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