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 #define pr_fmt(fmt) "[TTM] " fmt
  32
  33 #include <ttm/ttm_module.h>
  34 #include <ttm/ttm_bo_driver.h>
  35 #include <ttm/ttm_placement.h>
  36 #include <linux/mm.h>
  37 #include <linux/rbtree.h>
  38 #include <linux/module.h>
  39 #include <linux/uaccess.h>
  40
  41 #define TTM_BO_VM_NUM_PREFAULT 16
  42
  43 static struct ttm_buffer_object *ttm_bo_vm_lookup_rb(struct ttm_bo_device *bdev,
  44                                                      unsigned long page_start,
  45                                                      unsigned long num_pages)
  46 {
  47         struct rb_node *cur = bdev->addr_space_rb.rb_node;
  48         unsigned long cur_offset;
  49         struct ttm_buffer_object *bo;
  50         struct ttm_buffer_object *best_bo = NULL;
  51
  52         while (likely(cur != NULL)) {
  53                 bo = rb_entry(cur, struct ttm_buffer_object, vm_rb);
  54                 cur_offset = bo->vm_node->start;
  55                 if (page_start >= cur_offset) {
  56                         cur = cur->rb_right;
  57                         best_bo = bo;
  58                         if (page_start == cur_offset)
  59                                 break;
  60                 } else
  61                         cur = cur->rb_left;
  62         }
  63
  64         if (unlikely(best_bo == NULL))
  65                 return NULL;
  66
  67         if (unlikely((best_bo->vm_node->start + best_bo->num_pages) <
  68                      (page_start + num_pages)))
  69                 return NULL;
  70
  71         return best_bo;
  72 }
  73
  74 static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
  75 {
  76         struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
  77             vma->vm_private_data;
  78         struct ttm_bo_device *bdev = bo->bdev;
  79         unsigned long page_offset;
  80         unsigned long page_last;
  81         unsigned long pfn;
  82         struct ttm_tt *ttm = NULL;
  83         struct page *page;
  84         int ret;
  85         int i;
  86         unsigned long address = (unsigned long)vmf->virtual_address;
  87         int retval = VM_FAULT_NOPAGE;
  88         struct ttm_mem_type_manager *man =
  89                 &bdev->man[bo->mem.mem_type];
  90
  91         /*
  92          * Work around locking order reversal in fault / nopfn
  93          * between mmap_sem and bo_reserve: Perform a trylock operation
  94          * for reserve, and if it fails, retry the fault after scheduling.
  95          */
  96
  97         ret = ttm_bo_reserve(bo, true, true, false, 0);
  98         if (unlikely(ret != 0)) {
  99                 if (ret == -EBUSY)
 100                         set_need_resched();
 101                 return VM_FAULT_NOPAGE;
 102         }
 103
 104         if (bdev->driver->fault_reserve_notify) {
 105                 ret = bdev->driver->fault_reserve_notify(bo);
 106                 switch (ret) {
 107                 case 0:
 108                         break;
 109                 case -EBUSY:
 110                         set_need_resched();
 111                 case -ERESTARTSYS:
 112                         retval = VM_FAULT_NOPAGE;
 113                         goto out_unlock;
 114                 default:
 115                         retval = VM_FAULT_SIGBUS;
 116                         goto out_unlock;
 117                 }
 118         }
 119
 120         /*
 121          * Wait for buffer data in transit, due to a pipelined
 122          * move.
 123          */
 124
 125         spin_lock(&bdev->fence_lock);
 126         if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
 127                 ret = ttm_bo_wait(bo, false, true, false);
 128                 spin_unlock(&bdev->fence_lock);
 129                 if (unlikely(ret != 0)) {
 130                         retval = (ret != -ERESTARTSYS) ?
 131                             VM_FAULT_SIGBUS : VM_FAULT_NOPAGE;
 132                         goto out_unlock;
 133                 }
 134         } else
 135                 spin_unlock(&bdev->fence_lock);
 136
 137         ret = ttm_mem_io_lock(man, true);
 138         if (unlikely(ret != 0)) {
 139                 retval = VM_FAULT_NOPAGE;
 140                 goto out_unlock;
 141         }
 142         ret = ttm_mem_io_reserve_vm(bo);
 143         if (unlikely(ret != 0)) {
 144                 retval = VM_FAULT_SIGBUS;
 145                 goto out_io_unlock;
 146         }
 147
 148         page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
 149             bo->vm_node->start - vma->vm_pgoff;
 150         page_last = vma_pages(vma) +
 151             bo->vm_node->start - vma->vm_pgoff;
 152
 153         if (unlikely(page_offset >= bo->num_pages)) {
 154                 retval = VM_FAULT_SIGBUS;
 155                 goto out_io_unlock;
 156         }
 157
 158         /*
 159          * Strictly, we're not allowed to modify vma->vm_page_prot here,
 160          * since the mmap_sem is only held in read mode. However, we
 161          * modify only the caching bits of vma->vm_page_prot and
 162          * consider those bits protected by
 163          * the bo->mutex, as we should be the only writers.
 164          * There shouldn't really be any readers of these bits except
 165          * within vm_insert_mixed()? fork?
 166          *
 167          * TODO: Add a list of vmas to the bo, and change the
 168          * vma->vm_page_prot when the object changes caching policy, with
 169          * the correct locks held.
 170          */
 171         if (bo->mem.bus.is_iomem) {
 172                 vma->vm_page_prot = ttm_io_prot(bo->mem.placement,
 173                                                 vma->vm_page_prot);
 174         } else {
 175                 ttm = bo->ttm;
 176                 vma->vm_page_prot = (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
 177                     vm_get_page_prot(vma->vm_flags) :
 178                     ttm_io_prot(bo->mem.placement, vma->vm_page_prot);
 179
 180                 /* Allocate all page at once, most common usage */
 181                 if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
 182                         retval = VM_FAULT_OOM;
 183                         goto out_io_unlock;
 184                 }
 185         }
 186
 187         /*
 188          * Speculatively prefault a number of pages. Only error on
 189          * first page.
 190          */
 191         for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
 192                 if (bo->mem.bus.is_iomem)
 193                         pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset;
 194                 else {
 195                         page = ttm->pages[page_offset];
 196                         if (unlikely(!page && i == 0)) {
 197                                 retval = VM_FAULT_OOM;
 198                                 goto out_io_unlock;
 199                         } else if (unlikely(!page)) {
 200                                 break;
 201                         }
 202                         pfn = page_to_pfn(page);
 203                 }
 204
 205                 ret = vm_insert_mixed(vma, address, pfn);
 206                 /*
 207                  * Somebody beat us to this PTE or prefaulting to
 208                  * an already populated PTE, or prefaulting error.
 209                  */
 210
 211                 if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
 212                         break;
 213                 else if (unlikely(ret != 0)) {
 214                         retval =
 215                             (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
 216                         goto out_io_unlock;
 217                 }
 218
 219                 address += PAGE_SIZE;
 220                 if (unlikely(++page_offset >= page_last))
 221                         break;
 222         }
 223 out_io_unlock:
 224         ttm_mem_io_unlock(man);
 225 out_unlock:
 226         ttm_bo_unreserve(bo);
 227         return retval;
 228 }
 229
 230 static void ttm_bo_vm_open(struct vm_area_struct *vma)
 231 {
 232         struct ttm_buffer_object *bo =
 233             (struct ttm_buffer_object *)vma->vm_private_data;
 234
 235         (void)ttm_bo_reference(bo);
 236 }
 237
 238 static void ttm_bo_vm_close(struct vm_area_struct *vma)
 239 {
 240         struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
 241
 242         ttm_bo_unref(&bo);
 243         vma->vm_private_data = NULL;
 244 }
 245
 246 static const struct vm_operations_struct ttm_bo_vm_ops = {
 247         .fault = ttm_bo_vm_fault,
 248         .open = ttm_bo_vm_open,
 249         .close = ttm_bo_vm_close
 250 };
 251
 252 int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 253                 struct ttm_bo_device *bdev)
 254 {
 255         struct ttm_bo_driver *driver;
 256         struct ttm_buffer_object *bo;
 257         int ret;
 258
 259         read_lock(&bdev->vm_lock);
 260         bo = ttm_bo_vm_lookup_rb(bdev, vma->vm_pgoff,
 261                                  vma_pages(vma));
 262         if (likely(bo != NULL) && !kref_get_unless_zero(&bo->kref))
 263                 bo = NULL;
 264         read_unlock(&bdev->vm_lock);
 265
 266         if (unlikely(bo == NULL)) {
 267                 pr_err("Could not find buffer object to map\n");
 268                 return -EINVAL;
 269         }
 270
 271         driver = bo->bdev->driver;
 272         if (unlikely(!driver->verify_access)) {
 273                 ret = -EPERM;
 274                 goto out_unref;
 275         }
 276         ret = driver->verify_access(bo, filp);
 277         if (unlikely(ret != 0))
 278                 goto out_unref;
 279
 280         vma->vm_ops = &ttm_bo_vm_ops;
 281
 282         /*
 283          * Note: We're transferring the bo reference to
 284          * vma->vm_private_data here.
 285          */
 286
 287         vma->vm_private_data = bo;
 288         vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND | VM_DONTDUMP;
 289         return 0;
 290 out_unref:
 291         ttm_bo_unref(&bo);
 292         return ret;
 293 }
 294 EXPORT_SYMBOL(ttm_bo_mmap);
 295
 296 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 297 {
 298         if (vma->vm_pgoff != 0)
 299                 return -EACCES;
 300
 301         vma->vm_ops = &ttm_bo_vm_ops;
 302         vma->vm_private_data = ttm_bo_reference(bo);
 303         vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
 304         return 0;
 305 }
 306 EXPORT_SYMBOL(ttm_fbdev_mmap);
 307
 308
 309 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
 310                   const char __user *wbuf, char __user *rbuf, size_t count,
 311                   loff_t *f_pos, bool write)
 312 {
 313         struct ttm_buffer_object *bo;
 314         struct ttm_bo_driver *driver;
 315         struct ttm_bo_kmap_obj map;
 316         unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
 317         unsigned long kmap_offset;
 318         unsigned long kmap_end;
 319         unsigned long kmap_num;
 320         size_t io_size;
 321         unsigned int page_offset;
 322         char *virtual;
 323         int ret;
 324         bool no_wait = false;
 325         bool dummy;
 326
 327         read_lock(&bdev->vm_lock);
 328         bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
 329         if (likely(bo != NULL))
 330                 ttm_bo_reference(bo);
 331         read_unlock(&bdev->vm_lock);
 332
 333         if (unlikely(bo == NULL))
 334                 return -EFAULT;
 335
 336         driver = bo->bdev->driver;
 337         if (unlikely(!driver->verify_access)) {
 338                 ret = -EPERM;
 339                 goto out_unref;
 340         }
 341
 342         ret = driver->verify_access(bo, filp);
 343         if (unlikely(ret != 0))
 344                 goto out_unref;
 345
 346         kmap_offset = dev_offset - bo->vm_node->start;
 347         if (unlikely(kmap_offset >= bo->num_pages)) {
 348                 ret = -EFBIG;
 349                 goto out_unref;
 350         }
 351
 352         page_offset = *f_pos & ~PAGE_MASK;
 353         io_size = bo->num_pages - kmap_offset;
 354         io_size = (io_size << PAGE_SHIFT) - page_offset;
 355         if (count < io_size)
 356                 io_size = count;
 357
 358         kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
 359         kmap_num = kmap_end - kmap_offset + 1;
 360
 361         ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
 362
 363         switch (ret) {
 364         case 0:
 365                 break;
 366         case -EBUSY:
 367                 ret = -EAGAIN;
 368                 goto out_unref;
 369         default:
 370                 goto out_unref;
 371         }
 372
 373         ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
 374         if (unlikely(ret != 0)) {
 375                 ttm_bo_unreserve(bo);
 376                 goto out_unref;
 377         }
 378
 379         virtual = ttm_kmap_obj_virtual(&map, &dummy);
 380         virtual += page_offset;
 381
 382         if (write)
 383                 ret = copy_from_user(virtual, wbuf, io_size);
 384         else
 385                 ret = copy_to_user(rbuf, virtual, io_size);
 386
 387         ttm_bo_kunmap(&map);
 388         ttm_bo_unreserve(bo);
 389         ttm_bo_unref(&bo);
 390
 391         if (unlikely(ret != 0))
 392                 return -EFBIG;
 393
 394         *f_pos += io_size;
 395
 396         return io_size;
 397 out_unref:
 398         ttm_bo_unref(&bo);
 399         return ret;
 400 }
 401
 402 ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf,
 403                         char __user *rbuf, size_t count, loff_t *f_pos,
 404                         bool write)
 405 {
 406         struct ttm_bo_kmap_obj map;
 407         unsigned long kmap_offset;
 408         unsigned long kmap_end;
 409         unsigned long kmap_num;
 410         size_t io_size;
 411         unsigned int page_offset;
 412         char *virtual;
 413         int ret;
 414         bool no_wait = false;
 415         bool dummy;
 416
 417         kmap_offset = (*f_pos >> PAGE_SHIFT);
 418         if (unlikely(kmap_offset >= bo->num_pages))
 419                 return -EFBIG;
 420
 421         page_offset = *f_pos & ~PAGE_MASK;
 422         io_size = bo->num_pages - kmap_offset;
 423         io_size = (io_size << PAGE_SHIFT) - page_offset;
 424         if (count < io_size)
 425                 io_size = count;
 426
 427         kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
 428         kmap_num = kmap_end - kmap_offset + 1;
 429
 430         ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
 431
 432         switch (ret) {
 433         case 0:
 434                 break;
 435         case -EBUSY:
 436                 return -EAGAIN;
 437         default:
 438                 return ret;
 439         }
 440
 441         ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
 442         if (unlikely(ret != 0)) {
 443                 ttm_bo_unreserve(bo);
 444                 return ret;
 445         }
 446
 447         virtual = ttm_kmap_obj_virtual(&map, &dummy);
 448         virtual += page_offset;
 449
 450         if (write)
 451                 ret = copy_from_user(virtual, wbuf, io_size);
 452         else
 453                 ret = copy_to_user(rbuf, virtual, io_size);
 454
 455         ttm_bo_kunmap(&map);
 456         ttm_bo_unreserve(bo);
 457         ttm_bo_unref(&bo);
 458
 459         if (unlikely(ret != 0))
 460                 return ret;
 461
 462         *f_pos += io_size;
 463
 464         return io_size;
 465 }