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         if (bdev->driver->fault_reserve_notify) {
 136                 ret = bdev->driver->fault_reserve_notify(bo);
 137                 switch (ret) {
 138                 case 0:
 139                         break;
 140                 case -EBUSY:
 141                 case -ERESTARTSYS:
 142                         retval = VM_FAULT_NOPAGE;
 143                         goto out_unlock;
 144                 default:
 145                         retval = VM_FAULT_SIGBUS;
 146                         goto out_unlock;
 147                 }
 148         }
 149
 150         /*
 151          * Wait for buffer data in transit, due to a pipelined
 152          * move.
 153          */
 154         ret = ttm_bo_vm_fault_idle(bo, vma, vmf);
 155         if (unlikely(ret != 0)) {
 156                 retval = ret;
 157                 goto out_unlock;
 158         }
 159
 160         ret = ttm_mem_io_lock(man, true);
 161         if (unlikely(ret != 0)) {
 162                 retval = VM_FAULT_NOPAGE;
 163                 goto out_unlock;
 164         }
 165         ret = ttm_mem_io_reserve_vm(bo);
 166         if (unlikely(ret != 0)) {
 167                 retval = VM_FAULT_SIGBUS;
 168                 goto out_io_unlock;
 169         }
 170
 171         page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
 172                 vma->vm_pgoff - drm_vma_node_start(&bo->vma_node);
 173         page_last = vma_pages(vma) + vma->vm_pgoff -
 174                 drm_vma_node_start(&bo->vma_node);
 175
 176         if (unlikely(page_offset >= bo->num_pages)) {
 177                 retval = VM_FAULT_SIGBUS;
 178                 goto out_io_unlock;
 179         }
 180
 181         /*
 182          * Make a local vma copy to modify the page_prot member
 183          * and vm_flags if necessary. The vma parameter is protected
 184          * by mmap_sem in write mode.
 185          */
 186         cvma = *vma;
 187         cvma.vm_page_prot = vm_get_page_prot(cvma.vm_flags);
 188
 189         if (bo->mem.bus.is_iomem) {
 190                 cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
 191                                                 cvma.vm_page_prot);
 192         } else {
 193                 ttm = bo->ttm;
 194                 if (!(bo->mem.placement & TTM_PL_FLAG_CACHED))
 195                         cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
 196                                                         cvma.vm_page_prot);
 197
 198                 /* Allocate all page at once, most common usage */
 199                 if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
 200                         retval = VM_FAULT_OOM;
 201                         goto out_io_unlock;
 202                 }
 203         }
 204
 205         /*
 206          * Speculatively prefault a number of pages. Only error on
 207          * first page.
 208          */
 209         for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
 210                 if (bo->mem.bus.is_iomem)
 211                         pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset;
 212                 else {
 213                         page = ttm->pages[page_offset];
 214                         if (unlikely(!page && i == 0)) {
 215                                 retval = VM_FAULT_OOM;
 216                                 goto out_io_unlock;
 217                         } else if (unlikely(!page)) {
 218                                 break;
 219                         }
 220                         pfn = page_to_pfn(page);
 221                 }
 222
 223                 ret = vm_insert_mixed(&cvma, address, pfn);
 224                 /*
 225                  * Somebody beat us to this PTE or prefaulting to
 226                  * an already populated PTE, or prefaulting error.
 227                  */
 228
 229                 if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
 230                         break;
 231                 else if (unlikely(ret != 0)) {
 232                         retval =
 233                             (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
 234                         goto out_io_unlock;
 235                 }
 236
 237                 address += PAGE_SIZE;
 238                 if (unlikely(++page_offset >= page_last))
 239                         break;
 240         }
 241 out_io_unlock:
 242         ttm_mem_io_unlock(man);
 243 out_unlock:
 244         ttm_bo_unreserve(bo);
 245         return retval;
 246 }
 247
 248 static void ttm_bo_vm_open(struct vm_area_struct *vma)
 249 {
 250         struct ttm_buffer_object *bo =
 251             (struct ttm_buffer_object *)vma->vm_private_data;
 252
 253         (void)ttm_bo_reference(bo);
 254 }
 255
 256 static void ttm_bo_vm_close(struct vm_area_struct *vma)
 257 {
 258         struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
 259
 260         ttm_bo_unref(&bo);
 261         vma->vm_private_data = NULL;
 262 }
 263
 264 static const struct vm_operations_struct ttm_bo_vm_ops = {
 265         .fault = ttm_bo_vm_fault,
 266         .open = ttm_bo_vm_open,
 267         .close = ttm_bo_vm_close
 268 };
 269
 270 static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,
 271                                                   unsigned long offset,
 272                                                   unsigned long pages)
 273 {
 274         struct drm_vma_offset_node *node;
 275         struct ttm_buffer_object *bo = NULL;
 276
 277         drm_vma_offset_lock_lookup(&bdev->vma_manager);
 278
 279         node = drm_vma_offset_lookup_locked(&bdev->vma_manager, offset, pages);
 280         if (likely(node)) {
 281                 bo = container_of(node, struct ttm_buffer_object, vma_node);
 282                 if (!kref_get_unless_zero(&bo->kref))
 283                         bo = NULL;
 284         }
 285
 286         drm_vma_offset_unlock_lookup(&bdev->vma_manager);
 287
 288         if (!bo)
 289                 pr_err("Could not find buffer object to map\n");
 290
 291         return bo;
 292 }
 293
 294 int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 295                 struct ttm_bo_device *bdev)
 296 {
 297         struct ttm_bo_driver *driver;
 298         struct ttm_buffer_object *bo;
 299         int ret;
 300
 301         bo = ttm_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
 302         if (unlikely(!bo))
 303                 return -EINVAL;
 304
 305         driver = bo->bdev->driver;
 306         if (unlikely(!driver->verify_access)) {
 307                 ret = -EPERM;
 308                 goto out_unref;
 309         }
 310         ret = driver->verify_access(bo, filp);
 311         if (unlikely(ret != 0))
 312                 goto out_unref;
 313
 314         vma->vm_ops = &ttm_bo_vm_ops;
 315
 316         /*
 317          * Note: We're transferring the bo reference to
 318          * vma->vm_private_data here.
 319          */
 320
 321         vma->vm_private_data = bo;
 322         vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND | VM_DONTDUMP;
 323         return 0;
 324 out_unref:
 325         ttm_bo_unref(&bo);
 326         return ret;
 327 }
 328 EXPORT_SYMBOL(ttm_bo_mmap);
 329
 330 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 331 {
 332         if (vma->vm_pgoff != 0)
 333                 return -EACCES;
 334
 335         vma->vm_ops = &ttm_bo_vm_ops;
 336         vma->vm_private_data = ttm_bo_reference(bo);
 337         vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
 338         return 0;
 339 }
 340 EXPORT_SYMBOL(ttm_fbdev_mmap);