sys/dev/drm2/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  * Copyright (c) 2013 The FreeBSD Foundation
  32  * All rights reserved.
  33  *
  34  * Portions of this software were developed by Konstantin Belousov
  35  * <kib@FreeBSD.org> under sponsorship from the FreeBSD Foundation.
  36  */
  37
  38 #include <sys/cdefs.h>
  39 __FBSDID("$FreeBSD$");
  40
  41 #include "opt_vm.h"
  42
  43 #include <dev/drm2/drmP.h>
  44 #include <dev/drm2/ttm/ttm_module.h>
  45 #include <dev/drm2/ttm/ttm_bo_driver.h>
  46 #include <dev/drm2/ttm/ttm_placement.h>
  47
  48 #include <vm/vm.h>
  49 #include <vm/vm_page.h>
  50 #include <vm/vm_pageout.h>
  51
  52 #define TTM_BO_VM_NUM_PREFAULT 16
  53
  54 RB_GENERATE(ttm_bo_device_buffer_objects, ttm_buffer_object, vm_rb,
  55     ttm_bo_cmp_rb_tree_items);
  56
  57 int
  58 ttm_bo_cmp_rb_tree_items(struct ttm_buffer_object *a,
  59     struct ttm_buffer_object *b)
  60 {
  61
  62         if (a->vm_node->start < b->vm_node->start) {
  63                 return (-1);
  64         } else if (a->vm_node->start > b->vm_node->start) {
  65                 return (1);
  66         } else {
  67                 return (0);
  68         }
  69 }
  70
  71 static struct ttm_buffer_object *ttm_bo_vm_lookup_rb(struct ttm_bo_device *bdev,
  72                                                      unsigned long page_start,
  73                                                      unsigned long num_pages)
  74 {
  75         unsigned long cur_offset;
  76         struct ttm_buffer_object *bo;
  77         struct ttm_buffer_object *best_bo = NULL;
  78
  79         bo = RB_ROOT(&bdev->addr_space_rb);
  80         while (bo != NULL) {
  81                 cur_offset = bo->vm_node->start;
  82                 if (page_start >= cur_offset) {
  83                         best_bo = bo;
  84                         if (page_start == cur_offset)
  85                                 break;
  86                         bo = RB_RIGHT(bo, vm_rb);
  87                 } else
  88                         bo = RB_LEFT(bo, vm_rb);
  89         }
  90
  91         if (unlikely(best_bo == NULL))
  92                 return NULL;
  93
  94         if (unlikely((best_bo->vm_node->start + best_bo->num_pages) <
  95                      (page_start + num_pages)))
  96                 return NULL;
  97
  98         return best_bo;
  99 }
 100
 101 static int
 102 ttm_bo_vm_fault(vm_object_t vm_obj, vm_ooffset_t offset,
 103     int prot, vm_page_t *mres)
 104 {
 105
 106         struct ttm_buffer_object *bo = vm_obj->handle;
 107         struct ttm_bo_device *bdev = bo->bdev;
 108         struct ttm_tt *ttm = NULL;
 109         vm_page_t m, m1;
 110         int ret;
 111         int retval = VM_PAGER_OK;
 112         struct ttm_mem_type_manager *man =
 113                 &bdev->man[bo->mem.mem_type];
 114
 115         vm_object_pip_add(vm_obj, 1);
 116         if (*mres != NULL) {
 117                 vm_page_lock(*mres);
 118                 vm_page_remove(*mres);
 119                 vm_page_unlock(*mres);
 120         }
 121 retry:
 122         VM_OBJECT_WUNLOCK(vm_obj);
 123         m = NULL;
 124
 125 reserve:
 126         ret = ttm_bo_reserve(bo, false, false, false, 0);
 127         if (unlikely(ret != 0)) {
 128                 if (ret == -EBUSY) {
 129                         kern_yield(0);
 130                         goto reserve;
 131                 }
 132         }
 133
 134         if (bdev->driver->fault_reserve_notify) {
 135                 ret = bdev->driver->fault_reserve_notify(bo);
 136                 switch (ret) {
 137                 case 0:
 138                         break;
 139                 case -EBUSY:
 140                 case -ERESTARTSYS:
 141                 case -EINTR:
 142                         kern_yield(0);
 143                         goto reserve;
 144                 default:
 145                         retval = VM_PAGER_ERROR;
 146                         goto out_unlock;
 147                 }
 148         }
 149
 150         /*
 151          * Wait for buffer data in transit, due to a pipelined
 152          * move.
 153          */
 154
 155         mtx_lock(&bdev->fence_lock);
 156         if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
 157                 /*
 158                  * Here, the behavior differs between Linux and FreeBSD.
 159                  *
 160                  * On Linux, the wait is interruptible (3rd argument to
 161                  * ttm_bo_wait). There must be some mechanism to resume
 162                  * page fault handling, once the signal is processed.
 163                  *
 164                  * On FreeBSD, the wait is uninteruptible. This is not a
 165                  * problem as we can't end up with an unkillable process
 166                  * here, because the wait will eventually time out.
 167                  *
 168                  * An example of this situation is the Xorg process
 169                  * which uses SIGALRM internally. The signal could
 170                  * interrupt the wait, causing the page fault to fail
 171                  * and the process to receive SIGSEGV.
 172                  */
 173                 ret = ttm_bo_wait(bo, false, false, false);
 174                 mtx_unlock(&bdev->fence_lock);
 175                 if (unlikely(ret != 0)) {
 176                         retval = VM_PAGER_ERROR;
 177                         goto out_unlock;
 178                 }
 179         } else
 180                 mtx_unlock(&bdev->fence_lock);
 181
 182         ret = ttm_mem_io_lock(man, true);
 183         if (unlikely(ret != 0)) {
 184                 retval = VM_PAGER_ERROR;
 185                 goto out_unlock;
 186         }
 187         ret = ttm_mem_io_reserve_vm(bo);
 188         if (unlikely(ret != 0)) {
 189                 retval = VM_PAGER_ERROR;
 190                 goto out_io_unlock;
 191         }
 192
 193         /*
 194          * Strictly, we're not allowed to modify vma->vm_page_prot here,
 195          * since the mmap_sem is only held in read mode. However, we
 196          * modify only the caching bits of vma->vm_page_prot and
 197          * consider those bits protected by
 198          * the bo->mutex, as we should be the only writers.
 199          * There shouldn't really be any readers of these bits except
 200          * within vm_insert_mixed()? fork?
 201          *
 202          * TODO: Add a list of vmas to the bo, and change the
 203          * vma->vm_page_prot when the object changes caching policy, with
 204          * the correct locks held.
 205          */
 206         if (!bo->mem.bus.is_iomem) {
 207                 /* Allocate all page at once, most common usage */
 208                 ttm = bo->ttm;
 209                 if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
 210                         retval = VM_PAGER_ERROR;
 211                         goto out_io_unlock;
 212                 }
 213         }
 214
 215         if (bo->mem.bus.is_iomem) {
 216                 m = PHYS_TO_VM_PAGE(bo->mem.bus.base + bo->mem.bus.offset +
 217                     offset);
 218                 KASSERT((m->flags & PG_FICTITIOUS) != 0,
 219                     ("physical address %#jx not fictitious",
 220                     (uintmax_t)(bo->mem.bus.base + bo->mem.bus.offset
 221                     + offset)));
 222                 pmap_page_set_memattr(m, ttm_io_prot(bo->mem.placement));
 223         } else {
 224                 ttm = bo->ttm;
 225                 m = ttm->pages[OFF_TO_IDX(offset)];
 226                 if (unlikely(!m)) {
 227                         retval = VM_PAGER_ERROR;
 228                         goto out_io_unlock;
 229                 }
 230                 pmap_page_set_memattr(m,
 231                     (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
 232                     VM_MEMATTR_WRITE_BACK : ttm_io_prot(bo->mem.placement));
 233         }
 234
 235         VM_OBJECT_WLOCK(vm_obj);
 236         if (vm_page_busied(m)) {
 237                 vm_page_lock(m);
 238                 VM_OBJECT_WUNLOCK(vm_obj);
 239                 vm_page_busy_sleep(m, "ttmpbs", false);
 240                 VM_OBJECT_WLOCK(vm_obj);
 241                 ttm_mem_io_unlock(man);
 242                 ttm_bo_unreserve(bo);
 243                 goto retry;
 244         }
 245         m1 = vm_page_lookup(vm_obj, OFF_TO_IDX(offset));
 246         if (m1 == NULL) {
 247                 if (vm_page_insert(m, vm_obj, OFF_TO_IDX(offset))) {
 248                         VM_OBJECT_WUNLOCK(vm_obj);
 249                         VM_WAIT;
 250                         VM_OBJECT_WLOCK(vm_obj);
 251                         ttm_mem_io_unlock(man);
 252                         ttm_bo_unreserve(bo);
 253                         goto retry;
 254                 }
 255         } else {
 256                 KASSERT(m == m1,
 257                     ("inconsistent insert bo %p m %p m1 %p offset %jx",
 258                     bo, m, m1, (uintmax_t)offset));
 259         }
 260         m->valid = VM_PAGE_BITS_ALL;
 261         vm_page_xbusy(m);
 262         if (*mres != NULL) {
 263                 KASSERT(*mres != m, ("losing %p %p", *mres, m));
 264                 vm_page_lock(*mres);
 265                 vm_page_free(*mres);
 266                 vm_page_unlock(*mres);
 267         }
 268         *mres = m;
 269
 270 out_io_unlock1:
 271         ttm_mem_io_unlock(man);
 272 out_unlock1:
 273         ttm_bo_unreserve(bo);
 274         vm_object_pip_wakeup(vm_obj);
 275         return (retval);
 276
 277 out_io_unlock:
 278         VM_OBJECT_WLOCK(vm_obj);
 279         goto out_io_unlock1;
 280
 281 out_unlock:
 282         VM_OBJECT_WLOCK(vm_obj);
 283         goto out_unlock1;
 284 }
 285
 286 static int
 287 ttm_bo_vm_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
 288     vm_ooffset_t foff, struct ucred *cred, u_short *color)
 289 {
 290
 291         /*
 292          * On Linux, a reference to the buffer object is acquired here.
 293          * The reason is that this function is not called when the
 294          * mmap() is initialized, but only when a process forks for
 295          * instance. Therefore on Linux, the reference on the bo is
 296          * acquired either in ttm_bo_mmap() or ttm_bo_vm_open(). It's
 297          * then released in ttm_bo_vm_close().
 298          *
 299          * Here, this function is called during mmap() initialization.
 300          * Thus, the reference acquired in ttm_bo_mmap_single() is
 301          * sufficient.
 302          */
 303
 304         *color = 0;
 305         return (0);
 306 }
 307
 308 static void
 309 ttm_bo_vm_dtor(void *handle)
 310 {
 311         struct ttm_buffer_object *bo = handle;
 312
 313         ttm_bo_unref(&bo);
 314 }
 315
 316 static struct cdev_pager_ops ttm_pager_ops = {
 317         .cdev_pg_fault = ttm_bo_vm_fault,
 318         .cdev_pg_ctor = ttm_bo_vm_ctor,
 319         .cdev_pg_dtor = ttm_bo_vm_dtor
 320 };
 321
 322 int
 323 ttm_bo_mmap_single(struct ttm_bo_device *bdev, vm_ooffset_t *offset, vm_size_t size,
 324     struct vm_object **obj_res, int nprot)
 325 {
 326         struct ttm_bo_driver *driver;
 327         struct ttm_buffer_object *bo;
 328         struct vm_object *vm_obj;
 329         int ret;
 330
 331         rw_wlock(&bdev->vm_lock);
 332         bo = ttm_bo_vm_lookup_rb(bdev, OFF_TO_IDX(*offset), OFF_TO_IDX(size));
 333         if (likely(bo != NULL))
 334                 refcount_acquire(&bo->kref);
 335         rw_wunlock(&bdev->vm_lock);
 336
 337         if (unlikely(bo == NULL)) {
 338                 printf("[TTM] Could not find buffer object to map\n");
 339                 return (-EINVAL);
 340         }
 341
 342         driver = bo->bdev->driver;
 343         if (unlikely(!driver->verify_access)) {
 344                 ret = -EPERM;
 345                 goto out_unref;
 346         }
 347         ret = driver->verify_access(bo);
 348         if (unlikely(ret != 0))
 349                 goto out_unref;
 350
 351         vm_obj = cdev_pager_allocate(bo, OBJT_MGTDEVICE, &ttm_pager_ops,
 352             size, nprot, 0, curthread->td_ucred);
 353         if (vm_obj == NULL) {
 354                 ret = -EINVAL;
 355                 goto out_unref;
 356         }
 357         /*
 358          * Note: We're transferring the bo reference to vm_obj->handle here.
 359          */
 360         *offset = 0;
 361         *obj_res = vm_obj;
 362         return 0;
 363 out_unref:
 364         ttm_bo_unref(&bo);
 365         return ret;
 366 }
 367
 368 void
 369 ttm_bo_release_mmap(struct ttm_buffer_object *bo)
 370 {
 371         vm_object_t vm_obj;
 372         vm_page_t m;
 373         int i;
 374
 375         vm_obj = cdev_pager_lookup(bo);
 376         if (vm_obj == NULL)
 377                 return;
 378
 379         VM_OBJECT_WLOCK(vm_obj);
 380 retry:
 381         for (i = 0; i < bo->num_pages; i++) {
 382                 m = vm_page_lookup(vm_obj, i);
 383                 if (m == NULL)
 384                         continue;
 385                 if (vm_page_sleep_if_busy(m, "ttm_unm"))
 386                         goto retry;
 387                 cdev_pager_free_page(vm_obj, m);
 388         }
 389         VM_OBJECT_WUNLOCK(vm_obj);
 390
 391         vm_object_deallocate(vm_obj);
 392 }
 393
 394 #if 0
 395 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 396 {
 397         if (vma->vm_pgoff != 0)
 398                 return -EACCES;
 399
 400         vma->vm_ops = &ttm_bo_vm_ops;
 401         vma->vm_private_data = ttm_bo_reference(bo);
 402         vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
 403         return 0;
 404 }
 405
 406 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
 407                   const char __user *wbuf, char __user *rbuf, size_t count,
 408                   loff_t *f_pos, bool write)
 409 {
 410         struct ttm_buffer_object *bo;
 411         struct ttm_bo_driver *driver;
 412         struct ttm_bo_kmap_obj map;
 413         unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
 414         unsigned long kmap_offset;
 415         unsigned long kmap_end;
 416         unsigned long kmap_num;
 417         size_t io_size;
 418         unsigned int page_offset;
 419         char *virtual;
 420         int ret;
 421         bool no_wait = false;
 422         bool dummy;
 423
 424         read_lock(&bdev->vm_lock);
 425         bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
 426         if (likely(bo != NULL))
 427                 ttm_bo_reference(bo);
 428         read_unlock(&bdev->vm_lock);
 429
 430         if (unlikely(bo == NULL))
 431                 return -EFAULT;
 432
 433         driver = bo->bdev->driver;
 434         if (unlikely(!driver->verify_access)) {
 435                 ret = -EPERM;
 436                 goto out_unref;
 437         }
 438
 439         ret = driver->verify_access(bo, filp);
 440         if (unlikely(ret != 0))
 441                 goto out_unref;
 442
 443         kmap_offset = dev_offset - bo->vm_node->start;
 444         if (unlikely(kmap_offset >= bo->num_pages)) {
 445                 ret = -EFBIG;
 446                 goto out_unref;
 447         }
 448
 449         page_offset = *f_pos & ~PAGE_MASK;
 450         io_size = bo->num_pages - kmap_offset;
 451         io_size = (io_size << PAGE_SHIFT) - page_offset;
 452         if (count < io_size)
 453                 io_size = count;
 454
 455         kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
 456         kmap_num = kmap_end - kmap_offset + 1;
 457
 458         ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
 459
 460         switch (ret) {
 461         case 0:
 462                 break;
 463         case -EBUSY:
 464                 ret = -EAGAIN;
 465                 goto out_unref;
 466         default:
 467                 goto out_unref;
 468         }
 469
 470         ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
 471         if (unlikely(ret != 0)) {
 472                 ttm_bo_unreserve(bo);
 473                 goto out_unref;
 474         }
 475
 476         virtual = ttm_kmap_obj_virtual(&map, &dummy);
 477         virtual += page_offset;
 478
 479         if (write)
 480                 ret = copy_from_user(virtual, wbuf, io_size);
 481         else
 482                 ret = copy_to_user(rbuf, virtual, io_size);
 483
 484         ttm_bo_kunmap(&map);
 485         ttm_bo_unreserve(bo);
 486         ttm_bo_unref(&bo);
 487
 488         if (unlikely(ret != 0))
 489                 return -EFBIG;
 490
 491         *f_pos += io_size;
 492
 493         return io_size;
 494 out_unref:
 495         ttm_bo_unref(&bo);
 496         return ret;
 497 }
 498
 499 ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf,
 500                         char __user *rbuf, size_t count, loff_t *f_pos,
 501                         bool write)
 502 {
 503         struct ttm_bo_kmap_obj map;
 504         unsigned long kmap_offset;
 505         unsigned long kmap_end;
 506         unsigned long kmap_num;
 507         size_t io_size;
 508         unsigned int page_offset;
 509         char *virtual;
 510         int ret;
 511         bool no_wait = false;
 512         bool dummy;
 513
 514         kmap_offset = (*f_pos >> PAGE_SHIFT);
 515         if (unlikely(kmap_offset >= bo->num_pages))
 516                 return -EFBIG;
 517
 518         page_offset = *f_pos & ~PAGE_MASK;
 519         io_size = bo->num_pages - kmap_offset;
 520         io_size = (io_size << PAGE_SHIFT) - page_offset;
 521         if (count < io_size)
 522                 io_size = count;
 523
 524         kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
 525         kmap_num = kmap_end - kmap_offset + 1;
 526
 527         ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
 528
 529         switch (ret) {
 530         case 0:
 531                 break;
 532         case -EBUSY:
 533                 return -EAGAIN;
 534         default:
 535                 return ret;
 536         }
 537
 538         ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
 539         if (unlikely(ret != 0)) {
 540                 ttm_bo_unreserve(bo);
 541                 return ret;
 542         }
 543
 544         virtual = ttm_kmap_obj_virtual(&map, &dummy);
 545         virtual += page_offset;
 546
 547         if (write)
 548                 ret = copy_from_user(virtual, wbuf, io_size);
 549         else
 550                 ret = copy_to_user(rbuf, virtual, io_size);
 551
 552         ttm_bo_kunmap(&map);
 553         ttm_bo_unreserve(bo);
 554         ttm_bo_unref(&bo);
 555
 556         if (unlikely(ret != 0))
 557                 return ret;
 558
 559         *f_pos += io_size;
 560
 561         return io_size;
 562 }
 563 #endif