391 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg, 392 char __user *buf, size_t count, 393 loff_t off) 394 { 395 unsigned int done = 0; 396 397 if (off >= reg->size) 398 return -EINVAL; 399 400 count = min_t(size_t, count, reg->size - off); 401 402 if (!reg->ioaddr) { 403 reg->ioaddr = 404 ioremap(reg->addr, reg->size); 405 406 if (!reg->ioaddr) 407 return -ENOMEM; 408 } 409 410 while (count) { 411 size_t filled; 412 413 if (count >= 4 && !(off % 4)) { 414 u32 val; 415 416 val = ioread32(reg->ioaddr + off); 417 if (copy_to_user(buf, &val, 4)) 418 goto err; 419 420 filled = 4; 421 } else if (count >= 2 && !(off % 2)) { 422 u16 val; 423 424 val = ioread16(reg->ioaddr + off); 425 if (copy_to_user(buf, &val, 2)) 426 goto err; 427 428 filled = 2; 429 } else { 430 u8 val; 431 432 val = ioread8(reg->ioaddr + off); 433 if (copy_to_user(buf, &val, 1)) 434 goto err; 435 436 filled = 1; 437 } 438 439 440 count -= filled; 441 done += filled; 442 off += filled; 443 buf += filled; 444 } 445 446 return done; 447 err: 448 return -EFAULT; 449 } 450 451 ssize_t vfio_platform_read(struct vfio_device *core_vdev, 452 char __user *buf, size_t count, loff_t *ppos) 453 { 454 struct vfio_platform_device *vdev = 455 container_of(core_vdev, struct vfio_platform_device, vdev); 456 unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos); 457 loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK; 458 459 if (index >= vdev->num_regions) 460 return -EINVAL; 461 462 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)) 463 return -EINVAL; 464 465 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) 466 return vfio_platform_read_mmio(&vdev->regions[index], 467 buf, count, off); 468 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) 469 return -EINVAL; /* not implemented */ 470 471 return -EINVAL; 472 } 473 EXPORT_SYMBOL_GPL(vfio_platform_read); 474 475 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg, 476 const char __user *buf, size_t count, 477 loff_t off) 478 { 479 unsigned int done = 0; 480 481 if (off >= reg->size) 482 return -EINVAL; 483 484 count = min_t(size_t, count, reg->size - off); 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 ssize_t vfio_platform_write(struct vfio_device *core_vdev, const char __user *buf, 535 size_t count, loff_t *ppos) 536 { 537 struct vfio_platform_device *vdev = 538 container_of(core_vdev, struct vfio_platform_device, vdev); 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 EXPORT_SYMBOL_GPL(vfio_platform_write); 557 558 static int vfio_platform_mmap_mmio(struct vfio_platform_region region, 559 struct vm_area_struct *vma) 560 { 561 u64 req_len, pgoff, req_start; 562 563 req_len = vma->vm_end - vma->vm_start; 564 pgoff = vma->vm_pgoff & 565 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1); 566 req_start = pgoff << PAGE_SHIFT; 567 568 if (region.size < PAGE_SIZE || req_start + req_len > region.size) 569 return -EINVAL; 570 571 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 572 vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff; 573 574 return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, 575 req_len, vma->vm_page_prot); 576 } 577 578 int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma) 579 { 580 struct vfio_platform_device *vdev = 581 container_of(core_vdev, struct vfio_platform_device, vdev); 582 unsigned int index; 583 584 index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT); 585 586 if (vma->vm_end < vma->vm_start) 587 return -EINVAL; 588 if (!(vma->vm_flags & VM_SHARED)) 589 return -EINVAL; 590 if (index >= vdev->num_regions) 591 return -EINVAL; 592 if (vma->vm_start & ~PAGE_MASK) 593 return -EINVAL; 594 if (vma->vm_end & ~PAGE_MASK) 595 return -EINVAL; 596 597 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP)) 598 return -EINVAL; 599 600 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ) 601 && (vma->vm_flags & VM_READ)) 602 return -EINVAL; 603 604 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE) 605 && (vma->vm_flags & VM_WRITE)) 606 return -EINVAL; 607 608 vma->vm_private_data = vdev; 609 610 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) 611 return vfio_platform_mmap_mmio(vdev->regions[index], vma); 612 613 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) 614 return -EINVAL; /* not implemented */ 615 616 return -EINVAL; 617 } 618 EXPORT_SYMBOL_GPL(vfio_platform_mmap); 619 620 static int vfio_platform_of_probe(struct vfio_platform_device *vdev, 621 struct device *dev) 622 { 623 int ret; 624 625 ret = device_property_read_string(dev, "compatible", 626 &vdev->compat); 627 if (ret) 628 dev_err(dev, "Cannot retrieve compat for %s\n", vdev->name); 629 630 return ret; 631 } 632 633 /* 634 * There can be two kernel build combinations. One build where 635 * ACPI is not selected in Kconfig and another one with the ACPI Kconfig. 636 * 637 * In the first case, vfio_platform_acpi_probe will return since 638 * acpi_disabled is 1. DT user will not see any kind of messages from 639 * ACPI. 640 * 641 * In the second case, both DT and ACPI is compiled in but the system is 642 * booting with any of these combinations. 643 * 644 * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine 645 * terminates immediately without any messages. 646 * 647 * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are 648 * valid checks. We cannot claim that this system is DT. 649 */ 650 int vfio_platform_init_common(struct vfio_platform_device *vdev) 651 { 652 int ret; 653 struct device *dev = vdev->vdev.dev; 654 655 ret = vfio_platform_acpi_probe(vdev, dev); 656 if (ret) 657 ret = vfio_platform_of_probe(vdev, dev); 658 659 if (ret) 660 return ret; 661 662 vdev->device = dev; 663 mutex_init(&vdev->igate); 664 665 ret = vfio_platform_get_reset(vdev); 666 if (ret && vdev->reset_required) { 667 dev_err(dev, "No reset function found for device %s\n", 668 vdev->name); 669 return ret; 670 } 671 672 return 0; 673 } 674 EXPORT_SYMBOL_GPL(vfio_platform_init_common); 675 676 void vfio_platform_release_common(struct vfio_platform_device *vdev) 677 { 678 vfio_platform_put_reset(vdev); 679 } 680 EXPORT_SYMBOL_GPL(vfio_platform_release_common); 681 682 void __vfio_platform_register_reset(struct vfio_platform_reset_node *node) 683 { 684 mutex_lock(&driver_lock); 685 list_add(&node->link, &reset_list); 686 mutex_unlock(&driver_lock); 687 } 688 EXPORT_SYMBOL_GPL(__vfio_platform_register_reset); 689 690 void vfio_platform_unregister_reset(const char *compat, 691 vfio_platform_reset_fn_t fn) 692 { 693 struct vfio_platform_reset_node *iter, *temp; 694 695 mutex_lock(&driver_lock); 696 list_for_each_entry_safe(iter, temp, &reset_list, link) { 697 if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) { 698 list_del(&iter->link); 699 break; 700 } 701 } 702 703 mutex_unlock(&driver_lock); 704 705 } 706 EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset); 707 708 MODULE_VERSION(DRIVER_VERSION); 709 MODULE_LICENSE("GPL v2"); 710 MODULE_AUTHOR(DRIVER_AUTHOR); 711 MODULE_DESCRIPTION(DRIVER_DESC); 712