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_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);