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