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/slab.h>
  21 #include <linux/types.h>
  22 #include <linux/uaccess.h>
  23 #include <linux/vfio.h>
  24
  25 #include "vfio_platform_private.h"
  26
  27 #define DRIVER_VERSION  "0.10"
  28 #define DRIVER_AUTHOR   "Antonios Motakis <a.motakis@virtualopensystems.com>"
  29 #define DRIVER_DESC     "VFIO platform base module"
  30
  31 #define VFIO_PLATFORM_IS_ACPI(vdev) ((vdev)->acpihid != NULL)
  32
  33 static LIST_HEAD(reset_list);
  34 static DEFINE_MUTEX(driver_lock);
  35
  36 static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat,
  37                                         struct module **module)
  38 {
  39         struct vfio_platform_reset_node *iter;
  40         vfio_platform_reset_fn_t reset_fn = NULL;
  41
  42         mutex_lock(&driver_lock);
  43         list_for_each_entry(iter, &reset_list, link) {
  44                 if (!strcmp(iter->compat, compat) &&
  45                         try_module_get(iter->owner)) {
  46                         *module = iter->owner;
  47                         reset_fn = iter->of_reset;
  48                         break;
  49                 }
  50         }
  51         mutex_unlock(&driver_lock);
  52         return reset_fn;
  53 }
  54
  55 static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev,
  56                                     struct device *dev)
  57 {
  58         struct acpi_device *adev;
  59
  60         if (acpi_disabled)
  61                 return -ENOENT;
  62
  63         adev = ACPI_COMPANION(dev);
  64         if (!adev) {
  65                 pr_err("VFIO: ACPI companion device not found for %s\n",
  66                         vdev->name);
  67                 return -ENODEV;
  68         }
  69
  70 #ifdef CONFIG_ACPI
  71         vdev->acpihid = acpi_device_hid(adev);
  72 #endif
  73         return WARN_ON(!vdev->acpihid) ? -EINVAL : 0;
  74 }
  75
  76 static int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev,
  77                                   const char **extra_dbg)
  78 {
  79 #ifdef CONFIG_ACPI
  80         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  81         struct device *dev = vdev->device;
  82         acpi_handle handle = ACPI_HANDLE(dev);
  83         acpi_status acpi_ret;
  84
  85         acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, &buffer);
  86         if (ACPI_FAILURE(acpi_ret)) {
  87                 if (extra_dbg)
  88                         *extra_dbg = acpi_format_exception(acpi_ret);
  89                 return -EINVAL;
  90         }
  91
  92         return 0;
  93 #else
  94         return -ENOENT;
  95 #endif
  96 }
  97
  98 static bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev)
  99 {
 100 #ifdef CONFIG_ACPI
 101         struct device *dev = vdev->device;
 102         acpi_handle handle = ACPI_HANDLE(dev);
 103
 104         return acpi_has_method(handle, "_RST");
 105 #else
 106         return false;
 107 #endif
 108 }
 109
 110 static bool vfio_platform_has_reset(struct vfio_platform_device *vdev)
 111 {
 112         if (VFIO_PLATFORM_IS_ACPI(vdev))
 113                 return vfio_platform_acpi_has_reset(vdev);
 114
 115         return vdev->of_reset ? true : false;
 116 }
 117
 118 static int vfio_platform_get_reset(struct vfio_platform_device *vdev)
 119 {
 120         if (VFIO_PLATFORM_IS_ACPI(vdev))
 121                 return vfio_platform_acpi_has_reset(vdev) ? 0 : -ENOENT;
 122
 123         vdev->of_reset = vfio_platform_lookup_reset(vdev->compat,
 124                                                     &vdev->reset_module);
 125         if (!vdev->of_reset) {
 126                 request_module("vfio-reset:%s", vdev->compat);
 127                 vdev->of_reset = vfio_platform_lookup_reset(vdev->compat,
 128                                                         &vdev->reset_module);
 129         }
 130
 131         return vdev->of_reset ? 0 : -ENOENT;
 132 }
 133
 134 static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
 135 {
 136         if (VFIO_PLATFORM_IS_ACPI(vdev))
 137                 return;
 138
 139         if (vdev->of_reset)
 140                 module_put(vdev->reset_module);
 141 }
 142
 143 static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
 144 {
 145         int cnt = 0, i;
 146
 147         while (vdev->get_resource(vdev, cnt))
 148                 cnt++;
 149
 150         vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region),
 151                                 GFP_KERNEL);
 152         if (!vdev->regions)
 153                 return -ENOMEM;
 154
 155         for (i = 0; i < cnt;  i++) {
 156                 struct resource *res =
 157                         vdev->get_resource(vdev, i);
 158
 159                 if (!res)
 160                         goto err;
 161
 162                 vdev->regions[i].addr = res->start;
 163                 vdev->regions[i].size = resource_size(res);
 164                 vdev->regions[i].flags = 0;
 165
 166                 switch (resource_type(res)) {
 167                 case IORESOURCE_MEM:
 168                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO;
 169                         vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
 170                         if (!(res->flags & IORESOURCE_READONLY))
 171                                 vdev->regions[i].flags |=
 172                                         VFIO_REGION_INFO_FLAG_WRITE;
 173
 174                         /*
 175                          * Only regions addressed with PAGE granularity may be
 176                          * MMAPed securely.
 177                          */
 178                         if (!(vdev->regions[i].addr & ~PAGE_MASK) &&
 179                                         !(vdev->regions[i].size & ~PAGE_MASK))
 180                                 vdev->regions[i].flags |=
 181                                         VFIO_REGION_INFO_FLAG_MMAP;
 182
 183                         break;
 184                 case IORESOURCE_IO:
 185                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
 186                         break;
 187                 default:
 188                         goto err;
 189                 }
 190         }
 191
 192         vdev->num_regions = cnt;
 193
 194         return 0;
 195 err:
 196         kfree(vdev->regions);
 197         return -EINVAL;
 198 }
 199
 200 static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
 201 {
 202         int i;
 203
 204         for (i = 0; i < vdev->num_regions; i++)
 205                 iounmap(vdev->regions[i].ioaddr);
 206
 207         vdev->num_regions = 0;
 208         kfree(vdev->regions);
 209 }
 210
 211 static int vfio_platform_call_reset(struct vfio_platform_device *vdev,
 212                                     const char **extra_dbg)
 213 {
 214         if (VFIO_PLATFORM_IS_ACPI(vdev)) {
 215                 dev_info(vdev->device, "reset\n");
 216                 return vfio_platform_acpi_call_reset(vdev, extra_dbg);
 217         } else if (vdev->of_reset) {
 218                 dev_info(vdev->device, "reset\n");
 219                 return vdev->of_reset(vdev);
 220         }
 221
 222         dev_warn(vdev->device, "no reset function found!\n");
 223         return -EINVAL;
 224 }
 225
 226 static void vfio_platform_release(void *device_data)
 227 {
 228         struct vfio_platform_device *vdev = device_data;
 229
 230         mutex_lock(&driver_lock);
 231
 232         if (!(--vdev->refcnt)) {
 233                 const char *extra_dbg = NULL;
 234                 int ret;
 235
 236                 ret = vfio_platform_call_reset(vdev, &extra_dbg);
 237                 if (ret && vdev->reset_required) {
 238                         dev_warn(vdev->device, "reset driver is required and reset call failed in release (%d) %s\n",
 239                                  ret, extra_dbg ? extra_dbg : "");
 240                         WARN_ON(1);
 241                 }
 242                 vfio_platform_regions_cleanup(vdev);
 243                 vfio_platform_irq_cleanup(vdev);
 244         }
 245
 246         mutex_unlock(&driver_lock);
 247
 248         module_put(vdev->parent_module);
 249 }
 250
 251 static int vfio_platform_open(void *device_data)
 252 {
 253         struct vfio_platform_device *vdev = device_data;
 254         int ret;
 255
 256         if (!try_module_get(vdev->parent_module))
 257                 return -ENODEV;
 258
 259         mutex_lock(&driver_lock);
 260
 261         if (!vdev->refcnt) {
 262                 const char *extra_dbg = NULL;
 263
 264                 ret = vfio_platform_regions_init(vdev);
 265                 if (ret)
 266                         goto err_reg;
 267
 268                 ret = vfio_platform_irq_init(vdev);
 269                 if (ret)
 270                         goto err_irq;
 271
 272                 ret = vfio_platform_call_reset(vdev, &extra_dbg);
 273                 if (ret && vdev->reset_required) {
 274                         dev_warn(vdev->device, "reset driver is required and reset call failed in open (%d) %s\n",
 275                                  ret, extra_dbg ? extra_dbg : "");
 276                         goto err_rst;
 277                 }
 278         }
 279
 280         vdev->refcnt++;
 281
 282         mutex_unlock(&driver_lock);
 283         return 0;
 284
 285 err_rst:
 286         vfio_platform_irq_cleanup(vdev);
 287 err_irq:
 288         vfio_platform_regions_cleanup(vdev);
 289 err_reg:
 290         mutex_unlock(&driver_lock);
 291         module_put(THIS_MODULE);
 292         return ret;
 293 }
 294
 295 static long vfio_platform_ioctl(void *device_data,
 296                                 unsigned int cmd, unsigned long arg)
 297 {
 298         struct vfio_platform_device *vdev = device_data;
 299         unsigned long minsz;
 300
 301         if (cmd == VFIO_DEVICE_GET_INFO) {
 302                 struct vfio_device_info info;
 303
 304                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 305
 306                 if (copy_from_user(&info, (void __user *)arg, minsz))
 307                         return -EFAULT;
 308
 309                 if (info.argsz < minsz)
 310                         return -EINVAL;
 311
 312                 if (vfio_platform_has_reset(vdev))
 313                         vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
 314                 info.flags = vdev->flags;
 315                 info.num_regions = vdev->num_regions;
 316                 info.num_irqs = vdev->num_irqs;
 317
 318                 return copy_to_user((void __user *)arg, &info, minsz) ?
 319                         -EFAULT : 0;
 320
 321         } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
 322                 struct vfio_region_info info;
 323
 324                 minsz = offsetofend(struct vfio_region_info, offset);
 325
 326                 if (copy_from_user(&info, (void __user *)arg, minsz))
 327                         return -EFAULT;
 328
 329                 if (info.argsz < minsz)
 330                         return -EINVAL;
 331
 332                 if (info.index >= vdev->num_regions)
 333                         return -EINVAL;
 334
 335                 /* map offset to the physical address  */
 336                 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
 337                 info.size = vdev->regions[info.index].size;
 338                 info.flags = vdev->regions[info.index].flags;
 339
 340                 return copy_to_user((void __user *)arg, &info, minsz) ?
 341                         -EFAULT : 0;
 342
 343         } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
 344                 struct vfio_irq_info info;
 345
 346                 minsz = offsetofend(struct vfio_irq_info, count);
 347
 348                 if (copy_from_user(&info, (void __user *)arg, minsz))
 349                         return -EFAULT;
 350
 351                 if (info.argsz < minsz)
 352                         return -EINVAL;
 353
 354                 if (info.index >= vdev->num_irqs)
 355                         return -EINVAL;
 356
 357                 info.flags = vdev->irqs[info.index].flags;
 358                 info.count = vdev->irqs[info.index].count;
 359
 360                 return copy_to_user((void __user *)arg, &info, minsz) ?
 361                         -EFAULT : 0;
 362
 363         } else if (cmd == VFIO_DEVICE_SET_IRQS) {
 364                 struct vfio_irq_set hdr;
 365                 u8 *data = NULL;
 366                 int ret = 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                 if (hdr.argsz < minsz)
 374                         return -EINVAL;
 375
 376                 if (hdr.index >= vdev->num_irqs)
 377                         return -EINVAL;
 378
 379                 if (hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
 380                                   VFIO_IRQ_SET_ACTION_TYPE_MASK))
 381                         return -EINVAL;
 382
 383                 if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
 384                         size_t size;
 385
 386                         if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
 387                                 size = sizeof(uint8_t);
 388                         else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
 389                                 size = sizeof(int32_t);
 390                         else
 391                                 return -EINVAL;
 392
 393                         if (hdr.argsz - minsz < size)
 394                                 return -EINVAL;
 395
 396                         data = memdup_user((void __user *)(arg + minsz), size);
 397                         if (IS_ERR(data))
 398                                 return PTR_ERR(data);
 399                 }
 400
 401                 mutex_lock(&vdev->igate);
 402
 403                 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
 404                                                    hdr.start, hdr.count, data);
 405                 mutex_unlock(&vdev->igate);
 406                 kfree(data);
 407
 408                 return ret;
 409
 410         } else if (cmd == VFIO_DEVICE_RESET) {
 411                 return vfio_platform_call_reset(vdev, NULL);
 412         }
 413
 414         return -ENOTTY;
 415 }
 416
 417 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
 418                                        char __user *buf, size_t count,
 419                                        loff_t off)
 420 {
 421         unsigned int done = 0;
 422
 423         if (!reg->ioaddr) {
 424                 reg->ioaddr =
 425                         ioremap_nocache(reg->addr, reg->size);
 426
 427                 if (!reg->ioaddr)
 428                         return -ENOMEM;
 429         }
 430
 431         while (count) {
 432                 size_t filled;
 433
 434                 if (count >= 4 && !(off % 4)) {
 435                         u32 val;
 436
 437                         val = ioread32(reg->ioaddr + off);
 438                         if (copy_to_user(buf, &val, 4))
 439                                 goto err;
 440
 441                         filled = 4;
 442                 } else if (count >= 2 && !(off % 2)) {
 443                         u16 val;
 444
 445                         val = ioread16(reg->ioaddr + off);
 446                         if (copy_to_user(buf, &val, 2))
 447                                 goto err;
 448
 449                         filled = 2;
 450                 } else {
 451                         u8 val;
 452
 453                         val = ioread8(reg->ioaddr + off);
 454                         if (copy_to_user(buf, &val, 1))
 455                                 goto err;
 456
 457                         filled = 1;
 458                 }
 459
 460
 461                 count -= filled;
 462                 done += filled;
 463                 off += filled;
 464                 buf += filled;
 465         }
 466
 467         return done;
 468 err:
 469         return -EFAULT;
 470 }
 471
 472 static ssize_t vfio_platform_read(void *device_data, char __user *buf,
 473                                   size_t count, loff_t *ppos)
 474 {
 475         struct vfio_platform_device *vdev = device_data;
 476         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 477         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 478
 479         if (index >= vdev->num_regions)
 480                 return -EINVAL;
 481
 482         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
 483                 return -EINVAL;
 484
 485         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 486                 return vfio_platform_read_mmio(&vdev->regions[index],
 487                                                         buf, count, off);
 488         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 489                 return -EINVAL; /* not implemented */
 490
 491         return -EINVAL;
 492 }
 493
 494 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
 495                                         const char __user *buf, size_t count,
 496                                         loff_t off)
 497 {
 498         unsigned int done = 0;
 499
 500         if (!reg->ioaddr) {
 501                 reg->ioaddr =
 502                         ioremap_nocache(reg->addr, reg->size);
 503
 504                 if (!reg->ioaddr)
 505                         return -ENOMEM;
 506         }
 507
 508         while (count) {
 509                 size_t filled;
 510
 511                 if (count >= 4 && !(off % 4)) {
 512                         u32 val;
 513
 514                         if (copy_from_user(&val, buf, 4))
 515                                 goto err;
 516                         iowrite32(val, reg->ioaddr + off);
 517
 518                         filled = 4;
 519                 } else if (count >= 2 && !(off % 2)) {
 520                         u16 val;
 521
 522                         if (copy_from_user(&val, buf, 2))
 523                                 goto err;
 524                         iowrite16(val, reg->ioaddr + off);
 525
 526                         filled = 2;
 527                 } else {
 528                         u8 val;
 529
 530                         if (copy_from_user(&val, buf, 1))
 531                                 goto err;
 532                         iowrite8(val, reg->ioaddr + off);
 533
 534                         filled = 1;
 535                 }
 536
 537                 count -= filled;
 538                 done += filled;
 539                 off += filled;
 540                 buf += filled;
 541         }
 542
 543         return done;
 544 err:
 545         return -EFAULT;
 546 }
 547
 548 static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
 549                                    size_t count, loff_t *ppos)
 550 {
 551         struct vfio_platform_device *vdev = device_data;
 552         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 553         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 554
 555         if (index >= vdev->num_regions)
 556                 return -EINVAL;
 557
 558         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
 559                 return -EINVAL;
 560
 561         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 562                 return vfio_platform_write_mmio(&vdev->regions[index],
 563                                                         buf, count, off);
 564         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 565                 return -EINVAL; /* not implemented */
 566
 567         return -EINVAL;
 568 }
 569
 570 static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
 571                                    struct vm_area_struct *vma)
 572 {
 573         u64 req_len, pgoff, req_start;
 574
 575         req_len = vma->vm_end - vma->vm_start;
 576         pgoff = vma->vm_pgoff &
 577                 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
 578         req_start = pgoff << PAGE_SHIFT;
 579
 580         if (region.size < PAGE_SIZE || req_start + req_len > region.size)
 581                 return -EINVAL;
 582
 583         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 584         vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
 585
 586         return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
 587                                req_len, vma->vm_page_prot);
 588 }
 589
 590 static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma)
 591 {
 592         struct vfio_platform_device *vdev = device_data;
 593         unsigned int index;
 594
 595         index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);
 596
 597         if (vma->vm_end < vma->vm_start)
 598                 return -EINVAL;
 599         if (!(vma->vm_flags & VM_SHARED))
 600                 return -EINVAL;
 601         if (index >= vdev->num_regions)
 602                 return -EINVAL;
 603         if (vma->vm_start & ~PAGE_MASK)
 604                 return -EINVAL;
 605         if (vma->vm_end & ~PAGE_MASK)
 606                 return -EINVAL;
 607
 608         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
 609                 return -EINVAL;
 610
 611         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
 612                         && (vma->vm_flags & VM_READ))
 613                 return -EINVAL;
 614
 615         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
 616                         && (vma->vm_flags & VM_WRITE))
 617                 return -EINVAL;
 618
 619         vma->vm_private_data = vdev;
 620
 621         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 622                 return vfio_platform_mmap_mmio(vdev->regions[index], vma);
 623
 624         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 625                 return -EINVAL; /* not implemented */
 626
 627         return -EINVAL;
 628 }
 629
 630 static const struct vfio_device_ops vfio_platform_ops = {
 631         .name           = "vfio-platform",
 632         .open           = vfio_platform_open,
 633         .release        = vfio_platform_release,
 634         .ioctl          = vfio_platform_ioctl,
 635         .read           = vfio_platform_read,
 636         .write          = vfio_platform_write,
 637         .mmap           = vfio_platform_mmap,
 638 };
 639
 640 static int vfio_platform_of_probe(struct vfio_platform_device *vdev,
 641                            struct device *dev)
 642 {
 643         int ret;
 644
 645         ret = device_property_read_string(dev, "compatible",
 646                                           &vdev->compat);
 647         if (ret)
 648                 pr_err("VFIO: cannot retrieve compat for %s\n",
 649                         vdev->name);
 650
 651         return ret;
 652 }
 653
 654 /*
 655  * There can be two kernel build combinations. One build where
 656  * ACPI is not selected in Kconfig and another one with the ACPI Kconfig.
 657  *
 658  * In the first case, vfio_platform_acpi_probe will return since
 659  * acpi_disabled is 1. DT user will not see any kind of messages from
 660  * ACPI.
 661  *
 662  * In the second case, both DT and ACPI is compiled in but the system is
 663  * booting with any of these combinations.
 664  *
 665  * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine
 666  * terminates immediately without any messages.
 667  *
 668  * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are
 669  * valid checks. We cannot claim that this system is DT.
 670  */
 671 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 672                                struct device *dev)
 673 {
 674         struct iommu_group *group;
 675         int ret;
 676
 677         if (!vdev)
 678                 return -EINVAL;
 679
 680         ret = vfio_platform_acpi_probe(vdev, dev);
 681         if (ret)
 682                 ret = vfio_platform_of_probe(vdev, dev);
 683
 684         if (ret)
 685                 return ret;
 686
 687         vdev->device = dev;
 688
 689         ret = vfio_platform_get_reset(vdev);
 690         if (ret && vdev->reset_required) {
 691                 pr_err("vfio: no reset function found for device %s\n",
 692                        vdev->name);
 693                 return ret;
 694         }
 695
 696         group = vfio_iommu_group_get(dev);
 697         if (!group) {
 698                 pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
 699                 return -EINVAL;
 700         }
 701
 702         ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
 703         if (ret) {
 704                 vfio_iommu_group_put(group, dev);
 705                 return ret;
 706         }
 707
 708         mutex_init(&vdev->igate);
 709
 710         return 0;
 711 }
 712 EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
 713
 714 struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
 715 {
 716         struct vfio_platform_device *vdev;
 717
 718         vdev = vfio_del_group_dev(dev);
 719
 720         if (vdev) {
 721                 vfio_platform_put_reset(vdev);
 722                 vfio_iommu_group_put(dev->iommu_group, dev);
 723         }
 724
 725         return vdev;
 726 }
 727 EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
 728
 729 void __vfio_platform_register_reset(struct vfio_platform_reset_node *node)
 730 {
 731         mutex_lock(&driver_lock);
 732         list_add(&node->link, &reset_list);
 733         mutex_unlock(&driver_lock);
 734 }
 735 EXPORT_SYMBOL_GPL(__vfio_platform_register_reset);
 736
 737 void vfio_platform_unregister_reset(const char *compat,
 738                                     vfio_platform_reset_fn_t fn)
 739 {
 740         struct vfio_platform_reset_node *iter, *temp;
 741
 742         mutex_lock(&driver_lock);
 743         list_for_each_entry_safe(iter, temp, &reset_list, link) {
 744                 if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) {
 745                         list_del(&iter->link);
 746                         break;
 747                 }
 748         }
 749
 750         mutex_unlock(&driver_lock);
 751
 752 }
 753 EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset);
 754
 755 MODULE_VERSION(DRIVER_VERSION);
 756 MODULE_LICENSE("GPL v2");
 757 MODULE_AUTHOR(DRIVER_AUTHOR);
 758 MODULE_DESCRIPTION(DRIVER_DESC);