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: stable/10/sys/dev/drm2/ttm/ttm_bo_vm.c 307672 2016-10-20 13:12:19Z kib $"); 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 54RB_GENERATE(ttm_bo_device_buffer_objects, ttm_buffer_object, vm_rb, 55 ttm_bo_cmp_rb_tree_items); 56 57int 58ttm_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 71static 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 101static int 102ttm_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; 124retry: 125 VM_OBJECT_WUNLOCK(vm_obj); 126 m = NULL; 127 128reserve: 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", false); 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 273out_io_unlock1: 274 ttm_mem_io_unlock(man); 275out_unlock1: 276 ttm_bo_unreserve(bo); 277 vm_object_pip_wakeup(vm_obj); 278 return (retval); 279 280out_io_unlock: 281 VM_OBJECT_WLOCK(vm_obj); 282 goto out_io_unlock1; 283 284out_unlock: 285 VM_OBJECT_WLOCK(vm_obj); 286 goto out_unlock1; 287} 288 289static int 290ttm_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() initialization. 303 * Thus, the reference acquired in ttm_bo_mmap_single() is 304 * sufficient. 305 */ 306 307 *color = 0; 308 return (0); 309} 310 311static void 312ttm_bo_vm_dtor(void *handle) 313{ 314 struct ttm_buffer_object *bo = handle; 315 316 ttm_bo_unref(&bo); 317} 318 319static 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 325int 326ttm_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; 366out_unref: 367 ttm_bo_unref(&bo); 368 return ret; 369} 370 371void 372ttm_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); 383retry: 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 398int 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 409ssize_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; 497out_unref: 498 ttm_bo_unref(&bo); 499 return ret; 500} 501 502ssize_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 567