sys/dev/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  * 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  *$FreeBSD: head/sys/dev/drm2/ttm/ttm_bo_vm.c 253710 2013-07-27 16:44:37Z kib $
  38  */
  39
  40 #include "opt_vm.h"
  41
  42 #define pr_fmt(fmt) "[TTM] " fmt
  43
  44 #include <drm/ttm/ttm_module.h>
  45 #include <drm/ttm/ttm_bo_driver.h>
  46 #include <drm/ttm/ttm_placement.h>
  47 #include <vm/vm.h>
  48 #include <vm/vm_page.h>
  49 #include <linux/errno.h>
  50 #include <linux/export.h>
  51 #include <linux/rbtree.h>
  52
  53 #define TTM_BO_VM_NUM_PREFAULT 16
  54
  55 static struct ttm_buffer_object *ttm_bo_vm_lookup_rb(struct ttm_bo_device *bdev,
  56                                                      unsigned long page_start,
  57                                                      unsigned long num_pages)
  58 {
  59         struct rb_node *cur = bdev->addr_space_rb.rb_node;
  60         unsigned long cur_offset;
  61         struct ttm_buffer_object *bo;
  62         struct ttm_buffer_object *best_bo = NULL;
  63
  64         while (likely(cur != NULL)) {
  65                 bo = rb_entry(cur, struct ttm_buffer_object, vm_rb);
  66                 cur_offset = bo->vm_node->start;
  67                 if (page_start >= cur_offset) {
  68                         cur = cur->rb_right;
  69                         best_bo = bo;
  70                         if (page_start == cur_offset)
  71                                 break;
  72                 } else
  73                         cur = cur->rb_left;
  74         }
  75
  76         if (unlikely(best_bo == NULL))
  77                 return NULL;
  78
  79         if (unlikely((best_bo->vm_node->start + best_bo->num_pages) <
  80                      (page_start + num_pages)))
  81                 return NULL;
  82
  83         return best_bo;
  84 }
  85
  86 static int
  87 ttm_bo_vm_fault(vm_object_t vm_obj, vm_ooffset_t offset,
  88     int prot, vm_page_t *mres)
  89 {
  90         struct ttm_buffer_object *bo = vm_obj->handle;
  91         struct ttm_bo_device *bdev = bo->bdev;
  92         struct ttm_tt *ttm = NULL;
  93         vm_page_t m, m1, oldm;
  94         int ret;
  95         int retval = VM_PAGER_OK;
  96         struct ttm_mem_type_manager *man =
  97                 &bdev->man[bo->mem.mem_type];
  98
  99         vm_object_pip_add(vm_obj, 1);
 100         oldm = *mres;
 101         if (oldm != NULL) {
 102                 vm_page_remove(oldm);
 103                 *mres = NULL;
 104         } else
 105                 oldm = NULL;
 106 retry:
 107         VM_OBJECT_WUNLOCK(vm_obj);
 108         m = NULL;
 109
 110 reserve:
 111         ret = ttm_bo_reserve(bo, false, false, false, 0);
 112         if (unlikely(ret != 0)) {
 113                 if (ret == -EBUSY) {
 114                         lwkt_yield();
 115                         goto reserve;
 116                 }
 117         }
 118
 119         if (bdev->driver->fault_reserve_notify) {
 120                 ret = bdev->driver->fault_reserve_notify(bo);
 121                 switch (ret) {
 122                 case 0:
 123                         break;
 124                 case -EBUSY:
 125                 case -ERESTARTSYS:
 126                 case -EINTR:
 127                         lwkt_yield();
 128                         goto reserve;
 129                 default:
 130                         retval = VM_PAGER_ERROR;
 131                         goto out_unlock;
 132                 }
 133         }
 134
 135         /*
 136          * Wait for buffer data in transit, due to a pipelined
 137          * move.
 138          */
 139
 140         lockmgr(&bdev->fence_lock, LK_EXCLUSIVE);
 141         if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
 142                 /*
 143                  * Here, the behavior differs between Linux and FreeBSD.
 144                  *
 145                  * On Linux, the wait is interruptible (3rd argument to
 146                  * ttm_bo_wait). There must be some mechanism to resume
 147                  * page fault handling, once the signal is processed.
 148                  *
 149                  * On FreeBSD, the wait is uninteruptible. This is not a
 150                  * problem as we can't end up with an unkillable process
 151                  * here, because the wait will eventually time out.
 152                  *
 153                  * An example of this situation is the Xorg process
 154                  * which uses SIGALRM internally. The signal could
 155                  * interrupt the wait, causing the page fault to fail
 156                  * and the process to receive SIGSEGV.
 157                  */
 158                 ret = ttm_bo_wait(bo, false, false, false);
 159                 lockmgr(&bdev->fence_lock, LK_RELEASE);
 160                 if (unlikely(ret != 0)) {
 161                         retval = VM_PAGER_ERROR;
 162                         goto out_unlock;
 163                 }
 164         } else
 165                 lockmgr(&bdev->fence_lock, LK_RELEASE);
 166
 167         ret = ttm_mem_io_lock(man, true);
 168         if (unlikely(ret != 0)) {
 169                 retval = VM_PAGER_ERROR;
 170                 goto out_unlock;
 171         }
 172         ret = ttm_mem_io_reserve_vm(bo);
 173         if (unlikely(ret != 0)) {
 174                 retval = VM_PAGER_ERROR;
 175                 goto out_io_unlock;
 176         }
 177
 178         /*
 179          * Strictly, we're not allowed to modify vma->vm_page_prot here,
 180          * since the mmap_sem is only held in read mode. However, we
 181          * modify only the caching bits of vma->vm_page_prot and
 182          * consider those bits protected by
 183          * the bo->mutex, as we should be the only writers.
 184          * There shouldn't really be any readers of these bits except
 185          * within vm_insert_mixed()? fork?
 186          *
 187          * TODO: Add a list of vmas to the bo, and change the
 188          * vma->vm_page_prot when the object changes caching policy, with
 189          * the correct locks held.
 190          */
 191         if (!bo->mem.bus.is_iomem) {
 192                 /* Allocate all page at once, most common usage */
 193                 ttm = bo->ttm;
 194                 if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
 195                         retval = VM_PAGER_ERROR;
 196                         goto out_io_unlock;
 197                 }
 198         }
 199
 200         if (bo->mem.bus.is_iomem) {
 201                 m = vm_phys_fictitious_to_vm_page(bo->mem.bus.base +
 202                     bo->mem.bus.offset + offset);
 203                 pmap_page_set_memattr(m, ttm_io_prot(bo->mem.placement));
 204         } else {
 205                 ttm = bo->ttm;
 206                 m = ttm->pages[OFF_TO_IDX(offset)];
 207                 if (unlikely(!m)) {
 208                         retval = VM_PAGER_ERROR;
 209                         goto out_io_unlock;
 210                 }
 211                 pmap_page_set_memattr(m,
 212                     (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
 213                     VM_MEMATTR_WRITE_BACK : ttm_io_prot(bo->mem.placement));
 214         }
 215
 216         VM_OBJECT_WLOCK(vm_obj);
 217         if ((m->flags & PG_BUSY) != 0) {
 218 #if 0
 219                 vm_page_sleep(m, "ttmpbs");
 220 #endif
 221                 ttm_mem_io_unlock(man);
 222                 ttm_bo_unreserve(bo);
 223                 goto retry;
 224         }
 225         m->valid = VM_PAGE_BITS_ALL;
 226         *mres = m;
 227         m1 = vm_page_lookup(vm_obj, OFF_TO_IDX(offset));
 228         if (m1 == NULL) {
 229                 vm_page_insert(m, vm_obj, OFF_TO_IDX(offset));
 230         } else {
 231                 KASSERT(m == m1,
 232                     ("inconsistent insert bo %p m %p m1 %p offset %jx",
 233                     bo, m, m1, (uintmax_t)offset));
 234         }
 235         vm_page_busy_try(m, FALSE);
 236
 237         if (oldm != NULL) {
 238                 vm_page_free(oldm);
 239         }
 240
 241 out_io_unlock1:
 242         ttm_mem_io_unlock(man);
 243 out_unlock1:
 244         ttm_bo_unreserve(bo);
 245         vm_object_pip_wakeup(vm_obj);
 246         return (retval);
 247
 248 out_io_unlock:
 249         VM_OBJECT_WLOCK(vm_obj);
 250         goto out_io_unlock1;
 251
 252 out_unlock:
 253         VM_OBJECT_WLOCK(vm_obj);
 254         goto out_unlock1;
 255 }
 256
 257 static int
 258 ttm_bo_vm_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
 259     vm_ooffset_t foff, struct ucred *cred, u_short *color)
 260 {
 261
 262         /*
 263          * On Linux, a reference to the buffer object is acquired here.
 264          * The reason is that this function is not called when the
 265          * mmap() is initialized, but only when a process forks for
 266          * instance. Therefore on Linux, the reference on the bo is
 267          * acquired either in ttm_bo_mmap() or ttm_bo_vm_open(). It's
 268          * then released in ttm_bo_vm_close().
 269          *
 270          * Here, this function is called during mmap() intialization.
 271          * Thus, the reference acquired in ttm_bo_mmap_single() is
 272          * sufficient.
 273          */
 274         *color = 0;
 275         return (0);
 276 }
 277
 278 static void
 279 ttm_bo_vm_dtor(void *handle)
 280 {
 281         struct ttm_buffer_object *bo = handle;
 282
 283         ttm_bo_unref(&bo);
 284 }
 285
 286 static struct cdev_pager_ops ttm_pager_ops = {
 287         .cdev_pg_fault = ttm_bo_vm_fault,
 288         .cdev_pg_ctor = ttm_bo_vm_ctor,
 289         .cdev_pg_dtor = ttm_bo_vm_dtor
 290 };
 291
 292 int
 293 ttm_bo_mmap_single(struct ttm_bo_device *bdev, vm_ooffset_t *offset, vm_size_t size,
 294     struct vm_object **obj_res, int nprot)
 295 {
 296         struct ttm_bo_driver *driver;
 297         struct ttm_buffer_object *bo;
 298         struct vm_object *vm_obj;
 299         int ret;
 300
 301         *obj_res = NULL;
 302
 303         lockmgr(&bdev->vm_lock, LK_EXCLUSIVE);
 304         bo = ttm_bo_vm_lookup_rb(bdev, OFF_TO_IDX(*offset), OFF_TO_IDX(size));
 305         if (likely(bo != NULL))
 306                 kref_get(&bo->kref);
 307         lockmgr(&bdev->vm_lock, LK_RELEASE);
 308
 309         if (unlikely(bo == NULL)) {
 310                 kprintf("[TTM] Could not find buffer object to map\n");
 311                 return (EINVAL);
 312         }
 313
 314         driver = bo->bdev->driver;
 315         if (unlikely(!driver->verify_access)) {
 316                 ret = EPERM;
 317                 goto out_unref;
 318         }
 319         ret = -driver->verify_access(bo);
 320         if (unlikely(ret != 0))
 321                 goto out_unref;
 322
 323         vm_obj = cdev_pager_allocate(bo, OBJT_MGTDEVICE, &ttm_pager_ops,
 324             size, nprot, 0, curthread->td_ucred);
 325
 326         if (vm_obj == NULL) {
 327                 ret = EINVAL;
 328                 goto out_unref;
 329         }
 330         /*
 331          * Note: We're transferring the bo reference to vm_obj->handle here.
 332          */
 333         *offset = 0;
 334         *obj_res = vm_obj;
 335         return 0;
 336 out_unref:
 337         ttm_bo_unref(&bo);
 338         return ret;
 339 }
 340 EXPORT_SYMBOL(ttm_bo_mmap);
 341
 342 void
 343 ttm_bo_release_mmap(struct ttm_buffer_object *bo)
 344 {
 345         vm_object_t vm_obj;
 346         vm_page_t m;
 347         int i;
 348
 349         vm_obj = cdev_pager_lookup(bo);
 350         if (vm_obj == NULL)
 351                 return;
 352
 353         VM_OBJECT_WLOCK(vm_obj);
 354         for (i = 0; i < bo->num_pages; i++) {
 355                 m = vm_page_lookup_busy_wait(vm_obj, i, TRUE, "ttm_unm");
 356                 if (m == NULL)
 357                         continue;
 358                 cdev_pager_free_page(vm_obj, m);
 359         }
 360         VM_OBJECT_WUNLOCK(vm_obj);
 361
 362         vm_object_deallocate(vm_obj);
 363 }
 364
 365 #if 0
 366 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 367 {
 368         if (vma->vm_pgoff != 0)
 369                 return -EACCES;
 370
 371         vma->vm_ops = &ttm_bo_vm_ops;
 372         vma->vm_private_data = ttm_bo_reference(bo);
 373         vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
 374         return 0;
 375 }
 376 EXPORT_SYMBOL(ttm_fbdev_mmap);
 377
 378
 379 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
 380                   const char __user *wbuf, char __user *rbuf, size_t count,
 381                   loff_t *f_pos, bool write)
 382 {
 383         struct ttm_buffer_object *bo;
 384         struct ttm_bo_driver *driver;
 385         struct ttm_bo_kmap_obj map;
 386         unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
 387         unsigned long kmap_offset;
 388         unsigned long kmap_end;
 389         unsigned long kmap_num;
 390         size_t io_size;
 391         unsigned int page_offset;
 392         char *virtual;
 393         int ret;
 394         bool no_wait = false;
 395         bool dummy;
 396
 397         lockmgr(&bdev->vm_lock, LK_EXCLUSIVE);
 398         bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
 399         if (likely(bo != NULL))
 400                 ttm_bo_reference(bo);
 401         lockmgr(&bdev->vm_lock, LK_RELEASE);
 402
 403         if (unlikely(bo == NULL))
 404                 return -EFAULT;
 405
 406         driver = bo->bdev->driver;
 407         if (unlikely(!driver->verify_access)) {
 408                 ret = -EPERM;
 409                 goto out_unref;
 410         }
 411
 412         ret = driver->verify_access(bo, filp);
 413         if (unlikely(ret != 0))
 414                 goto out_unref;
 415
 416         kmap_offset = dev_offset - bo->vm_node->start;
 417         if (unlikely(kmap_offset >= bo->num_pages)) {
 418                 ret = -EFBIG;
 419                 goto out_unref;
 420         }
 421
 422         page_offset = *f_pos & ~PAGE_MASK;
 423         io_size = bo->num_pages - kmap_offset;
 424         io_size = (io_size << PAGE_SHIFT) - page_offset;
 425         if (count < io_size)
 426                 io_size = count;
 427
 428         kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
 429         kmap_num = kmap_end - kmap_offset + 1;
 430
 431         ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
 432
 433         switch (ret) {
 434         case 0:
 435                 break;
 436         case -EBUSY:
 437                 ret = -EAGAIN;
 438                 goto out_unref;
 439         default:
 440                 goto out_unref;
 441         }
 442
 443         ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
 444         if (unlikely(ret != 0)) {
 445                 ttm_bo_unreserve(bo);
 446                 goto out_unref;
 447         }
 448
 449         virtual = ttm_kmap_obj_virtual(&map, &dummy);
 450         virtual += page_offset;
 451
 452         if (write)
 453                 ret = copy_from_user(virtual, wbuf, io_size);
 454         else
 455                 ret = copy_to_user(rbuf, virtual, io_size);
 456
 457         ttm_bo_kunmap(&map);
 458         ttm_bo_unreserve(bo);
 459         ttm_bo_unref(&bo);
 460
 461         if (unlikely(ret != 0))
 462                 return -EFBIG;
 463
 464         *f_pos += io_size;
 465
 466         return io_size;
 467 out_unref:
 468         ttm_bo_unref(&bo);
 469         return ret;
 470 }
 471
 472 ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf,
 473                         char __user *rbuf, size_t count, loff_t *f_pos,
 474                         bool write)
 475 {
 476         struct ttm_bo_kmap_obj map;
 477         unsigned long kmap_offset;
 478         unsigned long kmap_end;
 479         unsigned long kmap_num;
 480         size_t io_size;
 481         unsigned int page_offset;
 482         char *virtual;
 483         int ret;
 484         bool no_wait = false;
 485         bool dummy;
 486
 487         kmap_offset = (*f_pos >> PAGE_SHIFT);
 488         if (unlikely(kmap_offset >= bo->num_pages))
 489                 return -EFBIG;
 490
 491         page_offset = *f_pos & ~PAGE_MASK;
 492         io_size = bo->num_pages - kmap_offset;
 493         io_size = (io_size << PAGE_SHIFT) - page_offset;
 494         if (count < io_size)
 495                 io_size = count;
 496
 497         kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
 498         kmap_num = kmap_end - kmap_offset + 1;
 499
 500         ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
 501
 502         switch (ret) {
 503         case 0:
 504                 break;
 505         case -EBUSY:
 506                 return -EAGAIN;
 507         default:
 508                 return ret;
 509         }
 510
 511         ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
 512         if (unlikely(ret != 0)) {
 513                 ttm_bo_unreserve(bo);
 514                 return ret;
 515         }
 516
 517         virtual = ttm_kmap_obj_virtual(&map, &dummy);
 518         virtual += page_offset;
 519
 520         if (write)
 521                 ret = copy_from_user(virtual, wbuf, io_size);
 522         else
 523                 ret = copy_to_user(rbuf, virtual, io_size);
 524
 525         ttm_bo_kunmap(&map);
 526         ttm_bo_unreserve(bo);
 527         ttm_bo_unref(&bo);
 528
 529         if (unlikely(ret != 0))
 530                 return ret;
 531
 532         *f_pos += io_size;
 533
 534         return io_size;
 535 }
 536 #endif