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
 106         /*
 107          * Work around locking order reversal in fault / nopfn
 108          * between mmap_sem and bo_reserve: Perform a trylock operation
 109          * for reserve, and if it fails, retry the fault after scheduling.
 110          */
 111
 112         ret = ttm_bo_reserve(bo, true, true, false, 0);
 113         if (unlikely(ret != 0)) {
 114                 if (ret == -EBUSY)
 115                         set_need_resched();
 116                 return VM_FAULT_NOPAGE;
 117         }
 118
 119         if (bdev->driver->fault_reserve_notify) {
 120                 ret = bdev->driver->fault_reserve_notify(bo);
 121                 switch (ret) {
 122                 case 0:
 123                         break;
 124                 case -EBUSY:
 125                         set_need_resched();
 126                 case -ERESTARTSYS:
 127                         retval = VM_FAULT_NOPAGE;
 128                         goto out_unlock;
 129                 default:
 130                         retval = VM_FAULT_SIGBUS;
 131                         goto out_unlock;
 132                 }
 133         }
 134
 135         /*
 136          * Wait for buffer data in transit, due to a pipelined
 137          * move.
 138          */
 139         ret = ttm_bo_vm_fault_idle(bo, vma, vmf);
 140         if (unlikely(ret != 0)) {
 141                 retval = ret;
 142                 goto out_unlock;
 143         }
 144
 145         ret = ttm_mem_io_lock(man, true);
 146         if (unlikely(ret != 0)) {
 147                 retval = VM_FAULT_NOPAGE;
 148                 goto out_unlock;
 149         }
 150         ret = ttm_mem_io_reserve_vm(bo);
 151         if (unlikely(ret != 0)) {
 152                 retval = VM_FAULT_SIGBUS;
 153                 goto out_io_unlock;
 154         }
 155
 156         page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
 157             drm_vma_node_start(&bo->vma_node) - vma->vm_pgoff;
 158         page_last = vma_pages(vma) +
 159             drm_vma_node_start(&bo->vma_node) - vma->vm_pgoff;
 160
 161         if (unlikely(page_offset >= bo->num_pages)) {
 162                 retval = VM_FAULT_SIGBUS;
 163                 goto out_io_unlock;
 164         }
 165
 166         /*
 167          * Strictly, we're not allowed to modify vma->vm_page_prot here,
 168          * since the mmap_sem is only held in read mode. However, we
 169          * modify only the caching bits of vma->vm_page_prot and
 170          * consider those bits protected by
 171          * the bo->mutex, as we should be the only writers.
 172          * There shouldn't really be any readers of these bits except
 173          * within vm_insert_mixed()? fork?
 174          *
 175          * TODO: Add a list of vmas to the bo, and change the
 176          * vma->vm_page_prot when the object changes caching policy, with
 177          * the correct locks held.
 178          */
 179         if (bo->mem.bus.is_iomem) {
 180                 vma->vm_page_prot = ttm_io_prot(bo->mem.placement,
 181                                                 vma->vm_page_prot);
 182         } else {
 183                 ttm = bo->ttm;
 184                 vma->vm_page_prot = (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
 185                     vm_get_page_prot(vma->vm_flags) :
 186                     ttm_io_prot(bo->mem.placement, vma->vm_page_prot);
 187
 188                 /* Allocate all page at once, most common usage */
 189                 if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
 190                         retval = VM_FAULT_OOM;
 191                         goto out_io_unlock;
 192                 }
 193         }
 194
 195         /*
 196          * Speculatively prefault a number of pages. Only error on
 197          * first page.
 198          */
 199         for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
 200                 if (bo->mem.bus.is_iomem)
 201                         pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset;
 202                 else {
 203                         page = ttm->pages[page_offset];
 204                         if (unlikely(!page && i == 0)) {
 205                                 retval = VM_FAULT_OOM;
 206                                 goto out_io_unlock;
 207                         } else if (unlikely(!page)) {
 208                                 break;
 209                         }
 210                         pfn = page_to_pfn(page);
 211                 }
 212
 213                 ret = vm_insert_mixed(vma, address, pfn);
 214                 /*
 215                  * Somebody beat us to this PTE or prefaulting to
 216                  * an already populated PTE, or prefaulting error.
 217                  */
 218
 219                 if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
 220                         break;
 221                 else if (unlikely(ret != 0)) {
 222                         retval =
 223                             (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
 224                         goto out_io_unlock;
 225                 }
 226
 227                 address += PAGE_SIZE;
 228                 if (unlikely(++page_offset >= page_last))
 229                         break;
 230         }
 231 out_io_unlock:
 232         ttm_mem_io_unlock(man);
 233 out_unlock:
 234         ttm_bo_unreserve(bo);
 235         return retval;
 236 }
 237
 238 static void ttm_bo_vm_open(struct vm_area_struct *vma)
 239 {
 240         struct ttm_buffer_object *bo =
 241             (struct ttm_buffer_object *)vma->vm_private_data;
 242
 243         (void)ttm_bo_reference(bo);
 244 }
 245
 246 static void ttm_bo_vm_close(struct vm_area_struct *vma)
 247 {
 248         struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
 249
 250         ttm_bo_unref(&bo);
 251         vma->vm_private_data = NULL;
 252 }
 253
 254 static const struct vm_operations_struct ttm_bo_vm_ops = {
 255         .fault = ttm_bo_vm_fault,
 256         .open = ttm_bo_vm_open,
 257         .close = ttm_bo_vm_close
 258 };
 259
 260 static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,
 261                                                   unsigned long offset,
 262                                                   unsigned long pages)
 263 {
 264         struct drm_vma_offset_node *node;
 265         struct ttm_buffer_object *bo = NULL;
 266
 267         drm_vma_offset_lock_lookup(&bdev->vma_manager);
 268
 269         node = drm_vma_offset_lookup_locked(&bdev->vma_manager, offset, pages);
 270         if (likely(node)) {
 271                 bo = container_of(node, struct ttm_buffer_object, vma_node);
 272                 if (!kref_get_unless_zero(&bo->kref))
 273                         bo = NULL;
 274         }
 275
 276         drm_vma_offset_unlock_lookup(&bdev->vma_manager);
 277
 278         if (!bo)
 279                 pr_err("Could not find buffer object to map\n");
 280
 281         return bo;
 282 }
 283
 284 int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 285                 struct ttm_bo_device *bdev)
 286 {
 287         struct ttm_bo_driver *driver;
 288         struct ttm_buffer_object *bo;
 289         int ret;
 290
 291         bo = ttm_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
 292         if (unlikely(!bo))
 293                 return -EINVAL;
 294
 295         driver = bo->bdev->driver;
 296         if (unlikely(!driver->verify_access)) {
 297                 ret = -EPERM;
 298                 goto out_unref;
 299         }
 300         ret = driver->verify_access(bo, filp);
 301         if (unlikely(ret != 0))
 302                 goto out_unref;
 303
 304         vma->vm_ops = &ttm_bo_vm_ops;
 305
 306         /*
 307          * Note: We're transferring the bo reference to
 308          * vma->vm_private_data here.
 309          */
 310
 311         vma->vm_private_data = bo;
 312         vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND | VM_DONTDUMP;
 313         return 0;
 314 out_unref:
 315         ttm_bo_unref(&bo);
 316         return ret;
 317 }
 318 EXPORT_SYMBOL(ttm_bo_mmap);
 319
 320 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 321 {
 322         if (vma->vm_pgoff != 0)
 323                 return -EACCES;
 324
 325         vma->vm_ops = &ttm_bo_vm_ops;
 326         vma->vm_private_data = ttm_bo_reference(bo);
 327         vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
 328         return 0;
 329 }
 330 EXPORT_SYMBOL(ttm_fbdev_mmap);