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