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         vdev->reset = vfio_platform_lookup_reset(vdev->compat,
  55                                                 &vdev->reset_module);
  56         if (!vdev->reset) {
  57                 request_module("vfio-reset:%s", vdev->compat);
  58                 vdev->reset = vfio_platform_lookup_reset(vdev->compat,
  59                                                          &vdev->reset_module);
  60         }
  61 }
  62
  63 static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
  64 {
  65         if (vdev->reset)
  66                 module_put(vdev->reset_module);
  67 }
  68
  69 static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
  70 {
  71         int cnt = 0, i;
  72
  73         while (vdev->get_resource(vdev, cnt))
  74                 cnt++;
  75
  76         vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region),
  77                                 GFP_KERNEL);
  78         if (!vdev->regions)
  79                 return -ENOMEM;
  80
  81         for (i = 0; i < cnt;  i++) {
  82                 struct resource *res =
  83                         vdev->get_resource(vdev, i);
  84
  85                 if (!res)
  86                         goto err;
  87
  88                 vdev->regions[i].addr = res->start;
  89                 vdev->regions[i].size = resource_size(res);
  90                 vdev->regions[i].flags = 0;
  91
  92                 switch (resource_type(res)) {
  93                 case IORESOURCE_MEM:
  94                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO;
  95                         vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
  96                         if (!(res->flags & IORESOURCE_READONLY))
  97                                 vdev->regions[i].flags |=
  98                                         VFIO_REGION_INFO_FLAG_WRITE;
  99
 100                         /*
 101                          * Only regions addressed with PAGE granularity may be
 102                          * MMAPed securely.
 103                          */
 104                         if (!(vdev->regions[i].addr & ~PAGE_MASK) &&
 105                                         !(vdev->regions[i].size & ~PAGE_MASK))
 106                                 vdev->regions[i].flags |=
 107                                         VFIO_REGION_INFO_FLAG_MMAP;
 108
 109                         break;
 110                 case IORESOURCE_IO:
 111                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
 112                         break;
 113                 default:
 114                         goto err;
 115                 }
 116         }
 117
 118         vdev->num_regions = cnt;
 119
 120         return 0;
 121 err:
 122         kfree(vdev->regions);
 123         return -EINVAL;
 124 }
 125
 126 static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
 127 {
 128         int i;
 129
 130         for (i = 0; i < vdev->num_regions; i++)
 131                 iounmap(vdev->regions[i].ioaddr);
 132
 133         vdev->num_regions = 0;
 134         kfree(vdev->regions);
 135 }
 136
 137 static void vfio_platform_release(void *device_data)
 138 {
 139         struct vfio_platform_device *vdev = device_data;
 140
 141         mutex_lock(&driver_lock);
 142
 143         if (!(--vdev->refcnt)) {
 144                 if (vdev->reset) {
 145                         dev_info(vdev->device, "reset\n");
 146                         vdev->reset(vdev);
 147                 } else {
 148                         dev_warn(vdev->device, "no reset function found!\n");
 149                 }
 150                 vfio_platform_regions_cleanup(vdev);
 151                 vfio_platform_irq_cleanup(vdev);
 152         }
 153
 154         mutex_unlock(&driver_lock);
 155
 156         module_put(vdev->parent_module);
 157 }
 158
 159 static int vfio_platform_open(void *device_data)
 160 {
 161         struct vfio_platform_device *vdev = device_data;
 162         int ret;
 163
 164         if (!try_module_get(vdev->parent_module))
 165                 return -ENODEV;
 166
 167         mutex_lock(&driver_lock);
 168
 169         if (!vdev->refcnt) {
 170                 ret = vfio_platform_regions_init(vdev);
 171                 if (ret)
 172                         goto err_reg;
 173
 174                 ret = vfio_platform_irq_init(vdev);
 175                 if (ret)
 176                         goto err_irq;
 177
 178                 if (vdev->reset) {
 179                         dev_info(vdev->device, "reset\n");
 180                         vdev->reset(vdev);
 181                 } else {
 182                         dev_warn(vdev->device, "no reset function found!\n");
 183                 }
 184         }
 185
 186         vdev->refcnt++;
 187
 188         mutex_unlock(&driver_lock);
 189         return 0;
 190
 191 err_irq:
 192         vfio_platform_regions_cleanup(vdev);
 193 err_reg:
 194         mutex_unlock(&driver_lock);
 195         module_put(THIS_MODULE);
 196         return ret;
 197 }
 198
 199 static long vfio_platform_ioctl(void *device_data,
 200                                 unsigned int cmd, unsigned long arg)
 201 {
 202         struct vfio_platform_device *vdev = device_data;
 203         unsigned long minsz;
 204
 205         if (cmd == VFIO_DEVICE_GET_INFO) {
 206                 struct vfio_device_info info;
 207
 208                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 209
 210                 if (copy_from_user(&info, (void __user *)arg, minsz))
 211                         return -EFAULT;
 212
 213                 if (info.argsz < minsz)
 214                         return -EINVAL;
 215
 216                 if (vdev->reset)
 217                         vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
 218                 info.flags = vdev->flags;
 219                 info.num_regions = vdev->num_regions;
 220                 info.num_irqs = vdev->num_irqs;
 221
 222                 return copy_to_user((void __user *)arg, &info, minsz);
 223
 224         } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
 225                 struct vfio_region_info info;
 226
 227                 minsz = offsetofend(struct vfio_region_info, offset);
 228
 229                 if (copy_from_user(&info, (void __user *)arg, minsz))
 230                         return -EFAULT;
 231
 232                 if (info.argsz < minsz)
 233                         return -EINVAL;
 234
 235                 if (info.index >= vdev->num_regions)
 236                         return -EINVAL;
 237
 238                 /* map offset to the physical address  */
 239                 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
 240                 info.size = vdev->regions[info.index].size;
 241                 info.flags = vdev->regions[info.index].flags;
 242
 243                 return copy_to_user((void __user *)arg, &info, minsz);
 244
 245         } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
 246                 struct vfio_irq_info info;
 247
 248                 minsz = offsetofend(struct vfio_irq_info, count);
 249
 250                 if (copy_from_user(&info, (void __user *)arg, minsz))
 251                         return -EFAULT;
 252
 253                 if (info.argsz < minsz)
 254                         return -EINVAL;
 255
 256                 if (info.index >= vdev->num_irqs)
 257                         return -EINVAL;
 258
 259                 info.flags = vdev->irqs[info.index].flags;
 260                 info.count = vdev->irqs[info.index].count;
 261
 262                 return copy_to_user((void __user *)arg, &info, minsz);
 263
 264         } else if (cmd == VFIO_DEVICE_SET_IRQS) {
 265                 struct vfio_irq_set hdr;
 266                 u8 *data = NULL;
 267                 int ret = 0;
 268
 269                 minsz = offsetofend(struct vfio_irq_set, count);
 270
 271                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 272                         return -EFAULT;
 273
 274                 if (hdr.argsz < minsz)
 275                         return -EINVAL;
 276
 277                 if (hdr.index >= vdev->num_irqs)
 278                         return -EINVAL;
 279
 280                 if (hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
 281                                   VFIO_IRQ_SET_ACTION_TYPE_MASK))
 282                         return -EINVAL;
 283
 284                 if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
 285                         size_t size;
 286
 287                         if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
 288                                 size = sizeof(uint8_t);
 289                         else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
 290                                 size = sizeof(int32_t);
 291                         else
 292                                 return -EINVAL;
 293
 294                         if (hdr.argsz - minsz < size)
 295                                 return -EINVAL;
 296
 297                         data = memdup_user((void __user *)(arg + minsz), size);
 298                         if (IS_ERR(data))
 299                                 return PTR_ERR(data);
 300                 }
 301
 302                 mutex_lock(&vdev->igate);
 303
 304                 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
 305                                                    hdr.start, hdr.count, data);
 306                 mutex_unlock(&vdev->igate);
 307                 kfree(data);
 308
 309                 return ret;
 310
 311         } else if (cmd == VFIO_DEVICE_RESET) {
 312                 if (vdev->reset)
 313                         return vdev->reset(vdev);
 314                 else
 315                         return -EINVAL;
 316         }
 317
 318         return -ENOTTY;
 319 }
 320
 321 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
 322                                        char __user *buf, size_t count,
 323                                        loff_t off)
 324 {
 325         unsigned int done = 0;
 326
 327         if (!reg->ioaddr) {
 328                 reg->ioaddr =
 329                         ioremap_nocache(reg->addr, reg->size);
 330
 331                 if (!reg->ioaddr)
 332                         return -ENOMEM;
 333         }
 334
 335         while (count) {
 336                 size_t filled;
 337
 338                 if (count >= 4 && !(off % 4)) {
 339                         u32 val;
 340
 341                         val = ioread32(reg->ioaddr + off);
 342                         if (copy_to_user(buf, &val, 4))
 343                                 goto err;
 344
 345                         filled = 4;
 346                 } else if (count >= 2 && !(off % 2)) {
 347                         u16 val;
 348
 349                         val = ioread16(reg->ioaddr + off);
 350                         if (copy_to_user(buf, &val, 2))
 351                                 goto err;
 352
 353                         filled = 2;
 354                 } else {
 355                         u8 val;
 356
 357                         val = ioread8(reg->ioaddr + off);
 358                         if (copy_to_user(buf, &val, 1))
 359                                 goto err;
 360
 361                         filled = 1;
 362                 }
 363
 364
 365                 count -= filled;
 366                 done += filled;
 367                 off += filled;
 368                 buf += filled;
 369         }
 370
 371         return done;
 372 err:
 373         return -EFAULT;
 374 }
 375
 376 static ssize_t vfio_platform_read(void *device_data, char __user *buf,
 377                                   size_t count, loff_t *ppos)
 378 {
 379         struct vfio_platform_device *vdev = device_data;
 380         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 381         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 382
 383         if (index >= vdev->num_regions)
 384                 return -EINVAL;
 385
 386         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
 387                 return -EINVAL;
 388
 389         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 390                 return vfio_platform_read_mmio(&vdev->regions[index],
 391                                                         buf, count, off);
 392         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 393                 return -EINVAL; /* not implemented */
 394
 395         return -EINVAL;
 396 }
 397
 398 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
 399                                         const char __user *buf, size_t count,
 400                                         loff_t off)
 401 {
 402         unsigned int done = 0;
 403
 404         if (!reg->ioaddr) {
 405                 reg->ioaddr =
 406                         ioremap_nocache(reg->addr, reg->size);
 407
 408                 if (!reg->ioaddr)
 409                         return -ENOMEM;
 410         }
 411
 412         while (count) {
 413                 size_t filled;
 414
 415                 if (count >= 4 && !(off % 4)) {
 416                         u32 val;
 417
 418                         if (copy_from_user(&val, buf, 4))
 419                                 goto err;
 420                         iowrite32(val, reg->ioaddr + off);
 421
 422                         filled = 4;
 423                 } else if (count >= 2 && !(off % 2)) {
 424                         u16 val;
 425
 426                         if (copy_from_user(&val, buf, 2))
 427                                 goto err;
 428                         iowrite16(val, reg->ioaddr + off);
 429
 430                         filled = 2;
 431                 } else {
 432                         u8 val;
 433
 434                         if (copy_from_user(&val, buf, 1))
 435                                 goto err;
 436                         iowrite8(val, reg->ioaddr + off);
 437
 438                         filled = 1;
 439                 }
 440
 441                 count -= filled;
 442                 done += filled;
 443                 off += filled;
 444                 buf += filled;
 445         }
 446
 447         return done;
 448 err:
 449         return -EFAULT;
 450 }
 451
 452 static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
 453                                    size_t count, loff_t *ppos)
 454 {
 455         struct vfio_platform_device *vdev = device_data;
 456         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 457         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 458
 459         if (index >= vdev->num_regions)
 460                 return -EINVAL;
 461
 462         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
 463                 return -EINVAL;
 464
 465         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 466                 return vfio_platform_write_mmio(&vdev->regions[index],
 467                                                         buf, count, off);
 468         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 469                 return -EINVAL; /* not implemented */
 470
 471         return -EINVAL;
 472 }
 473
 474 static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
 475                                    struct vm_area_struct *vma)
 476 {
 477         u64 req_len, pgoff, req_start;
 478
 479         req_len = vma->vm_end - vma->vm_start;
 480         pgoff = vma->vm_pgoff &
 481                 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
 482         req_start = pgoff << PAGE_SHIFT;
 483
 484         if (region.size < PAGE_SIZE || req_start + req_len > region.size)
 485                 return -EINVAL;
 486
 487         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 488         vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
 489
 490         return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
 491                                req_len, vma->vm_page_prot);
 492 }
 493
 494 static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma)
 495 {
 496         struct vfio_platform_device *vdev = device_data;
 497         unsigned int index;
 498
 499         index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);
 500
 501         if (vma->vm_end < vma->vm_start)
 502                 return -EINVAL;
 503         if (!(vma->vm_flags & VM_SHARED))
 504                 return -EINVAL;
 505         if (index >= vdev->num_regions)
 506                 return -EINVAL;
 507         if (vma->vm_start & ~PAGE_MASK)
 508                 return -EINVAL;
 509         if (vma->vm_end & ~PAGE_MASK)
 510                 return -EINVAL;
 511
 512         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
 513                 return -EINVAL;
 514
 515         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
 516                         && (vma->vm_flags & VM_READ))
 517                 return -EINVAL;
 518
 519         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
 520                         && (vma->vm_flags & VM_WRITE))
 521                 return -EINVAL;
 522
 523         vma->vm_private_data = vdev;
 524
 525         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 526                 return vfio_platform_mmap_mmio(vdev->regions[index], vma);
 527
 528         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 529                 return -EINVAL; /* not implemented */
 530
 531         return -EINVAL;
 532 }
 533
 534 static const struct vfio_device_ops vfio_platform_ops = {
 535         .name           = "vfio-platform",
 536         .open           = vfio_platform_open,
 537         .release        = vfio_platform_release,
 538         .ioctl          = vfio_platform_ioctl,
 539         .read           = vfio_platform_read,
 540         .write          = vfio_platform_write,
 541         .mmap           = vfio_platform_mmap,
 542 };
 543
 544 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 545                                struct device *dev)
 546 {
 547         struct iommu_group *group;
 548         int ret;
 549
 550         if (!vdev)
 551                 return -EINVAL;
 552
 553         ret = device_property_read_string(dev, "compatible", &vdev->compat);
 554         if (ret) {
 555                 pr_err("VFIO: cannot retrieve compat for %s\n", vdev->name);
 556                 return -EINVAL;
 557         }
 558
 559         vdev->device = dev;
 560
 561         group = iommu_group_get(dev);
 562         if (!group) {
 563                 pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
 564                 return -EINVAL;
 565         }
 566
 567         ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
 568         if (ret) {
 569                 iommu_group_put(group);
 570                 return ret;
 571         }
 572
 573         vfio_platform_get_reset(vdev);
 574
 575         mutex_init(&vdev->igate);
 576
 577         return 0;
 578 }
 579 EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
 580
 581 struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
 582 {
 583         struct vfio_platform_device *vdev;
 584
 585         vdev = vfio_del_group_dev(dev);
 586
 587         if (vdev) {
 588                 vfio_platform_put_reset(vdev);
 589                 iommu_group_put(dev->iommu_group);
 590         }
 591
 592         return vdev;
 593 }
 594 EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
 595
 596 void __vfio_platform_register_reset(struct vfio_platform_reset_node *node)
 597 {
 598         mutex_lock(&driver_lock);
 599         list_add(&node->link, &reset_list);
 600         mutex_unlock(&driver_lock);
 601 }
 602 EXPORT_SYMBOL_GPL(__vfio_platform_register_reset);
 603
 604 void vfio_platform_unregister_reset(const char *compat,
 605                                     vfio_platform_reset_fn_t fn)
 606 {
 607         struct vfio_platform_reset_node *iter, *temp;
 608
 609         mutex_lock(&driver_lock);
 610         list_for_each_entry_safe(iter, temp, &reset_list, link) {
 611                 if (!strcmp(iter->compat, compat) && (iter->reset == fn)) {
 612                         list_del(&iter->link);
 613                         break;
 614                 }
 615         }
 616
 617         mutex_unlock(&driver_lock);
 618
 619 }
 620 EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset);
 621
 622 MODULE_VERSION(DRIVER_VERSION);
 623 MODULE_LICENSE("GPL v2");
 624 MODULE_AUTHOR(DRIVER_AUTHOR);
 625 MODULE_DESCRIPTION(DRIVER_DESC);