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                 /* Allocate all page at once, most common usage */
 179                 if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
 180                         retval = VM_FAULT_OOM;
 181                         goto out_io_unlock;
 182                 }
 183         }
 184
 185         /*
 186          * Speculatively prefault a number of pages. Only error on
 187          * first page.
 188          */
 189         for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
 190                 if (bo->mem.bus.is_iomem)
 191                         pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset;
 192                 else {
 193                         page = ttm->pages[page_offset];
 194                         if (unlikely(!page && i == 0)) {
 195                                 retval = VM_FAULT_OOM;
 196                                 goto out_io_unlock;
 197                         } else if (unlikely(!page)) {
 198                                 break;
 199                         }
 200                         pfn = page_to_pfn(page);
 201                 }
 202
 203                 ret = vm_insert_mixed(vma, address, pfn);
 204                 /*
 205                  * Somebody beat us to this PTE or prefaulting to
 206                  * an already populated PTE, or prefaulting error.
 207                  */
 208
 209                 if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
 210                         break;
 211                 else if (unlikely(ret != 0)) {
 212                         retval =
 213                             (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
 214                         goto out_io_unlock;
 215                 }
 216
 217                 address += PAGE_SIZE;
 218                 if (unlikely(++page_offset >= page_last))
 219                         break;
 220         }
 221 out_io_unlock:
 222         ttm_mem_io_unlock(man);
 223 out_unlock:
 224         ttm_bo_unreserve(bo);
 225         return retval;
 226 }
 227
 228 static void ttm_bo_vm_open(struct vm_area_struct *vma)
 229 {
 230         struct ttm_buffer_object *bo =
 231             (struct ttm_buffer_object *)vma->vm_private_data;
 232
 233         (void)ttm_bo_reference(bo);
 234 }
 235
 236 static void ttm_bo_vm_close(struct vm_area_struct *vma)
 237 {
 238         struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
 239
 240         ttm_bo_unref(&bo);
 241         vma->vm_private_data = NULL;
 242 }
 243
 244 static const struct vm_operations_struct ttm_bo_vm_ops = {
 245         .fault = ttm_bo_vm_fault,
 246         .open = ttm_bo_vm_open,
 247         .close = ttm_bo_vm_close
 248 };
 249
 250 int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 251                 struct ttm_bo_device *bdev)
 252 {
 253         struct ttm_bo_driver *driver;
 254         struct ttm_buffer_object *bo;
 255         int ret;
 256
 257         read_lock(&bdev->vm_lock);
 258         bo = ttm_bo_vm_lookup_rb(bdev, vma->vm_pgoff,
 259                                  (vma->vm_end - vma->vm_start) >> PAGE_SHIFT);
 260         if (likely(bo != NULL))
 261                 ttm_bo_reference(bo);
 262         read_unlock(&bdev->vm_lock);
 263
 264         if (unlikely(bo == NULL)) {
 265                 printk(KERN_ERR TTM_PFX
 266                        "Could not find buffer object to map.\n");
 267                 return -EINVAL;
 268         }
 269
 270         driver = bo->bdev->driver;
 271         if (unlikely(!driver->verify_access)) {
 272                 ret = -EPERM;
 273                 goto out_unref;
 274         }
 275         ret = driver->verify_access(bo, filp);
 276         if (unlikely(ret != 0))
 277                 goto out_unref;
 278
 279         vma->vm_ops = &ttm_bo_vm_ops;
 280
 281         /*
 282          * Note: We're transferring the bo reference to
 283          * vma->vm_private_data here.
 284          */
 285
 286         vma->vm_private_data = bo;
 287         vma->vm_flags |= VM_RESERVED | VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
 288         return 0;
 289 out_unref:
 290         ttm_bo_unref(&bo);
 291         return ret;
 292 }
 293 EXPORT_SYMBOL(ttm_bo_mmap);
 294
 295 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 296 {
 297         if (vma->vm_pgoff != 0)
 298                 return -EACCES;
 299
 300         vma->vm_ops = &ttm_bo_vm_ops;
 301         vma->vm_private_data = ttm_bo_reference(bo);
 302         vma->vm_flags |= VM_RESERVED | VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
 303         return 0;
 304 }
 305 EXPORT_SYMBOL(ttm_fbdev_mmap);
 306
 307
 308 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
 309                   const char __user *wbuf, char __user *rbuf, size_t count,
 310                   loff_t *f_pos, bool write)
 311 {
 312         struct ttm_buffer_object *bo;
 313         struct ttm_bo_driver *driver;
 314         struct ttm_bo_kmap_obj map;
 315         unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
 316         unsigned long kmap_offset;
 317         unsigned long kmap_end;
 318         unsigned long kmap_num;
 319         size_t io_size;
 320         unsigned int page_offset;
 321         char *virtual;
 322         int ret;
 323         bool no_wait = false;
 324         bool dummy;
 325
 326         read_lock(&bdev->vm_lock);
 327         bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
 328         if (likely(bo != NULL))
 329                 ttm_bo_reference(bo);
 330         read_unlock(&bdev->vm_lock);
 331
 332         if (unlikely(bo == NULL))
 333                 return -EFAULT;
 334
 335         driver = bo->bdev->driver;
 336         if (unlikely(!driver->verify_access)) {
 337                 ret = -EPERM;
 338                 goto out_unref;
 339         }
 340
 341         ret = driver->verify_access(bo, filp);
 342         if (unlikely(ret != 0))
 343                 goto out_unref;
 344
 345         kmap_offset = dev_offset - bo->vm_node->start;
 346         if (unlikely(kmap_offset >= bo->num_pages)) {
 347                 ret = -EFBIG;
 348                 goto out_unref;
 349         }
 350
 351         page_offset = *f_pos & ~PAGE_MASK;
 352         io_size = bo->num_pages - kmap_offset;
 353         io_size = (io_size << PAGE_SHIFT) - page_offset;
 354         if (count < io_size)
 355                 io_size = count;
 356
 357         kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
 358         kmap_num = kmap_end - kmap_offset + 1;
 359
 360         ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
 361
 362         switch (ret) {
 363         case 0:
 364                 break;
 365         case -EBUSY:
 366                 ret = -EAGAIN;
 367                 goto out_unref;
 368         default:
 369                 goto out_unref;
 370         }
 371
 372         ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
 373         if (unlikely(ret != 0)) {
 374                 ttm_bo_unreserve(bo);
 375                 goto out_unref;
 376         }
 377
 378         virtual = ttm_kmap_obj_virtual(&map, &dummy);
 379         virtual += page_offset;
 380
 381         if (write)
 382                 ret = copy_from_user(virtual, wbuf, io_size);
 383         else
 384                 ret = copy_to_user(rbuf, virtual, io_size);
 385
 386         ttm_bo_kunmap(&map);
 387         ttm_bo_unreserve(bo);
 388         ttm_bo_unref(&bo);
 389
 390         if (unlikely(ret != 0))
 391                 return -EFBIG;
 392
 393         *f_pos += io_size;
 394
 395         return io_size;
 396 out_unref:
 397         ttm_bo_unref(&bo);
 398         return ret;
 399 }
 400
 401 ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf,
 402                         char __user *rbuf, size_t count, loff_t *f_pos,
 403                         bool write)
 404 {
 405         struct ttm_bo_kmap_obj map;
 406         unsigned long kmap_offset;
 407         unsigned long kmap_end;
 408         unsigned long kmap_num;
 409         size_t io_size;
 410         unsigned int page_offset;
 411         char *virtual;
 412         int ret;
 413         bool no_wait = false;
 414         bool dummy;
 415
 416         kmap_offset = (*f_pos >> PAGE_SHIFT);
 417         if (unlikely(kmap_offset >= bo->num_pages))
 418                 return -EFBIG;
 419
 420         page_offset = *f_pos & ~PAGE_MASK;
 421         io_size = bo->num_pages - kmap_offset;
 422         io_size = (io_size << PAGE_SHIFT) - page_offset;
 423         if (count < io_size)
 424                 io_size = count;
 425
 426         kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
 427         kmap_num = kmap_end - kmap_offset + 1;
 428
 429         ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
 430
 431         switch (ret) {
 432         case 0:
 433                 break;
 434         case -EBUSY:
 435                 return -EAGAIN;
 436         default:
 437                 return ret;
 438         }
 439
 440         ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
 441         if (unlikely(ret != 0)) {
 442                 ttm_bo_unreserve(bo);
 443                 return ret;
 444         }
 445
 446         virtual = ttm_kmap_obj_virtual(&map, &dummy);
 447         virtual += page_offset;
 448
 449         if (write)
 450                 ret = copy_from_user(virtual, wbuf, io_size);
 451         else
 452                 ret = copy_to_user(rbuf, virtual, io_size);
 453
 454         ttm_bo_kunmap(&map);
 455         ttm_bo_unreserve(bo);
 456         ttm_bo_unref(&bo);
 457
 458         if (unlikely(ret != 0))
 459                 return ret;
 460
 461         *f_pos += io_size;
 462
 463         return io_size;
 464 }