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 *info, 277 struct vfio_info_cap *caps) 278 { 279 struct vfio_platform_device *vdev = 280 container_of(core_vdev, struct vfio_platform_device, vdev); 281 282 if (info->index >= vdev->num_regions) 283 return -EINVAL; 284 285 /* map offset to the physical address */ 286 info->offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info->index); 287 info->size = vdev->regions[info->index].size; 288 info->flags = vdev->regions[info->index].flags; 289 return 0; 290 } 291 EXPORT_SYMBOL_GPL(vfio_platform_ioctl_get_region_info); 292 293 long vfio_platform_ioctl(struct vfio_device *core_vdev, 294 unsigned int cmd, unsigned long arg) 295 { 296 struct vfio_platform_device *vdev = 297 container_of(core_vdev, struct vfio_platform_device, vdev); 298 299 unsigned long minsz; 300 301 if (cmd == VFIO_DEVICE_GET_INFO) { 302 struct vfio_device_info info; 303 304 minsz = offsetofend(struct vfio_device_info, num_irqs); 305 306 if (copy_from_user(&info, (void __user *)arg, minsz)) 307 return -EFAULT; 308 309 if (info.argsz < minsz) 310 return -EINVAL; 311 312 if (vfio_platform_has_reset(vdev)) 313 vdev->flags |= VFIO_DEVICE_FLAGS_RESET; 314 info.flags = vdev->flags; 315 info.num_regions = vdev->num_regions; 316 info.num_irqs = vdev->num_irqs; 317 318 return copy_to_user((void __user *)arg, &info, minsz) ? 319 -EFAULT : 0; 320 321 } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) { 322 struct vfio_irq_info info; 323 324 minsz = offsetofend(struct vfio_irq_info, count); 325 326 if (copy_from_user(&info, (void __user *)arg, minsz)) 327 return -EFAULT; 328 329 if (info.argsz < minsz) 330 return -EINVAL; 331 332 if (info.index >= vdev->num_irqs) 333 return -EINVAL; 334 335 info.flags = vdev->irqs[info.index].flags; 336 info.count = vdev->irqs[info.index].count; 337 338 return copy_to_user((void __user *)arg, &info, minsz) ? 339 -EFAULT : 0; 340 341 } else if (cmd == VFIO_DEVICE_SET_IRQS) { 342 struct vfio_irq_set hdr; 343 u8 *data = NULL; 344 int ret = 0; 345 size_t data_size = 0; 346 347 minsz = offsetofend(struct vfio_irq_set, count); 348 349 if (copy_from_user(&hdr, (void __user *)arg, minsz)) 350 return -EFAULT; 351 352 ret = vfio_set_irqs_validate_and_prepare(&hdr, vdev->num_irqs, 353 vdev->num_irqs, &data_size); 354 if (ret) 355 return ret; 356 357 if (data_size) { 358 data = memdup_user((void __user *)(arg + minsz), 359 data_size); 360 if (IS_ERR(data)) 361 return PTR_ERR(data); 362 } 363 364 mutex_lock(&vdev->igate); 365 366 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index, 367 hdr.start, hdr.count, data); 368 mutex_unlock(&vdev->igate); 369 kfree(data); 370 371 return ret; 372 373 } else if (cmd == VFIO_DEVICE_RESET) { 374 return vfio_platform_call_reset(vdev, NULL); 375 } 376 377 return -ENOTTY; 378 } 379 EXPORT_SYMBOL_GPL(vfio_platform_ioctl); 380 381 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg, 382 char __user *buf, size_t count, 383 loff_t off) 384 { 385 unsigned int done = 0; 386 387 if (off >= reg->size) 388 return -EINVAL; 389 390 count = min_t(size_t, count, reg->size - off); 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 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 EXPORT_SYMBOL_GPL(vfio_platform_read); 464 465 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg, 466 const char __user *buf, size_t count, 467 loff_t off) 468 { 469 unsigned int done = 0; 470 471 if (off >= reg->size) 472 return -EINVAL; 473 474 count = min_t(size_t, count, reg->size - off); 475 476 if (!reg->ioaddr) { 477 reg->ioaddr = 478 ioremap(reg->addr, reg->size); 479 480 if (!reg->ioaddr) 481 return -ENOMEM; 482 } 483 484 while (count) { 485 size_t filled; 486 487 if (count >= 4 && !(off % 4)) { 488 u32 val; 489 490 if (copy_from_user(&val, buf, 4)) 491 goto err; 492 iowrite32(val, reg->ioaddr + off); 493 494 filled = 4; 495 } else if (count >= 2 && !(off % 2)) { 496 u16 val; 497 498 if (copy_from_user(&val, buf, 2)) 499 goto err; 500 iowrite16(val, reg->ioaddr + off); 501 502 filled = 2; 503 } else { 504 u8 val; 505 506 if (copy_from_user(&val, buf, 1)) 507 goto err; 508 iowrite8(val, reg->ioaddr + off); 509 510 filled = 1; 511 } 512 513 count -= filled; 514 done += filled; 515 off += filled; 516 buf += filled; 517 } 518 519 return done; 520 err: 521 return -EFAULT; 522 } 523 524 ssize_t vfio_platform_write(struct vfio_device *core_vdev, const char __user *buf, 525 size_t count, loff_t *ppos) 526 { 527 struct vfio_platform_device *vdev = 528 container_of(core_vdev, struct vfio_platform_device, vdev); 529 unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos); 530 loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK; 531 532 if (index >= vdev->num_regions) 533 return -EINVAL; 534 535 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)) 536 return -EINVAL; 537 538 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) 539 return vfio_platform_write_mmio(&vdev->regions[index], 540 buf, count, off); 541 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) 542 return -EINVAL; /* not implemented */ 543 544 return -EINVAL; 545 } 546 EXPORT_SYMBOL_GPL(vfio_platform_write); 547 548 static int vfio_platform_mmap_mmio(struct vfio_platform_region region, 549 struct vm_area_struct *vma) 550 { 551 u64 req_len, pgoff, req_start; 552 553 req_len = vma->vm_end - vma->vm_start; 554 pgoff = vma->vm_pgoff & 555 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1); 556 req_start = pgoff << PAGE_SHIFT; 557 558 if (region.size < PAGE_SIZE || req_start + req_len > region.size) 559 return -EINVAL; 560 561 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 562 vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff; 563 564 return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, 565 req_len, vma->vm_page_prot); 566 } 567 568 int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma) 569 { 570 struct vfio_platform_device *vdev = 571 container_of(core_vdev, struct vfio_platform_device, vdev); 572 unsigned int index; 573 574 index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT); 575 576 if (vma->vm_end < vma->vm_start) 577 return -EINVAL; 578 if (!(vma->vm_flags & VM_SHARED)) 579 return -EINVAL; 580 if (index >= vdev->num_regions) 581 return -EINVAL; 582 if (vma->vm_start & ~PAGE_MASK) 583 return -EINVAL; 584 if (vma->vm_end & ~PAGE_MASK) 585 return -EINVAL; 586 587 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP)) 588 return -EINVAL; 589 590 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ) 591 && (vma->vm_flags & VM_READ)) 592 return -EINVAL; 593 594 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE) 595 && (vma->vm_flags & VM_WRITE)) 596 return -EINVAL; 597 598 vma->vm_private_data = vdev; 599 600 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) 601 return vfio_platform_mmap_mmio(vdev->regions[index], vma); 602 603 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) 604 return -EINVAL; /* not implemented */ 605 606 return -EINVAL; 607 } 608 EXPORT_SYMBOL_GPL(vfio_platform_mmap); 609 610 static int vfio_platform_of_probe(struct vfio_platform_device *vdev, 611 struct device *dev) 612 { 613 int ret; 614 615 ret = device_property_read_string(dev, "compatible", 616 &vdev->compat); 617 if (ret) 618 dev_err(dev, "Cannot retrieve compat for %s\n", vdev->name); 619 620 return ret; 621 } 622 623 /* 624 * There can be two kernel build combinations. One build where 625 * ACPI is not selected in Kconfig and another one with the ACPI Kconfig. 626 * 627 * In the first case, vfio_platform_acpi_probe will return since 628 * acpi_disabled is 1. DT user will not see any kind of messages from 629 * ACPI. 630 * 631 * In the second case, both DT and ACPI is compiled in but the system is 632 * booting with any of these combinations. 633 * 634 * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine 635 * terminates immediately without any messages. 636 * 637 * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are 638 * valid checks. We cannot claim that this system is DT. 639 */ 640 int vfio_platform_init_common(struct vfio_platform_device *vdev) 641 { 642 int ret; 643 struct device *dev = vdev->vdev.dev; 644 645 ret = vfio_platform_acpi_probe(vdev, dev); 646 if (ret) 647 ret = vfio_platform_of_probe(vdev, dev); 648 649 if (ret) 650 return ret; 651 652 vdev->device = dev; 653 mutex_init(&vdev->igate); 654 655 ret = vfio_platform_get_reset(vdev); 656 if (ret && vdev->reset_required) { 657 dev_err(dev, "No reset function found for device %s\n", 658 vdev->name); 659 return ret; 660 } 661 662 return 0; 663 } 664 EXPORT_SYMBOL_GPL(vfio_platform_init_common); 665 666 void vfio_platform_release_common(struct vfio_platform_device *vdev) 667 { 668 vfio_platform_put_reset(vdev); 669 } 670 EXPORT_SYMBOL_GPL(vfio_platform_release_common); 671 672 void __vfio_platform_register_reset(struct vfio_platform_reset_node *node) 673 { 674 mutex_lock(&driver_lock); 675 list_add(&node->link, &reset_list); 676 mutex_unlock(&driver_lock); 677 } 678 EXPORT_SYMBOL_GPL(__vfio_platform_register_reset); 679 680 void vfio_platform_unregister_reset(const char *compat, 681 vfio_platform_reset_fn_t fn) 682 { 683 struct vfio_platform_reset_node *iter, *temp; 684 685 mutex_lock(&driver_lock); 686 list_for_each_entry_safe(iter, temp, &reset_list, link) { 687 if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) { 688 list_del(&iter->link); 689 break; 690 } 691 } 692 693 mutex_unlock(&driver_lock); 694 695 } 696 EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset); 697 698 MODULE_VERSION(DRIVER_VERSION); 699 MODULE_LICENSE("GPL v2"); 700 MODULE_AUTHOR(DRIVER_AUTHOR); 701 MODULE_DESCRIPTION(DRIVER_DESC); 702