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             drm_vma_node_start(&bo->vma_node) - vma->vm_pgoff;
 182         page_last = vma_pages(vma) +
 183             drm_vma_node_start(&bo->vma_node) - vma->vm_pgoff;
 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                         pfn = page_to_pfn(page);
 230                 }
 231
 232                 if (vma->vm_flags & VM_MIXEDMAP)
 233                         ret = vm_insert_mixed(&cvma, address, pfn);
 234                 else
 235                         ret = vm_insert_pfn(&cvma, address, pfn);
 236
 237                 /*
 238                  * Somebody beat us to this PTE or prefaulting to
 239                  * an already populated PTE, or prefaulting error.
 240                  */
 241
 242                 if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
 243                         break;
 244                 else if (unlikely(ret != 0)) {
 245                         retval =
 246                             (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
 247                         goto out_io_unlock;
 248                 }
 249
 250                 address += PAGE_SIZE;
 251                 if (unlikely(++page_offset >= page_last))
 252                         break;
 253         }
 254 out_io_unlock:
 255         ttm_mem_io_unlock(man);
 256 out_unlock:
 257         ttm_bo_unreserve(bo);
 258         return retval;
 259 }
 260
 261 static void ttm_bo_vm_open(struct vm_area_struct *vma)
 262 {
 263         struct ttm_buffer_object *bo =
 264             (struct ttm_buffer_object *)vma->vm_private_data;
 265
 266         (void)ttm_bo_reference(bo);
 267 }
 268
 269 static void ttm_bo_vm_close(struct vm_area_struct *vma)
 270 {
 271         struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
 272
 273         ttm_bo_unref(&bo);
 274         vma->vm_private_data = NULL;
 275 }
 276
 277 static const struct vm_operations_struct ttm_bo_vm_ops = {
 278         .fault = ttm_bo_vm_fault,
 279         .open = ttm_bo_vm_open,
 280         .close = ttm_bo_vm_close
 281 };
 282
 283 static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,
 284                                                   unsigned long offset,
 285                                                   unsigned long pages)
 286 {
 287         struct drm_vma_offset_node *node;
 288         struct ttm_buffer_object *bo = NULL;
 289
 290         drm_vma_offset_lock_lookup(&bdev->vma_manager);
 291
 292         node = drm_vma_offset_lookup_locked(&bdev->vma_manager, offset, pages);
 293         if (likely(node)) {
 294                 bo = container_of(node, struct ttm_buffer_object, vma_node);
 295                 if (!kref_get_unless_zero(&bo->kref))
 296                         bo = NULL;
 297         }
 298
 299         drm_vma_offset_unlock_lookup(&bdev->vma_manager);
 300
 301         if (!bo)
 302                 pr_err("Could not find buffer object to map\n");
 303
 304         return bo;
 305 }
 306
 307 int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 308                 struct ttm_bo_device *bdev)
 309 {
 310         struct ttm_bo_driver *driver;
 311         struct ttm_buffer_object *bo;
 312         int ret;
 313
 314         bo = ttm_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
 315         if (unlikely(!bo))
 316                 return -EINVAL;
 317
 318         driver = bo->bdev->driver;
 319         if (unlikely(!driver->verify_access)) {
 320                 ret = -EPERM;
 321                 goto out_unref;
 322         }
 323         ret = driver->verify_access(bo, filp);
 324         if (unlikely(ret != 0))
 325                 goto out_unref;
 326
 327         vma->vm_ops = &ttm_bo_vm_ops;
 328
 329         /*
 330          * Note: We're transferring the bo reference to
 331          * vma->vm_private_data here.
 332          */
 333
 334         vma->vm_private_data = bo;
 335
 336         /*
 337          * PFNMAP is faster than MIXEDMAP due to reduced page
 338          * administration. So use MIXEDMAP only if private VMA, where
 339          * we need to support COW.
 340          */
 341         vma->vm_flags |= (vma->vm_flags & VM_SHARED) ? VM_PFNMAP : VM_MIXEDMAP;
 342         vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
 343         return 0;
 344 out_unref:
 345         ttm_bo_unref(&bo);
 346         return ret;
 347 }
 348 EXPORT_SYMBOL(ttm_bo_mmap);
 349
 350 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 351 {
 352         if (vma->vm_pgoff != 0)
 353                 return -EACCES;
 354
 355         vma->vm_ops = &ttm_bo_vm_ops;
 356         vma->vm_private_data = ttm_bo_reference(bo);
 357         vma->vm_flags |= (vma->vm_flags & VM_SHARED) ? VM_PFNMAP : VM_MIXEDMAP;
 358         vma->vm_flags |= VM_IO | VM_DONTEXPAND;
 359         return 0;
 360 }
 361 EXPORT_SYMBOL(ttm_fbdev_mmap);