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