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