release/src-rt-6.x.4708/linux/linux-2.6.36/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
  87
  88         ret = ttm_bo_reserve(bo, true, true, false, 0);
  89         if (unlikely(ret != 0)) {
  90                 if (ret == -EBUSY)
  91                         set_need_resched();
  92                 return VM_FAULT_NOPAGE;
  93         }
  94
  95         if (bdev->driver->fault_reserve_notify) {
  96                 ret = bdev->driver->fault_reserve_notify(bo);
  97                 switch (ret) {
  98                 case 0:
  99                         break;
 100                 case -EBUSY:
 101                         set_need_resched();
 102                 case -ERESTARTSYS:
 103                         retval = VM_FAULT_NOPAGE;
 104                         goto out_unlock;
 105                 default:
 106                         retval = VM_FAULT_SIGBUS;
 107                         goto out_unlock;
 108                 }
 109         }
 110
 111         /*
 112          * Wait for buffer data in transit, due to a pipelined
 113          * move.
 114          */
 115
 116         spin_lock(&bo->lock);
 117         if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
 118                 ret = ttm_bo_wait(bo, false, true, false);
 119                 spin_unlock(&bo->lock);
 120                 if (unlikely(ret != 0)) {
 121                         retval = (ret != -ERESTARTSYS) ?
 122                             VM_FAULT_SIGBUS : VM_FAULT_NOPAGE;
 123                         goto out_unlock;
 124                 }
 125         } else
 126                 spin_unlock(&bo->lock);
 127
 128
 129         ret = ttm_mem_io_reserve(bdev, &bo->mem);
 130         if (ret) {
 131                 retval = VM_FAULT_SIGBUS;
 132                 goto out_unlock;
 133         }
 134
 135         page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
 136             bo->vm_node->start - vma->vm_pgoff;
 137         page_last = ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) +
 138             bo->vm_node->start - vma->vm_pgoff;
 139
 140         if (unlikely(page_offset >= bo->num_pages)) {
 141                 retval = VM_FAULT_SIGBUS;
 142                 goto out_unlock;
 143         }
 144
 145         /*
 146          * Strictly, we're not allowed to modify vma->vm_page_prot here,
 147          * since the mmap_sem is only held in read mode. However, we
 148          * modify only the caching bits of vma->vm_page_prot and
 149          * consider those bits protected by
 150          * the bo->mutex, as we should be the only writers.
 151          * There shouldn't really be any readers of these bits except
 152          * within vm_insert_mixed()? fork?
 153          *
 154          * TODO: Add a list of vmas to the bo, and change the
 155          * vma->vm_page_prot when the object changes caching policy, with
 156          * the correct locks held.
 157          */
 158         if (bo->mem.bus.is_iomem) {
 159                 vma->vm_page_prot = ttm_io_prot(bo->mem.placement,
 160                                                 vma->vm_page_prot);
 161         } else {
 162                 ttm = bo->ttm;
 163                 vma->vm_page_prot = (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
 164                     vm_get_page_prot(vma->vm_flags) :
 165                     ttm_io_prot(bo->mem.placement, vma->vm_page_prot);
 166         }
 167
 168         /*
 169          * Speculatively prefault a number of pages. Only error on
 170          * first page.
 171          */
 172
 173         for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
 174                 if (bo->mem.bus.is_iomem)
 175                         pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + 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                 address += PAGE_SIZE;
 202                 if (unlikely(++page_offset >= page_last))
 203                         break;
 204         }
 205
 206 out_unlock:
 207         ttm_bo_unreserve(bo);
 208         return retval;
 209 }
 210
 211 static void ttm_bo_vm_open(struct vm_area_struct *vma)
 212 {
 213         struct ttm_buffer_object *bo =
 214             (struct ttm_buffer_object *)vma->vm_private_data;
 215
 216         (void)ttm_bo_reference(bo);
 217 }
 218
 219 static void ttm_bo_vm_close(struct vm_area_struct *vma)
 220 {
 221         struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
 222
 223         ttm_bo_unref(&bo);
 224         vma->vm_private_data = NULL;
 225 }
 226
 227 static const struct vm_operations_struct ttm_bo_vm_ops = {
 228         .fault = ttm_bo_vm_fault,
 229         .open = ttm_bo_vm_open,
 230         .close = ttm_bo_vm_close
 231 };
 232
 233 int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 234                 struct ttm_bo_device *bdev)
 235 {
 236         struct ttm_bo_driver *driver;
 237         struct ttm_buffer_object *bo;
 238         int ret;
 239
 240         read_lock(&bdev->vm_lock);
 241         bo = ttm_bo_vm_lookup_rb(bdev, vma->vm_pgoff,
 242                                  (vma->vm_end - vma->vm_start) >> PAGE_SHIFT);
 243         if (likely(bo != NULL))
 244                 ttm_bo_reference(bo);
 245         read_unlock(&bdev->vm_lock);
 246
 247         if (unlikely(bo == NULL)) {
 248                 printk(KERN_ERR TTM_PFX
 249                        "Could not find buffer object to map.\n");
 250                 return -EINVAL;
 251         }
 252
 253         driver = bo->bdev->driver;
 254         if (unlikely(!driver->verify_access)) {
 255                 ret = -EPERM;
 256                 goto out_unref;
 257         }
 258         ret = driver->verify_access(bo, filp);
 259         if (unlikely(ret != 0))
 260                 goto out_unref;
 261
 262         vma->vm_ops = &ttm_bo_vm_ops;
 263
 264         /*
 265          * Note: We're transferring the bo reference to
 266          * vma->vm_private_data here.
 267          */
 268
 269         vma->vm_private_data = bo;
 270         vma->vm_flags |= VM_RESERVED | VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
 271         return 0;
 272 out_unref:
 273         ttm_bo_unref(&bo);
 274         return ret;
 275 }
 276 EXPORT_SYMBOL(ttm_bo_mmap);
 277
 278 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 279 {
 280         if (vma->vm_pgoff != 0)
 281                 return -EACCES;
 282
 283         vma->vm_ops = &ttm_bo_vm_ops;
 284         vma->vm_private_data = ttm_bo_reference(bo);
 285         vma->vm_flags |= VM_RESERVED | VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
 286         return 0;
 287 }
 288 EXPORT_SYMBOL(ttm_fbdev_mmap);
 289
 290
 291 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
 292                   const char __user *wbuf, char __user *rbuf, size_t count,
 293                   loff_t *f_pos, bool write)
 294 {
 295         struct ttm_buffer_object *bo;
 296         struct ttm_bo_driver *driver;
 297         struct ttm_bo_kmap_obj map;
 298         unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
 299         unsigned long kmap_offset;
 300         unsigned long kmap_end;
 301         unsigned long kmap_num;
 302         size_t io_size;
 303         unsigned int page_offset;
 304         char *virtual;
 305         int ret;
 306         bool no_wait = false;
 307         bool dummy;
 308
 309         read_lock(&bdev->vm_lock);
 310         bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
 311         if (likely(bo != NULL))
 312                 ttm_bo_reference(bo);
 313         read_unlock(&bdev->vm_lock);
 314
 315         if (unlikely(bo == NULL))
 316                 return -EFAULT;
 317
 318         driver = bo->bdev->driver;
 319         if (unlikely(!driver->verify_access)) {
 320                 ret = -EPERM;
 321                 goto out_unref;
 322         }
 323
 324         ret = driver->verify_access(bo, filp);
 325         if (unlikely(ret != 0))
 326                 goto out_unref;
 327
 328         kmap_offset = dev_offset - bo->vm_node->start;
 329         if (unlikely(kmap_offset >= bo->num_pages)) {
 330                 ret = -EFBIG;
 331                 goto out_unref;
 332         }
 333
 334         page_offset = *f_pos & ~PAGE_MASK;
 335         io_size = bo->num_pages - kmap_offset;
 336         io_size = (io_size << PAGE_SHIFT) - page_offset;
 337         if (count < io_size)
 338                 io_size = count;
 339
 340         kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
 341         kmap_num = kmap_end - kmap_offset + 1;
 342
 343         ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
 344
 345         switch (ret) {
 346         case 0:
 347                 break;
 348         case -EBUSY:
 349                 ret = -EAGAIN;
 350                 goto out_unref;
 351         default:
 352                 goto out_unref;
 353         }
 354
 355         ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
 356         if (unlikely(ret != 0)) {
 357                 ttm_bo_unreserve(bo);
 358                 goto out_unref;
 359         }
 360
 361         virtual = ttm_kmap_obj_virtual(&map, &dummy);
 362         virtual += page_offset;
 363
 364         if (write)
 365                 ret = copy_from_user(virtual, wbuf, io_size);
 366         else
 367                 ret = copy_to_user(rbuf, virtual, io_size);
 368
 369         ttm_bo_kunmap(&map);
 370         ttm_bo_unreserve(bo);
 371         ttm_bo_unref(&bo);
 372
 373         if (unlikely(ret != 0))
 374                 return -EFBIG;
 375
 376         *f_pos += io_size;
 377
 378         return io_size;
 379 out_unref:
 380         ttm_bo_unref(&bo);
 381         return ret;
 382 }
 383
 384 ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf,
 385                         char __user *rbuf, size_t count, loff_t *f_pos,
 386                         bool write)
 387 {
 388         struct ttm_bo_kmap_obj map;
 389         unsigned long kmap_offset;
 390         unsigned long kmap_end;
 391         unsigned long kmap_num;
 392         size_t io_size;
 393         unsigned int page_offset;
 394         char *virtual;
 395         int ret;
 396         bool no_wait = false;
 397         bool dummy;
 398
 399         kmap_offset = (*f_pos >> PAGE_SHIFT);
 400         if (unlikely(kmap_offset >= bo->num_pages))
 401                 return -EFBIG;
 402
 403         page_offset = *f_pos & ~PAGE_MASK;
 404         io_size = bo->num_pages - kmap_offset;
 405         io_size = (io_size << PAGE_SHIFT) - page_offset;
 406         if (count < io_size)
 407                 io_size = count;
 408
 409         kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
 410         kmap_num = kmap_end - kmap_offset + 1;
 411
 412         ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
 413
 414         switch (ret) {
 415         case 0:
 416                 break;
 417         case -EBUSY:
 418                 return -EAGAIN;
 419         default:
 420                 return ret;
 421         }
 422
 423         ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
 424         if (unlikely(ret != 0)) {
 425                 ttm_bo_unreserve(bo);
 426                 return ret;
 427         }
 428
 429         virtual = ttm_kmap_obj_virtual(&map, &dummy);
 430         virtual += page_offset;
 431
 432         if (write)
 433                 ret = copy_from_user(virtual, wbuf, io_size);
 434         else
 435                 ret = copy_to_user(rbuf, virtual, io_size);
 436
 437         ttm_bo_kunmap(&map);
 438         ttm_bo_unreserve(bo);
 439         ttm_bo_unref(&bo);
 440
 441         if (unlikely(ret != 0))
 442                 return ret;
 443
 444         *f_pos += io_size;
 445
 446         return io_size;
 447 }