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