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