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 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);