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 static DEFINE_MUTEX(driver_lock);
  27
  28 static const struct vfio_platform_reset_combo reset_lookup_table[] = {
  29 };
  30
  31 static void vfio_platform_get_reset(struct vfio_platform_device *vdev,
  32                                     struct device *dev)
  33 {
  34         const char *compat;
  35         int (*reset)(struct vfio_platform_device *);
  36         int ret, i;
  37
  38         ret = device_property_read_string(dev, "compatible", &compat);
  39         if (ret)
  40                 return;
  41
  42         for (i = 0 ; i < ARRAY_SIZE(reset_lookup_table); i++) {
  43                 if (!strcmp(reset_lookup_table[i].compat, compat)) {
  44                         request_module(reset_lookup_table[i].module_name);
  45                         reset = __symbol_get(
  46                                 reset_lookup_table[i].reset_function_name);
  47                         if (reset) {
  48                                 vdev->reset = reset;
  49                                 return;
  50                         }
  51                 }
  52         }
  53 }
  54
  55 static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
  56 {
  57         if (vdev->reset)
  58                 symbol_put_addr(vdev->reset);
  59 }
  60
  61 static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
  62 {
  63         int cnt = 0, i;
  64
  65         while (vdev->get_resource(vdev, cnt))
  66                 cnt++;
  67
  68         vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region),
  69                                 GFP_KERNEL);
  70         if (!vdev->regions)
  71                 return -ENOMEM;
  72
  73         for (i = 0; i < cnt;  i++) {
  74                 struct resource *res =
  75                         vdev->get_resource(vdev, i);
  76
  77                 if (!res)
  78                         goto err;
  79
  80                 vdev->regions[i].addr = res->start;
  81                 vdev->regions[i].size = resource_size(res);
  82                 vdev->regions[i].flags = 0;
  83
  84                 switch (resource_type(res)) {
  85                 case IORESOURCE_MEM:
  86                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO;
  87                         vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
  88                         if (!(res->flags & IORESOURCE_READONLY))
  89                                 vdev->regions[i].flags |=
  90                                         VFIO_REGION_INFO_FLAG_WRITE;
  91
  92                         /*
  93                          * Only regions addressed with PAGE granularity may be
  94                          * MMAPed securely.
  95                          */
  96                         if (!(vdev->regions[i].addr & ~PAGE_MASK) &&
  97                                         !(vdev->regions[i].size & ~PAGE_MASK))
  98                                 vdev->regions[i].flags |=
  99                                         VFIO_REGION_INFO_FLAG_MMAP;
 100
 101                         break;
 102                 case IORESOURCE_IO:
 103                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
 104                         break;
 105                 default:
 106                         goto err;
 107                 }
 108         }
 109
 110         vdev->num_regions = cnt;
 111
 112         return 0;
 113 err:
 114         kfree(vdev->regions);
 115         return -EINVAL;
 116 }
 117
 118 static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
 119 {
 120         int i;
 121
 122         for (i = 0; i < vdev->num_regions; i++)
 123                 iounmap(vdev->regions[i].ioaddr);
 124
 125         vdev->num_regions = 0;
 126         kfree(vdev->regions);
 127 }
 128
 129 static void vfio_platform_release(void *device_data)
 130 {
 131         struct vfio_platform_device *vdev = device_data;
 132
 133         mutex_lock(&driver_lock);
 134
 135         if (!(--vdev->refcnt)) {
 136                 if (vdev->reset)
 137                         vdev->reset(vdev);
 138                 vfio_platform_regions_cleanup(vdev);
 139                 vfio_platform_irq_cleanup(vdev);
 140         }
 141
 142         mutex_unlock(&driver_lock);
 143
 144         module_put(THIS_MODULE);
 145 }
 146
 147 static int vfio_platform_open(void *device_data)
 148 {
 149         struct vfio_platform_device *vdev = device_data;
 150         int ret;
 151
 152         if (!try_module_get(THIS_MODULE))
 153                 return -ENODEV;
 154
 155         mutex_lock(&driver_lock);
 156
 157         if (!vdev->refcnt) {
 158                 ret = vfio_platform_regions_init(vdev);
 159                 if (ret)
 160                         goto err_reg;
 161
 162                 ret = vfio_platform_irq_init(vdev);
 163                 if (ret)
 164                         goto err_irq;
 165
 166                 if (vdev->reset)
 167                         vdev->reset(vdev);
 168         }
 169
 170         vdev->refcnt++;
 171
 172         mutex_unlock(&driver_lock);
 173         return 0;
 174
 175 err_irq:
 176         vfio_platform_regions_cleanup(vdev);
 177 err_reg:
 178         mutex_unlock(&driver_lock);
 179         module_put(THIS_MODULE);
 180         return ret;
 181 }
 182
 183 static long vfio_platform_ioctl(void *device_data,
 184                                 unsigned int cmd, unsigned long arg)
 185 {
 186         struct vfio_platform_device *vdev = device_data;
 187         unsigned long minsz;
 188
 189         if (cmd == VFIO_DEVICE_GET_INFO) {
 190                 struct vfio_device_info info;
 191
 192                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 193
 194                 if (copy_from_user(&info, (void __user *)arg, minsz))
 195                         return -EFAULT;
 196
 197                 if (info.argsz < minsz)
 198                         return -EINVAL;
 199
 200                 if (vdev->reset)
 201                         vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
 202                 info.flags = vdev->flags;
 203                 info.num_regions = vdev->num_regions;
 204                 info.num_irqs = vdev->num_irqs;
 205
 206                 return copy_to_user((void __user *)arg, &info, minsz);
 207
 208         } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
 209                 struct vfio_region_info info;
 210
 211                 minsz = offsetofend(struct vfio_region_info, offset);
 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 (info.index >= vdev->num_regions)
 220                         return -EINVAL;
 221
 222                 /* map offset to the physical address  */
 223                 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
 224                 info.size = vdev->regions[info.index].size;
 225                 info.flags = vdev->regions[info.index].flags;
 226
 227                 return copy_to_user((void __user *)arg, &info, minsz);
 228
 229         } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
 230                 struct vfio_irq_info info;
 231
 232                 minsz = offsetofend(struct vfio_irq_info, count);
 233
 234                 if (copy_from_user(&info, (void __user *)arg, minsz))
 235                         return -EFAULT;
 236
 237                 if (info.argsz < minsz)
 238                         return -EINVAL;
 239
 240                 if (info.index >= vdev->num_irqs)
 241                         return -EINVAL;
 242
 243                 info.flags = vdev->irqs[info.index].flags;
 244                 info.count = vdev->irqs[info.index].count;
 245
 246                 return copy_to_user((void __user *)arg, &info, minsz);
 247
 248         } else if (cmd == VFIO_DEVICE_SET_IRQS) {
 249                 struct vfio_irq_set hdr;
 250                 u8 *data = NULL;
 251                 int ret = 0;
 252
 253                 minsz = offsetofend(struct vfio_irq_set, count);
 254
 255                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 256                         return -EFAULT;
 257
 258                 if (hdr.argsz < minsz)
 259                         return -EINVAL;
 260
 261                 if (hdr.index >= vdev->num_irqs)
 262                         return -EINVAL;
 263
 264                 if (hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
 265                                   VFIO_IRQ_SET_ACTION_TYPE_MASK))
 266                         return -EINVAL;
 267
 268                 if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
 269                         size_t size;
 270
 271                         if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
 272                                 size = sizeof(uint8_t);
 273                         else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
 274                                 size = sizeof(int32_t);
 275                         else
 276                                 return -EINVAL;
 277
 278                         if (hdr.argsz - minsz < size)
 279                                 return -EINVAL;
 280
 281                         data = memdup_user((void __user *)(arg + minsz), size);
 282                         if (IS_ERR(data))
 283                                 return PTR_ERR(data);
 284                 }
 285
 286                 mutex_lock(&vdev->igate);
 287
 288                 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
 289                                                    hdr.start, hdr.count, data);
 290                 mutex_unlock(&vdev->igate);
 291                 kfree(data);
 292
 293                 return ret;
 294
 295         } else if (cmd == VFIO_DEVICE_RESET) {
 296                 if (vdev->reset)
 297                         return vdev->reset(vdev);
 298                 else
 299                         return -EINVAL;
 300         }
 301
 302         return -ENOTTY;
 303 }
 304
 305 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg,
 306                                        char __user *buf, size_t count,
 307                                        loff_t off)
 308 {
 309         unsigned int done = 0;
 310
 311         if (!reg.ioaddr) {
 312                 reg.ioaddr =
 313                         ioremap_nocache(reg.addr, reg.size);
 314
 315                 if (!reg.ioaddr)
 316                         return -ENOMEM;
 317         }
 318
 319         while (count) {
 320                 size_t filled;
 321
 322                 if (count >= 4 && !(off % 4)) {
 323                         u32 val;
 324
 325                         val = ioread32(reg.ioaddr + off);
 326                         if (copy_to_user(buf, &val, 4))
 327                                 goto err;
 328
 329                         filled = 4;
 330                 } else if (count >= 2 && !(off % 2)) {
 331                         u16 val;
 332
 333                         val = ioread16(reg.ioaddr + off);
 334                         if (copy_to_user(buf, &val, 2))
 335                                 goto err;
 336
 337                         filled = 2;
 338                 } else {
 339                         u8 val;
 340
 341                         val = ioread8(reg.ioaddr + off);
 342                         if (copy_to_user(buf, &val, 1))
 343                                 goto err;
 344
 345                         filled = 1;
 346                 }
 347
 348
 349                 count -= filled;
 350                 done += filled;
 351                 off += filled;
 352                 buf += filled;
 353         }
 354
 355         return done;
 356 err:
 357         return -EFAULT;
 358 }
 359
 360 static ssize_t vfio_platform_read(void *device_data, char __user *buf,
 361                                   size_t count, loff_t *ppos)
 362 {
 363         struct vfio_platform_device *vdev = device_data;
 364         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 365         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 366
 367         if (index >= vdev->num_regions)
 368                 return -EINVAL;
 369
 370         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
 371                 return -EINVAL;
 372
 373         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 374                 return vfio_platform_read_mmio(vdev->regions[index],
 375                                                         buf, count, off);
 376         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 377                 return -EINVAL; /* not implemented */
 378
 379         return -EINVAL;
 380 }
 381
 382 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg,
 383                                         const char __user *buf, size_t count,
 384                                         loff_t off)
 385 {
 386         unsigned int done = 0;
 387
 388         if (!reg.ioaddr) {
 389                 reg.ioaddr =
 390                         ioremap_nocache(reg.addr, reg.size);
 391
 392                 if (!reg.ioaddr)
 393                         return -ENOMEM;
 394         }
 395
 396         while (count) {
 397                 size_t filled;
 398
 399                 if (count >= 4 && !(off % 4)) {
 400                         u32 val;
 401
 402                         if (copy_from_user(&val, buf, 4))
 403                                 goto err;
 404                         iowrite32(val, reg.ioaddr + off);
 405
 406                         filled = 4;
 407                 } else if (count >= 2 && !(off % 2)) {
 408                         u16 val;
 409
 410                         if (copy_from_user(&val, buf, 2))
 411                                 goto err;
 412                         iowrite16(val, reg.ioaddr + off);
 413
 414                         filled = 2;
 415                 } else {
 416                         u8 val;
 417
 418                         if (copy_from_user(&val, buf, 1))
 419                                 goto err;
 420                         iowrite8(val, reg.ioaddr + off);
 421
 422                         filled = 1;
 423                 }
 424
 425                 count -= filled;
 426                 done += filled;
 427                 off += filled;
 428                 buf += filled;
 429         }
 430
 431         return done;
 432 err:
 433         return -EFAULT;
 434 }
 435
 436 static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
 437                                    size_t count, loff_t *ppos)
 438 {
 439         struct vfio_platform_device *vdev = device_data;
 440         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 441         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 442
 443         if (index >= vdev->num_regions)
 444                 return -EINVAL;
 445
 446         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
 447                 return -EINVAL;
 448
 449         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 450                 return vfio_platform_write_mmio(vdev->regions[index],
 451                                                         buf, count, off);
 452         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 453                 return -EINVAL; /* not implemented */
 454
 455         return -EINVAL;
 456 }
 457
 458 static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
 459                                    struct vm_area_struct *vma)
 460 {
 461         u64 req_len, pgoff, req_start;
 462
 463         req_len = vma->vm_end - vma->vm_start;
 464         pgoff = vma->vm_pgoff &
 465                 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
 466         req_start = pgoff << PAGE_SHIFT;
 467
 468         if (region.size < PAGE_SIZE || req_start + req_len > region.size)
 469                 return -EINVAL;
 470
 471         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 472         vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
 473
 474         return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
 475                                req_len, vma->vm_page_prot);
 476 }
 477
 478 static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma)
 479 {
 480         struct vfio_platform_device *vdev = device_data;
 481         unsigned int index;
 482
 483         index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);
 484
 485         if (vma->vm_end < vma->vm_start)
 486                 return -EINVAL;
 487         if (!(vma->vm_flags & VM_SHARED))
 488                 return -EINVAL;
 489         if (index >= vdev->num_regions)
 490                 return -EINVAL;
 491         if (vma->vm_start & ~PAGE_MASK)
 492                 return -EINVAL;
 493         if (vma->vm_end & ~PAGE_MASK)
 494                 return -EINVAL;
 495
 496         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
 497                 return -EINVAL;
 498
 499         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
 500                         && (vma->vm_flags & VM_READ))
 501                 return -EINVAL;
 502
 503         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
 504                         && (vma->vm_flags & VM_WRITE))
 505                 return -EINVAL;
 506
 507         vma->vm_private_data = vdev;
 508
 509         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 510                 return vfio_platform_mmap_mmio(vdev->regions[index], vma);
 511
 512         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 513                 return -EINVAL; /* not implemented */
 514
 515         return -EINVAL;
 516 }
 517
 518 static const struct vfio_device_ops vfio_platform_ops = {
 519         .name           = "vfio-platform",
 520         .open           = vfio_platform_open,
 521         .release        = vfio_platform_release,
 522         .ioctl          = vfio_platform_ioctl,
 523         .read           = vfio_platform_read,
 524         .write          = vfio_platform_write,
 525         .mmap           = vfio_platform_mmap,
 526 };
 527
 528 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 529                                struct device *dev)
 530 {
 531         struct iommu_group *group;
 532         int ret;
 533
 534         if (!vdev)
 535                 return -EINVAL;
 536
 537         group = iommu_group_get(dev);
 538         if (!group) {
 539                 pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
 540                 return -EINVAL;
 541         }
 542
 543         ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
 544         if (ret) {
 545                 iommu_group_put(group);
 546                 return ret;
 547         }
 548
 549         vfio_platform_get_reset(vdev, dev);
 550
 551         mutex_init(&vdev->igate);
 552
 553         return 0;
 554 }
 555 EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
 556
 557 struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
 558 {
 559         struct vfio_platform_device *vdev;
 560
 561         vdev = vfio_del_group_dev(dev);
 562
 563         if (vdev) {
 564                 vfio_platform_put_reset(vdev);
 565                 iommu_group_put(dev->iommu_group);
 566         }
 567
 568         return vdev;
 569 }
 570 EXPORT_SYMBOL_GPL(vfio_platform_remove_common);