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