drivers/vfio/platform/vfio_platform_common.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2013 - Virtual Open Systems
   4  * Author: Antonios Motakis <[email protected]>
   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 <[email protected]>"
  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 static void vfio_platform_release(struct vfio_device *core_vdev)
 222 {
 223         struct vfio_platform_device *vdev =
 224                 container_of(core_vdev, struct vfio_platform_device, vdev);
 225
 226         mutex_lock(&driver_lock);
 227
 228         if (!(--vdev->refcnt)) {
 229                 const char *extra_dbg = NULL;
 230                 int ret;
 231
 232                 ret = vfio_platform_call_reset(vdev, &extra_dbg);
 233                 if (ret && vdev->reset_required) {
 234                         dev_warn(vdev->device, "reset driver is required and reset call failed in release (%d) %s\n",
 235                                  ret, extra_dbg ? extra_dbg : "");
 236                         WARN_ON(1);
 237                 }
 238                 pm_runtime_put(vdev->device);
 239                 vfio_platform_regions_cleanup(vdev);
 240                 vfio_platform_irq_cleanup(vdev);
 241         }
 242
 243         mutex_unlock(&driver_lock);
 244 }
 245
 246 static int vfio_platform_open(struct vfio_device *core_vdev)
 247 {
 248         struct vfio_platform_device *vdev =
 249                 container_of(core_vdev, struct vfio_platform_device, vdev);
 250         int ret;
 251
 252         mutex_lock(&driver_lock);
 253
 254         if (!vdev->refcnt) {
 255                 const char *extra_dbg = NULL;
 256
 257                 ret = vfio_platform_regions_init(vdev);
 258                 if (ret)
 259                         goto err_reg;
 260
 261                 ret = vfio_platform_irq_init(vdev);
 262                 if (ret)
 263                         goto err_irq;
 264
 265                 ret = pm_runtime_get_sync(vdev->device);
 266                 if (ret < 0)
 267                         goto err_rst;
 268
 269                 ret = vfio_platform_call_reset(vdev, &extra_dbg);
 270                 if (ret && vdev->reset_required) {
 271                         dev_warn(vdev->device, "reset driver is required and reset call failed in open (%d) %s\n",
 272                                  ret, extra_dbg ? extra_dbg : "");
 273                         goto err_rst;
 274                 }
 275         }
 276
 277         vdev->refcnt++;
 278
 279         mutex_unlock(&driver_lock);
 280         return 0;
 281
 282 err_rst:
 283         pm_runtime_put(vdev->device);
 284         vfio_platform_irq_cleanup(vdev);
 285 err_irq:
 286         vfio_platform_regions_cleanup(vdev);
 287 err_reg:
 288         mutex_unlock(&driver_lock);
 289         return ret;
 290 }
 291
 292 static long vfio_platform_ioctl(struct vfio_device *core_vdev,
 293                                 unsigned int cmd, unsigned long arg)
 294 {
 295         struct vfio_platform_device *vdev =
 296                 container_of(core_vdev, struct vfio_platform_device, vdev);
 297
 298         unsigned long minsz;
 299
 300         if (cmd == VFIO_DEVICE_GET_INFO) {
 301                 struct vfio_device_info info;
 302
 303                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 304
 305                 if (copy_from_user(&info, (void __user *)arg, minsz))
 306                         return -EFAULT;
 307
 308                 if (info.argsz < minsz)
 309                         return -EINVAL;
 310
 311                 if (vfio_platform_has_reset(vdev))
 312                         vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
 313                 info.flags = vdev->flags;
 314                 info.num_regions = vdev->num_regions;
 315                 info.num_irqs = vdev->num_irqs;
 316
 317                 return copy_to_user((void __user *)arg, &info, minsz) ?
 318                         -EFAULT : 0;
 319
 320         } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
 321                 struct vfio_region_info info;
 322
 323                 minsz = offsetofend(struct vfio_region_info, offset);
 324
 325                 if (copy_from_user(&info, (void __user *)arg, minsz))
 326                         return -EFAULT;
 327
 328                 if (info.argsz < minsz)
 329                         return -EINVAL;
 330
 331                 if (info.index >= vdev->num_regions)
 332                         return -EINVAL;
 333
 334                 /* map offset to the physical address  */
 335                 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
 336                 info.size = vdev->regions[info.index].size;
 337                 info.flags = vdev->regions[info.index].flags;
 338
 339                 return copy_to_user((void __user *)arg, &info, minsz) ?
 340                         -EFAULT : 0;
 341
 342         } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
 343                 struct vfio_irq_info info;
 344
 345                 minsz = offsetofend(struct vfio_irq_info, count);
 346
 347                 if (copy_from_user(&info, (void __user *)arg, minsz))
 348                         return -EFAULT;
 349
 350                 if (info.argsz < minsz)
 351                         return -EINVAL;
 352
 353                 if (info.index >= vdev->num_irqs)
 354                         return -EINVAL;
 355
 356                 info.flags = vdev->irqs[info.index].flags;
 357                 info.count = vdev->irqs[info.index].count;
 358
 359                 return copy_to_user((void __user *)arg, &info, minsz) ?
 360                         -EFAULT : 0;
 361
 362         } else if (cmd == VFIO_DEVICE_SET_IRQS) {
 363                 struct vfio_irq_set hdr;
 364                 u8 *data = NULL;
 365                 int ret = 0;
 366                 size_t data_size = 0;
 367
 368                 minsz = offsetofend(struct vfio_irq_set, count);
 369
 370                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 371                         return -EFAULT;
 372
 373                 ret = vfio_set_irqs_validate_and_prepare(&hdr, vdev->num_irqs,
 374                                                  vdev->num_irqs, &data_size);
 375                 if (ret)
 376                         return ret;
 377
 378                 if (data_size) {
 379                         data = memdup_user((void __user *)(arg + minsz),
 380                                             data_size);
 381                         if (IS_ERR(data))
 382                                 return PTR_ERR(data);
 383                 }
 384
 385                 mutex_lock(&vdev->igate);
 386
 387                 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
 388                                                    hdr.start, hdr.count, data);
 389                 mutex_unlock(&vdev->igate);
 390                 kfree(data);
 391
 392                 return ret;
 393
 394         } else if (cmd == VFIO_DEVICE_RESET) {
 395                 return vfio_platform_call_reset(vdev, NULL);
 396         }
 397
 398         return -ENOTTY;
 399 }
 400
 401 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
 402                                        char __user *buf, size_t count,
 403                                        loff_t off)
 404 {
 405         unsigned int done = 0;
 406
 407         if (!reg->ioaddr) {
 408                 reg->ioaddr =
 409                         ioremap(reg->addr, reg->size);
 410
 411                 if (!reg->ioaddr)
 412                         return -ENOMEM;
 413         }
 414
 415         while (count) {
 416                 size_t filled;
 417
 418                 if (count >= 4 && !(off % 4)) {
 419                         u32 val;
 420
 421                         val = ioread32(reg->ioaddr + off);
 422                         if (copy_to_user(buf, &val, 4))
 423                                 goto err;
 424
 425                         filled = 4;
 426                 } else if (count >= 2 && !(off % 2)) {
 427                         u16 val;
 428
 429                         val = ioread16(reg->ioaddr + off);
 430                         if (copy_to_user(buf, &val, 2))
 431                                 goto err;
 432
 433                         filled = 2;
 434                 } else {
 435                         u8 val;
 436
 437                         val = ioread8(reg->ioaddr + off);
 438                         if (copy_to_user(buf, &val, 1))
 439                                 goto err;
 440
 441                         filled = 1;
 442                 }
 443
 444
 445                 count -= filled;
 446                 done += filled;
 447                 off += filled;
 448                 buf += filled;
 449         }
 450
 451         return done;
 452 err:
 453         return -EFAULT;
 454 }
 455
 456 static ssize_t vfio_platform_read(struct vfio_device *core_vdev,
 457                                   char __user *buf, size_t count, loff_t *ppos)
 458 {
 459         struct vfio_platform_device *vdev =
 460                 container_of(core_vdev, struct vfio_platform_device, vdev);
 461         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 462         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 463
 464         if (index >= vdev->num_regions)
 465                 return -EINVAL;
 466
 467         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
 468                 return -EINVAL;
 469
 470         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 471                 return vfio_platform_read_mmio(&vdev->regions[index],
 472                                                         buf, count, off);
 473         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 474                 return -EINVAL; /* not implemented */
 475
 476         return -EINVAL;
 477 }
 478
 479 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
 480                                         const char __user *buf, size_t count,
 481                                         loff_t off)
 482 {
 483         unsigned int done = 0;
 484
 485         if (!reg->ioaddr) {
 486                 reg->ioaddr =
 487                         ioremap(reg->addr, reg->size);
 488
 489                 if (!reg->ioaddr)
 490                         return -ENOMEM;
 491         }
 492
 493         while (count) {
 494                 size_t filled;
 495
 496                 if (count >= 4 && !(off % 4)) {
 497                         u32 val;
 498
 499                         if (copy_from_user(&val, buf, 4))
 500                                 goto err;
 501                         iowrite32(val, reg->ioaddr + off);
 502
 503                         filled = 4;
 504                 } else if (count >= 2 && !(off % 2)) {
 505                         u16 val;
 506
 507                         if (copy_from_user(&val, buf, 2))
 508                                 goto err;
 509                         iowrite16(val, reg->ioaddr + off);
 510
 511                         filled = 2;
 512                 } else {
 513                         u8 val;
 514
 515                         if (copy_from_user(&val, buf, 1))
 516                                 goto err;
 517                         iowrite8(val, reg->ioaddr + off);
 518
 519                         filled = 1;
 520                 }
 521
 522                 count -= filled;
 523                 done += filled;
 524                 off += filled;
 525                 buf += filled;
 526         }
 527
 528         return done;
 529 err:
 530         return -EFAULT;
 531 }
 532
 533 static ssize_t vfio_platform_write(struct vfio_device *core_vdev, const char __user *buf,
 534                                    size_t count, loff_t *ppos)
 535 {
 536         struct vfio_platform_device *vdev =
 537                 container_of(core_vdev, struct vfio_platform_device, vdev);
 538         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 539         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 540
 541         if (index >= vdev->num_regions)
 542                 return -EINVAL;
 543
 544         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
 545                 return -EINVAL;
 546
 547         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 548                 return vfio_platform_write_mmio(&vdev->regions[index],
 549                                                         buf, count, off);
 550         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 551                 return -EINVAL; /* not implemented */
 552
 553         return -EINVAL;
 554 }
 555
 556 static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
 557                                    struct vm_area_struct *vma)
 558 {
 559         u64 req_len, pgoff, req_start;
 560
 561         req_len = vma->vm_end - vma->vm_start;
 562         pgoff = vma->vm_pgoff &
 563                 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
 564         req_start = pgoff << PAGE_SHIFT;
 565
 566         if (region.size < PAGE_SIZE || req_start + req_len > region.size)
 567                 return -EINVAL;
 568
 569         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 570         vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
 571
 572         return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
 573                                req_len, vma->vm_page_prot);
 574 }
 575
 576 static int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma)
 577 {
 578         struct vfio_platform_device *vdev =
 579                 container_of(core_vdev, struct vfio_platform_device, vdev);
 580         unsigned int index;
 581
 582         index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);
 583
 584         if (vma->vm_end < vma->vm_start)
 585                 return -EINVAL;
 586         if (!(vma->vm_flags & VM_SHARED))
 587                 return -EINVAL;
 588         if (index >= vdev->num_regions)
 589                 return -EINVAL;
 590         if (vma->vm_start & ~PAGE_MASK)
 591                 return -EINVAL;
 592         if (vma->vm_end & ~PAGE_MASK)
 593                 return -EINVAL;
 594
 595         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
 596                 return -EINVAL;
 597
 598         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
 599                         && (vma->vm_flags & VM_READ))
 600                 return -EINVAL;
 601
 602         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
 603                         && (vma->vm_flags & VM_WRITE))
 604                 return -EINVAL;
 605
 606         vma->vm_private_data = vdev;
 607
 608         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 609                 return vfio_platform_mmap_mmio(vdev->regions[index], vma);
 610
 611         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 612                 return -EINVAL; /* not implemented */
 613
 614         return -EINVAL;
 615 }
 616
 617 static const struct vfio_device_ops vfio_platform_ops = {
 618         .name           = "vfio-platform",
 619         .open           = vfio_platform_open,
 620         .release        = vfio_platform_release,
 621         .ioctl          = vfio_platform_ioctl,
 622         .read           = vfio_platform_read,
 623         .write          = vfio_platform_write,
 624         .mmap           = vfio_platform_mmap,
 625 };
 626
 627 static int vfio_platform_of_probe(struct vfio_platform_device *vdev,
 628                            struct device *dev)
 629 {
 630         int ret;
 631
 632         ret = device_property_read_string(dev, "compatible",
 633                                           &vdev->compat);
 634         if (ret)
 635                 dev_err(dev, "Cannot retrieve compat for %s\n", vdev->name);
 636
 637         return ret;
 638 }
 639
 640 /*
 641  * There can be two kernel build combinations. One build where
 642  * ACPI is not selected in Kconfig and another one with the ACPI Kconfig.
 643  *
 644  * In the first case, vfio_platform_acpi_probe will return since
 645  * acpi_disabled is 1. DT user will not see any kind of messages from
 646  * ACPI.
 647  *
 648  * In the second case, both DT and ACPI is compiled in but the system is
 649  * booting with any of these combinations.
 650  *
 651  * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine
 652  * terminates immediately without any messages.
 653  *
 654  * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are
 655  * valid checks. We cannot claim that this system is DT.
 656  */
 657 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 658                                struct device *dev)
 659 {
 660         struct iommu_group *group;
 661         int ret;
 662
 663         vfio_init_group_dev(&vdev->vdev, dev, &vfio_platform_ops);
 664
 665         ret = vfio_platform_acpi_probe(vdev, dev);
 666         if (ret)
 667                 ret = vfio_platform_of_probe(vdev, dev);
 668
 669         if (ret)
 670                 return ret;
 671
 672         vdev->device = dev;
 673
 674         ret = vfio_platform_get_reset(vdev);
 675         if (ret && vdev->reset_required) {
 676                 dev_err(dev, "No reset function found for device %s\n",
 677                         vdev->name);
 678                 return ret;
 679         }
 680
 681         group = vfio_iommu_group_get(dev);
 682         if (!group) {
 683                 dev_err(dev, "No IOMMU group for device %s\n", vdev->name);
 684                 ret = -EINVAL;
 685                 goto put_reset;
 686         }
 687
 688         ret = vfio_register_group_dev(&vdev->vdev);
 689         if (ret)
 690                 goto put_iommu;
 691
 692         mutex_init(&vdev->igate);
 693
 694         pm_runtime_enable(dev);
 695         return 0;
 696
 697 put_iommu:
 698         vfio_iommu_group_put(group, dev);
 699 put_reset:
 700         vfio_platform_put_reset(vdev);
 701         return ret;
 702 }
 703 EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
 704
 705 void vfio_platform_remove_common(struct vfio_platform_device *vdev)
 706 {
 707         vfio_unregister_group_dev(&vdev->vdev);
 708
 709         pm_runtime_disable(vdev->device);
 710         vfio_platform_put_reset(vdev);
 711         vfio_iommu_group_put(vdev->vdev.dev->iommu_group, vdev->vdev.dev);
 712 }
 713 EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
 714
 715 void __vfio_platform_register_reset(struct vfio_platform_reset_node *node)
 716 {
 717         mutex_lock(&driver_lock);
 718         list_add(&node->link, &reset_list);
 719         mutex_unlock(&driver_lock);
 720 }
 721 EXPORT_SYMBOL_GPL(__vfio_platform_register_reset);
 722
 723 void vfio_platform_unregister_reset(const char *compat,
 724                                     vfio_platform_reset_fn_t fn)
 725 {
 726         struct vfio_platform_reset_node *iter, *temp;
 727
 728         mutex_lock(&driver_lock);
 729         list_for_each_entry_safe(iter, temp, &reset_list, link) {
 730                 if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) {
 731                         list_del(&iter->link);
 732                         break;
 733                 }
 734         }
 735
 736         mutex_unlock(&driver_lock);
 737
 738 }
 739 EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset);
 740
 741 MODULE_VERSION(DRIVER_VERSION);
 742 MODULE_LICENSE("GPL v2");
 743 MODULE_AUTHOR(DRIVER_AUTHOR);
 744 MODULE_DESCRIPTION(DRIVER_DESC);