drivers/gpu/drm/ttm/ttm_bo_vm.c

   1 /**************************************************************************
   2  *
   3  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  22  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  24  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27 /*
  28  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
  29  */
  30
  31 #include <ttm/ttm_module.h>
  32 #include <ttm/ttm_bo_driver.h>
  33 #include <ttm/ttm_placement.h>
  34 #include <linux/mm.h>
  35 #include <linux/rbtree.h>
  36 #include <linux/module.h>
  37 #include <linux/uaccess.h>
  38
  39 #define TTM_BO_VM_NUM_PREFAULT 16
  40
  41 static struct ttm_buffer_object *ttm_bo_vm_lookup_rb(struct ttm_bo_device *bdev,
  42                                                      unsigned long page_start,
  43                                                      unsigned long num_pages)
  44 {
  45         struct rb_node *cur = bdev->addr_space_rb.rb_node;
  46         unsigned long cur_offset;
  47         struct ttm_buffer_object *bo;
  48         struct ttm_buffer_object *best_bo = NULL;
  49
  50         while (likely(cur != NULL)) {
  51                 bo = rb_entry(cur, struct ttm_buffer_object, vm_rb);
  52                 cur_offset = bo->vm_node->start;
  53                 if (page_start >= cur_offset) {
  54                         cur = cur->rb_right;
  55                         best_bo = bo;
  56                         if (page_start == cur_offset)
  57                                 break;
  58                 } else
  59                         cur = cur->rb_left;
  60         }
  61
  62         if (unlikely(best_bo == NULL))
  63                 return NULL;
  64
  65         if (unlikely((best_bo->vm_node->start + best_bo->num_pages) <
  66                      (page_start + num_pages)))
  67                 return NULL;
  68
  69         return best_bo;
  70 }
  71
  72 static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
  73 {
  74         struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
  75             vma->vm_private_data;
  76         struct ttm_bo_device *bdev = bo->bdev;
  77         unsigned long page_offset;
  78         unsigned long page_last;
  79         unsigned long pfn;
  80         struct ttm_tt *ttm = NULL;
  81         struct page *page;
  82         int ret;
  83         int i;
  84         unsigned long address = (unsigned long)vmf->virtual_address;
  85         int retval = VM_FAULT_NOPAGE;
  86         struct ttm_mem_type_manager *man =
  87                 &bdev->man[bo->mem.mem_type];
  88
  89         /*
  90          * Work around locking order reversal in fault / nopfn
  91          * between mmap_sem and bo_reserve: Perform a trylock operation
  92          * for reserve, and if it fails, retry the fault after scheduling.
  93          */
  94
  95         ret = ttm_bo_reserve(bo, true, true, false, 0);
  96         if (unlikely(ret != 0)) {
  97                 if (ret == -EBUSY)
  98                         set_need_resched();
  99                 return VM_FAULT_NOPAGE;
 100         }
 101
 102         if (bdev->driver->fault_reserve_notify) {
 103                 ret = bdev->driver->fault_reserve_notify(bo);
 104                 switch (ret) {
 105                 case 0:
 106                         break;
 107                 case -EBUSY:
 108                         set_need_resched();
 109                 case -ERESTARTSYS:
 110                         retval = VM_FAULT_NOPAGE;
 111                         goto out_unlock;
 112                 default:
 113                         retval = VM_FAULT_SIGBUS;
 114                         goto out_unlock;
 115                 }
 116         }
 117
 118         /*
 119          * Wait for buffer data in transit, due to a pipelined
 120          * move.
 121          */
 122
 123         spin_lock(&bdev->fence_lock);
 124         if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
 125                 ret = ttm_bo_wait(bo, false, true, false);
 126                 spin_unlock(&bdev->fence_lock);
 127                 if (unlikely(ret != 0)) {
 128                         retval = (ret != -ERESTARTSYS) ?
 129                             VM_FAULT_SIGBUS : VM_FAULT_NOPAGE;
 130                         goto out_unlock;
 131                 }
 132         } else
 133                 spin_unlock(&bdev->fence_lock);
 134
 135         ret = ttm_mem_io_lock(man, true);
 136         if (unlikely(ret != 0)) {
 137                 retval = VM_FAULT_NOPAGE;
 138                 goto out_unlock;
 139         }
 140         ret = ttm_mem_io_reserve_vm(bo);
 141         if (unlikely(ret != 0)) {
 142                 retval = VM_FAULT_SIGBUS;
 143                 goto out_io_unlock;
 144         }
 145
 146         page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
 147             bo->vm_node->start - vma->vm_pgoff;
 148         page_last = ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) +
 149             bo->vm_node->start - vma->vm_pgoff;
 150
 151         if (unlikely(page_offset >= bo->num_pages)) {
 152                 retval = VM_FAULT_SIGBUS;
 153                 goto out_io_unlock;
 154         }
 155
 156         /*
 157          * Strictly, we're not allowed to modify vma->vm_page_prot here,
 158          * since the mmap_sem is only held in read mode. However, we
 159          * modify only the caching bits of vma->vm_page_prot and
 160          * consider those bits protected by
 161          * the bo->mutex, as we should be the only writers.
 162          * There shouldn't really be any readers of these bits except
 163          * within vm_insert_mixed()? fork?
 164          *
 165          * TODO: Add a list of vmas to the bo, and change the
 166          * vma->vm_page_prot when the object changes caching policy, with
 167          * the correct locks held.
 168          */
 169         if (bo->mem.bus.is_iomem) {
 170                 vma->vm_page_prot = ttm_io_prot(bo->mem.placement,
 171                                                 vma->vm_page_prot);
 172         } else {
 173                 ttm = bo->ttm;
 174                 vma->vm_page_prot = (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
 175                     vm_get_page_prot(vma->vm_flags) :
 176                     ttm_io_prot(bo->mem.placement, vma->vm_page_prot);
 177         }
 178
 179         /*
 180          * Speculatively prefault a number of pages. Only error on
 181          * first page.
 182          */
 183
 184         for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
 185                 if (bo->mem.bus.is_iomem)
 186                         pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset;
 187                 else {
 188                         page = ttm_tt_get_page(ttm, page_offset);
 189                         if (unlikely(!page && i == 0)) {
 190                                 retval = VM_FAULT_OOM;
 191                                 goto out_io_unlock;
 192                         } else if (unlikely(!page)) {
 193                                 break;
 194                         }
 195                         pfn = page_to_pfn(page);
 196                 }
 197
 198                 ret = vm_insert_mixed(vma, address, pfn);
 199                 /*
 200                  * Somebody beat us to this PTE or prefaulting to
 201                  * an already populated PTE, or prefaulting error.
 202                  */
 203
 204                 if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
 205                         break;
 206                 else if (unlikely(ret != 0)) {
 207                         retval =
 208                             (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
 209                         goto out_io_unlock;
 210                 }
 211
 212                 address += PAGE_SIZE;
 213                 if (unlikely(++page_offset >= page_last))
 214                         break;
 215         }
 216 out_io_unlock:
 217         ttm_mem_io_unlock(man);
 218 out_unlock:
 219         ttm_bo_unreserve(bo);
 220         return retval;
 221 }
 222
 223 static void ttm_bo_vm_open(struct vm_area_struct *vma)
 224 {
 225         struct ttm_buffer_object *bo =
 226             (struct ttm_buffer_object *)vma->vm_private_data;
 227
 228         (void)ttm_bo_reference(bo);
 229 }
 230
 231 static void ttm_bo_vm_close(struct vm_area_struct *vma)
 232 {
 233         struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
 234
 235         ttm_bo_unref(&bo);
 236         vma->vm_private_data = NULL;
 237 }
 238
 239 static const struct vm_operations_struct ttm_bo_vm_ops = {
 240         .fault = ttm_bo_vm_fault,
 241         .open = ttm_bo_vm_open,
 242         .close = ttm_bo_vm_close
 243 };
 244
 245 int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 246                 struct ttm_bo_device *bdev)
 247 {
 248         struct ttm_bo_driver *driver;
 249         struct ttm_buffer_object *bo;
 250         int ret;
 251
 252         read_lock(&bdev->vm_lock);
 253         bo = ttm_bo_vm_lookup_rb(bdev, vma->vm_pgoff,
 254                                  (vma->vm_end - vma->vm_start) >> PAGE_SHIFT);
 255         if (likely(bo != NULL))
 256                 ttm_bo_reference(bo);
 257         read_unlock(&bdev->vm_lock);
 258
 259         if (unlikely(bo == NULL)) {
 260                 printk(KERN_ERR TTM_PFX
 261                        "Could not find buffer object to map.\n");
 262                 return -EINVAL;
 263         }
 264
 265         driver = bo->bdev->driver;
 266         if (unlikely(!driver->verify_access)) {
 267                 ret = -EPERM;
 268                 goto out_unref;
 269         }
 270         ret = driver->verify_access(bo, filp);
 271         if (unlikely(ret != 0))
 272                 goto out_unref;
 273
 274         vma->vm_ops = &ttm_bo_vm_ops;
 275
 276         /*
 277          * Note: We're transferring the bo reference to
 278          * vma->vm_private_data here.
 279          */
 280
 281         vma->vm_private_data = bo;
 282         vma->vm_flags |= VM_RESERVED | VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
 283         return 0;
 284 out_unref:
 285         ttm_bo_unref(&bo);
 286         return ret;
 287 }
 288 EXPORT_SYMBOL(ttm_bo_mmap);
 289
 290 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 291 {
 292         if (vma->vm_pgoff != 0)
 293                 return -EACCES;
 294
 295         vma->vm_ops = &ttm_bo_vm_ops;
 296         vma->vm_private_data = ttm_bo_reference(bo);
 297         vma->vm_flags |= VM_RESERVED | VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
 298         return 0;
 299 }
 300 EXPORT_SYMBOL(ttm_fbdev_mmap);
 301
 302
 303 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
 304                   const char __user *wbuf, char __user *rbuf, size_t count,
 305                   loff_t *f_pos, bool write)
 306 {
 307         struct ttm_buffer_object *bo;
 308         struct ttm_bo_driver *driver;
 309         struct ttm_bo_kmap_obj map;
 310         unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
 311         unsigned long kmap_offset;
 312         unsigned long kmap_end;
 313         unsigned long kmap_num;
 314         size_t io_size;
 315         unsigned int page_offset;
 316         char *virtual;
 317         int ret;
 318         bool no_wait = false;
 319         bool dummy;
 320
 321         read_lock(&bdev->vm_lock);
 322         bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
 323         if (likely(bo != NULL))
 324                 ttm_bo_reference(bo);
 325         read_unlock(&bdev->vm_lock);
 326
 327         if (unlikely(bo == NULL))
 328                 return -EFAULT;
 329
 330         driver = bo->bdev->driver;
 331         if (unlikely(!driver->verify_access)) {
 332                 ret = -EPERM;
 333                 goto out_unref;
 334         }
 335
 336         ret = driver->verify_access(bo, filp);
 337         if (unlikely(ret != 0))
 338                 goto out_unref;
 339
 340         kmap_offset = dev_offset - bo->vm_node->start;
 341         if (unlikely(kmap_offset >= bo->num_pages)) {
 342                 ret = -EFBIG;
 343                 goto out_unref;
 344         }
 345
 346         page_offset = *f_pos & ~PAGE_MASK;
 347         io_size = bo->num_pages - kmap_offset;
 348         io_size = (io_size << PAGE_SHIFT) - page_offset;
 349         if (count < io_size)
 350                 io_size = count;
 351
 352         kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
 353         kmap_num = kmap_end - kmap_offset + 1;
 354
 355         ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
 356
 357         switch (ret) {
 358         case 0:
 359                 break;
 360         case -EBUSY:
 361                 ret = -EAGAIN;
 362                 goto out_unref;
 363         default:
 364                 goto out_unref;
 365         }
 366
 367         ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
 368         if (unlikely(ret != 0)) {
 369                 ttm_bo_unreserve(bo);
 370                 goto out_unref;
 371         }
 372
 373         virtual = ttm_kmap_obj_virtual(&map, &dummy);
 374         virtual += page_offset;
 375
 376         if (write)
 377                 ret = copy_from_user(virtual, wbuf, io_size);
 378         else
 379                 ret = copy_to_user(rbuf, virtual, io_size);
 380
 381         ttm_bo_kunmap(&map);
 382         ttm_bo_unreserve(bo);
 383         ttm_bo_unref(&bo);
 384
 385         if (unlikely(ret != 0))
 386                 return -EFBIG;
 387
 388         *f_pos += io_size;
 389
 390         return io_size;
 391 out_unref:
 392         ttm_bo_unref(&bo);
 393         return ret;
 394 }
 395
 396 ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf,
 397                         char __user *rbuf, size_t count, loff_t *f_pos,
 398                         bool write)
 399 {
 400         struct ttm_bo_kmap_obj map;
 401         unsigned long kmap_offset;
 402         unsigned long kmap_end;
 403         unsigned long kmap_num;
 404         size_t io_size;
 405         unsigned int page_offset;
 406         char *virtual;
 407         int ret;
 408         bool no_wait = false;
 409         bool dummy;
 410
 411         kmap_offset = (*f_pos >> PAGE_SHIFT);
 412         if (unlikely(kmap_offset >= bo->num_pages))
 413                 return -EFBIG;
 414
 415         page_offset = *f_pos & ~PAGE_MASK;
 416         io_size = bo->num_pages - kmap_offset;
 417         io_size = (io_size << PAGE_SHIFT) - page_offset;
 418         if (count < io_size)
 419                 io_size = count;
 420
 421         kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
 422         kmap_num = kmap_end - kmap_offset + 1;
 423
 424         ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
 425
 426         switch (ret) {
 427         case 0:
 428                 break;
 429         case -EBUSY:
 430                 return -EAGAIN;
 431         default:
 432                 return ret;
 433         }
 434
 435         ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
 436         if (unlikely(ret != 0)) {
 437                 ttm_bo_unreserve(bo);
 438                 return ret;
 439         }
 440
 441         virtual = ttm_kmap_obj_virtual(&map, &dummy);
 442         virtual += page_offset;
 443
 444         if (write)
 445                 ret = copy_from_user(virtual, wbuf, io_size);
 446         else
 447                 ret = copy_to_user(rbuf, virtual, io_size);
 448
 449         ttm_bo_kunmap(&map);
 450         ttm_bo_unreserve(bo);
 451         ttm_bo_unref(&bo);
 452
 453         if (unlikely(ret != 0))
 454                 return ret;
 455
 456         *f_pos += io_size;
 457
 458         return io_size;
 459 }