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