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); 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 if (!res) 154 goto err; 155 156 vdev->regions[i].addr = res->start; 157 vdev->regions[i].size = resource_size(res); 158 vdev->regions[i].flags = 0; 159 160 switch (resource_type(res)) { 161 case IORESOURCE_MEM: 162 vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO; 163 vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ; 164 if (!(res->flags & IORESOURCE_READONLY)) 165 vdev->regions[i].flags |= 166 VFIO_REGION_INFO_FLAG_WRITE; 167 168 /* 169 * Only regions addressed with PAGE granularity may be 170 * MMAPed securely. 171 */ 172 if (!(vdev->regions[i].addr & ~PAGE_MASK) && 173 !(vdev->regions[i].size & ~PAGE_MASK)) 174 vdev->regions[i].flags |= 175 VFIO_REGION_INFO_FLAG_MMAP; 176 177 break; 178 case IORESOURCE_IO: 179 vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO; 180 break; 181 default: 182 goto err; 183 } 184 } 185 186 vdev->num_regions = cnt; 187 188 return 0; 189 err: 190 kfree(vdev->regions); 191 return -EINVAL; 192 } 193 194 static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev) 195 { 196 int i; 197 198 for (i = 0; i < vdev->num_regions; i++) 199 iounmap(vdev->regions[i].ioaddr); 200 201 vdev->num_regions = 0; 202 kfree(vdev->regions); 203 } 204 205 static int vfio_platform_call_reset(struct vfio_platform_device *vdev, 206 const char **extra_dbg) 207 { 208 if (VFIO_PLATFORM_IS_ACPI(vdev)) { 209 dev_info(vdev->device, "reset\n"); 210 return vfio_platform_acpi_call_reset(vdev, extra_dbg); 211 } else if (vdev->of_reset) { 212 dev_info(vdev->device, "reset\n"); 213 return vdev->of_reset(vdev); 214 } 215 216 dev_warn(vdev->device, "no reset function found!\n"); 217 return -EINVAL; 218 } 219 220 void vfio_platform_close_device(struct vfio_device *core_vdev) 221 { 222 struct vfio_platform_device *vdev = 223 container_of(core_vdev, struct vfio_platform_device, vdev); 224 const char *extra_dbg = NULL; 225 int ret; 226 227 ret = vfio_platform_call_reset(vdev, &extra_dbg); 228 if (WARN_ON(ret && vdev->reset_required)) { 229 dev_warn( 230 vdev->device, 231 "reset driver is required and reset call failed in release (%d) %s\n", 232 ret, extra_dbg ? extra_dbg : ""); 233 } 234 pm_runtime_put(vdev->device); 235 vfio_platform_regions_cleanup(vdev); 236 vfio_platform_irq_cleanup(vdev); 237 } 238 EXPORT_SYMBOL_GPL(vfio_platform_close_device); 239 240 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 EXPORT_SYMBOL_GPL(vfio_platform_open_device); 277 278 long vfio_platform_ioctl(struct vfio_device *core_vdev, 279 unsigned int cmd, unsigned long arg) 280 { 281 struct vfio_platform_device *vdev = 282 container_of(core_vdev, struct vfio_platform_device, vdev); 283 284 unsigned long minsz; 285 286 if (cmd == VFIO_DEVICE_GET_INFO) { 287 struct vfio_device_info info; 288 289 minsz = offsetofend(struct vfio_device_info, num_irqs); 290 291 if (copy_from_user(&info, (void __user *)arg, minsz)) 292 return -EFAULT; 293 294 if (info.argsz < minsz) 295 return -EINVAL; 296 297 if (vfio_platform_has_reset(vdev)) 298 vdev->flags |= VFIO_DEVICE_FLAGS_RESET; 299 info.flags = vdev->flags; 300 info.num_regions = vdev->num_regions; 301 info.num_irqs = vdev->num_irqs; 302 303 return copy_to_user((void __user *)arg, &info, minsz) ? 304 -EFAULT : 0; 305 306 } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) { 307 struct vfio_region_info info; 308 309 minsz = offsetofend(struct vfio_region_info, offset); 310 311 if (copy_from_user(&info, (void __user *)arg, minsz)) 312 return -EFAULT; 313 314 if (info.argsz < minsz) 315 return -EINVAL; 316 317 if (info.index >= vdev->num_regions) 318 return -EINVAL; 319 320 /* map offset to the physical address */ 321 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index); 322 info.size = vdev->regions[info.index].size; 323 info.flags = vdev->regions[info.index].flags; 324 325 return copy_to_user((void __user *)arg, &info, minsz) ? 326 -EFAULT : 0; 327 328 } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) { 329 struct vfio_irq_info info; 330 331 minsz = offsetofend(struct vfio_irq_info, count); 332 333 if (copy_from_user(&info, (void __user *)arg, minsz)) 334 return -EFAULT; 335 336 if (info.argsz < minsz) 337 return -EINVAL; 338 339 if (info.index >= vdev->num_irqs) 340 return -EINVAL; 341 342 info.flags = vdev->irqs[info.index].flags; 343 info.count = vdev->irqs[info.index].count; 344 345 return copy_to_user((void __user *)arg, &info, minsz) ? 346 -EFAULT : 0; 347 348 } else if (cmd == VFIO_DEVICE_SET_IRQS) { 349 struct vfio_irq_set hdr; 350 u8 *data = NULL; 351 int ret = 0; 352 size_t data_size = 0; 353 354 minsz = offsetofend(struct vfio_irq_set, count); 355 356 if (copy_from_user(&hdr, (void __user *)arg, minsz)) 357 return -EFAULT; 358 359 ret = vfio_set_irqs_validate_and_prepare(&hdr, vdev->num_irqs, 360 vdev->num_irqs, &data_size); 361 if (ret) 362 return ret; 363 364 if (data_size) { 365 data = memdup_user((void __user *)(arg + minsz), 366 data_size); 367 if (IS_ERR(data)) 368 return PTR_ERR(data); 369 } 370 371 mutex_lock(&vdev->igate); 372 373 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index, 374 hdr.start, hdr.count, data); 375 mutex_unlock(&vdev->igate); 376 kfree(data); 377 378 return ret; 379 380 } else if (cmd == VFIO_DEVICE_RESET) { 381 return vfio_platform_call_reset(vdev, NULL); 382 } 383 384 return -ENOTTY; 385 } 386 EXPORT_SYMBOL_GPL(vfio_platform_ioctl); 387 388 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg, 389 char __user *buf, size_t count, 390 loff_t off) 391 { 392 unsigned int done = 0; 393 394 if (!reg->ioaddr) { 395 reg->ioaddr = 396 ioremap(reg->addr, reg->size); 397 398 if (!reg->ioaddr) 399 return -ENOMEM; 400 } 401 402 while (count) { 403 size_t filled; 404 405 if (count >= 4 && !(off % 4)) { 406 u32 val; 407 408 val = ioread32(reg->ioaddr + off); 409 if (copy_to_user(buf, &val, 4)) 410 goto err; 411 412 filled = 4; 413 } else if (count >= 2 && !(off % 2)) { 414 u16 val; 415 416 val = ioread16(reg->ioaddr + off); 417 if (copy_to_user(buf, &val, 2)) 418 goto err; 419 420 filled = 2; 421 } else { 422 u8 val; 423 424 val = ioread8(reg->ioaddr + off); 425 if (copy_to_user(buf, &val, 1)) 426 goto err; 427 428 filled = 1; 429 } 430 431 432 count -= filled; 433 done += filled; 434 off += filled; 435 buf += filled; 436 } 437 438 return done; 439 err: 440 return -EFAULT; 441 } 442 443 ssize_t vfio_platform_read(struct vfio_device *core_vdev, 444 char __user *buf, size_t count, loff_t *ppos) 445 { 446 struct vfio_platform_device *vdev = 447 container_of(core_vdev, struct vfio_platform_device, vdev); 448 unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos); 449 loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK; 450 451 if (index >= vdev->num_regions) 452 return -EINVAL; 453 454 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)) 455 return -EINVAL; 456 457 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) 458 return vfio_platform_read_mmio(&vdev->regions[index], 459 buf, count, off); 460 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) 461 return -EINVAL; /* not implemented */ 462 463 return -EINVAL; 464 } 465 EXPORT_SYMBOL_GPL(vfio_platform_read); 466 467 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg, 468 const char __user *buf, size_t count, 469 loff_t off) 470 { 471 unsigned int done = 0; 472 473 if (!reg->ioaddr) { 474 reg->ioaddr = 475 ioremap(reg->addr, reg->size); 476 477 if (!reg->ioaddr) 478 return -ENOMEM; 479 } 480 481 while (count) { 482 size_t filled; 483 484 if (count >= 4 && !(off % 4)) { 485 u32 val; 486 487 if (copy_from_user(&val, buf, 4)) 488 goto err; 489 iowrite32(val, reg->ioaddr + off); 490 491 filled = 4; 492 } else if (count >= 2 && !(off % 2)) { 493 u16 val; 494 495 if (copy_from_user(&val, buf, 2)) 496 goto err; 497 iowrite16(val, reg->ioaddr + off); 498 499 filled = 2; 500 } else { 501 u8 val; 502 503 if (copy_from_user(&val, buf, 1)) 504 goto err; 505 iowrite8(val, reg->ioaddr + off); 506 507 filled = 1; 508 } 509 510 count -= filled; 511 done += filled; 512 off += filled; 513 buf += filled; 514 } 515 516 return done; 517 err: 518 return -EFAULT; 519 } 520 521 ssize_t vfio_platform_write(struct vfio_device *core_vdev, const char __user *buf, 522 size_t count, loff_t *ppos) 523 { 524 struct vfio_platform_device *vdev = 525 container_of(core_vdev, struct vfio_platform_device, vdev); 526 unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos); 527 loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK; 528 529 if (index >= vdev->num_regions) 530 return -EINVAL; 531 532 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)) 533 return -EINVAL; 534 535 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) 536 return vfio_platform_write_mmio(&vdev->regions[index], 537 buf, count, off); 538 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) 539 return -EINVAL; /* not implemented */ 540 541 return -EINVAL; 542 } 543 EXPORT_SYMBOL_GPL(vfio_platform_write); 544 545 static int vfio_platform_mmap_mmio(struct vfio_platform_region region, 546 struct vm_area_struct *vma) 547 { 548 u64 req_len, pgoff, req_start; 549 550 req_len = vma->vm_end - vma->vm_start; 551 pgoff = vma->vm_pgoff & 552 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1); 553 req_start = pgoff << PAGE_SHIFT; 554 555 if (region.size < PAGE_SIZE || req_start + req_len > region.size) 556 return -EINVAL; 557 558 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 559 vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff; 560 561 return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, 562 req_len, vma->vm_page_prot); 563 } 564 565 int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma) 566 { 567 struct vfio_platform_device *vdev = 568 container_of(core_vdev, struct vfio_platform_device, vdev); 569 unsigned int index; 570 571 index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT); 572 573 if (vma->vm_end < vma->vm_start) 574 return -EINVAL; 575 if (!(vma->vm_flags & VM_SHARED)) 576 return -EINVAL; 577 if (index >= vdev->num_regions) 578 return -EINVAL; 579 if (vma->vm_start & ~PAGE_MASK) 580 return -EINVAL; 581 if (vma->vm_end & ~PAGE_MASK) 582 return -EINVAL; 583 584 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP)) 585 return -EINVAL; 586 587 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ) 588 && (vma->vm_flags & VM_READ)) 589 return -EINVAL; 590 591 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE) 592 && (vma->vm_flags & VM_WRITE)) 593 return -EINVAL; 594 595 vma->vm_private_data = vdev; 596 597 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) 598 return vfio_platform_mmap_mmio(vdev->regions[index], vma); 599 600 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) 601 return -EINVAL; /* not implemented */ 602 603 return -EINVAL; 604 } 605 EXPORT_SYMBOL_GPL(vfio_platform_mmap); 606 607 static int vfio_platform_of_probe(struct vfio_platform_device *vdev, 608 struct device *dev) 609 { 610 int ret; 611 612 ret = device_property_read_string(dev, "compatible", 613 &vdev->compat); 614 if (ret) 615 dev_err(dev, "Cannot retrieve compat for %s\n", vdev->name); 616 617 return ret; 618 } 619 620 /* 621 * There can be two kernel build combinations. One build where 622 * ACPI is not selected in Kconfig and another one with the ACPI Kconfig. 623 * 624 * In the first case, vfio_platform_acpi_probe will return since 625 * acpi_disabled is 1. DT user will not see any kind of messages from 626 * ACPI. 627 * 628 * In the second case, both DT and ACPI is compiled in but the system is 629 * booting with any of these combinations. 630 * 631 * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine 632 * terminates immediately without any messages. 633 * 634 * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are 635 * valid checks. We cannot claim that this system is DT. 636 */ 637 int vfio_platform_init_common(struct vfio_platform_device *vdev) 638 { 639 int ret; 640 struct device *dev = vdev->vdev.dev; 641 642 ret = vfio_platform_acpi_probe(vdev, dev); 643 if (ret) 644 ret = vfio_platform_of_probe(vdev, dev); 645 646 if (ret) 647 return ret; 648 649 vdev->device = dev; 650 mutex_init(&vdev->igate); 651 652 ret = vfio_platform_get_reset(vdev); 653 if (ret && vdev->reset_required) 654 dev_err(dev, "No reset function found for device %s\n", 655 vdev->name); 656 return ret; 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