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 <drm/drm_vma_manager.h>
  37 #include <linux/mm.h>
  38 #include <linux/rbtree.h>
  39 #include <linux/module.h>
  40 #include <linux/uaccess.h>
  41
  42 #define TTM_BO_VM_NUM_PREFAULT 16
  43
  44 static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
  45                                 struct vm_area_struct *vma,
  46                                 struct vm_fault *vmf)
  47 {
  48         int ret = 0;
  49
  50         if (likely(!test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)))
  51                 goto out_unlock;
  52
  53         /*
  54          * Quick non-stalling check for idle.
  55          */
  56         ret = ttm_bo_wait(bo, false, false, true);
  57         if (likely(ret == 0))
  58                 goto out_unlock;
  59
  60         /*
  61          * If possible, avoid waiting for GPU with mmap_sem
  62          * held.
  63          */
  64         if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
  65                 ret = VM_FAULT_RETRY;
  66                 if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
  67                         goto out_unlock;
  68
  69                 ttm_bo_reference(bo);
  70                 up_read(&vma->vm_mm->mmap_sem);
  71                 (void) ttm_bo_wait(bo, false, true, false);
  72                 ttm_bo_unreserve(bo);
  73                 ttm_bo_unref(&bo);
  74                 goto out_unlock;
  75         }
  76
  77         /*
  78          * Ordinary wait.
  79          */
  80         ret = ttm_bo_wait(bo, false, true, false);
  81         if (unlikely(ret != 0))
  82                 ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
  83                         VM_FAULT_NOPAGE;
  84
  85 out_unlock:
  86         return ret;
  87 }
  88
  89 static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
  90 {
  91         struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
  92             vma->vm_private_data;
  93         struct ttm_bo_device *bdev = bo->bdev;
  94         unsigned long page_offset;
  95         unsigned long page_last;
  96         unsigned long pfn;
  97         struct ttm_tt *ttm = NULL;
  98         struct page *page;
  99         int ret;
 100         int i;
 101         unsigned long address = (unsigned long)vmf->virtual_address;
 102         int retval = VM_FAULT_NOPAGE;
 103         struct ttm_mem_type_manager *man =
 104                 &bdev->man[bo->mem.mem_type];
 105         struct vm_area_struct cvma;
 106
 107         /*
 108          * Work around locking order reversal in fault / nopfn
 109          * between mmap_sem and bo_reserve: Perform a trylock operation
 110          * for reserve, and if it fails, retry the fault after waiting
 111          * for the buffer to become unreserved.
 112          */
 113         ret = ttm_bo_reserve(bo, true, true, false, NULL);
 114         if (unlikely(ret != 0)) {
 115                 if (ret != -EBUSY)
 116                         return VM_FAULT_NOPAGE;
 117
 118                 if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
 119                         if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
 120                                 ttm_bo_reference(bo);
 121                                 up_read(&vma->vm_mm->mmap_sem);
 122                                 (void) ttm_bo_wait_unreserved(bo);
 123                                 ttm_bo_unref(&bo);
 124                         }
 125
 126                         return VM_FAULT_RETRY;
 127                 }
 128
 129                 /*
 130                  * If we'd want to change locking order to
 131                  * mmap_sem -> bo::reserve, we'd use a blocking reserve here
 132                  * instead of retrying the fault...
 133                  */
 134                 return VM_FAULT_NOPAGE;
 135         }
 136
 137         /*
 138          * Refuse to fault imported pages. This should be handled
 139          * (if at all) by redirecting mmap to the exporter.
 140          */
 141         if (bo->ttm && (bo->ttm->page_flags & TTM_PAGE_FLAG_SG)) {
 142                 retval = VM_FAULT_SIGBUS;
 143                 goto out_unlock;
 144         }
 145
 146         if (bdev->driver->fault_reserve_notify) {
 147                 ret = bdev->driver->fault_reserve_notify(bo);
 148                 switch (ret) {
 149                 case 0:
 150                         break;
 151                 case -EBUSY:
 152                 case -ERESTARTSYS:
 153                         retval = VM_FAULT_NOPAGE;
 154                         goto out_unlock;
 155                 default:
 156                         retval = VM_FAULT_SIGBUS;
 157                         goto out_unlock;
 158                 }
 159         }
 160
 161         /*
 162          * Wait for buffer data in transit, due to a pipelined
 163          * move.
 164          */
 165         ret = ttm_bo_vm_fault_idle(bo, vma, vmf);
 166         if (unlikely(ret != 0)) {
 167                 retval = ret;
 168
 169                 if (retval == VM_FAULT_RETRY &&
 170                     !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
 171                         /* The BO has already been unreserved. */
 172                         return retval;
 173                 }
 174
 175                 goto out_unlock;
 176         }
 177
 178         ret = ttm_mem_io_lock(man, true);
 179         if (unlikely(ret != 0)) {
 180                 retval = VM_FAULT_NOPAGE;
 181                 goto out_unlock;
 182         }
 183         ret = ttm_mem_io_reserve_vm(bo);
 184         if (unlikely(ret != 0)) {
 185                 retval = VM_FAULT_SIGBUS;
 186                 goto out_io_unlock;
 187         }
 188
 189         page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
 190                 vma->vm_pgoff - drm_vma_node_start(&bo->vma_node);
 191         page_last = vma_pages(vma) + vma->vm_pgoff -
 192                 drm_vma_node_start(&bo->vma_node);
 193
 194         if (unlikely(page_offset >= bo->num_pages)) {
 195                 retval = VM_FAULT_SIGBUS;
 196                 goto out_io_unlock;
 197         }
 198
 199         /*
 200          * Make a local vma copy to modify the page_prot member
 201          * and vm_flags if necessary. The vma parameter is protected
 202          * by mmap_sem in write mode.
 203          */
 204         cvma = *vma;
 205         cvma.vm_page_prot = vm_get_page_prot(cvma.vm_flags);
 206
 207         if (bo->mem.bus.is_iomem) {
 208                 cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
 209                                                 cvma.vm_page_prot);
 210         } else {
 211                 ttm = bo->ttm;
 212                 cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
 213                                                 cvma.vm_page_prot);
 214
 215                 /* Allocate all page at once, most common usage */
 216                 if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
 217                         retval = VM_FAULT_OOM;
 218                         goto out_io_unlock;
 219                 }
 220         }
 221
 222         /*
 223          * Speculatively prefault a number of pages. Only error on
 224          * first page.
 225          */
 226         for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
 227                 if (bo->mem.bus.is_iomem)
 228                         pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset;
 229                 else {
 230                         page = ttm->pages[page_offset];
 231                         if (unlikely(!page && i == 0)) {
 232                                 retval = VM_FAULT_OOM;
 233                                 goto out_io_unlock;
 234                         } else if (unlikely(!page)) {
 235                                 break;
 236                         }
 237                         page->mapping = vma->vm_file->f_mapping;
 238                         page->index = drm_vma_node_start(&bo->vma_node) +
 239                                 page_offset;
 240                         pfn = page_to_pfn(page);
 241                 }
 242
 243                 if (vma->vm_flags & VM_MIXEDMAP)
 244                         ret = vm_insert_mixed(&cvma, address, pfn);
 245                 else
 246                         ret = vm_insert_pfn(&cvma, address, pfn);
 247
 248                 /*
 249                  * Somebody beat us to this PTE or prefaulting to
 250                  * an already populated PTE, or prefaulting error.
 251                  */
 252
 253                 if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
 254                         break;
 255                 else if (unlikely(ret != 0)) {
 256                         retval =
 257                             (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
 258                         goto out_io_unlock;
 259                 }
 260
 261                 address += PAGE_SIZE;
 262                 if (unlikely(++page_offset >= page_last))
 263                         break;
 264         }
 265 out_io_unlock:
 266         ttm_mem_io_unlock(man);
 267 out_unlock:
 268         ttm_bo_unreserve(bo);
 269         return retval;
 270 }
 271
 272 static void ttm_bo_vm_open(struct vm_area_struct *vma)
 273 {
 274         struct ttm_buffer_object *bo =
 275             (struct ttm_buffer_object *)vma->vm_private_data;
 276
 277         WARN_ON(bo->bdev->dev_mapping != vma->vm_file->f_mapping);
 278
 279         (void)ttm_bo_reference(bo);
 280 }
 281
 282 static void ttm_bo_vm_close(struct vm_area_struct *vma)
 283 {
 284         struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
 285
 286         ttm_bo_unref(&bo);
 287         vma->vm_private_data = NULL;
 288 }
 289
 290 static const struct vm_operations_struct ttm_bo_vm_ops = {
 291         .fault = ttm_bo_vm_fault,
 292         .open = ttm_bo_vm_open,
 293         .close = ttm_bo_vm_close
 294 };
 295
 296 static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,
 297                                                   unsigned long offset,
 298                                                   unsigned long pages)
 299 {
 300         struct drm_vma_offset_node *node;
 301         struct ttm_buffer_object *bo = NULL;
 302
 303         drm_vma_offset_lock_lookup(&bdev->vma_manager);
 304
 305         node = drm_vma_offset_lookup_locked(&bdev->vma_manager, offset, pages);
 306         if (likely(node)) {
 307                 bo = container_of(node, struct ttm_buffer_object, vma_node);
 308                 if (!kref_get_unless_zero(&bo->kref))
 309                         bo = NULL;
 310         }
 311
 312         drm_vma_offset_unlock_lookup(&bdev->vma_manager);
 313
 314         if (!bo)
 315                 pr_err("Could not find buffer object to map\n");
 316
 317         return bo;
 318 }
 319
 320 int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 321                 struct ttm_bo_device *bdev)
 322 {
 323         struct ttm_bo_driver *driver;
 324         struct ttm_buffer_object *bo;
 325         int ret;
 326
 327         bo = ttm_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
 328         if (unlikely(!bo))
 329                 return -EINVAL;
 330
 331         driver = bo->bdev->driver;
 332         if (unlikely(!driver->verify_access)) {
 333                 ret = -EPERM;
 334                 goto out_unref;
 335         }
 336         ret = driver->verify_access(bo, filp);
 337         if (unlikely(ret != 0))
 338                 goto out_unref;
 339
 340         vma->vm_ops = &ttm_bo_vm_ops;
 341
 342         /*
 343          * Note: We're transferring the bo reference to
 344          * vma->vm_private_data here.
 345          */
 346
 347         vma->vm_private_data = bo;
 348
 349         /*
 350          * We'd like to use VM_PFNMAP on shared mappings, where
 351          * (vma->vm_flags & VM_SHARED) != 0, for performance reasons,
 352          * but for some reason VM_PFNMAP + x86 PAT + write-combine is very
 353          * bad for performance. Until that has been sorted out, use
 354          * VM_MIXEDMAP on all mappings. See freedesktop.org bug #75719
 355          */
 356         vma->vm_flags |= VM_MIXEDMAP;
 357         vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
 358         return 0;
 359 out_unref:
 360         ttm_bo_unref(&bo);
 361         return ret;
 362 }
 363 EXPORT_SYMBOL(ttm_bo_mmap);
 364
 365 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 366 {
 367         if (vma->vm_pgoff != 0)
 368                 return -EACCES;
 369
 370         vma->vm_ops = &ttm_bo_vm_ops;
 371         vma->vm_private_data = ttm_bo_reference(bo);
 372         vma->vm_flags |= VM_MIXEDMAP;
 373         vma->vm_flags |= VM_IO | VM_DONTEXPAND;
 374         return 0;
 375 }
 376 EXPORT_SYMBOL(ttm_fbdev_mmap);