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 <drm/ttm/ttm_module.h>
  34 #include <drm/ttm/ttm_bo_driver.h>
  35 #include <drm/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 #include <linux/mem_encrypt.h>
  43
  44 #define TTM_BO_VM_NUM_PREFAULT 16
  45
  46 static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
  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 (dma_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                 ttm_bo_reference(bo);
  70                 up_read(&vmf->vma->vm_mm->mmap_sem);
  71                 (void) dma_fence_wait(bo->moving, true);
  72                 ttm_bo_unreserve(bo);
  73                 ttm_bo_unref(&bo);
  74                 goto out_unlock;
  75         }
  76
  77         /*
  78          * Ordinary wait.
  79          */
  80         ret = dma_fence_wait(bo->moving, true);
  81         if (unlikely(ret != 0)) {
  82                 ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
  83                         VM_FAULT_NOPAGE;
  84                 goto out_unlock;
  85         }
  86
  87 out_clear:
  88         dma_fence_put(bo->moving);
  89         bo->moving = NULL;
  90
  91 out_unlock:
  92         return ret;
  93 }
  94
  95 static int ttm_bo_vm_fault(struct vm_fault *vmf)
  96 {
  97         struct vm_area_struct *vma = vmf->vma;
  98         struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
  99             vma->vm_private_data;
 100         struct ttm_bo_device *bdev = bo->bdev;
 101         unsigned long page_offset;
 102         unsigned long page_last;
 103         unsigned long pfn;
 104         struct ttm_tt *ttm = NULL;
 105         struct page *page;
 106         int ret;
 107         int i;
 108         unsigned long address = vmf->address;
 109         int retval = VM_FAULT_NOPAGE;
 110         struct ttm_mem_type_manager *man =
 111                 &bdev->man[bo->mem.mem_type];
 112         struct vm_area_struct cvma;
 113
 114         /*
 115          * Work around locking order reversal in fault / nopfn
 116          * between mmap_sem and bo_reserve: Perform a trylock operation
 117          * for reserve, and if it fails, retry the fault after waiting
 118          * for the buffer to become unreserved.
 119          */
 120         ret = ttm_bo_reserve(bo, true, true, NULL);
 121         if (unlikely(ret != 0)) {
 122                 if (ret != -EBUSY)
 123                         return VM_FAULT_NOPAGE;
 124
 125                 if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
 126                         if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
 127                                 ttm_bo_reference(bo);
 128                                 up_read(&vmf->vma->vm_mm->mmap_sem);
 129                                 (void) ttm_bo_wait_unreserved(bo);
 130                                 ttm_bo_unref(&bo);
 131                         }
 132
 133                         return VM_FAULT_RETRY;
 134                 }
 135
 136                 /*
 137                  * If we'd want to change locking order to
 138                  * mmap_sem -> bo::reserve, we'd use a blocking reserve here
 139                  * instead of retrying the fault...
 140                  */
 141                 return VM_FAULT_NOPAGE;
 142         }
 143
 144         /*
 145          * Refuse to fault imported pages. This should be handled
 146          * (if at all) by redirecting mmap to the exporter.
 147          */
 148         if (bo->ttm && (bo->ttm->page_flags & TTM_PAGE_FLAG_SG)) {
 149                 retval = VM_FAULT_SIGBUS;
 150                 goto out_unlock;
 151         }
 152
 153         if (bdev->driver->fault_reserve_notify) {
 154                 ret = bdev->driver->fault_reserve_notify(bo);
 155                 switch (ret) {
 156                 case 0:
 157                         break;
 158                 case -EBUSY:
 159                 case -ERESTARTSYS:
 160                         retval = VM_FAULT_NOPAGE;
 161                         goto out_unlock;
 162                 default:
 163                         retval = VM_FAULT_SIGBUS;
 164                         goto out_unlock;
 165                 }
 166         }
 167
 168         /*
 169          * Wait for buffer data in transit, due to a pipelined
 170          * move.
 171          */
 172         ret = ttm_bo_vm_fault_idle(bo, vmf);
 173         if (unlikely(ret != 0)) {
 174                 retval = ret;
 175
 176                 if (retval == VM_FAULT_RETRY &&
 177                     !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
 178                         /* The BO has already been unreserved. */
 179                         return retval;
 180                 }
 181
 182                 goto out_unlock;
 183         }
 184
 185         ret = ttm_mem_io_lock(man, true);
 186         if (unlikely(ret != 0)) {
 187                 retval = VM_FAULT_NOPAGE;
 188                 goto out_unlock;
 189         }
 190         ret = ttm_mem_io_reserve_vm(bo);
 191         if (unlikely(ret != 0)) {
 192                 retval = VM_FAULT_SIGBUS;
 193                 goto out_io_unlock;
 194         }
 195
 196         page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
 197                 vma->vm_pgoff - drm_vma_node_start(&bo->vma_node);
 198         page_last = vma_pages(vma) + vma->vm_pgoff -
 199                 drm_vma_node_start(&bo->vma_node);
 200
 201         if (unlikely(page_offset >= bo->num_pages)) {
 202                 retval = VM_FAULT_SIGBUS;
 203                 goto out_io_unlock;
 204         }
 205
 206         /*
 207          * Make a local vma copy to modify the page_prot member
 208          * and vm_flags if necessary. The vma parameter is protected
 209          * by mmap_sem in write mode.
 210          */
 211         cvma = *vma;
 212         cvma.vm_page_prot = vm_get_page_prot(cvma.vm_flags);
 213
 214         if (bo->mem.bus.is_iomem) {
 215                 cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
 216                                                 cvma.vm_page_prot);
 217         } else {
 218                 ttm = bo->ttm;
 219                 cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
 220                                                 cvma.vm_page_prot);
 221
 222                 /* Allocate all page at once, most common usage */
 223                 if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
 224                         retval = VM_FAULT_OOM;
 225                         goto out_io_unlock;
 226                 }
 227         }
 228
 229         /*
 230          * Speculatively prefault a number of pages. Only error on
 231          * first page.
 232          */
 233         for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
 234                 if (bo->mem.bus.is_iomem) {
 235                         /* Iomem should not be marked encrypted */
 236                         cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot);
 237                         pfn = bdev->driver->io_mem_pfn(bo, page_offset);
 238                 } else {
 239                         page = ttm->pages[page_offset];
 240                         if (unlikely(!page && i == 0)) {
 241                                 retval = VM_FAULT_OOM;
 242                                 goto out_io_unlock;
 243                         } else if (unlikely(!page)) {
 244                                 break;
 245                         }
 246                         page->mapping = vma->vm_file->f_mapping;
 247                         page->index = drm_vma_node_start(&bo->vma_node) +
 248                                 page_offset;
 249                         pfn = page_to_pfn(page);
 250                 }
 251
 252                 if (vma->vm_flags & VM_MIXEDMAP)
 253                         ret = vm_insert_mixed(&cvma, address,
 254                                         __pfn_to_pfn_t(pfn, PFN_DEV));
 255                 else
 256                         ret = vm_insert_pfn(&cvma, address, pfn);
 257
 258                 /*
 259                  * Somebody beat us to this PTE or prefaulting to
 260                  * an already populated PTE, or prefaulting error.
 261                  */
 262
 263                 if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
 264                         break;
 265                 else if (unlikely(ret != 0)) {
 266                         retval =
 267                             (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
 268                         goto out_io_unlock;
 269                 }
 270
 271                 address += PAGE_SIZE;
 272                 if (unlikely(++page_offset >= page_last))
 273                         break;
 274         }
 275 out_io_unlock:
 276         ttm_mem_io_unlock(man);
 277 out_unlock:
 278         ttm_bo_unreserve(bo);
 279         return retval;
 280 }
 281
 282 static void ttm_bo_vm_open(struct vm_area_struct *vma)
 283 {
 284         struct ttm_buffer_object *bo =
 285             (struct ttm_buffer_object *)vma->vm_private_data;
 286
 287         WARN_ON(bo->bdev->dev_mapping != vma->vm_file->f_mapping);
 288
 289         (void)ttm_bo_reference(bo);
 290 }
 291
 292 static void ttm_bo_vm_close(struct vm_area_struct *vma)
 293 {
 294         struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
 295
 296         ttm_bo_unref(&bo);
 297         vma->vm_private_data = NULL;
 298 }
 299
 300 static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo,
 301                                  unsigned long offset,
 302                                  uint8_t *buf, int len, int write)
 303 {
 304         unsigned long page = offset >> PAGE_SHIFT;
 305         unsigned long bytes_left = len;
 306         int ret;
 307
 308         /* Copy a page at a time, that way no extra virtual address
 309          * mapping is needed
 310          */
 311         offset -= page << PAGE_SHIFT;
 312         do {
 313                 unsigned long bytes = min(bytes_left, PAGE_SIZE - offset);
 314                 struct ttm_bo_kmap_obj map;
 315                 void *ptr;
 316                 bool is_iomem;
 317
 318                 ret = ttm_bo_kmap(bo, page, 1, &map);
 319                 if (ret)
 320                         return ret;
 321
 322                 ptr = (uint8_t *)ttm_kmap_obj_virtual(&map, &is_iomem) + offset;
 323                 WARN_ON_ONCE(is_iomem);
 324                 if (write)
 325                         memcpy(ptr, buf, bytes);
 326                 else
 327                         memcpy(buf, ptr, bytes);
 328                 ttm_bo_kunmap(&map);
 329
 330                 page++;
 331                 buf += bytes;
 332                 bytes_left -= bytes;
 333                 offset = 0;
 334         } while (bytes_left);
 335
 336         return len;
 337 }
 338
 339 static int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
 340                             void *buf, int len, int write)
 341 {
 342         unsigned long offset = (addr) - vma->vm_start;
 343         struct ttm_buffer_object *bo = vma->vm_private_data;
 344         int ret;
 345
 346         if (len < 1 || (offset + len) >> PAGE_SHIFT > bo->num_pages)
 347                 return -EIO;
 348
 349         ret = ttm_bo_reserve(bo, true, false, NULL);
 350         if (ret)
 351                 return ret;
 352
 353         switch (bo->mem.mem_type) {
 354         case TTM_PL_SYSTEM:
 355                 if (unlikely(bo->ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 356                         ret = ttm_tt_swapin(bo->ttm);
 357                         if (unlikely(ret != 0))
 358                                 return ret;
 359                 }
 360                 /* fall through */
 361         case TTM_PL_TT:
 362                 ret = ttm_bo_vm_access_kmap(bo, offset, buf, len, write);
 363                 break;
 364         default:
 365                 if (bo->bdev->driver->access_memory)
 366                         ret = bo->bdev->driver->access_memory(
 367                                 bo, offset, buf, len, write);
 368                 else
 369                         ret = -EIO;
 370         }
 371
 372         ttm_bo_unreserve(bo);
 373
 374         return ret;
 375 }
 376
 377 static const struct vm_operations_struct ttm_bo_vm_ops = {
 378         .fault = ttm_bo_vm_fault,
 379         .open = ttm_bo_vm_open,
 380         .close = ttm_bo_vm_close,
 381         .access = ttm_bo_vm_access
 382 };
 383
 384 static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,
 385                                                   unsigned long offset,
 386                                                   unsigned long pages)
 387 {
 388         struct drm_vma_offset_node *node;
 389         struct ttm_buffer_object *bo = NULL;
 390
 391         drm_vma_offset_lock_lookup(&bdev->vma_manager);
 392
 393         node = drm_vma_offset_lookup_locked(&bdev->vma_manager, offset, pages);
 394         if (likely(node)) {
 395                 bo = container_of(node, struct ttm_buffer_object, vma_node);
 396                 if (!kref_get_unless_zero(&bo->kref))
 397                         bo = NULL;
 398         }
 399
 400         drm_vma_offset_unlock_lookup(&bdev->vma_manager);
 401
 402         if (!bo)
 403                 pr_err("Could not find buffer object to map\n");
 404
 405         return bo;
 406 }
 407
 408 unsigned long ttm_bo_default_io_mem_pfn(struct ttm_buffer_object *bo,
 409                                         unsigned long page_offset)
 410 {
 411         return ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT)
 412                 + page_offset;
 413 }
 414 EXPORT_SYMBOL(ttm_bo_default_io_mem_pfn);
 415
 416 int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 417                 struct ttm_bo_device *bdev)
 418 {
 419         struct ttm_bo_driver *driver;
 420         struct ttm_buffer_object *bo;
 421         int ret;
 422
 423         bo = ttm_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
 424         if (unlikely(!bo))
 425                 return -EINVAL;
 426
 427         driver = bo->bdev->driver;
 428         if (unlikely(!driver->verify_access)) {
 429                 ret = -EPERM;
 430                 goto out_unref;
 431         }
 432         ret = driver->verify_access(bo, filp);
 433         if (unlikely(ret != 0))
 434                 goto out_unref;
 435
 436         vma->vm_ops = &ttm_bo_vm_ops;
 437
 438         /*
 439          * Note: We're transferring the bo reference to
 440          * vma->vm_private_data here.
 441          */
 442
 443         vma->vm_private_data = bo;
 444
 445         /*
 446          * We'd like to use VM_PFNMAP on shared mappings, where
 447          * (vma->vm_flags & VM_SHARED) != 0, for performance reasons,
 448          * but for some reason VM_PFNMAP + x86 PAT + write-combine is very
 449          * bad for performance. Until that has been sorted out, use
 450          * VM_MIXEDMAP on all mappings. See freedesktop.org bug #75719
 451          */
 452         vma->vm_flags |= VM_MIXEDMAP;
 453         vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
 454         return 0;
 455 out_unref:
 456         ttm_bo_unref(&bo);
 457         return ret;
 458 }
 459 EXPORT_SYMBOL(ttm_bo_mmap);
 460
 461 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 462 {
 463         if (vma->vm_pgoff != 0)
 464                 return -EACCES;
 465
 466         vma->vm_ops = &ttm_bo_vm_ops;
 467         vma->vm_private_data = ttm_bo_reference(bo);
 468         vma->vm_flags |= VM_MIXEDMAP;
 469         vma->vm_flags |= VM_IO | VM_DONTEXPAND;
 470         return 0;
 471 }
 472 EXPORT_SYMBOL(ttm_fbdev_mmap);