kernel/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 int vfio_platform_regions_init(struct vfio_platform_device *vdev)
  29 {
  30         int cnt = 0, i;
  31
  32         while (vdev->get_resource(vdev, cnt))
  33                 cnt++;
  34
  35         vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region),
  36                                 GFP_KERNEL);
  37         if (!vdev->regions)
  38                 return -ENOMEM;
  39
  40         for (i = 0; i < cnt;  i++) {
  41                 struct resource *res =
  42                         vdev->get_resource(vdev, i);
  43
  44                 if (!res)
  45                         goto err;
  46
  47                 vdev->regions[i].addr = res->start;
  48                 vdev->regions[i].size = resource_size(res);
  49                 vdev->regions[i].flags = 0;
  50
  51                 switch (resource_type(res)) {
  52                 case IORESOURCE_MEM:
  53                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO;
  54                         vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
  55                         if (!(res->flags & IORESOURCE_READONLY))
  56                                 vdev->regions[i].flags |=
  57                                         VFIO_REGION_INFO_FLAG_WRITE;
  58
  59                         /*
  60                          * Only regions addressed with PAGE granularity may be
  61                          * MMAPed securely.
  62                          */
  63                         if (!(vdev->regions[i].addr & ~PAGE_MASK) &&
  64                                         !(vdev->regions[i].size & ~PAGE_MASK))
  65                                 vdev->regions[i].flags |=
  66                                         VFIO_REGION_INFO_FLAG_MMAP;
  67
  68                         break;
  69                 case IORESOURCE_IO:
  70                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
  71                         break;
  72                 default:
  73                         goto err;
  74                 }
  75         }
  76
  77         vdev->num_regions = cnt;
  78
  79         return 0;
  80 err:
  81         kfree(vdev->regions);
  82         return -EINVAL;
  83 }
  84
  85 static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
  86 {
  87         int i;
  88
  89         for (i = 0; i < vdev->num_regions; i++)
  90                 iounmap(vdev->regions[i].ioaddr);
  91
  92         vdev->num_regions = 0;
  93         kfree(vdev->regions);
  94 }
  95
  96 static void vfio_platform_release(void *device_data)
  97 {
  98         struct vfio_platform_device *vdev = device_data;
  99
 100         mutex_lock(&driver_lock);
 101
 102         if (!(--vdev->refcnt)) {
 103                 vfio_platform_regions_cleanup(vdev);
 104                 vfio_platform_irq_cleanup(vdev);
 105         }
 106
 107         mutex_unlock(&driver_lock);
 108
 109         module_put(THIS_MODULE);
 110 }
 111
 112 static int vfio_platform_open(void *device_data)
 113 {
 114         struct vfio_platform_device *vdev = device_data;
 115         int ret;
 116
 117         if (!try_module_get(THIS_MODULE))
 118                 return -ENODEV;
 119
 120         mutex_lock(&driver_lock);
 121
 122         if (!vdev->refcnt) {
 123                 ret = vfio_platform_regions_init(vdev);
 124                 if (ret)
 125                         goto err_reg;
 126
 127                 ret = vfio_platform_irq_init(vdev);
 128                 if (ret)
 129                         goto err_irq;
 130         }
 131
 132         vdev->refcnt++;
 133
 134         mutex_unlock(&driver_lock);
 135         return 0;
 136
 137 err_irq:
 138         vfio_platform_regions_cleanup(vdev);
 139 err_reg:
 140         mutex_unlock(&driver_lock);
 141         module_put(THIS_MODULE);
 142         return ret;
 143 }
 144
 145 static long vfio_platform_ioctl(void *device_data,
 146                                 unsigned int cmd, unsigned long arg)
 147 {
 148         struct vfio_platform_device *vdev = device_data;
 149         unsigned long minsz;
 150
 151         if (cmd == VFIO_DEVICE_GET_INFO) {
 152                 struct vfio_device_info info;
 153
 154                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 155
 156                 if (copy_from_user(&info, (void __user *)arg, minsz))
 157                         return -EFAULT;
 158
 159                 if (info.argsz < minsz)
 160                         return -EINVAL;
 161
 162                 info.flags = vdev->flags;
 163                 info.num_regions = vdev->num_regions;
 164                 info.num_irqs = vdev->num_irqs;
 165
 166                 return copy_to_user((void __user *)arg, &info, minsz);
 167
 168         } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
 169                 struct vfio_region_info info;
 170
 171                 minsz = offsetofend(struct vfio_region_info, offset);
 172
 173                 if (copy_from_user(&info, (void __user *)arg, minsz))
 174                         return -EFAULT;
 175
 176                 if (info.argsz < minsz)
 177                         return -EINVAL;
 178
 179                 if (info.index >= vdev->num_regions)
 180                         return -EINVAL;
 181
 182                 /* map offset to the physical address  */
 183                 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
 184                 info.size = vdev->regions[info.index].size;
 185                 info.flags = vdev->regions[info.index].flags;
 186
 187                 return copy_to_user((void __user *)arg, &info, minsz);
 188
 189         } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
 190                 struct vfio_irq_info info;
 191
 192                 minsz = offsetofend(struct vfio_irq_info, count);
 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 (info.index >= vdev->num_irqs)
 201                         return -EINVAL;
 202
 203                 info.flags = vdev->irqs[info.index].flags;
 204                 info.count = vdev->irqs[info.index].count;
 205
 206                 return copy_to_user((void __user *)arg, &info, minsz);
 207
 208         } else if (cmd == VFIO_DEVICE_SET_IRQS) {
 209                 struct vfio_irq_set hdr;
 210                 u8 *data = NULL;
 211                 int ret = 0;
 212
 213                 minsz = offsetofend(struct vfio_irq_set, count);
 214
 215                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 216                         return -EFAULT;
 217
 218                 if (hdr.argsz < minsz)
 219                         return -EINVAL;
 220
 221                 if (hdr.index >= vdev->num_irqs)
 222                         return -EINVAL;
 223
 224                 if (hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
 225                                   VFIO_IRQ_SET_ACTION_TYPE_MASK))
 226                         return -EINVAL;
 227
 228                 if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
 229                         size_t size;
 230
 231                         if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
 232                                 size = sizeof(uint8_t);
 233                         else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
 234                                 size = sizeof(int32_t);
 235                         else
 236                                 return -EINVAL;
 237
 238                         if (hdr.argsz - minsz < size)
 239                                 return -EINVAL;
 240
 241                         data = memdup_user((void __user *)(arg + minsz), size);
 242                         if (IS_ERR(data))
 243                                 return PTR_ERR(data);
 244                 }
 245
 246                 mutex_lock(&vdev->igate);
 247
 248                 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
 249                                                    hdr.start, hdr.count, data);
 250                 mutex_unlock(&vdev->igate);
 251                 kfree(data);
 252
 253                 return ret;
 254
 255         } else if (cmd == VFIO_DEVICE_RESET)
 256                 return -EINVAL;
 257
 258         return -ENOTTY;
 259 }
 260
 261 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg,
 262                                        char __user *buf, size_t count,
 263                                        loff_t off)
 264 {
 265         unsigned int done = 0;
 266
 267         if (!reg.ioaddr) {
 268                 reg.ioaddr =
 269                         ioremap_nocache(reg.addr, reg.size);
 270
 271                 if (!reg.ioaddr)
 272                         return -ENOMEM;
 273         }
 274
 275         while (count) {
 276                 size_t filled;
 277
 278                 if (count >= 4 && !(off % 4)) {
 279                         u32 val;
 280
 281                         val = ioread32(reg.ioaddr + off);
 282                         if (copy_to_user(buf, &val, 4))
 283                                 goto err;
 284
 285                         filled = 4;
 286                 } else if (count >= 2 && !(off % 2)) {
 287                         u16 val;
 288
 289                         val = ioread16(reg.ioaddr + off);
 290                         if (copy_to_user(buf, &val, 2))
 291                                 goto err;
 292
 293                         filled = 2;
 294                 } else {
 295                         u8 val;
 296
 297                         val = ioread8(reg.ioaddr + off);
 298                         if (copy_to_user(buf, &val, 1))
 299                                 goto err;
 300
 301                         filled = 1;
 302                 }
 303
 304
 305                 count -= filled;
 306                 done += filled;
 307                 off += filled;
 308                 buf += filled;
 309         }
 310
 311         return done;
 312 err:
 313         return -EFAULT;
 314 }
 315
 316 static ssize_t vfio_platform_read(void *device_data, char __user *buf,
 317                                   size_t count, loff_t *ppos)
 318 {
 319         struct vfio_platform_device *vdev = device_data;
 320         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 321         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 322
 323         if (index >= vdev->num_regions)
 324                 return -EINVAL;
 325
 326         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
 327                 return -EINVAL;
 328
 329         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 330                 return vfio_platform_read_mmio(vdev->regions[index],
 331                                                         buf, count, off);
 332         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 333                 return -EINVAL; /* not implemented */
 334
 335         return -EINVAL;
 336 }
 337
 338 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg,
 339                                         const char __user *buf, size_t count,
 340                                         loff_t off)
 341 {
 342         unsigned int done = 0;
 343
 344         if (!reg.ioaddr) {
 345                 reg.ioaddr =
 346                         ioremap_nocache(reg.addr, reg.size);
 347
 348                 if (!reg.ioaddr)
 349                         return -ENOMEM;
 350         }
 351
 352         while (count) {
 353                 size_t filled;
 354
 355                 if (count >= 4 && !(off % 4)) {
 356                         u32 val;
 357
 358                         if (copy_from_user(&val, buf, 4))
 359                                 goto err;
 360                         iowrite32(val, reg.ioaddr + off);
 361
 362                         filled = 4;
 363                 } else if (count >= 2 && !(off % 2)) {
 364                         u16 val;
 365
 366                         if (copy_from_user(&val, buf, 2))
 367                                 goto err;
 368                         iowrite16(val, reg.ioaddr + off);
 369
 370                         filled = 2;
 371                 } else {
 372                         u8 val;
 373
 374                         if (copy_from_user(&val, buf, 1))
 375                                 goto err;
 376                         iowrite8(val, reg.ioaddr + off);
 377
 378                         filled = 1;
 379                 }
 380
 381                 count -= filled;
 382                 done += filled;
 383                 off += filled;
 384                 buf += filled;
 385         }
 386
 387         return done;
 388 err:
 389         return -EFAULT;
 390 }
 391
 392 static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
 393                                    size_t count, loff_t *ppos)
 394 {
 395         struct vfio_platform_device *vdev = device_data;
 396         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 397         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 398
 399         if (index >= vdev->num_regions)
 400                 return -EINVAL;
 401
 402         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
 403                 return -EINVAL;
 404
 405         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 406                 return vfio_platform_write_mmio(vdev->regions[index],
 407                                                         buf, count, off);
 408         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 409                 return -EINVAL; /* not implemented */
 410
 411         return -EINVAL;
 412 }
 413
 414 static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
 415                                    struct vm_area_struct *vma)
 416 {
 417         u64 req_len, pgoff, req_start;
 418
 419         req_len = vma->vm_end - vma->vm_start;
 420         pgoff = vma->vm_pgoff &
 421                 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
 422         req_start = pgoff << PAGE_SHIFT;
 423
 424         if (region.size < PAGE_SIZE || req_start + req_len > region.size)
 425                 return -EINVAL;
 426
 427         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 428         vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
 429
 430         return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
 431                                req_len, vma->vm_page_prot);
 432 }
 433
 434 static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma)
 435 {
 436         struct vfio_platform_device *vdev = device_data;
 437         unsigned int index;
 438
 439         index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);
 440
 441         if (vma->vm_end < vma->vm_start)
 442                 return -EINVAL;
 443         if (!(vma->vm_flags & VM_SHARED))
 444                 return -EINVAL;
 445         if (index >= vdev->num_regions)
 446                 return -EINVAL;
 447         if (vma->vm_start & ~PAGE_MASK)
 448                 return -EINVAL;
 449         if (vma->vm_end & ~PAGE_MASK)
 450                 return -EINVAL;
 451
 452         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
 453                 return -EINVAL;
 454
 455         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
 456                         && (vma->vm_flags & VM_READ))
 457                 return -EINVAL;
 458
 459         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
 460                         && (vma->vm_flags & VM_WRITE))
 461                 return -EINVAL;
 462
 463         vma->vm_private_data = vdev;
 464
 465         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 466                 return vfio_platform_mmap_mmio(vdev->regions[index], vma);
 467
 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 const struct vfio_device_ops vfio_platform_ops = {
 475         .name           = "vfio-platform",
 476         .open           = vfio_platform_open,
 477         .release        = vfio_platform_release,
 478         .ioctl          = vfio_platform_ioctl,
 479         .read           = vfio_platform_read,
 480         .write          = vfio_platform_write,
 481         .mmap           = vfio_platform_mmap,
 482 };
 483
 484 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 485                                struct device *dev)
 486 {
 487         struct iommu_group *group;
 488         int ret;
 489
 490         if (!vdev)
 491                 return -EINVAL;
 492
 493         group = iommu_group_get(dev);
 494         if (!group) {
 495                 pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
 496                 return -EINVAL;
 497         }
 498
 499         ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
 500         if (ret) {
 501                 iommu_group_put(group);
 502                 return ret;
 503         }
 504
 505         mutex_init(&vdev->igate);
 506
 507         return 0;
 508 }
 509 EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
 510
 511 struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
 512 {
 513         struct vfio_platform_device *vdev;
 514
 515         vdev = vfio_del_group_dev(dev);
 516         if (vdev)
 517                 iommu_group_put(dev->iommu_group);
 518
 519         return vdev;
 520 }
 521 EXPORT_SYMBOL_GPL(vfio_platform_remove_common);