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 static LIST_HEAD(reset_list);
  32 static DEFINE_MUTEX(driver_lock);
  33
  34 static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat,
  35                                         struct module **module)
  36 {
  37         struct vfio_platform_reset_node *iter;
  38         vfio_platform_reset_fn_t reset_fn = NULL;
  39
  40         mutex_lock(&driver_lock);
  41         list_for_each_entry(iter, &reset_list, link) {
  42                 if (!strcmp(iter->compat, compat) &&
  43                         try_module_get(iter->owner)) {
  44                         *module = iter->owner;
  45                         reset_fn = iter->of_reset;
  46                         break;
  47                 }
  48         }
  49         mutex_unlock(&driver_lock);
  50         return reset_fn;
  51 }
  52
  53 static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev,
  54                                     struct device *dev)
  55 {
  56         struct acpi_device *adev;
  57
  58         if (acpi_disabled)
  59                 return -ENOENT;
  60
  61         adev = ACPI_COMPANION(dev);
  62         if (!adev) {
  63                 pr_err("VFIO: ACPI companion device not found for %s\n",
  64                         vdev->name);
  65                 return -ENODEV;
  66         }
  67
  68 #ifdef CONFIG_ACPI
  69         vdev->acpihid = acpi_device_hid(adev);
  70 #endif
  71         return WARN_ON(!vdev->acpihid) ? -EINVAL : 0;
  72 }
  73
  74 static bool vfio_platform_has_reset(struct vfio_platform_device *vdev)
  75 {
  76         return vdev->of_reset ? true : false;
  77 }
  78
  79 static void vfio_platform_get_reset(struct vfio_platform_device *vdev)
  80 {
  81         vdev->of_reset = vfio_platform_lookup_reset(vdev->compat,
  82                                                     &vdev->reset_module);
  83         if (!vdev->of_reset) {
  84                 request_module("vfio-reset:%s", vdev->compat);
  85                 vdev->of_reset = vfio_platform_lookup_reset(vdev->compat,
  86                                                         &vdev->reset_module);
  87         }
  88 }
  89
  90 static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
  91 {
  92         if (vdev->of_reset)
  93                 module_put(vdev->reset_module);
  94 }
  95
  96 static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
  97 {
  98         int cnt = 0, i;
  99
 100         while (vdev->get_resource(vdev, cnt))
 101                 cnt++;
 102
 103         vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region),
 104                                 GFP_KERNEL);
 105         if (!vdev->regions)
 106                 return -ENOMEM;
 107
 108         for (i = 0; i < cnt;  i++) {
 109                 struct resource *res =
 110                         vdev->get_resource(vdev, i);
 111
 112                 if (!res)
 113                         goto err;
 114
 115                 vdev->regions[i].addr = res->start;
 116                 vdev->regions[i].size = resource_size(res);
 117                 vdev->regions[i].flags = 0;
 118
 119                 switch (resource_type(res)) {
 120                 case IORESOURCE_MEM:
 121                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO;
 122                         vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
 123                         if (!(res->flags & IORESOURCE_READONLY))
 124                                 vdev->regions[i].flags |=
 125                                         VFIO_REGION_INFO_FLAG_WRITE;
 126
 127                         /*
 128                          * Only regions addressed with PAGE granularity may be
 129                          * MMAPed securely.
 130                          */
 131                         if (!(vdev->regions[i].addr & ~PAGE_MASK) &&
 132                                         !(vdev->regions[i].size & ~PAGE_MASK))
 133                                 vdev->regions[i].flags |=
 134                                         VFIO_REGION_INFO_FLAG_MMAP;
 135
 136                         break;
 137                 case IORESOURCE_IO:
 138                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
 139                         break;
 140                 default:
 141                         goto err;
 142                 }
 143         }
 144
 145         vdev->num_regions = cnt;
 146
 147         return 0;
 148 err:
 149         kfree(vdev->regions);
 150         return -EINVAL;
 151 }
 152
 153 static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
 154 {
 155         int i;
 156
 157         for (i = 0; i < vdev->num_regions; i++)
 158                 iounmap(vdev->regions[i].ioaddr);
 159
 160         vdev->num_regions = 0;
 161         kfree(vdev->regions);
 162 }
 163
 164 static int vfio_platform_call_reset(struct vfio_platform_device *vdev)
 165 {
 166         if (vdev->of_reset) {
 167                 dev_info(vdev->device, "reset\n");
 168                 return vdev->of_reset(vdev);
 169         }
 170
 171         dev_warn(vdev->device, "no reset function found!\n");
 172         return -EINVAL;
 173 }
 174
 175 static void vfio_platform_release(void *device_data)
 176 {
 177         struct vfio_platform_device *vdev = device_data;
 178
 179         mutex_lock(&driver_lock);
 180
 181         if (!(--vdev->refcnt)) {
 182                 vfio_platform_call_reset(vdev);
 183                 vfio_platform_regions_cleanup(vdev);
 184                 vfio_platform_irq_cleanup(vdev);
 185         }
 186
 187         mutex_unlock(&driver_lock);
 188
 189         module_put(vdev->parent_module);
 190 }
 191
 192 static int vfio_platform_open(void *device_data)
 193 {
 194         struct vfio_platform_device *vdev = device_data;
 195         int ret;
 196
 197         if (!try_module_get(vdev->parent_module))
 198                 return -ENODEV;
 199
 200         mutex_lock(&driver_lock);
 201
 202         if (!vdev->refcnt) {
 203                 ret = vfio_platform_regions_init(vdev);
 204                 if (ret)
 205                         goto err_reg;
 206
 207                 ret = vfio_platform_irq_init(vdev);
 208                 if (ret)
 209                         goto err_irq;
 210
 211                 vfio_platform_call_reset(vdev);
 212         }
 213
 214         vdev->refcnt++;
 215
 216         mutex_unlock(&driver_lock);
 217         return 0;
 218
 219 err_irq:
 220         vfio_platform_regions_cleanup(vdev);
 221 err_reg:
 222         mutex_unlock(&driver_lock);
 223         module_put(THIS_MODULE);
 224         return ret;
 225 }
 226
 227 static long vfio_platform_ioctl(void *device_data,
 228                                 unsigned int cmd, unsigned long arg)
 229 {
 230         struct vfio_platform_device *vdev = device_data;
 231         unsigned long minsz;
 232
 233         if (cmd == VFIO_DEVICE_GET_INFO) {
 234                 struct vfio_device_info info;
 235
 236                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 237
 238                 if (copy_from_user(&info, (void __user *)arg, minsz))
 239                         return -EFAULT;
 240
 241                 if (info.argsz < minsz)
 242                         return -EINVAL;
 243
 244                 if (vfio_platform_has_reset(vdev))
 245                         vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
 246                 info.flags = vdev->flags;
 247                 info.num_regions = vdev->num_regions;
 248                 info.num_irqs = vdev->num_irqs;
 249
 250                 return copy_to_user((void __user *)arg, &info, minsz) ?
 251                         -EFAULT : 0;
 252
 253         } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
 254                 struct vfio_region_info info;
 255
 256                 minsz = offsetofend(struct vfio_region_info, offset);
 257
 258                 if (copy_from_user(&info, (void __user *)arg, minsz))
 259                         return -EFAULT;
 260
 261                 if (info.argsz < minsz)
 262                         return -EINVAL;
 263
 264                 if (info.index >= vdev->num_regions)
 265                         return -EINVAL;
 266
 267                 /* map offset to the physical address  */
 268                 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
 269                 info.size = vdev->regions[info.index].size;
 270                 info.flags = vdev->regions[info.index].flags;
 271
 272                 return copy_to_user((void __user *)arg, &info, minsz) ?
 273                         -EFAULT : 0;
 274
 275         } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
 276                 struct vfio_irq_info info;
 277
 278                 minsz = offsetofend(struct vfio_irq_info, count);
 279
 280                 if (copy_from_user(&info, (void __user *)arg, minsz))
 281                         return -EFAULT;
 282
 283                 if (info.argsz < minsz)
 284                         return -EINVAL;
 285
 286                 if (info.index >= vdev->num_irqs)
 287                         return -EINVAL;
 288
 289                 info.flags = vdev->irqs[info.index].flags;
 290                 info.count = vdev->irqs[info.index].count;
 291
 292                 return copy_to_user((void __user *)arg, &info, minsz) ?
 293                         -EFAULT : 0;
 294
 295         } else if (cmd == VFIO_DEVICE_SET_IRQS) {
 296                 struct vfio_irq_set hdr;
 297                 u8 *data = NULL;
 298                 int ret = 0;
 299
 300                 minsz = offsetofend(struct vfio_irq_set, count);
 301
 302                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 303                         return -EFAULT;
 304
 305                 if (hdr.argsz < minsz)
 306                         return -EINVAL;
 307
 308                 if (hdr.index >= vdev->num_irqs)
 309                         return -EINVAL;
 310
 311                 if (hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
 312                                   VFIO_IRQ_SET_ACTION_TYPE_MASK))
 313                         return -EINVAL;
 314
 315                 if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
 316                         size_t size;
 317
 318                         if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
 319                                 size = sizeof(uint8_t);
 320                         else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
 321                                 size = sizeof(int32_t);
 322                         else
 323                                 return -EINVAL;
 324
 325                         if (hdr.argsz - minsz < size)
 326                                 return -EINVAL;
 327
 328                         data = memdup_user((void __user *)(arg + minsz), size);
 329                         if (IS_ERR(data))
 330                                 return PTR_ERR(data);
 331                 }
 332
 333                 mutex_lock(&vdev->igate);
 334
 335                 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
 336                                                    hdr.start, hdr.count, data);
 337                 mutex_unlock(&vdev->igate);
 338                 kfree(data);
 339
 340                 return ret;
 341
 342         } else if (cmd == VFIO_DEVICE_RESET) {
 343                 return vfio_platform_call_reset(vdev);
 344         }
 345
 346         return -ENOTTY;
 347 }
 348
 349 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
 350                                        char __user *buf, size_t count,
 351                                        loff_t off)
 352 {
 353         unsigned int done = 0;
 354
 355         if (!reg->ioaddr) {
 356                 reg->ioaddr =
 357                         ioremap_nocache(reg->addr, reg->size);
 358
 359                 if (!reg->ioaddr)
 360                         return -ENOMEM;
 361         }
 362
 363         while (count) {
 364                 size_t filled;
 365
 366                 if (count >= 4 && !(off % 4)) {
 367                         u32 val;
 368
 369                         val = ioread32(reg->ioaddr + off);
 370                         if (copy_to_user(buf, &val, 4))
 371                                 goto err;
 372
 373                         filled = 4;
 374                 } else if (count >= 2 && !(off % 2)) {
 375                         u16 val;
 376
 377                         val = ioread16(reg->ioaddr + off);
 378                         if (copy_to_user(buf, &val, 2))
 379                                 goto err;
 380
 381                         filled = 2;
 382                 } else {
 383                         u8 val;
 384
 385                         val = ioread8(reg->ioaddr + off);
 386                         if (copy_to_user(buf, &val, 1))
 387                                 goto err;
 388
 389                         filled = 1;
 390                 }
 391
 392
 393                 count -= filled;
 394                 done += filled;
 395                 off += filled;
 396                 buf += filled;
 397         }
 398
 399         return done;
 400 err:
 401         return -EFAULT;
 402 }
 403
 404 static ssize_t vfio_platform_read(void *device_data, char __user *buf,
 405                                   size_t count, loff_t *ppos)
 406 {
 407         struct vfio_platform_device *vdev = device_data;
 408         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 409         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 410
 411         if (index >= vdev->num_regions)
 412                 return -EINVAL;
 413
 414         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
 415                 return -EINVAL;
 416
 417         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 418                 return vfio_platform_read_mmio(&vdev->regions[index],
 419                                                         buf, count, off);
 420         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 421                 return -EINVAL; /* not implemented */
 422
 423         return -EINVAL;
 424 }
 425
 426 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
 427                                         const char __user *buf, size_t count,
 428                                         loff_t off)
 429 {
 430         unsigned int done = 0;
 431
 432         if (!reg->ioaddr) {
 433                 reg->ioaddr =
 434                         ioremap_nocache(reg->addr, reg->size);
 435
 436                 if (!reg->ioaddr)
 437                         return -ENOMEM;
 438         }
 439
 440         while (count) {
 441                 size_t filled;
 442
 443                 if (count >= 4 && !(off % 4)) {
 444                         u32 val;
 445
 446                         if (copy_from_user(&val, buf, 4))
 447                                 goto err;
 448                         iowrite32(val, reg->ioaddr + off);
 449
 450                         filled = 4;
 451                 } else if (count >= 2 && !(off % 2)) {
 452                         u16 val;
 453
 454                         if (copy_from_user(&val, buf, 2))
 455                                 goto err;
 456                         iowrite16(val, reg->ioaddr + off);
 457
 458                         filled = 2;
 459                 } else {
 460                         u8 val;
 461
 462                         if (copy_from_user(&val, buf, 1))
 463                                 goto err;
 464                         iowrite8(val, reg->ioaddr + off);
 465
 466                         filled = 1;
 467                 }
 468
 469                 count -= filled;
 470                 done += filled;
 471                 off += filled;
 472                 buf += filled;
 473         }
 474
 475         return done;
 476 err:
 477         return -EFAULT;
 478 }
 479
 480 static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
 481                                    size_t count, loff_t *ppos)
 482 {
 483         struct vfio_platform_device *vdev = device_data;
 484         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 485         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 486
 487         if (index >= vdev->num_regions)
 488                 return -EINVAL;
 489
 490         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
 491                 return -EINVAL;
 492
 493         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 494                 return vfio_platform_write_mmio(&vdev->regions[index],
 495                                                         buf, count, off);
 496         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 497                 return -EINVAL; /* not implemented */
 498
 499         return -EINVAL;
 500 }
 501
 502 static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
 503                                    struct vm_area_struct *vma)
 504 {
 505         u64 req_len, pgoff, req_start;
 506
 507         req_len = vma->vm_end - vma->vm_start;
 508         pgoff = vma->vm_pgoff &
 509                 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
 510         req_start = pgoff << PAGE_SHIFT;
 511
 512         if (region.size < PAGE_SIZE || req_start + req_len > region.size)
 513                 return -EINVAL;
 514
 515         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 516         vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
 517
 518         return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
 519                                req_len, vma->vm_page_prot);
 520 }
 521
 522 static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma)
 523 {
 524         struct vfio_platform_device *vdev = device_data;
 525         unsigned int index;
 526
 527         index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);
 528
 529         if (vma->vm_end < vma->vm_start)
 530                 return -EINVAL;
 531         if (!(vma->vm_flags & VM_SHARED))
 532                 return -EINVAL;
 533         if (index >= vdev->num_regions)
 534                 return -EINVAL;
 535         if (vma->vm_start & ~PAGE_MASK)
 536                 return -EINVAL;
 537         if (vma->vm_end & ~PAGE_MASK)
 538                 return -EINVAL;
 539
 540         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
 541                 return -EINVAL;
 542
 543         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
 544                         && (vma->vm_flags & VM_READ))
 545                 return -EINVAL;
 546
 547         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
 548                         && (vma->vm_flags & VM_WRITE))
 549                 return -EINVAL;
 550
 551         vma->vm_private_data = vdev;
 552
 553         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 554                 return vfio_platform_mmap_mmio(vdev->regions[index], vma);
 555
 556         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 557                 return -EINVAL; /* not implemented */
 558
 559         return -EINVAL;
 560 }
 561
 562 static const struct vfio_device_ops vfio_platform_ops = {
 563         .name           = "vfio-platform",
 564         .open           = vfio_platform_open,
 565         .release        = vfio_platform_release,
 566         .ioctl          = vfio_platform_ioctl,
 567         .read           = vfio_platform_read,
 568         .write          = vfio_platform_write,
 569         .mmap           = vfio_platform_mmap,
 570 };
 571
 572 int vfio_platform_of_probe(struct vfio_platform_device *vdev,
 573                            struct device *dev)
 574 {
 575         int ret;
 576
 577         ret = device_property_read_string(dev, "compatible",
 578                                           &vdev->compat);
 579         if (ret)
 580                 pr_err("VFIO: cannot retrieve compat for %s\n",
 581                         vdev->name);
 582
 583         return ret;
 584 }
 585
 586 /*
 587  * There can be two kernel build combinations. One build where
 588  * ACPI is not selected in Kconfig and another one with the ACPI Kconfig.
 589  *
 590  * In the first case, vfio_platform_acpi_probe will return since
 591  * acpi_disabled is 1. DT user will not see any kind of messages from
 592  * ACPI.
 593  *
 594  * In the second case, both DT and ACPI is compiled in but the system is
 595  * booting with any of these combinations.
 596  *
 597  * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine
 598  * terminates immediately without any messages.
 599  *
 600  * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are
 601  * valid checks. We cannot claim that this system is DT.
 602  */
 603 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 604                                struct device *dev)
 605 {
 606         struct iommu_group *group;
 607         int ret;
 608
 609         if (!vdev)
 610                 return -EINVAL;
 611
 612         ret = vfio_platform_acpi_probe(vdev, dev);
 613         if (ret)
 614                 ret = vfio_platform_of_probe(vdev, dev);
 615
 616         if (ret)
 617                 return ret;
 618
 619         vdev->device = dev;
 620
 621         group = vfio_iommu_group_get(dev);
 622         if (!group) {
 623                 pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
 624                 return -EINVAL;
 625         }
 626
 627         ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
 628         if (ret) {
 629                 vfio_iommu_group_put(group, dev);
 630                 return ret;
 631         }
 632
 633         vfio_platform_get_reset(vdev);
 634
 635         mutex_init(&vdev->igate);
 636
 637         return 0;
 638 }
 639 EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
 640
 641 struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
 642 {
 643         struct vfio_platform_device *vdev;
 644
 645         vdev = vfio_del_group_dev(dev);
 646
 647         if (vdev) {
 648                 vfio_platform_put_reset(vdev);
 649                 vfio_iommu_group_put(dev->iommu_group, dev);
 650         }
 651
 652         return vdev;
 653 }
 654 EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
 655
 656 void __vfio_platform_register_reset(struct vfio_platform_reset_node *node)
 657 {
 658         mutex_lock(&driver_lock);
 659         list_add(&node->link, &reset_list);
 660         mutex_unlock(&driver_lock);
 661 }
 662 EXPORT_SYMBOL_GPL(__vfio_platform_register_reset);
 663
 664 void vfio_platform_unregister_reset(const char *compat,
 665                                     vfio_platform_reset_fn_t fn)
 666 {
 667         struct vfio_platform_reset_node *iter, *temp;
 668
 669         mutex_lock(&driver_lock);
 670         list_for_each_entry_safe(iter, temp, &reset_list, link) {
 671                 if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) {
 672                         list_del(&iter->link);
 673                         break;
 674                 }
 675         }
 676
 677         mutex_unlock(&driver_lock);
 678
 679 }
 680 EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset);
 681
 682 MODULE_VERSION(DRIVER_VERSION);
 683 MODULE_LICENSE("GPL v2");
 684 MODULE_AUTHOR(DRIVER_AUTHOR);
 685 MODULE_DESCRIPTION(DRIVER_DESC);