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(struct vm_area_struct *vma, struct vm_fault *vmf)
  45 {
  46         struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
  47             vma->vm_private_data;
  48         struct ttm_bo_device *bdev = bo->bdev;
  49         unsigned long page_offset;
  50         unsigned long page_last;
  51         unsigned long pfn;
  52         struct ttm_tt *ttm = NULL;
  53         struct page *page;
  54         int ret;
  55         int i;
  56         unsigned long address = (unsigned long)vmf->virtual_address;
  57         int retval = VM_FAULT_NOPAGE;
  58         struct ttm_mem_type_manager *man =
  59                 &bdev->man[bo->mem.mem_type];
  60
  61         /*
  62          * Work around locking order reversal in fault / nopfn
  63          * between mmap_sem and bo_reserve: Perform a trylock operation
  64          * for reserve, and if it fails, retry the fault after scheduling.
  65          */
  66
  67         ret = ttm_bo_reserve(bo, true, true, false, 0);
  68         if (unlikely(ret != 0)) {
  69                 if (ret == -EBUSY)
  70                         set_need_resched();
  71                 return VM_FAULT_NOPAGE;
  72         }
  73
  74         if (bdev->driver->fault_reserve_notify) {
  75                 ret = bdev->driver->fault_reserve_notify(bo);
  76                 switch (ret) {
  77                 case 0:
  78                         break;
  79                 case -EBUSY:
  80                         set_need_resched();
  81                 case -ERESTARTSYS:
  82                         retval = VM_FAULT_NOPAGE;
  83                         goto out_unlock;
  84                 default:
  85                         retval = VM_FAULT_SIGBUS;
  86                         goto out_unlock;
  87                 }
  88         }
  89
  90         /*
  91          * Wait for buffer data in transit, due to a pipelined
  92          * move.
  93          */
  94
  95         spin_lock(&bdev->fence_lock);
  96         if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
  97                 ret = ttm_bo_wait(bo, false, true, false);
  98                 spin_unlock(&bdev->fence_lock);
  99                 if (unlikely(ret != 0)) {
 100                         retval = (ret != -ERESTARTSYS) ?
 101                             VM_FAULT_SIGBUS : VM_FAULT_NOPAGE;
 102                         goto out_unlock;
 103                 }
 104         } else
 105                 spin_unlock(&bdev->fence_lock);
 106
 107         ret = ttm_mem_io_lock(man, true);
 108         if (unlikely(ret != 0)) {
 109                 retval = VM_FAULT_NOPAGE;
 110                 goto out_unlock;
 111         }
 112         ret = ttm_mem_io_reserve_vm(bo);
 113         if (unlikely(ret != 0)) {
 114                 retval = VM_FAULT_SIGBUS;
 115                 goto out_io_unlock;
 116         }
 117
 118         page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
 119                 vma->vm_pgoff - drm_vma_node_start(&bo->vma_node);
 120         page_last = vma_pages(vma) + vma->vm_pgoff -
 121                 drm_vma_node_start(&bo->vma_node);
 122
 123         if (unlikely(page_offset >= bo->num_pages)) {
 124                 retval = VM_FAULT_SIGBUS;
 125                 goto out_io_unlock;
 126         }
 127
 128         /*
 129          * Strictly, we're not allowed to modify vma->vm_page_prot here,
 130          * since the mmap_sem is only held in read mode. However, we
 131          * modify only the caching bits of vma->vm_page_prot and
 132          * consider those bits protected by
 133          * the bo->mutex, as we should be the only writers.
 134          * There shouldn't really be any readers of these bits except
 135          * within vm_insert_mixed()? fork?
 136          *
 137          * TODO: Add a list of vmas to the bo, and change the
 138          * vma->vm_page_prot when the object changes caching policy, with
 139          * the correct locks held.
 140          */
 141         if (bo->mem.bus.is_iomem) {
 142                 vma->vm_page_prot = ttm_io_prot(bo->mem.placement,
 143                                                 vma->vm_page_prot);
 144         } else {
 145                 ttm = bo->ttm;
 146                 vma->vm_page_prot = (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
 147                     vm_get_page_prot(vma->vm_flags) :
 148                     ttm_io_prot(bo->mem.placement, vma->vm_page_prot);
 149
 150                 /* Allocate all page at once, most common usage */
 151                 if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
 152                         retval = VM_FAULT_OOM;
 153                         goto out_io_unlock;
 154                 }
 155         }
 156
 157         /*
 158          * Speculatively prefault a number of pages. Only error on
 159          * first page.
 160          */
 161         for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
 162                 if (bo->mem.bus.is_iomem)
 163                         pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset;
 164                 else {
 165                         page = ttm->pages[page_offset];
 166                         if (unlikely(!page && i == 0)) {
 167                                 retval = VM_FAULT_OOM;
 168                                 goto out_io_unlock;
 169                         } else if (unlikely(!page)) {
 170                                 break;
 171                         }
 172                         pfn = page_to_pfn(page);
 173                 }
 174
 175                 ret = vm_insert_mixed(vma, address, pfn);
 176                 /*
 177                  * Somebody beat us to this PTE or prefaulting to
 178                  * an already populated PTE, or prefaulting error.
 179                  */
 180
 181                 if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
 182                         break;
 183                 else if (unlikely(ret != 0)) {
 184                         retval =
 185                             (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
 186                         goto out_io_unlock;
 187                 }
 188
 189                 address += PAGE_SIZE;
 190                 if (unlikely(++page_offset >= page_last))
 191                         break;
 192         }
 193 out_io_unlock:
 194         ttm_mem_io_unlock(man);
 195 out_unlock:
 196         ttm_bo_unreserve(bo);
 197         return retval;
 198 }
 199
 200 static void ttm_bo_vm_open(struct vm_area_struct *vma)
 201 {
 202         struct ttm_buffer_object *bo =
 203             (struct ttm_buffer_object *)vma->vm_private_data;
 204
 205         (void)ttm_bo_reference(bo);
 206 }
 207
 208 static void ttm_bo_vm_close(struct vm_area_struct *vma)
 209 {
 210         struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
 211
 212         ttm_bo_unref(&bo);
 213         vma->vm_private_data = NULL;
 214 }
 215
 216 static const struct vm_operations_struct ttm_bo_vm_ops = {
 217         .fault = ttm_bo_vm_fault,
 218         .open = ttm_bo_vm_open,
 219         .close = ttm_bo_vm_close
 220 };
 221
 222 static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,
 223                                                   unsigned long offset,
 224                                                   unsigned long pages)
 225 {
 226         struct drm_vma_offset_node *node;
 227         struct ttm_buffer_object *bo = NULL;
 228
 229         drm_vma_offset_lock_lookup(&bdev->vma_manager);
 230
 231         node = drm_vma_offset_lookup_locked(&bdev->vma_manager, offset, pages);
 232         if (likely(node)) {
 233                 bo = container_of(node, struct ttm_buffer_object, vma_node);
 234                 if (!kref_get_unless_zero(&bo->kref))
 235                         bo = NULL;
 236         }
 237
 238         drm_vma_offset_unlock_lookup(&bdev->vma_manager);
 239
 240         if (!bo)
 241                 pr_err("Could not find buffer object to map\n");
 242
 243         return bo;
 244 }
 245
 246 int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 247                 struct ttm_bo_device *bdev)
 248 {
 249         struct ttm_bo_driver *driver;
 250         struct ttm_buffer_object *bo;
 251         int ret;
 252
 253         bo = ttm_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
 254         if (unlikely(!bo))
 255                 return -EINVAL;
 256
 257         driver = bo->bdev->driver;
 258         if (unlikely(!driver->verify_access)) {
 259                 ret = -EPERM;
 260                 goto out_unref;
 261         }
 262         ret = driver->verify_access(bo, filp);
 263         if (unlikely(ret != 0))
 264                 goto out_unref;
 265
 266         vma->vm_ops = &ttm_bo_vm_ops;
 267
 268         /*
 269          * Note: We're transferring the bo reference to
 270          * vma->vm_private_data here.
 271          */
 272
 273         vma->vm_private_data = bo;
 274         vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND | VM_DONTDUMP;
 275         return 0;
 276 out_unref:
 277         ttm_bo_unref(&bo);
 278         return ret;
 279 }
 280 EXPORT_SYMBOL(ttm_bo_mmap);
 281
 282 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 283 {
 284         if (vma->vm_pgoff != 0)
 285                 return -EACCES;
 286
 287         vma->vm_ops = &ttm_bo_vm_ops;
 288         vma->vm_private_data = ttm_bo_reference(bo);
 289         vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
 290         return 0;
 291 }
 292 EXPORT_SYMBOL(ttm_fbdev_mmap);