drivers/vfio/platform/vfio_platform_common.c

   1 /*
   2  * Copyright (C) 2013 - Virtual Open Systems
   3  * Author: Antonios Motakis <a.motakis@virtualopensystems.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License, version 2, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <linux/device.h>
  16 #include <linux/acpi.h>
  17 #include <linux/iommu.h>
  18 #include <linux/module.h>
  19 #include <linux/mutex.h>
  20 #include <linux/pm_runtime.h>
  21 #include <linux/slab.h>
  22 #include <linux/types.h>
  23 #include <linux/uaccess.h>
  24 #include <linux/vfio.h>
  25
  26 #include "vfio_platform_private.h"
  27
  28 #define DRIVER_VERSION  "0.10"
  29 #define DRIVER_AUTHOR   "Antonios Motakis <a.motakis@virtualopensystems.com>"
  30 #define DRIVER_DESC     "VFIO platform base module"
  31
  32 #define VFIO_PLATFORM_IS_ACPI(vdev) ((vdev)->acpihid != NULL)
  33
  34 static LIST_HEAD(reset_list);
  35 static DEFINE_MUTEX(driver_lock);
  36
  37 static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat,
  38                                         struct module **module)
  39 {
  40         struct vfio_platform_reset_node *iter;
  41         vfio_platform_reset_fn_t reset_fn = NULL;
  42
  43         mutex_lock(&driver_lock);
  44         list_for_each_entry(iter, &reset_list, link) {
  45                 if (!strcmp(iter->compat, compat) &&
  46                         try_module_get(iter->owner)) {
  47                         *module = iter->owner;
  48                         reset_fn = iter->of_reset;
  49                         break;
  50                 }
  51         }
  52         mutex_unlock(&driver_lock);
  53         return reset_fn;
  54 }
  55
  56 static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev,
  57                                     struct device *dev)
  58 {
  59         struct acpi_device *adev;
  60
  61         if (acpi_disabled)
  62                 return -ENOENT;
  63
  64         adev = ACPI_COMPANION(dev);
  65         if (!adev) {
  66                 pr_err("VFIO: ACPI companion device not found for %s\n",
  67                         vdev->name);
  68                 return -ENODEV;
  69         }
  70
  71 #ifdef CONFIG_ACPI
  72         vdev->acpihid = acpi_device_hid(adev);
  73 #endif
  74         return WARN_ON(!vdev->acpihid) ? -EINVAL : 0;
  75 }
  76
  77 static int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev,
  78                                   const char **extra_dbg)
  79 {
  80 #ifdef CONFIG_ACPI
  81         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  82         struct device *dev = vdev->device;
  83         acpi_handle handle = ACPI_HANDLE(dev);
  84         acpi_status acpi_ret;
  85
  86         acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, &buffer);
  87         if (ACPI_FAILURE(acpi_ret)) {
  88                 if (extra_dbg)
  89                         *extra_dbg = acpi_format_exception(acpi_ret);
  90                 return -EINVAL;
  91         }
  92
  93         return 0;
  94 #else
  95         return -ENOENT;
  96 #endif
  97 }
  98
  99 static bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev)
 100 {
 101 #ifdef CONFIG_ACPI
 102         struct device *dev = vdev->device;
 103         acpi_handle handle = ACPI_HANDLE(dev);
 104
 105         return acpi_has_method(handle, "_RST");
 106 #else
 107         return false;
 108 #endif
 109 }
 110
 111 static bool vfio_platform_has_reset(struct vfio_platform_device *vdev)
 112 {
 113         if (VFIO_PLATFORM_IS_ACPI(vdev))
 114                 return vfio_platform_acpi_has_reset(vdev);
 115
 116         return vdev->of_reset ? true : false;
 117 }
 118
 119 static int vfio_platform_get_reset(struct vfio_platform_device *vdev)
 120 {
 121         if (VFIO_PLATFORM_IS_ACPI(vdev))
 122                 return vfio_platform_acpi_has_reset(vdev) ? 0 : -ENOENT;
 123
 124         vdev->of_reset = vfio_platform_lookup_reset(vdev->compat,
 125                                                     &vdev->reset_module);
 126         if (!vdev->of_reset) {
 127                 request_module("vfio-reset:%s", vdev->compat);
 128                 vdev->of_reset = vfio_platform_lookup_reset(vdev->compat,
 129                                                         &vdev->reset_module);
 130         }
 131
 132         return vdev->of_reset ? 0 : -ENOENT;
 133 }
 134
 135 static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
 136 {
 137         if (VFIO_PLATFORM_IS_ACPI(vdev))
 138                 return;
 139
 140         if (vdev->of_reset)
 141                 module_put(vdev->reset_module);
 142 }
 143
 144 static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
 145 {
 146         int cnt = 0, i;
 147
 148         while (vdev->get_resource(vdev, cnt))
 149                 cnt++;
 150
 151         vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region),
 152                                 GFP_KERNEL);
 153         if (!vdev->regions)
 154                 return -ENOMEM;
 155
 156         for (i = 0; i < cnt;  i++) {
 157                 struct resource *res =
 158                         vdev->get_resource(vdev, i);
 159
 160                 if (!res)
 161                         goto err;
 162
 163                 vdev->regions[i].addr = res->start;
 164                 vdev->regions[i].size = resource_size(res);
 165                 vdev->regions[i].flags = 0;
 166
 167                 switch (resource_type(res)) {
 168                 case IORESOURCE_MEM:
 169                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO;
 170                         vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
 171                         if (!(res->flags & IORESOURCE_READONLY))
 172                                 vdev->regions[i].flags |=
 173                                         VFIO_REGION_INFO_FLAG_WRITE;
 174
 175                         /*
 176                          * Only regions addressed with PAGE granularity may be
 177                          * MMAPed securely.
 178                          */
 179                         if (!(vdev->regions[i].addr & ~PAGE_MASK) &&
 180                                         !(vdev->regions[i].size & ~PAGE_MASK))
 181                                 vdev->regions[i].flags |=
 182                                         VFIO_REGION_INFO_FLAG_MMAP;
 183
 184                         break;
 185                 case IORESOURCE_IO:
 186                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
 187                         break;
 188                 default:
 189                         goto err;
 190                 }
 191         }
 192
 193         vdev->num_regions = cnt;
 194
 195         return 0;
 196 err:
 197         kfree(vdev->regions);
 198         return -EINVAL;
 199 }
 200
 201 static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
 202 {
 203         int i;
 204
 205         for (i = 0; i < vdev->num_regions; i++)
 206                 iounmap(vdev->regions[i].ioaddr);
 207
 208         vdev->num_regions = 0;
 209         kfree(vdev->regions);
 210 }
 211
 212 static int vfio_platform_call_reset(struct vfio_platform_device *vdev,
 213                                     const char **extra_dbg)
 214 {
 215         if (VFIO_PLATFORM_IS_ACPI(vdev)) {
 216                 dev_info(vdev->device, "reset\n");
 217                 return vfio_platform_acpi_call_reset(vdev, extra_dbg);
 218         } else if (vdev->of_reset) {
 219                 dev_info(vdev->device, "reset\n");
 220                 return vdev->of_reset(vdev);
 221         }
 222
 223         dev_warn(vdev->device, "no reset function found!\n");
 224         return -EINVAL;
 225 }
 226
 227 static void vfio_platform_release(void *device_data)
 228 {
 229         struct vfio_platform_device *vdev = device_data;
 230
 231         mutex_lock(&driver_lock);
 232
 233         if (!(--vdev->refcnt)) {
 234                 const char *extra_dbg = NULL;
 235                 int ret;
 236
 237                 ret = vfio_platform_call_reset(vdev, &extra_dbg);
 238                 if (ret && vdev->reset_required) {
 239                         dev_warn(vdev->device, "reset driver is required and reset call failed in release (%d) %s\n",
 240                                  ret, extra_dbg ? extra_dbg : "");
 241                         WARN_ON(1);
 242                 }
 243                 pm_runtime_put(vdev->device);
 244                 vfio_platform_regions_cleanup(vdev);
 245                 vfio_platform_irq_cleanup(vdev);
 246         }
 247
 248         mutex_unlock(&driver_lock);
 249
 250         module_put(vdev->parent_module);
 251 }
 252
 253 static int vfio_platform_open(void *device_data)
 254 {
 255         struct vfio_platform_device *vdev = device_data;
 256         int ret;
 257
 258         if (!try_module_get(vdev->parent_module))
 259                 return -ENODEV;
 260
 261         mutex_lock(&driver_lock);
 262
 263         if (!vdev->refcnt) {
 264                 const char *extra_dbg = NULL;
 265
 266                 ret = vfio_platform_regions_init(vdev);
 267                 if (ret)
 268                         goto err_reg;
 269
 270                 ret = vfio_platform_irq_init(vdev);
 271                 if (ret)
 272                         goto err_irq;
 273
 274                 ret = pm_runtime_get_sync(vdev->device);
 275                 if (ret < 0)
 276                         goto err_pm;
 277
 278                 ret = vfio_platform_call_reset(vdev, &extra_dbg);
 279                 if (ret && vdev->reset_required) {
 280                         dev_warn(vdev->device, "reset driver is required and reset call failed in open (%d) %s\n",
 281                                  ret, extra_dbg ? extra_dbg : "");
 282                         goto err_rst;
 283                 }
 284         }
 285
 286         vdev->refcnt++;
 287
 288         mutex_unlock(&driver_lock);
 289         return 0;
 290
 291 err_rst:
 292         pm_runtime_put(vdev->device);
 293 err_pm:
 294         vfio_platform_irq_cleanup(vdev);
 295 err_irq:
 296         vfio_platform_regions_cleanup(vdev);
 297 err_reg:
 298         mutex_unlock(&driver_lock);
 299         module_put(THIS_MODULE);
 300         return ret;
 301 }
 302
 303 static long vfio_platform_ioctl(void *device_data,
 304                                 unsigned int cmd, unsigned long arg)
 305 {
 306         struct vfio_platform_device *vdev = device_data;
 307         unsigned long minsz;
 308
 309         if (cmd == VFIO_DEVICE_GET_INFO) {
 310                 struct vfio_device_info info;
 311
 312                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 313
 314                 if (copy_from_user(&info, (void __user *)arg, minsz))
 315                         return -EFAULT;
 316
 317                 if (info.argsz < minsz)
 318                         return -EINVAL;
 319
 320                 if (vfio_platform_has_reset(vdev))
 321                         vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
 322                 info.flags = vdev->flags;
 323                 info.num_regions = vdev->num_regions;
 324                 info.num_irqs = vdev->num_irqs;
 325
 326                 return copy_to_user((void __user *)arg, &info, minsz) ?
 327                         -EFAULT : 0;
 328
 329         } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
 330                 struct vfio_region_info info;
 331
 332                 minsz = offsetofend(struct vfio_region_info, offset);
 333
 334                 if (copy_from_user(&info, (void __user *)arg, minsz))
 335                         return -EFAULT;
 336
 337                 if (info.argsz < minsz)
 338                         return -EINVAL;
 339
 340                 if (info.index >= vdev->num_regions)
 341                         return -EINVAL;
 342
 343                 /* map offset to the physical address  */
 344                 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
 345                 info.size = vdev->regions[info.index].size;
 346                 info.flags = vdev->regions[info.index].flags;
 347
 348                 return copy_to_user((void __user *)arg, &info, minsz) ?
 349                         -EFAULT : 0;
 350
 351         } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
 352                 struct vfio_irq_info info;
 353
 354                 minsz = offsetofend(struct vfio_irq_info, count);
 355
 356                 if (copy_from_user(&info, (void __user *)arg, minsz))
 357                         return -EFAULT;
 358
 359                 if (info.argsz < minsz)
 360                         return -EINVAL;
 361
 362                 if (info.index >= vdev->num_irqs)
 363                         return -EINVAL;
 364
 365                 info.flags = vdev->irqs[info.index].flags;
 366                 info.count = vdev->irqs[info.index].count;
 367
 368                 return copy_to_user((void __user *)arg, &info, minsz) ?
 369                         -EFAULT : 0;
 370
 371         } else if (cmd == VFIO_DEVICE_SET_IRQS) {
 372                 struct vfio_irq_set hdr;
 373                 u8 *data = NULL;
 374                 int ret = 0;
 375                 size_t data_size = 0;
 376
 377                 minsz = offsetofend(struct vfio_irq_set, count);
 378
 379                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 380                         return -EFAULT;
 381
 382                 ret = vfio_set_irqs_validate_and_prepare(&hdr, vdev->num_irqs,
 383                                                  vdev->num_irqs, &data_size);
 384                 if (ret)
 385                         return ret;
 386
 387                 if (data_size) {
 388                         data = memdup_user((void __user *)(arg + minsz),
 389                                             data_size);
 390                         if (IS_ERR(data))
 391                                 return PTR_ERR(data);
 392                 }
 393
 394                 mutex_lock(&vdev->igate);
 395
 396                 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
 397                                                    hdr.start, hdr.count, data);
 398                 mutex_unlock(&vdev->igate);
 399                 kfree(data);
 400
 401                 return ret;
 402
 403         } else if (cmd == VFIO_DEVICE_RESET) {
 404                 return vfio_platform_call_reset(vdev, NULL);
 405         }
 406
 407         return -ENOTTY;
 408 }
 409
 410 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
 411                                        char __user *buf, size_t count,
 412                                        loff_t off)
 413 {
 414         unsigned int done = 0;
 415
 416         if (!reg->ioaddr) {
 417                 reg->ioaddr =
 418                         ioremap_nocache(reg->addr, reg->size);
 419
 420                 if (!reg->ioaddr)
 421                         return -ENOMEM;
 422         }
 423
 424         while (count) {
 425                 size_t filled;
 426
 427                 if (count >= 4 && !(off % 4)) {
 428                         u32 val;
 429
 430                         val = ioread32(reg->ioaddr + off);
 431                         if (copy_to_user(buf, &val, 4))
 432                                 goto err;
 433
 434                         filled = 4;
 435                 } else if (count >= 2 && !(off % 2)) {
 436                         u16 val;
 437
 438                         val = ioread16(reg->ioaddr + off);
 439                         if (copy_to_user(buf, &val, 2))
 440                                 goto err;
 441
 442                         filled = 2;
 443                 } else {
 444                         u8 val;
 445
 446                         val = ioread8(reg->ioaddr + off);
 447                         if (copy_to_user(buf, &val, 1))
 448                                 goto err;
 449
 450                         filled = 1;
 451                 }
 452
 453
 454                 count -= filled;
 455                 done += filled;
 456                 off += filled;
 457                 buf += filled;
 458         }
 459
 460         return done;
 461 err:
 462         return -EFAULT;
 463 }
 464
 465 static ssize_t vfio_platform_read(void *device_data, char __user *buf,
 466                                   size_t count, loff_t *ppos)
 467 {
 468         struct vfio_platform_device *vdev = device_data;
 469         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 470         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 471
 472         if (index >= vdev->num_regions)
 473                 return -EINVAL;
 474
 475         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
 476                 return -EINVAL;
 477
 478         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 479                 return vfio_platform_read_mmio(&vdev->regions[index],
 480                                                         buf, count, off);
 481         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 482                 return -EINVAL; /* not implemented */
 483
 484         return -EINVAL;
 485 }
 486
 487 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
 488                                         const char __user *buf, size_t count,
 489                                         loff_t off)
 490 {
 491         unsigned int done = 0;
 492
 493         if (!reg->ioaddr) {
 494                 reg->ioaddr =
 495                         ioremap_nocache(reg->addr, reg->size);
 496
 497                 if (!reg->ioaddr)
 498                         return -ENOMEM;
 499         }
 500
 501         while (count) {
 502                 size_t filled;
 503
 504                 if (count >= 4 && !(off % 4)) {
 505                         u32 val;
 506
 507                         if (copy_from_user(&val, buf, 4))
 508                                 goto err;
 509                         iowrite32(val, reg->ioaddr + off);
 510
 511                         filled = 4;
 512                 } else if (count >= 2 && !(off % 2)) {
 513                         u16 val;
 514
 515                         if (copy_from_user(&val, buf, 2))
 516                                 goto err;
 517                         iowrite16(val, reg->ioaddr + off);
 518
 519                         filled = 2;
 520                 } else {
 521                         u8 val;
 522
 523                         if (copy_from_user(&val, buf, 1))
 524                                 goto err;
 525                         iowrite8(val, reg->ioaddr + off);
 526
 527                         filled = 1;
 528                 }
 529
 530                 count -= filled;
 531                 done += filled;
 532                 off += filled;
 533                 buf += filled;
 534         }
 535
 536         return done;
 537 err:
 538         return -EFAULT;
 539 }
 540
 541 static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
 542                                    size_t count, loff_t *ppos)
 543 {
 544         struct vfio_platform_device *vdev = device_data;
 545         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 546         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 547
 548         if (index >= vdev->num_regions)
 549                 return -EINVAL;
 550
 551         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
 552                 return -EINVAL;
 553
 554         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 555                 return vfio_platform_write_mmio(&vdev->regions[index],
 556                                                         buf, count, off);
 557         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 558                 return -EINVAL; /* not implemented */
 559
 560         return -EINVAL;
 561 }
 562
 563 static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
 564                                    struct vm_area_struct *vma)
 565 {
 566         u64 req_len, pgoff, req_start;
 567
 568         req_len = vma->vm_end - vma->vm_start;
 569         pgoff = vma->vm_pgoff &
 570                 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
 571         req_start = pgoff << PAGE_SHIFT;
 572
 573         if (region.size < PAGE_SIZE || req_start + req_len > region.size)
 574                 return -EINVAL;
 575
 576         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 577         vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
 578
 579         return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
 580                                req_len, vma->vm_page_prot);
 581 }
 582
 583 static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma)
 584 {
 585         struct vfio_platform_device *vdev = device_data;
 586         unsigned int index;
 587
 588         index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);
 589
 590         if (vma->vm_end < vma->vm_start)
 591                 return -EINVAL;
 592         if (!(vma->vm_flags & VM_SHARED))
 593                 return -EINVAL;
 594         if (index >= vdev->num_regions)
 595                 return -EINVAL;
 596         if (vma->vm_start & ~PAGE_MASK)
 597                 return -EINVAL;
 598         if (vma->vm_end & ~PAGE_MASK)
 599                 return -EINVAL;
 600
 601         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
 602                 return -EINVAL;
 603
 604         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
 605                         && (vma->vm_flags & VM_READ))
 606                 return -EINVAL;
 607
 608         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
 609                         && (vma->vm_flags & VM_WRITE))
 610                 return -EINVAL;
 611
 612         vma->vm_private_data = vdev;
 613
 614         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 615                 return vfio_platform_mmap_mmio(vdev->regions[index], vma);
 616
 617         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 618                 return -EINVAL; /* not implemented */
 619
 620         return -EINVAL;
 621 }
 622
 623 static const struct vfio_device_ops vfio_platform_ops = {
 624         .name           = "vfio-platform",
 625         .open           = vfio_platform_open,
 626         .release        = vfio_platform_release,
 627         .ioctl          = vfio_platform_ioctl,
 628         .read           = vfio_platform_read,
 629         .write          = vfio_platform_write,
 630         .mmap           = vfio_platform_mmap,
 631 };
 632
 633 static int vfio_platform_of_probe(struct vfio_platform_device *vdev,
 634                            struct device *dev)
 635 {
 636         int ret;
 637
 638         ret = device_property_read_string(dev, "compatible",
 639                                           &vdev->compat);
 640         if (ret)
 641                 pr_err("VFIO: Cannot retrieve compat for %s\n", vdev->name);
 642
 643         return ret;
 644 }
 645
 646 /*
 647  * There can be two kernel build combinations. One build where
 648  * ACPI is not selected in Kconfig and another one with the ACPI Kconfig.
 649  *
 650  * In the first case, vfio_platform_acpi_probe will return since
 651  * acpi_disabled is 1. DT user will not see any kind of messages from
 652  * ACPI.
 653  *
 654  * In the second case, both DT and ACPI is compiled in but the system is
 655  * booting with any of these combinations.
 656  *
 657  * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine
 658  * terminates immediately without any messages.
 659  *
 660  * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are
 661  * valid checks. We cannot claim that this system is DT.
 662  */
 663 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 664                                struct device *dev)
 665 {
 666         struct iommu_group *group;
 667         int ret;
 668
 669         if (!vdev)
 670                 return -EINVAL;
 671
 672         ret = vfio_platform_acpi_probe(vdev, dev);
 673         if (ret)
 674                 ret = vfio_platform_of_probe(vdev, dev);
 675
 676         if (ret)
 677                 return ret;
 678
 679         vdev->device = dev;
 680
 681         ret = vfio_platform_get_reset(vdev);
 682         if (ret && vdev->reset_required) {
 683                 pr_err("VFIO: No reset function found for device %s\n",
 684                        vdev->name);
 685                 return ret;
 686         }
 687
 688         group = vfio_iommu_group_get(dev);
 689         if (!group) {
 690                 pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
 691                 ret = -EINVAL;
 692                 goto put_reset;
 693         }
 694
 695         ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
 696         if (ret)
 697                 goto put_iommu;
 698
 699         mutex_init(&vdev->igate);
 700
 701         pm_runtime_enable(vdev->device);
 702         return 0;
 703
 704 put_iommu:
 705         vfio_iommu_group_put(group, dev);
 706 put_reset:
 707         vfio_platform_put_reset(vdev);
 708         return ret;
 709 }
 710 EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
 711
 712 struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
 713 {
 714         struct vfio_platform_device *vdev;
 715
 716         vdev = vfio_del_group_dev(dev);
 717
 718         if (vdev) {
 719                 pm_runtime_disable(vdev->device);
 720                 vfio_platform_put_reset(vdev);
 721                 vfio_iommu_group_put(dev->iommu_group, dev);
 722         }
 723
 724         return vdev;
 725 }
 726 EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
 727
 728 void __vfio_platform_register_reset(struct vfio_platform_reset_node *node)
 729 {
 730         mutex_lock(&driver_lock);
 731         list_add(&node->link, &reset_list);
 732         mutex_unlock(&driver_lock);
 733 }
 734 EXPORT_SYMBOL_GPL(__vfio_platform_register_reset);
 735
 736 void vfio_platform_unregister_reset(const char *compat,
 737                                     vfio_platform_reset_fn_t fn)
 738 {
 739         struct vfio_platform_reset_node *iter, *temp;
 740
 741         mutex_lock(&driver_lock);
 742         list_for_each_entry_safe(iter, temp, &reset_list, link) {
 743                 if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) {
 744                         list_del(&iter->link);
 745                         break;
 746                 }
 747         }
 748
 749         mutex_unlock(&driver_lock);
 750
 751 }
 752 EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset);
 753
 754 MODULE_VERSION(DRIVER_VERSION);
 755 MODULE_LICENSE("GPL v2");
 756 MODULE_AUTHOR(DRIVER_AUTHOR);
 757 MODULE_DESCRIPTION(DRIVER_DESC);