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 int vfio_platform_regions_init(struct vfio_platform_device *vdev)
  32 {
  33         int cnt = 0, i;
  34
  35         while (vdev->get_resource(vdev, cnt))
  36                 cnt++;
  37
  38         vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region),
  39                                 GFP_KERNEL);
  40         if (!vdev->regions)
  41                 return -ENOMEM;
  42
  43         for (i = 0; i < cnt;  i++) {
  44                 struct resource *res =
  45                         vdev->get_resource(vdev, i);
  46
  47                 if (!res)
  48                         goto err;
  49
  50                 vdev->regions[i].addr = res->start;
  51                 vdev->regions[i].size = resource_size(res);
  52                 vdev->regions[i].flags = 0;
  53
  54                 switch (resource_type(res)) {
  55                 case IORESOURCE_MEM:
  56                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO;
  57                         vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
  58                         if (!(res->flags & IORESOURCE_READONLY))
  59                                 vdev->regions[i].flags |=
  60                                         VFIO_REGION_INFO_FLAG_WRITE;
  61
  62                         /*
  63                          * Only regions addressed with PAGE granularity may be
  64                          * MMAPed securely.
  65                          */
  66                         if (!(vdev->regions[i].addr & ~PAGE_MASK) &&
  67                                         !(vdev->regions[i].size & ~PAGE_MASK))
  68                                 vdev->regions[i].flags |=
  69                                         VFIO_REGION_INFO_FLAG_MMAP;
  70
  71                         break;
  72                 case IORESOURCE_IO:
  73                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
  74                         break;
  75                 default:
  76                         goto err;
  77                 }
  78         }
  79
  80         vdev->num_regions = cnt;
  81
  82         return 0;
  83 err:
  84         kfree(vdev->regions);
  85         return -EINVAL;
  86 }
  87
  88 static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
  89 {
  90         int i;
  91
  92         for (i = 0; i < vdev->num_regions; i++)
  93                 iounmap(vdev->regions[i].ioaddr);
  94
  95         vdev->num_regions = 0;
  96         kfree(vdev->regions);
  97 }
  98
  99 static void vfio_platform_release(void *device_data)
 100 {
 101         struct vfio_platform_device *vdev = device_data;
 102
 103         mutex_lock(&driver_lock);
 104
 105         if (!(--vdev->refcnt)) {
 106                 vfio_platform_regions_cleanup(vdev);
 107                 vfio_platform_irq_cleanup(vdev);
 108         }
 109
 110         mutex_unlock(&driver_lock);
 111
 112         module_put(THIS_MODULE);
 113 }
 114
 115 static int vfio_platform_open(void *device_data)
 116 {
 117         struct vfio_platform_device *vdev = device_data;
 118         int ret;
 119
 120         if (!try_module_get(THIS_MODULE))
 121                 return -ENODEV;
 122
 123         mutex_lock(&driver_lock);
 124
 125         if (!vdev->refcnt) {
 126                 ret = vfio_platform_regions_init(vdev);
 127                 if (ret)
 128                         goto err_reg;
 129
 130                 ret = vfio_platform_irq_init(vdev);
 131                 if (ret)
 132                         goto err_irq;
 133         }
 134
 135         vdev->refcnt++;
 136
 137         mutex_unlock(&driver_lock);
 138         return 0;
 139
 140 err_irq:
 141         vfio_platform_regions_cleanup(vdev);
 142 err_reg:
 143         mutex_unlock(&driver_lock);
 144         module_put(THIS_MODULE);
 145         return ret;
 146 }
 147
 148 static long vfio_platform_ioctl(void *device_data,
 149                                 unsigned int cmd, unsigned long arg)
 150 {
 151         struct vfio_platform_device *vdev = device_data;
 152         unsigned long minsz;
 153
 154         if (cmd == VFIO_DEVICE_GET_INFO) {
 155                 struct vfio_device_info info;
 156
 157                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 158
 159                 if (copy_from_user(&info, (void __user *)arg, minsz))
 160                         return -EFAULT;
 161
 162                 if (info.argsz < minsz)
 163                         return -EINVAL;
 164
 165                 info.flags = vdev->flags;
 166                 info.num_regions = vdev->num_regions;
 167                 info.num_irqs = vdev->num_irqs;
 168
 169                 return copy_to_user((void __user *)arg, &info, minsz);
 170
 171         } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
 172                 struct vfio_region_info info;
 173
 174                 minsz = offsetofend(struct vfio_region_info, offset);
 175
 176                 if (copy_from_user(&info, (void __user *)arg, minsz))
 177                         return -EFAULT;
 178
 179                 if (info.argsz < minsz)
 180                         return -EINVAL;
 181
 182                 if (info.index >= vdev->num_regions)
 183                         return -EINVAL;
 184
 185                 /* map offset to the physical address  */
 186                 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
 187                 info.size = vdev->regions[info.index].size;
 188                 info.flags = vdev->regions[info.index].flags;
 189
 190                 return copy_to_user((void __user *)arg, &info, minsz);
 191
 192         } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
 193                 struct vfio_irq_info info;
 194
 195                 minsz = offsetofend(struct vfio_irq_info, count);
 196
 197                 if (copy_from_user(&info, (void __user *)arg, minsz))
 198                         return -EFAULT;
 199
 200                 if (info.argsz < minsz)
 201                         return -EINVAL;
 202
 203                 if (info.index >= vdev->num_irqs)
 204                         return -EINVAL;
 205
 206                 info.flags = vdev->irqs[info.index].flags;
 207                 info.count = vdev->irqs[info.index].count;
 208
 209                 return copy_to_user((void __user *)arg, &info, minsz);
 210
 211         } else if (cmd == VFIO_DEVICE_SET_IRQS) {
 212                 struct vfio_irq_set hdr;
 213                 u8 *data = NULL;
 214                 int ret = 0;
 215
 216                 minsz = offsetofend(struct vfio_irq_set, count);
 217
 218                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 219                         return -EFAULT;
 220
 221                 if (hdr.argsz < minsz)
 222                         return -EINVAL;
 223
 224                 if (hdr.index >= vdev->num_irqs)
 225                         return -EINVAL;
 226
 227                 if (hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
 228                                   VFIO_IRQ_SET_ACTION_TYPE_MASK))
 229                         return -EINVAL;
 230
 231                 if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
 232                         size_t size;
 233
 234                         if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
 235                                 size = sizeof(uint8_t);
 236                         else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
 237                                 size = sizeof(int32_t);
 238                         else
 239                                 return -EINVAL;
 240
 241                         if (hdr.argsz - minsz < size)
 242                                 return -EINVAL;
 243
 244                         data = memdup_user((void __user *)(arg + minsz), size);
 245                         if (IS_ERR(data))
 246                                 return PTR_ERR(data);
 247                 }
 248
 249                 mutex_lock(&vdev->igate);
 250
 251                 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
 252                                                    hdr.start, hdr.count, data);
 253                 mutex_unlock(&vdev->igate);
 254                 kfree(data);
 255
 256                 return ret;
 257
 258         } else if (cmd == VFIO_DEVICE_RESET)
 259                 return -EINVAL;
 260
 261         return -ENOTTY;
 262 }
 263
 264 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg,
 265                                        char __user *buf, size_t count,
 266                                        loff_t off)
 267 {
 268         unsigned int done = 0;
 269
 270         if (!reg.ioaddr) {
 271                 reg.ioaddr =
 272                         ioremap_nocache(reg.addr, reg.size);
 273
 274                 if (!reg.ioaddr)
 275                         return -ENOMEM;
 276         }
 277
 278         while (count) {
 279                 size_t filled;
 280
 281                 if (count >= 4 && !(off % 4)) {
 282                         u32 val;
 283
 284                         val = ioread32(reg.ioaddr + off);
 285                         if (copy_to_user(buf, &val, 4))
 286                                 goto err;
 287
 288                         filled = 4;
 289                 } else if (count >= 2 && !(off % 2)) {
 290                         u16 val;
 291
 292                         val = ioread16(reg.ioaddr + off);
 293                         if (copy_to_user(buf, &val, 2))
 294                                 goto err;
 295
 296                         filled = 2;
 297                 } else {
 298                         u8 val;
 299
 300                         val = ioread8(reg.ioaddr + off);
 301                         if (copy_to_user(buf, &val, 1))
 302                                 goto err;
 303
 304                         filled = 1;
 305                 }
 306
 307
 308                 count -= filled;
 309                 done += filled;
 310                 off += filled;
 311                 buf += filled;
 312         }
 313
 314         return done;
 315 err:
 316         return -EFAULT;
 317 }
 318
 319 static ssize_t vfio_platform_read(void *device_data, char __user *buf,
 320                                   size_t count, loff_t *ppos)
 321 {
 322         struct vfio_platform_device *vdev = device_data;
 323         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 324         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 325
 326         if (index >= vdev->num_regions)
 327                 return -EINVAL;
 328
 329         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
 330                 return -EINVAL;
 331
 332         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 333                 return vfio_platform_read_mmio(vdev->regions[index],
 334                                                         buf, count, off);
 335         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 336                 return -EINVAL; /* not implemented */
 337
 338         return -EINVAL;
 339 }
 340
 341 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg,
 342                                         const char __user *buf, size_t count,
 343                                         loff_t off)
 344 {
 345         unsigned int done = 0;
 346
 347         if (!reg.ioaddr) {
 348                 reg.ioaddr =
 349                         ioremap_nocache(reg.addr, reg.size);
 350
 351                 if (!reg.ioaddr)
 352                         return -ENOMEM;
 353         }
 354
 355         while (count) {
 356                 size_t filled;
 357
 358                 if (count >= 4 && !(off % 4)) {
 359                         u32 val;
 360
 361                         if (copy_from_user(&val, buf, 4))
 362                                 goto err;
 363                         iowrite32(val, reg.ioaddr + off);
 364
 365                         filled = 4;
 366                 } else if (count >= 2 && !(off % 2)) {
 367                         u16 val;
 368
 369                         if (copy_from_user(&val, buf, 2))
 370                                 goto err;
 371                         iowrite16(val, reg.ioaddr + off);
 372
 373                         filled = 2;
 374                 } else {
 375                         u8 val;
 376
 377                         if (copy_from_user(&val, buf, 1))
 378                                 goto err;
 379                         iowrite8(val, reg.ioaddr + off);
 380
 381                         filled = 1;
 382                 }
 383
 384                 count -= filled;
 385                 done += filled;
 386                 off += filled;
 387                 buf += filled;
 388         }
 389
 390         return done;
 391 err:
 392         return -EFAULT;
 393 }
 394
 395 static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
 396                                    size_t count, loff_t *ppos)
 397 {
 398         struct vfio_platform_device *vdev = device_data;
 399         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
 400         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
 401
 402         if (index >= vdev->num_regions)
 403                 return -EINVAL;
 404
 405         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
 406                 return -EINVAL;
 407
 408         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 409                 return vfio_platform_write_mmio(vdev->regions[index],
 410                                                         buf, count, off);
 411         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 412                 return -EINVAL; /* not implemented */
 413
 414         return -EINVAL;
 415 }
 416
 417 static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
 418                                    struct vm_area_struct *vma)
 419 {
 420         u64 req_len, pgoff, req_start;
 421
 422         req_len = vma->vm_end - vma->vm_start;
 423         pgoff = vma->vm_pgoff &
 424                 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
 425         req_start = pgoff << PAGE_SHIFT;
 426
 427         if (region.size < PAGE_SIZE || req_start + req_len > region.size)
 428                 return -EINVAL;
 429
 430         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 431         vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
 432
 433         return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
 434                                req_len, vma->vm_page_prot);
 435 }
 436
 437 static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma)
 438 {
 439         struct vfio_platform_device *vdev = device_data;
 440         unsigned int index;
 441
 442         index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);
 443
 444         if (vma->vm_end < vma->vm_start)
 445                 return -EINVAL;
 446         if (!(vma->vm_flags & VM_SHARED))
 447                 return -EINVAL;
 448         if (index >= vdev->num_regions)
 449                 return -EINVAL;
 450         if (vma->vm_start & ~PAGE_MASK)
 451                 return -EINVAL;
 452         if (vma->vm_end & ~PAGE_MASK)
 453                 return -EINVAL;
 454
 455         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
 456                 return -EINVAL;
 457
 458         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
 459                         && (vma->vm_flags & VM_READ))
 460                 return -EINVAL;
 461
 462         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
 463                         && (vma->vm_flags & VM_WRITE))
 464                 return -EINVAL;
 465
 466         vma->vm_private_data = vdev;
 467
 468         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
 469                 return vfio_platform_mmap_mmio(vdev->regions[index], vma);
 470
 471         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 472                 return -EINVAL; /* not implemented */
 473
 474         return -EINVAL;
 475 }
 476
 477 static const struct vfio_device_ops vfio_platform_ops = {
 478         .name           = "vfio-platform",
 479         .open           = vfio_platform_open,
 480         .release        = vfio_platform_release,
 481         .ioctl          = vfio_platform_ioctl,
 482         .read           = vfio_platform_read,
 483         .write          = vfio_platform_write,
 484         .mmap           = vfio_platform_mmap,
 485 };
 486
 487 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 488                                struct device *dev)
 489 {
 490         struct iommu_group *group;
 491         int ret;
 492
 493         if (!vdev)
 494                 return -EINVAL;
 495
 496         group = iommu_group_get(dev);
 497         if (!group) {
 498                 pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
 499                 return -EINVAL;
 500         }
 501
 502         ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
 503         if (ret) {
 504                 iommu_group_put(group);
 505                 return ret;
 506         }
 507
 508         mutex_init(&vdev->igate);
 509
 510         return 0;
 511 }
 512 EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
 513
 514 struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
 515 {
 516         struct vfio_platform_device *vdev;
 517
 518         vdev = vfio_del_group_dev(dev);
 519         if (vdev)
 520                 iommu_group_put(dev->iommu_group);
 521
 522         return vdev;
 523 }
 524 EXPORT_SYMBOL_GPL(vfio_platform_remove_common);