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                 .compat = "calxeda,hb-xgmac",
  31                 .reset_function_name = "vfio_platform_calxedaxgmac_reset",
  32                 .module_name = "vfio-platform-calxedaxgmac",
  33         },
  34 };
  35
  36 static void vfio_platform_get_reset(struct vfio_platform_device *vdev,
  37                                     struct device *dev)
  38 {
  39         const char *compat;
  40         int (*reset)(struct vfio_platform_device *);
  41         int ret, i;
  42
  43         ret = device_property_read_string(dev, "compatible", &compat);
  44         if (ret)
  45                 return;
  46
  47         for (i = 0 ; i < ARRAY_SIZE(reset_lookup_table); i++) {
  48                 if (!strcmp(reset_lookup_table[i].compat, compat)) {
  49                         request_module(reset_lookup_table[i].module_name);
  50                         reset = __symbol_get(
  51                                 reset_lookup_table[i].reset_function_name);
  52                         if (reset) {
  53                                 vdev->reset = reset;
  54                                 return;
  55                         }
  56                 }
  57         }
  58 }
  59
  60 static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
  61 {
  62         if (vdev->reset)
  63                 symbol_put_addr(vdev->reset);
  64 }
  65
  66 static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
  67 {
  68         int cnt = 0, i;
  69
  70         while (vdev->get_resource(vdev, cnt))
  71                 cnt++;
  72
  73         vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region),
  74                                 GFP_KERNEL);
  75         if (!vdev->regions)
  76                 return -ENOMEM;
  77
  78         for (i = 0; i < cnt;  i++) {
  79                 struct resource *res =
  80                         vdev->get_resource(vdev, i);
  81
  82                 if (!res)
  83                         goto err;
  84
  85                 vdev->regions[i].addr = res->start;
  86                 vdev->regions[i].size = resource_size(res);
  87                 vdev->regions[i].flags = 0;
  88
  89                 switch (resource_type(res)) {
  90                 case IORESOURCE_MEM:
  91                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO;
  92                         vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
  93                         if (!(res->flags & IORESOURCE_READONLY))
  94                                 vdev->regions[i].flags |=
  95                                         VFIO_REGION_INFO_FLAG_WRITE;
  96
  97                         /*
  98                          * Only regions addressed with PAGE granularity may be
  99                          * MMAPed securely.
 100                          */
 101                         if (!(vdev->regions[i].addr & ~PAGE_MASK) &&
 102                                         !(vdev->regions[i].size & ~PAGE_MASK))
 103                                 vdev->regions[i].flags |=
 104                                         VFIO_REGION_INFO_FLAG_MMAP;
 105
 106                         break;
 107                 case IORESOURCE_IO:
 108                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
 109                         break;
 110                 default:
 111                         goto err;
 112                 }
 113         }
 114
 115         vdev->num_regions = cnt;
 116
 117         return 0;
 118 err:
 119         kfree(vdev->regions);
 120         return -EINVAL;
 121 }
 122
 123 static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
 124 {
 125         int i;
 126
 127         for (i = 0; i < vdev->num_regions; i++)
 128                 iounmap(vdev->regions[i].ioaddr);
 129
 130         vdev->num_regions = 0;
 131         kfree(vdev->regions);
 132 }
 133
 134 static void vfio_platform_release(void *device_data)
 135 {
 136         struct vfio_platform_device *vdev = device_data;
 137
 138         mutex_lock(&driver_lock);
 139
 140         if (!(--vdev->refcnt)) {
 141                 if (vdev->reset)
 142                         vdev->reset(vdev);
 143                 vfio_platform_regions_cleanup(vdev);
 144                 vfio_platform_irq_cleanup(vdev);
 145         }
 146
 147         mutex_unlock(&driver_lock);
 148
 149         module_put(THIS_MODULE);
 150 }
 151
 152 static int vfio_platform_open(void *device_data)
 153 {
 154         struct vfio_platform_device *vdev = device_data;
 155         int ret;
 156
 157         if (!try_module_get(THIS_MODULE))
 158                 return -ENODEV;
 159
 160         mutex_lock(&driver_lock);
 161
 162         if (!vdev->refcnt) {
 163                 ret = vfio_platform_regions_init(vdev);
 164                 if (ret)
 165                         goto err_reg;
 166
 167                 ret = vfio_platform_irq_init(vdev);
 168                 if (ret)
 169                         goto err_irq;
 170
 171                 if (vdev->reset)
 172                         vdev->reset(vdev);
 173         }
 174
 175         vdev->refcnt++;
 176
 177         mutex_unlock(&driver_lock);
 178         return 0;
 179
 180 err_irq:
 181         vfio_platform_regions_cleanup(vdev);
 182 err_reg:
 183         mutex_unlock(&driver_lock);
 184         module_put(THIS_MODULE);
 185         return ret;
 186 }
 187
 188 static long vfio_platform_ioctl(void *device_data,
 189                                 unsigned int cmd, unsigned long arg)
 190 {
 191         struct vfio_platform_device *vdev = device_data;
 192         unsigned long minsz;
 193
 194         if (cmd == VFIO_DEVICE_GET_INFO) {
 195                 struct vfio_device_info info;
 196
 197                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 198
 199                 if (copy_from_user(&info, (void __user *)arg, minsz))
 200                         return -EFAULT;
 201
 202                 if (info.argsz < minsz)
 203                         return -EINVAL;
 204
 205                 if (vdev->reset)
 206                         vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
 207                 info.flags = vdev->flags;
 208                 info.num_regions = vdev->num_regions;
 209                 info.num_irqs = vdev->num_irqs;
 210
 211                 return copy_to_user((void __user *)arg, &info, minsz);
 212
 213         } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
 214                 struct vfio_region_info info;
 215
 216                 minsz = offsetofend(struct vfio_region_info, offset);
 217
 218                 if (copy_from_user(&info, (void __user *)arg, minsz))
 219                         return -EFAULT;
 220
 221                 if (info.argsz < minsz)
 222                         return -EINVAL;
 223
 224                 if (info.index >= vdev->num_regions)
 225                         return -EINVAL;
 226
 227                 /* map offset to the physical address  */
 228                 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
 229                 info.size = vdev->regions[info.index].size;
 230                 info.flags = vdev->regions[info.index].flags;
 231
 232                 return copy_to_user((void __user *)arg, &info, minsz);
 233
 234         } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
 235                 struct vfio_irq_info info;
 236
 237                 minsz = offsetofend(struct vfio_irq_info, count);
 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 (info.index >= vdev->num_irqs)
 246                         return -EINVAL;
 247
 248                 info.flags = vdev->irqs[info.index].flags;
 249                 info.count = vdev->irqs[info.index].count;
 250
 251                 return copy_to_user((void __user *)arg, &info, minsz);
 252
 253         } else if (cmd == VFIO_DEVICE_SET_IRQS) {
 254                 struct vfio_irq_set hdr;
 255                 u8 *data = NULL;
 256                 int ret = 0;
 257
 258                 minsz = offsetofend(struct vfio_irq_set, count);
 259
 260                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 261                         return -EFAULT;
 262
 263                 if (hdr.argsz < minsz)
 264                         return -EINVAL;
 265
 266                 if (hdr.index >= vdev->num_irqs)
 267                         return -EINVAL;
 268
 269                 if (hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
 270                                   VFIO_IRQ_SET_ACTION_TYPE_MASK))
 271                         return -EINVAL;
 272
 273                 if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
 274                         size_t size;
 275
 276                         if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
 277                                 size = sizeof(uint8_t);
 278                         else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
 279                                 size = sizeof(int32_t);
 280                         else
 281                                 return -EINVAL;
 282
 283                         if (hdr.argsz - minsz < size)
 284                                 return -EINVAL;
 285
 286                         data = memdup_user((void __user *)(arg + minsz), size);
 287                         if (IS_ERR(data))
 288                                 return PTR_ERR(data);
 289                 }
 290
 291                 mutex_lock(&vdev->igate);
 292
 293                 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
 294                                                    hdr.start, hdr.count, data);
 295                 mutex_unlock(&vdev->igate);
 296                 kfree(data);
 297
 298                 return ret;
 299
 300         } else if (cmd == VFIO_DEVICE_RESET) {
 301                 if (vdev->reset)
 302                         return vdev->reset(vdev);
 303                 else
 304                         return -EINVAL;
 305         }
 306
 307         return -ENOTTY;
 308 }
 309
 310 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg,
 311                                        char __user *buf, size_t count,
 312                                        loff_t off)
 313 {
 314         unsigned int done = 0;
 315
 316         if (!reg.ioaddr) {
 317                 reg.ioaddr =
 318                         ioremap_nocache(reg.addr, reg.size);
 319
 320                 if (!reg.ioaddr)
 321                         return -ENOMEM;
 322         }
 323
 324         while (count) {
 325                 size_t filled;
 326
 327                 if (count >= 4 && !(off % 4)) {
 328                         u32 val;
 329
 330                         val = ioread32(reg.ioaddr + off);
 331                         if (copy_to_user(buf, &val, 4))
 332                                 goto err;
 333
 334                         filled = 4;
 335                 } else if (count >= 2 && !(off % 2)) {
 336                         u16 val;
 337
 338                         val = ioread16(reg.ioaddr + off);
 339                         if (copy_to_user(buf, &val, 2))
 340                                 goto err;
 341
 342                         filled = 2;
 343                 } else {
 344                         u8 val;
 345
 346                         val = ioread8(reg.ioaddr + off);
 347                         if (copy_to_user(buf, &val, 1))
 348                                 goto err;
 349
 350                         filled = 1;
 351                 }
 352
 353
 354                 count -= filled;
 355                 done += filled;
 356                 off += filled;
 357                 buf += filled;
 358         }
 359
 360         return done;
 361 err:
 362         return -EFAULT;
 363 }
 364
 365 static ssize_t vfio_platform_read(void *device_data, char __user *buf,
 366                                   size_t count, loff_t *ppos)
 367 {
 368         struct vfio_platform_device *vdev = device_data;
 369         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 370         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 371
 372         if (index >= vdev->num_regions)
 373                 return -EINVAL;
 374
 375         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
 376                 return -EINVAL;
 377
 378         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 379                 return vfio_platform_read_mmio(vdev->regions[index],
 380                                                         buf, count, off);
 381         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 382                 return -EINVAL; /* not implemented */
 383
 384         return -EINVAL;
 385 }
 386
 387 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg,
 388                                         const char __user *buf, size_t count,
 389                                         loff_t off)
 390 {
 391         unsigned int done = 0;
 392
 393         if (!reg.ioaddr) {
 394                 reg.ioaddr =
 395                         ioremap_nocache(reg.addr, reg.size);
 396
 397                 if (!reg.ioaddr)
 398                         return -ENOMEM;
 399         }
 400
 401         while (count) {
 402                 size_t filled;
 403
 404                 if (count >= 4 && !(off % 4)) {
 405                         u32 val;
 406
 407                         if (copy_from_user(&val, buf, 4))
 408                                 goto err;
 409                         iowrite32(val, reg.ioaddr + off);
 410
 411                         filled = 4;
 412                 } else if (count >= 2 && !(off % 2)) {
 413                         u16 val;
 414
 415                         if (copy_from_user(&val, buf, 2))
 416                                 goto err;
 417                         iowrite16(val, reg.ioaddr + off);
 418
 419                         filled = 2;
 420                 } else {
 421                         u8 val;
 422
 423                         if (copy_from_user(&val, buf, 1))
 424                                 goto err;
 425                         iowrite8(val, reg.ioaddr + off);
 426
 427                         filled = 1;
 428                 }
 429
 430                 count -= filled;
 431                 done += filled;
 432                 off += filled;
 433                 buf += filled;
 434         }
 435
 436         return done;
 437 err:
 438         return -EFAULT;
 439 }
 440
 441 static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
 442                                    size_t count, loff_t *ppos)
 443 {
 444         struct vfio_platform_device *vdev = device_data;
 445         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 446         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 447
 448         if (index >= vdev->num_regions)
 449                 return -EINVAL;
 450
 451         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
 452                 return -EINVAL;
 453
 454         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 455                 return vfio_platform_write_mmio(vdev->regions[index],
 456                                                         buf, count, off);
 457         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 458                 return -EINVAL; /* not implemented */
 459
 460         return -EINVAL;
 461 }
 462
 463 static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
 464                                    struct vm_area_struct *vma)
 465 {
 466         u64 req_len, pgoff, req_start;
 467
 468         req_len = vma->vm_end - vma->vm_start;
 469         pgoff = vma->vm_pgoff &
 470                 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
 471         req_start = pgoff << PAGE_SHIFT;
 472
 473         if (region.size < PAGE_SIZE || req_start + req_len > region.size)
 474                 return -EINVAL;
 475
 476         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 477         vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
 478
 479         return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
 480                                req_len, vma->vm_page_prot);
 481 }
 482
 483 static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma)
 484 {
 485         struct vfio_platform_device *vdev = device_data;
 486         unsigned int index;
 487
 488         index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);
 489
 490         if (vma->vm_end < vma->vm_start)
 491                 return -EINVAL;
 492         if (!(vma->vm_flags & VM_SHARED))
 493                 return -EINVAL;
 494         if (index >= vdev->num_regions)
 495                 return -EINVAL;
 496         if (vma->vm_start & ~PAGE_MASK)
 497                 return -EINVAL;
 498         if (vma->vm_end & ~PAGE_MASK)
 499                 return -EINVAL;
 500
 501         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
 502                 return -EINVAL;
 503
 504         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
 505                         && (vma->vm_flags & VM_READ))
 506                 return -EINVAL;
 507
 508         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
 509                         && (vma->vm_flags & VM_WRITE))
 510                 return -EINVAL;
 511
 512         vma->vm_private_data = vdev;
 513
 514         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 515                 return vfio_platform_mmap_mmio(vdev->regions[index], vma);
 516
 517         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 518                 return -EINVAL; /* not implemented */
 519
 520         return -EINVAL;
 521 }
 522
 523 static const struct vfio_device_ops vfio_platform_ops = {
 524         .name           = "vfio-platform",
 525         .open           = vfio_platform_open,
 526         .release        = vfio_platform_release,
 527         .ioctl          = vfio_platform_ioctl,
 528         .read           = vfio_platform_read,
 529         .write          = vfio_platform_write,
 530         .mmap           = vfio_platform_mmap,
 531 };
 532
 533 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 534                                struct device *dev)
 535 {
 536         struct iommu_group *group;
 537         int ret;
 538
 539         if (!vdev)
 540                 return -EINVAL;
 541
 542         group = iommu_group_get(dev);
 543         if (!group) {
 544                 pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
 545                 return -EINVAL;
 546         }
 547
 548         ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
 549         if (ret) {
 550                 iommu_group_put(group);
 551                 return ret;
 552         }
 553
 554         vfio_platform_get_reset(vdev, dev);
 555
 556         mutex_init(&vdev->igate);
 557
 558         return 0;
 559 }
 560 EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
 561
 562 struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
 563 {
 564         struct vfio_platform_device *vdev;
 565
 566         vdev = vfio_del_group_dev(dev);
 567
 568         if (vdev) {
 569                 vfio_platform_put_reset(vdev);
 570                 iommu_group_put(dev->iommu_group);
 571         }
 572
 573         return vdev;
 574 }
 575 EXPORT_SYMBOL_GPL(vfio_platform_remove_common);