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 -ERESTARTSYS:
 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 = PHYS_TO_VM_PAGE(bo->mem.bus.base + bo->mem.bus.offset +
 220                     offset);
 221                 KASSERT((m->flags & PG_FICTITIOUS) != 0,
 222                     ("physical address %#jx not fictitious",
 223                     (uintmax_t)(bo->mem.bus.base + bo->mem.bus.offset
 224                     + offset)));
 225                 pmap_page_set_memattr(m, ttm_io_prot(bo->mem.placement));
 226         } else {
 227                 ttm = bo->ttm;
 228                 m = ttm->pages[OFF_TO_IDX(offset)];
 229                 if (unlikely(!m)) {
 230                         retval = VM_PAGER_ERROR;
 231                         goto out_io_unlock;
 232                 }
 233                 pmap_page_set_memattr(m,
 234                     (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
 235                     VM_MEMATTR_WRITE_BACK : ttm_io_prot(bo->mem.placement));
 236         }
 237
 238         VM_OBJECT_WLOCK(vm_obj);
 239         if (vm_page_busied(m)) {
 240                 vm_page_lock(m);
 241                 VM_OBJECT_WUNLOCK(vm_obj);
 242                 vm_page_busy_sleep(m, "ttmpbs");
 243                 VM_OBJECT_WLOCK(vm_obj);
 244                 ttm_mem_io_unlock(man);
 245                 ttm_bo_unreserve(bo);
 246                 goto retry;
 247         }
 248         m1 = vm_page_lookup(vm_obj, OFF_TO_IDX(offset));
 249         if (m1 == NULL) {
 250                 if (vm_page_insert(m, vm_obj, OFF_TO_IDX(offset))) {
 251                         VM_OBJECT_WUNLOCK(vm_obj);
 252                         VM_WAIT;
 253                         VM_OBJECT_WLOCK(vm_obj);
 254                         ttm_mem_io_unlock(man);
 255                         ttm_bo_unreserve(bo);
 256                         goto retry;
 257                 }
 258         } else {
 259                 KASSERT(m == m1,
 260                     ("inconsistent insert bo %p m %p m1 %p offset %jx",
 261                     bo, m, m1, (uintmax_t)offset));
 262         }
 263         m->valid = VM_PAGE_BITS_ALL;
 264         *mres = m;
 265         vm_page_xbusy(m);
 266
 267         if (oldm != NULL) {
 268                 vm_page_lock(oldm);
 269                 vm_page_free(oldm);
 270                 vm_page_unlock(oldm);
 271         }
 272
 273 out_io_unlock1:
 274         ttm_mem_io_unlock(man);
 275 out_unlock1:
 276         ttm_bo_unreserve(bo);
 277         vm_object_pip_wakeup(vm_obj);
 278         return (retval);
 279
 280 out_io_unlock:
 281         VM_OBJECT_WLOCK(vm_obj);
 282         goto out_io_unlock1;
 283
 284 out_unlock:
 285         VM_OBJECT_WLOCK(vm_obj);
 286         goto out_unlock1;
 287 }
 288
 289 static int
 290 ttm_bo_vm_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
 291     vm_ooffset_t foff, struct ucred *cred, u_short *color)
 292 {
 293
 294         /*
 295          * On Linux, a reference to the buffer object is acquired here.
 296          * The reason is that this function is not called when the
 297          * mmap() is initialized, but only when a process forks for
 298          * instance. Therefore on Linux, the reference on the bo is
 299          * acquired either in ttm_bo_mmap() or ttm_bo_vm_open(). It's
 300          * then released in ttm_bo_vm_close().
 301          *
 302          * Here, this function is called during mmap() intialization.
 303          * Thus, the reference acquired in ttm_bo_mmap_single() is
 304          * sufficient.
 305          */
 306
 307         *color = 0;
 308         return (0);
 309 }
 310
 311 static void
 312 ttm_bo_vm_dtor(void *handle)
 313 {
 314         struct ttm_buffer_object *bo = handle;
 315
 316         ttm_bo_unref(&bo);
 317 }
 318
 319 static struct cdev_pager_ops ttm_pager_ops = {
 320         .cdev_pg_fault = ttm_bo_vm_fault,
 321         .cdev_pg_ctor = ttm_bo_vm_ctor,
 322         .cdev_pg_dtor = ttm_bo_vm_dtor
 323 };
 324
 325 int
 326 ttm_bo_mmap_single(struct ttm_bo_device *bdev, vm_ooffset_t *offset, vm_size_t size,
 327     struct vm_object **obj_res, int nprot)
 328 {
 329         struct ttm_bo_driver *driver;
 330         struct ttm_buffer_object *bo;
 331         struct vm_object *vm_obj;
 332         int ret;
 333
 334         rw_wlock(&bdev->vm_lock);
 335         bo = ttm_bo_vm_lookup_rb(bdev, OFF_TO_IDX(*offset), OFF_TO_IDX(size));
 336         if (likely(bo != NULL))
 337                 refcount_acquire(&bo->kref);
 338         rw_wunlock(&bdev->vm_lock);
 339
 340         if (unlikely(bo == NULL)) {
 341                 printf("[TTM] Could not find buffer object to map\n");
 342                 return (-EINVAL);
 343         }
 344
 345         driver = bo->bdev->driver;
 346         if (unlikely(!driver->verify_access)) {
 347                 ret = -EPERM;
 348                 goto out_unref;
 349         }
 350         ret = driver->verify_access(bo);
 351         if (unlikely(ret != 0))
 352                 goto out_unref;
 353
 354         vm_obj = cdev_pager_allocate(bo, OBJT_MGTDEVICE, &ttm_pager_ops,
 355             size, nprot, 0, curthread->td_ucred);
 356         if (vm_obj == NULL) {
 357                 ret = -EINVAL;
 358                 goto out_unref;
 359         }
 360         /*
 361          * Note: We're transferring the bo reference to vm_obj->handle here.
 362          */
 363         *offset = 0;
 364         *obj_res = vm_obj;
 365         return 0;
 366 out_unref:
 367         ttm_bo_unref(&bo);
 368         return ret;
 369 }
 370
 371 void
 372 ttm_bo_release_mmap(struct ttm_buffer_object *bo)
 373 {
 374         vm_object_t vm_obj;
 375         vm_page_t m;
 376         int i;
 377
 378         vm_obj = cdev_pager_lookup(bo);
 379         if (vm_obj == NULL)
 380                 return;
 381
 382         VM_OBJECT_WLOCK(vm_obj);
 383 retry:
 384         for (i = 0; i < bo->num_pages; i++) {
 385                 m = vm_page_lookup(vm_obj, i);
 386                 if (m == NULL)
 387                         continue;
 388                 if (vm_page_sleep_if_busy(m, "ttm_unm"))
 389                         goto retry;
 390                 cdev_pager_free_page(vm_obj, m);
 391         }
 392         VM_OBJECT_WUNLOCK(vm_obj);
 393
 394         vm_object_deallocate(vm_obj);
 395 }
 396
 397 #if 0
 398 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 399 {
 400         if (vma->vm_pgoff != 0)
 401                 return -EACCES;
 402
 403         vma->vm_ops = &ttm_bo_vm_ops;
 404         vma->vm_private_data = ttm_bo_reference(bo);
 405         vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
 406         return 0;
 407 }
 408
 409 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
 410                   const char __user *wbuf, char __user *rbuf, size_t count,
 411                   loff_t *f_pos, bool write)
 412 {
 413         struct ttm_buffer_object *bo;
 414         struct ttm_bo_driver *driver;
 415         struct ttm_bo_kmap_obj map;
 416         unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
 417         unsigned long kmap_offset;
 418         unsigned long kmap_end;
 419         unsigned long kmap_num;
 420         size_t io_size;
 421         unsigned int page_offset;
 422         char *virtual;
 423         int ret;
 424         bool no_wait = false;
 425         bool dummy;
 426
 427         read_lock(&bdev->vm_lock);
 428         bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
 429         if (likely(bo != NULL))
 430                 ttm_bo_reference(bo);
 431         read_unlock(&bdev->vm_lock);
 432
 433         if (unlikely(bo == NULL))
 434                 return -EFAULT;
 435
 436         driver = bo->bdev->driver;
 437         if (unlikely(!driver->verify_access)) {
 438                 ret = -EPERM;
 439                 goto out_unref;
 440         }
 441
 442         ret = driver->verify_access(bo, filp);
 443         if (unlikely(ret != 0))
 444                 goto out_unref;
 445
 446         kmap_offset = dev_offset - bo->vm_node->start;
 447         if (unlikely(kmap_offset >= bo->num_pages)) {
 448                 ret = -EFBIG;
 449                 goto out_unref;
 450         }
 451
 452         page_offset = *f_pos & ~PAGE_MASK;
 453         io_size = bo->num_pages - kmap_offset;
 454         io_size = (io_size << PAGE_SHIFT) - page_offset;
 455         if (count < io_size)
 456                 io_size = count;
 457
 458         kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
 459         kmap_num = kmap_end - kmap_offset + 1;
 460
 461         ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
 462
 463         switch (ret) {
 464         case 0:
 465                 break;
 466         case -EBUSY:
 467                 ret = -EAGAIN;
 468                 goto out_unref;
 469         default:
 470                 goto out_unref;
 471         }
 472
 473         ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
 474         if (unlikely(ret != 0)) {
 475                 ttm_bo_unreserve(bo);
 476                 goto out_unref;
 477         }
 478
 479         virtual = ttm_kmap_obj_virtual(&map, &dummy);
 480         virtual += page_offset;
 481
 482         if (write)
 483                 ret = copy_from_user(virtual, wbuf, io_size);
 484         else
 485                 ret = copy_to_user(rbuf, virtual, io_size);
 486
 487         ttm_bo_kunmap(&map);
 488         ttm_bo_unreserve(bo);
 489         ttm_bo_unref(&bo);
 490
 491         if (unlikely(ret != 0))
 492                 return -EFBIG;
 493
 494         *f_pos += io_size;
 495
 496         return io_size;
 497 out_unref:
 498         ttm_bo_unref(&bo);
 499         return ret;
 500 }
 501
 502 ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf,
 503                         char __user *rbuf, size_t count, loff_t *f_pos,
 504                         bool write)
 505 {
 506         struct ttm_bo_kmap_obj map;
 507         unsigned long kmap_offset;
 508         unsigned long kmap_end;
 509         unsigned long kmap_num;
 510         size_t io_size;
 511         unsigned int page_offset;
 512         char *virtual;
 513         int ret;
 514         bool no_wait = false;
 515         bool dummy;
 516
 517         kmap_offset = (*f_pos >> PAGE_SHIFT);
 518         if (unlikely(kmap_offset >= bo->num_pages))
 519                 return -EFBIG;
 520
 521         page_offset = *f_pos & ~PAGE_MASK;
 522         io_size = bo->num_pages - kmap_offset;
 523         io_size = (io_size << PAGE_SHIFT) - page_offset;
 524         if (count < io_size)
 525                 io_size = count;
 526
 527         kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
 528         kmap_num = kmap_end - kmap_offset + 1;
 529
 530         ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
 531
 532         switch (ret) {
 533         case 0:
 534                 break;
 535         case -EBUSY:
 536                 return -EAGAIN;
 537         default:
 538                 return ret;
 539         }
 540
 541         ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
 542         if (unlikely(ret != 0)) {
 543                 ttm_bo_unreserve(bo);
 544                 return ret;
 545         }
 546
 547         virtual = ttm_kmap_obj_virtual(&map, &dummy);
 548         virtual += page_offset;
 549
 550         if (write)
 551                 ret = copy_from_user(virtual, wbuf, io_size);
 552         else
 553                 ret = copy_to_user(rbuf, virtual, io_size);
 554
 555         ttm_bo_kunmap(&map);
 556         ttm_bo_unreserve(bo);
 557         ttm_bo_unref(&bo);
 558
 559         if (unlikely(ret != 0))
 560                 return ret;
 561
 562         *f_pos += io_size;
 563
 564         return io_size;
 565 }
 566 #endif