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