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/iommu.h>
  17 #include <linux/module.h>
  18 #include <linux/mutex.h>
  19 #include <linux/slab.h>
  20 #include <linux/types.h>
  21 #include <linux/uaccess.h>
  22 #include <linux/vfio.h>
  23
  24 #include "vfio_platform_private.h"
  25
  26 #define DRIVER_VERSION  "0.10"
  27 #define DRIVER_AUTHOR   "Antonios Motakis <a.motakis@virtualopensystems.com>"
  28 #define DRIVER_DESC     "VFIO platform base module"
  29
  30 static LIST_HEAD(reset_list);
  31 static DEFINE_MUTEX(driver_lock);
  32
  33 static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat,
  34                                         struct module **module)
  35 {
  36         struct vfio_platform_reset_node *iter;
  37         vfio_platform_reset_fn_t reset_fn = NULL;
  38
  39         mutex_lock(&driver_lock);
  40         list_for_each_entry(iter, &reset_list, link) {
  41                 if (!strcmp(iter->compat, compat) &&
  42                         try_module_get(iter->owner)) {
  43                         *module = iter->owner;
  44                         reset_fn = iter->reset;
  45                         break;
  46                 }
  47         }
  48         mutex_unlock(&driver_lock);
  49         return reset_fn;
  50 }
  51
  52 static void vfio_platform_get_reset(struct vfio_platform_device *vdev)
  53 {
  54         char modname[256];
  55
  56         vdev->reset = vfio_platform_lookup_reset(vdev->compat,
  57                                                 &vdev->reset_module);
  58         if (!vdev->reset) {
  59                 snprintf(modname, 256, "vfio-reset:%s", vdev->compat);
  60                 request_module(modname);
  61                 vdev->reset = vfio_platform_lookup_reset(vdev->compat,
  62                                                          &vdev->reset_module);
  63         }
  64 }
  65
  66 static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
  67 {
  68         if (vdev->reset)
  69                 module_put(vdev->reset_module);
  70 }
  71
  72 static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
  73 {
  74         int cnt = 0, i;
  75
  76         while (vdev->get_resource(vdev, cnt))
  77                 cnt++;
  78
  79         vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region),
  80                                 GFP_KERNEL);
  81         if (!vdev->regions)
  82                 return -ENOMEM;
  83
  84         for (i = 0; i < cnt;  i++) {
  85                 struct resource *res =
  86                         vdev->get_resource(vdev, i);
  87
  88                 if (!res)
  89                         goto err;
  90
  91                 vdev->regions[i].addr = res->start;
  92                 vdev->regions[i].size = resource_size(res);
  93                 vdev->regions[i].flags = 0;
  94
  95                 switch (resource_type(res)) {
  96                 case IORESOURCE_MEM:
  97                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO;
  98                         vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
  99                         if (!(res->flags & IORESOURCE_READONLY))
 100                                 vdev->regions[i].flags |=
 101                                         VFIO_REGION_INFO_FLAG_WRITE;
 102
 103                         /*
 104                          * Only regions addressed with PAGE granularity may be
 105                          * MMAPed securely.
 106                          */
 107                         if (!(vdev->regions[i].addr & ~PAGE_MASK) &&
 108                                         !(vdev->regions[i].size & ~PAGE_MASK))
 109                                 vdev->regions[i].flags |=
 110                                         VFIO_REGION_INFO_FLAG_MMAP;
 111
 112                         break;
 113                 case IORESOURCE_IO:
 114                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
 115                         break;
 116                 default:
 117                         goto err;
 118                 }
 119         }
 120
 121         vdev->num_regions = cnt;
 122
 123         return 0;
 124 err:
 125         kfree(vdev->regions);
 126         return -EINVAL;
 127 }
 128
 129 static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
 130 {
 131         int i;
 132
 133         for (i = 0; i < vdev->num_regions; i++)
 134                 iounmap(vdev->regions[i].ioaddr);
 135
 136         vdev->num_regions = 0;
 137         kfree(vdev->regions);
 138 }
 139
 140 static void vfio_platform_release(void *device_data)
 141 {
 142         struct vfio_platform_device *vdev = device_data;
 143
 144         mutex_lock(&driver_lock);
 145
 146         if (!(--vdev->refcnt)) {
 147                 if (vdev->reset) {
 148                         dev_info(vdev->device, "reset\n");
 149                         vdev->reset(vdev);
 150                 } else {
 151                         dev_warn(vdev->device, "no reset function found!\n");
 152                 }
 153                 vfio_platform_regions_cleanup(vdev);
 154                 vfio_platform_irq_cleanup(vdev);
 155         }
 156
 157         mutex_unlock(&driver_lock);
 158
 159         module_put(vdev->parent_module);
 160 }
 161
 162 static int vfio_platform_open(void *device_data)
 163 {
 164         struct vfio_platform_device *vdev = device_data;
 165         int ret;
 166
 167         if (!try_module_get(vdev->parent_module))
 168                 return -ENODEV;
 169
 170         mutex_lock(&driver_lock);
 171
 172         if (!vdev->refcnt) {
 173                 ret = vfio_platform_regions_init(vdev);
 174                 if (ret)
 175                         goto err_reg;
 176
 177                 ret = vfio_platform_irq_init(vdev);
 178                 if (ret)
 179                         goto err_irq;
 180
 181                 if (vdev->reset) {
 182                         dev_info(vdev->device, "reset\n");
 183                         vdev->reset(vdev);
 184                 } else {
 185                         dev_warn(vdev->device, "no reset function found!\n");
 186                 }
 187         }
 188
 189         vdev->refcnt++;
 190
 191         mutex_unlock(&driver_lock);
 192         return 0;
 193
 194 err_irq:
 195         vfio_platform_regions_cleanup(vdev);
 196 err_reg:
 197         mutex_unlock(&driver_lock);
 198         module_put(THIS_MODULE);
 199         return ret;
 200 }
 201
 202 static long vfio_platform_ioctl(void *device_data,
 203                                 unsigned int cmd, unsigned long arg)
 204 {
 205         struct vfio_platform_device *vdev = device_data;
 206         unsigned long minsz;
 207
 208         if (cmd == VFIO_DEVICE_GET_INFO) {
 209                 struct vfio_device_info info;
 210
 211                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 212
 213                 if (copy_from_user(&info, (void __user *)arg, minsz))
 214                         return -EFAULT;
 215
 216                 if (info.argsz < minsz)
 217                         return -EINVAL;
 218
 219                 if (vdev->reset)
 220                         vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
 221                 info.flags = vdev->flags;
 222                 info.num_regions = vdev->num_regions;
 223                 info.num_irqs = vdev->num_irqs;
 224
 225                 return copy_to_user((void __user *)arg, &info, minsz);
 226
 227         } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
 228                 struct vfio_region_info info;
 229
 230                 minsz = offsetofend(struct vfio_region_info, offset);
 231
 232                 if (copy_from_user(&info, (void __user *)arg, minsz))
 233                         return -EFAULT;
 234
 235                 if (info.argsz < minsz)
 236                         return -EINVAL;
 237
 238                 if (info.index >= vdev->num_regions)
 239                         return -EINVAL;
 240
 241                 /* map offset to the physical address  */
 242                 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
 243                 info.size = vdev->regions[info.index].size;
 244                 info.flags = vdev->regions[info.index].flags;
 245
 246                 return copy_to_user((void __user *)arg, &info, minsz);
 247
 248         } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
 249                 struct vfio_irq_info info;
 250
 251                 minsz = offsetofend(struct vfio_irq_info, count);
 252
 253                 if (copy_from_user(&info, (void __user *)arg, minsz))
 254                         return -EFAULT;
 255
 256                 if (info.argsz < minsz)
 257                         return -EINVAL;
 258
 259                 if (info.index >= vdev->num_irqs)
 260                         return -EINVAL;
 261
 262                 info.flags = vdev->irqs[info.index].flags;
 263                 info.count = vdev->irqs[info.index].count;
 264
 265                 return copy_to_user((void __user *)arg, &info, minsz);
 266
 267         } else if (cmd == VFIO_DEVICE_SET_IRQS) {
 268                 struct vfio_irq_set hdr;
 269                 u8 *data = NULL;
 270                 int ret = 0;
 271
 272                 minsz = offsetofend(struct vfio_irq_set, count);
 273
 274                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 275                         return -EFAULT;
 276
 277                 if (hdr.argsz < minsz)
 278                         return -EINVAL;
 279
 280                 if (hdr.index >= vdev->num_irqs)
 281                         return -EINVAL;
 282
 283                 if (hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
 284                                   VFIO_IRQ_SET_ACTION_TYPE_MASK))
 285                         return -EINVAL;
 286
 287                 if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
 288                         size_t size;
 289
 290                         if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
 291                                 size = sizeof(uint8_t);
 292                         else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
 293                                 size = sizeof(int32_t);
 294                         else
 295                                 return -EINVAL;
 296
 297                         if (hdr.argsz - minsz < size)
 298                                 return -EINVAL;
 299
 300                         data = memdup_user((void __user *)(arg + minsz), size);
 301                         if (IS_ERR(data))
 302                                 return PTR_ERR(data);
 303                 }
 304
 305                 mutex_lock(&vdev->igate);
 306
 307                 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
 308                                                    hdr.start, hdr.count, data);
 309                 mutex_unlock(&vdev->igate);
 310                 kfree(data);
 311
 312                 return ret;
 313
 314         } else if (cmd == VFIO_DEVICE_RESET) {
 315                 if (vdev->reset)
 316                         return vdev->reset(vdev);
 317                 else
 318                         return -EINVAL;
 319         }
 320
 321         return -ENOTTY;
 322 }
 323
 324 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
 325                                        char __user *buf, size_t count,
 326                                        loff_t off)
 327 {
 328         unsigned int done = 0;
 329
 330         if (!reg->ioaddr) {
 331                 reg->ioaddr =
 332                         ioremap_nocache(reg->addr, reg->size);
 333
 334                 if (!reg->ioaddr)
 335                         return -ENOMEM;
 336         }
 337
 338         while (count) {
 339                 size_t filled;
 340
 341                 if (count >= 4 && !(off % 4)) {
 342                         u32 val;
 343
 344                         val = ioread32(reg->ioaddr + off);
 345                         if (copy_to_user(buf, &val, 4))
 346                                 goto err;
 347
 348                         filled = 4;
 349                 } else if (count >= 2 && !(off % 2)) {
 350                         u16 val;
 351
 352                         val = ioread16(reg->ioaddr + off);
 353                         if (copy_to_user(buf, &val, 2))
 354                                 goto err;
 355
 356                         filled = 2;
 357                 } else {
 358                         u8 val;
 359
 360                         val = ioread8(reg->ioaddr + off);
 361                         if (copy_to_user(buf, &val, 1))
 362                                 goto err;
 363
 364                         filled = 1;
 365                 }
 366
 367
 368                 count -= filled;
 369                 done += filled;
 370                 off += filled;
 371                 buf += filled;
 372         }
 373
 374         return done;
 375 err:
 376         return -EFAULT;
 377 }
 378
 379 static ssize_t vfio_platform_read(void *device_data, char __user *buf,
 380                                   size_t count, loff_t *ppos)
 381 {
 382         struct vfio_platform_device *vdev = device_data;
 383         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 384         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 385
 386         if (index >= vdev->num_regions)
 387                 return -EINVAL;
 388
 389         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
 390                 return -EINVAL;
 391
 392         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 393                 return vfio_platform_read_mmio(&vdev->regions[index],
 394                                                         buf, count, off);
 395         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 396                 return -EINVAL; /* not implemented */
 397
 398         return -EINVAL;
 399 }
 400
 401 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
 402                                         const 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                         if (copy_from_user(&val, buf, 4))
 422                                 goto err;
 423                         iowrite32(val, reg->ioaddr + off);
 424
 425                         filled = 4;
 426                 } else if (count >= 2 && !(off % 2)) {
 427                         u16 val;
 428
 429                         if (copy_from_user(&val, buf, 2))
 430                                 goto err;
 431                         iowrite16(val, reg->ioaddr + off);
 432
 433                         filled = 2;
 434                 } else {
 435                         u8 val;
 436
 437                         if (copy_from_user(&val, buf, 1))
 438                                 goto err;
 439                         iowrite8(val, reg->ioaddr + off);
 440
 441                         filled = 1;
 442                 }
 443
 444                 count -= filled;
 445                 done += filled;
 446                 off += filled;
 447                 buf += filled;
 448         }
 449
 450         return done;
 451 err:
 452         return -EFAULT;
 453 }
 454
 455 static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
 456                                    size_t count, loff_t *ppos)
 457 {
 458         struct vfio_platform_device *vdev = device_data;
 459         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 460         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 461
 462         if (index >= vdev->num_regions)
 463                 return -EINVAL;
 464
 465         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
 466                 return -EINVAL;
 467
 468         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 469                 return vfio_platform_write_mmio(&vdev->regions[index],
 470                                                         buf, count, off);
 471         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 472                 return -EINVAL; /* not implemented */
 473
 474         return -EINVAL;
 475 }
 476
 477 static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
 478                                    struct vm_area_struct *vma)
 479 {
 480         u64 req_len, pgoff, req_start;
 481
 482         req_len = vma->vm_end - vma->vm_start;
 483         pgoff = vma->vm_pgoff &
 484                 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
 485         req_start = pgoff << PAGE_SHIFT;
 486
 487         if (region.size < PAGE_SIZE || req_start + req_len > region.size)
 488                 return -EINVAL;
 489
 490         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 491         vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
 492
 493         return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
 494                                req_len, vma->vm_page_prot);
 495 }
 496
 497 static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma)
 498 {
 499         struct vfio_platform_device *vdev = device_data;
 500         unsigned int index;
 501
 502         index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);
 503
 504         if (vma->vm_end < vma->vm_start)
 505                 return -EINVAL;
 506         if (!(vma->vm_flags & VM_SHARED))
 507                 return -EINVAL;
 508         if (index >= vdev->num_regions)
 509                 return -EINVAL;
 510         if (vma->vm_start & ~PAGE_MASK)
 511                 return -EINVAL;
 512         if (vma->vm_end & ~PAGE_MASK)
 513                 return -EINVAL;
 514
 515         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
 516                 return -EINVAL;
 517
 518         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
 519                         && (vma->vm_flags & VM_READ))
 520                 return -EINVAL;
 521
 522         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
 523                         && (vma->vm_flags & VM_WRITE))
 524                 return -EINVAL;
 525
 526         vma->vm_private_data = vdev;
 527
 528         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 529                 return vfio_platform_mmap_mmio(vdev->regions[index], vma);
 530
 531         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 532                 return -EINVAL; /* not implemented */
 533
 534         return -EINVAL;
 535 }
 536
 537 static const struct vfio_device_ops vfio_platform_ops = {
 538         .name           = "vfio-platform",
 539         .open           = vfio_platform_open,
 540         .release        = vfio_platform_release,
 541         .ioctl          = vfio_platform_ioctl,
 542         .read           = vfio_platform_read,
 543         .write          = vfio_platform_write,
 544         .mmap           = vfio_platform_mmap,
 545 };
 546
 547 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 548                                struct device *dev)
 549 {
 550         struct iommu_group *group;
 551         int ret;
 552
 553         if (!vdev)
 554                 return -EINVAL;
 555
 556         ret = device_property_read_string(dev, "compatible", &vdev->compat);
 557         if (ret) {
 558                 pr_err("VFIO: cannot retrieve compat for %s\n", vdev->name);
 559                 return -EINVAL;
 560         }
 561
 562         vdev->device = dev;
 563
 564         group = iommu_group_get(dev);
 565         if (!group) {
 566                 pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
 567                 return -EINVAL;
 568         }
 569
 570         ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
 571         if (ret) {
 572                 iommu_group_put(group);
 573                 return ret;
 574         }
 575
 576         vfio_platform_get_reset(vdev);
 577
 578         mutex_init(&vdev->igate);
 579
 580         return 0;
 581 }
 582 EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
 583
 584 struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
 585 {
 586         struct vfio_platform_device *vdev;
 587
 588         vdev = vfio_del_group_dev(dev);
 589
 590         if (vdev) {
 591                 vfio_platform_put_reset(vdev);
 592                 iommu_group_put(dev->iommu_group);
 593         }
 594
 595         return vdev;
 596 }
 597 EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
 598
 599 void __vfio_platform_register_reset(struct vfio_platform_reset_node *node)
 600 {
 601         mutex_lock(&driver_lock);
 602         list_add(&node->link, &reset_list);
 603         mutex_unlock(&driver_lock);
 604 }
 605 EXPORT_SYMBOL_GPL(__vfio_platform_register_reset);
 606
 607 void vfio_platform_unregister_reset(const char *compat,
 608                                     vfio_platform_reset_fn_t fn)
 609 {
 610         struct vfio_platform_reset_node *iter, *temp;
 611
 612         mutex_lock(&driver_lock);
 613         list_for_each_entry_safe(iter, temp, &reset_list, link) {
 614                 if (!strcmp(iter->compat, compat) && (iter->reset == fn)) {
 615                         list_del(&iter->link);
 616                         break;
 617                 }
 618         }
 619
 620         mutex_unlock(&driver_lock);
 621
 622 }
 623 EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset);
 624
 625 MODULE_VERSION(DRIVER_VERSION);
 626 MODULE_LICENSE("GPL v2");
 627 MODULE_AUTHOR(DRIVER_AUTHOR);
 628 MODULE_DESCRIPTION(DRIVER_DESC);