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         RB_FOREACH(bo, ttm_bo_device_buffer_objects, &bdev->addr_space_rb) {
  80                 cur_offset = bo->vm_node->start;
  81                 if (page_start >= cur_offset) {
  82                         best_bo = bo;
  83                         if (page_start == cur_offset)
  84                                 break;
  85                 }
  86         }
  87
  88         if (unlikely(best_bo == NULL))
  89                 return NULL;
  90
  91         if (unlikely((best_bo->vm_node->start + best_bo->num_pages) <
  92                      (page_start + num_pages)))
  93                 return NULL;
  94
  95         return best_bo;
  96 }
  97
  98 static int
  99 ttm_bo_vm_fault(vm_object_t vm_obj, vm_ooffset_t offset,
 100     int prot, vm_page_t *mres)
 101 {
 102
 103         struct ttm_buffer_object *bo = vm_obj->handle;
 104         struct ttm_bo_device *bdev = bo->bdev;
 105         struct ttm_tt *ttm = NULL;
 106         vm_page_t m, m1, oldm;
 107         int ret;
 108         int retval = VM_PAGER_OK;
 109         struct ttm_mem_type_manager *man =
 110                 &bdev->man[bo->mem.mem_type];
 111
 112         vm_object_pip_add(vm_obj, 1);
 113         oldm = *mres;
 114         if (oldm != NULL) {
 115                 vm_page_lock(oldm);
 116                 vm_page_remove(oldm);
 117                 vm_page_unlock(oldm);
 118                 *mres = NULL;
 119         } else
 120                 oldm = NULL;
 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 -ERESTART:
 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 = vm_phys_fictitious_to_vm_page(bo->mem.bus.base +
 217                     bo->mem.bus.offset + offset);
 218                 pmap_page_set_memattr(m, ttm_io_prot(bo->mem.placement));
 219         } else {
 220                 ttm = bo->ttm;
 221                 m = ttm->pages[OFF_TO_IDX(offset)];
 222                 if (unlikely(!m)) {
 223                         retval = VM_PAGER_ERROR;
 224                         goto out_io_unlock;
 225                 }
 226                 pmap_page_set_memattr(m,
 227                     (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
 228                     VM_MEMATTR_WRITE_BACK : ttm_io_prot(bo->mem.placement));
 229         }
 230
 231         VM_OBJECT_WLOCK(vm_obj);
 232         if (vm_page_busied(m)) {
 233                 vm_page_lock(m);
 234                 VM_OBJECT_WUNLOCK(vm_obj);
 235                 vm_page_busy_sleep(m, "ttmpbs");
 236                 VM_OBJECT_WLOCK(vm_obj);
 237                 ttm_mem_io_unlock(man);
 238                 ttm_bo_unreserve(bo);
 239                 goto retry;
 240         }
 241         m1 = vm_page_lookup(vm_obj, OFF_TO_IDX(offset));
 242         if (m1 == NULL) {
 243                 if (vm_page_insert(m, vm_obj, OFF_TO_IDX(offset))) {
 244                         VM_OBJECT_WUNLOCK(vm_obj);
 245                         VM_WAIT;
 246                         VM_OBJECT_WLOCK(vm_obj);
 247                         ttm_mem_io_unlock(man);
 248                         ttm_bo_unreserve(bo);
 249                         goto retry;
 250                 }
 251         } else {
 252                 KASSERT(m == m1,
 253                     ("inconsistent insert bo %p m %p m1 %p offset %jx",
 254                     bo, m, m1, (uintmax_t)offset));
 255         }
 256         m->valid = VM_PAGE_BITS_ALL;
 257         *mres = m;
 258         vm_page_xbusy(m);
 259
 260         if (oldm != NULL) {
 261                 vm_page_lock(oldm);
 262                 vm_page_free(oldm);
 263                 vm_page_unlock(oldm);
 264         }
 265
 266 out_io_unlock1:
 267         ttm_mem_io_unlock(man);
 268 out_unlock1:
 269         ttm_bo_unreserve(bo);
 270         vm_object_pip_wakeup(vm_obj);
 271         return (retval);
 272
 273 out_io_unlock:
 274         VM_OBJECT_WLOCK(vm_obj);
 275         goto out_io_unlock1;
 276
 277 out_unlock:
 278         VM_OBJECT_WLOCK(vm_obj);
 279         goto out_unlock1;
 280 }
 281
 282 static int
 283 ttm_bo_vm_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
 284     vm_ooffset_t foff, struct ucred *cred, u_short *color)
 285 {
 286
 287         /*
 288          * On Linux, a reference to the buffer object is acquired here.
 289          * The reason is that this function is not called when the
 290          * mmap() is initialized, but only when a process forks for
 291          * instance. Therefore on Linux, the reference on the bo is
 292          * acquired either in ttm_bo_mmap() or ttm_bo_vm_open(). It's
 293          * then released in ttm_bo_vm_close().
 294          *
 295          * Here, this function is called during mmap() intialization.
 296          * Thus, the reference acquired in ttm_bo_mmap_single() is
 297          * sufficient.
 298          */
 299
 300         *color = 0;
 301         return (0);
 302 }
 303
 304 static void
 305 ttm_bo_vm_dtor(void *handle)
 306 {
 307         struct ttm_buffer_object *bo = handle;
 308
 309         ttm_bo_unref(&bo);
 310 }
 311
 312 static struct cdev_pager_ops ttm_pager_ops = {
 313         .cdev_pg_fault = ttm_bo_vm_fault,
 314         .cdev_pg_ctor = ttm_bo_vm_ctor,
 315         .cdev_pg_dtor = ttm_bo_vm_dtor
 316 };
 317
 318 int
 319 ttm_bo_mmap_single(struct ttm_bo_device *bdev, vm_ooffset_t *offset, vm_size_t size,
 320     struct vm_object **obj_res, int nprot)
 321 {
 322         struct ttm_bo_driver *driver;
 323         struct ttm_buffer_object *bo;
 324         struct vm_object *vm_obj;
 325         int ret;
 326
 327         rw_wlock(&bdev->vm_lock);
 328         bo = ttm_bo_vm_lookup_rb(bdev, OFF_TO_IDX(*offset), OFF_TO_IDX(size));
 329         if (likely(bo != NULL))
 330                 refcount_acquire(&bo->kref);
 331         rw_wunlock(&bdev->vm_lock);
 332
 333         if (unlikely(bo == NULL)) {
 334                 printf("[TTM] Could not find buffer object to map\n");
 335                 return (EINVAL);
 336         }
 337
 338         driver = bo->bdev->driver;
 339         if (unlikely(!driver->verify_access)) {
 340                 ret = EPERM;
 341                 goto out_unref;
 342         }
 343         ret = -driver->verify_access(bo);
 344         if (unlikely(ret != 0))
 345                 goto out_unref;
 346
 347         vm_obj = cdev_pager_allocate(bo, OBJT_MGTDEVICE, &ttm_pager_ops,
 348             size, nprot, 0, curthread->td_ucred);
 349         if (vm_obj == NULL) {
 350                 ret = EINVAL;
 351                 goto out_unref;
 352         }
 353         /*
 354          * Note: We're transferring the bo reference to vm_obj->handle here.
 355          */
 356         *offset = 0;
 357         *obj_res = vm_obj;
 358         return 0;
 359 out_unref:
 360         ttm_bo_unref(&bo);
 361         return ret;
 362 }
 363
 364 void
 365 ttm_bo_release_mmap(struct ttm_buffer_object *bo)
 366 {
 367         vm_object_t vm_obj;
 368         vm_page_t m;
 369         int i;
 370
 371         vm_obj = cdev_pager_lookup(bo);
 372         if (vm_obj == NULL)
 373                 return;
 374
 375         VM_OBJECT_WLOCK(vm_obj);
 376 retry:
 377         for (i = 0; i < bo->num_pages; i++) {
 378                 m = vm_page_lookup(vm_obj, i);
 379                 if (m == NULL)
 380                         continue;
 381                 if (vm_page_sleep_if_busy(m, "ttm_unm"))
 382                         goto retry;
 383                 cdev_pager_free_page(vm_obj, m);
 384         }
 385         VM_OBJECT_WUNLOCK(vm_obj);
 386
 387         vm_object_deallocate(vm_obj);
 388 }
 389
 390 #if 0
 391 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 392 {
 393         if (vma->vm_pgoff != 0)
 394                 return -EACCES;
 395
 396         vma->vm_ops = &ttm_bo_vm_ops;
 397         vma->vm_private_data = ttm_bo_reference(bo);
 398         vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
 399         return 0;
 400 }
 401
 402 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
 403                   const char __user *wbuf, char __user *rbuf, size_t count,
 404                   loff_t *f_pos, bool write)
 405 {
 406         struct ttm_buffer_object *bo;
 407         struct ttm_bo_driver *driver;
 408         struct ttm_bo_kmap_obj map;
 409         unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
 410         unsigned long kmap_offset;
 411         unsigned long kmap_end;
 412         unsigned long kmap_num;
 413         size_t io_size;
 414         unsigned int page_offset;
 415         char *virtual;
 416         int ret;
 417         bool no_wait = false;
 418         bool dummy;
 419
 420         read_lock(&bdev->vm_lock);
 421         bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
 422         if (likely(bo != NULL))
 423                 ttm_bo_reference(bo);
 424         read_unlock(&bdev->vm_lock);
 425
 426         if (unlikely(bo == NULL))
 427                 return -EFAULT;
 428
 429         driver = bo->bdev->driver;
 430         if (unlikely(!driver->verify_access)) {
 431                 ret = -EPERM;
 432                 goto out_unref;
 433         }
 434
 435         ret = driver->verify_access(bo, filp);
 436         if (unlikely(ret != 0))
 437                 goto out_unref;
 438
 439         kmap_offset = dev_offset - bo->vm_node->start;
 440         if (unlikely(kmap_offset >= bo->num_pages)) {
 441                 ret = -EFBIG;
 442                 goto out_unref;
 443         }
 444
 445         page_offset = *f_pos & ~PAGE_MASK;
 446         io_size = bo->num_pages - kmap_offset;
 447         io_size = (io_size << PAGE_SHIFT) - page_offset;
 448         if (count < io_size)
 449                 io_size = count;
 450
 451         kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
 452         kmap_num = kmap_end - kmap_offset + 1;
 453
 454         ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
 455
 456         switch (ret) {
 457         case 0:
 458                 break;
 459         case -EBUSY:
 460                 ret = -EAGAIN;
 461                 goto out_unref;
 462         default:
 463                 goto out_unref;
 464         }
 465
 466         ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
 467         if (unlikely(ret != 0)) {
 468                 ttm_bo_unreserve(bo);
 469                 goto out_unref;
 470         }
 471
 472         virtual = ttm_kmap_obj_virtual(&map, &dummy);
 473         virtual += page_offset;
 474
 475         if (write)
 476                 ret = copy_from_user(virtual, wbuf, io_size);
 477         else
 478                 ret = copy_to_user(rbuf, virtual, io_size);
 479
 480         ttm_bo_kunmap(&map);
 481         ttm_bo_unreserve(bo);
 482         ttm_bo_unref(&bo);
 483
 484         if (unlikely(ret != 0))
 485                 return -EFBIG;
 486
 487         *f_pos += io_size;
 488
 489         return io_size;
 490 out_unref:
 491         ttm_bo_unref(&bo);
 492         return ret;
 493 }
 494
 495 ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf,
 496                         char __user *rbuf, size_t count, loff_t *f_pos,
 497                         bool write)
 498 {
 499         struct ttm_bo_kmap_obj map;
 500         unsigned long kmap_offset;
 501         unsigned long kmap_end;
 502         unsigned long kmap_num;
 503         size_t io_size;
 504         unsigned int page_offset;
 505         char *virtual;
 506         int ret;
 507         bool no_wait = false;
 508         bool dummy;
 509
 510         kmap_offset = (*f_pos >> PAGE_SHIFT);
 511         if (unlikely(kmap_offset >= bo->num_pages))
 512                 return -EFBIG;
 513
 514         page_offset = *f_pos & ~PAGE_MASK;
 515         io_size = bo->num_pages - kmap_offset;
 516         io_size = (io_size << PAGE_SHIFT) - page_offset;
 517         if (count < io_size)
 518                 io_size = count;
 519
 520         kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
 521         kmap_num = kmap_end - kmap_offset + 1;
 522
 523         ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
 524
 525         switch (ret) {
 526         case 0:
 527                 break;
 528         case -EBUSY:
 529                 return -EAGAIN;
 530         default:
 531                 return ret;
 532         }
 533
 534         ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
 535         if (unlikely(ret != 0)) {
 536                 ttm_bo_unreserve(bo);
 537                 return ret;
 538         }
 539
 540         virtual = ttm_kmap_obj_virtual(&map, &dummy);
 541         virtual += page_offset;
 542
 543         if (write)
 544                 ret = copy_from_user(virtual, wbuf, io_size);
 545         else
 546                 ret = copy_to_user(rbuf, virtual, io_size);
 547
 548         ttm_bo_kunmap(&map);
 549         ttm_bo_unreserve(bo);
 550         ttm_bo_unref(&bo);
 551
 552         if (unlikely(ret != 0))
 553                 return ret;
 554
 555         *f_pos += io_size;
 556
 557         return io_size;
 558 }
 559 #endif