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