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/export.h> 50 51 RB_GENERATE(ttm_bo_device_buffer_objects, ttm_buffer_object, vm_rb, 52 ttm_bo_cmp_rb_tree_items); 53 54 55 #define TTM_BO_VM_NUM_PREFAULT 16 56 57 int 58 ttm_bo_cmp_rb_tree_items(struct ttm_buffer_object *a, 59 struct ttm_buffer_object *b) 60 { 61 if (a->vm_node->start < b->vm_node->start) { 62 return (-1); 63 } else if (a->vm_node->start > b->vm_node->start) { 64 return (1); 65 } else { 66 return (0); 67 } 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 struct ttm_buffer_object *bo = vm_obj->handle; 106 struct ttm_bo_device *bdev = bo->bdev; 107 struct ttm_tt *ttm = NULL; 108 vm_page_t m, m1, oldm; 109 int ret; 110 int retval = VM_PAGER_OK; 111 struct ttm_mem_type_manager *man = 112 &bdev->man[bo->mem.mem_type]; 113 114 vm_object_pip_add(vm_obj, 1); 115 oldm = *mres; 116 if (oldm != NULL) { 117 vm_page_remove(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 lwkt_yield(); 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 lwkt_yield(); 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 lockmgr(&bdev->fence_lock, LK_EXCLUSIVE); 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 lockmgr(&bdev->fence_lock, LK_RELEASE); 175 if (unlikely(ret != 0)) { 176 retval = VM_PAGER_ERROR; 177 goto out_unlock; 178 } 179 } else 180 lockmgr(&bdev->fence_lock, LK_RELEASE); 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 ((m->flags & PG_BUSY) != 0) { 233 #if 0 234 vm_page_sleep(m, "ttmpbs"); 235 #endif 236 ttm_mem_io_unlock(man); 237 ttm_bo_unreserve(bo); 238 goto retry; 239 } 240 m->valid = VM_PAGE_BITS_ALL; 241 *mres = m; 242 m1 = vm_page_lookup(vm_obj, OFF_TO_IDX(offset)); 243 if (m1 == NULL) { 244 vm_page_insert(m, vm_obj, OFF_TO_IDX(offset)); 245 } else { 246 KASSERT(m == m1, 247 ("inconsistent insert bo %p m %p m1 %p offset %jx", 248 bo, m, m1, (uintmax_t)offset)); 249 } 250 vm_page_busy_try(m, FALSE); 251 252 if (oldm != NULL) { 253 vm_page_free(oldm); 254 } 255 256 out_io_unlock1: 257 ttm_mem_io_unlock(man); 258 out_unlock1: 259 ttm_bo_unreserve(bo); 260 vm_object_pip_wakeup(vm_obj); 261 return (retval); 262 263 out_io_unlock: 264 VM_OBJECT_WLOCK(vm_obj); 265 goto out_io_unlock1; 266 267 out_unlock: 268 VM_OBJECT_WLOCK(vm_obj); 269 goto out_unlock1; 270 } 271 272 static int 273 ttm_bo_vm_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 274 vm_ooffset_t foff, struct ucred *cred, u_short *color) 275 { 276 277 /* 278 * On Linux, a reference to the buffer object is acquired here. 279 * The reason is that this function is not called when the 280 * mmap() is initialized, but only when a process forks for 281 * instance. Therefore on Linux, the reference on the bo is 282 * acquired either in ttm_bo_mmap() or ttm_bo_vm_open(). It's 283 * then released in ttm_bo_vm_close(). 284 * 285 * Here, this function is called during mmap() intialization. 286 * Thus, the reference acquired in ttm_bo_mmap_single() is 287 * sufficient. 288 */ 289 *color = 0; 290 return (0); 291 } 292 293 static void 294 ttm_bo_vm_dtor(void *handle) 295 { 296 struct ttm_buffer_object *bo = handle; 297 298 ttm_bo_unref(&bo); 299 } 300 301 static struct cdev_pager_ops ttm_pager_ops = { 302 .cdev_pg_fault = ttm_bo_vm_fault, 303 .cdev_pg_ctor = ttm_bo_vm_ctor, 304 .cdev_pg_dtor = ttm_bo_vm_dtor 305 }; 306 307 int 308 ttm_bo_mmap_single(struct ttm_bo_device *bdev, vm_ooffset_t *offset, vm_size_t size, 309 struct vm_object **obj_res, int nprot) 310 { 311 struct ttm_bo_driver *driver; 312 struct ttm_buffer_object *bo; 313 struct vm_object *vm_obj; 314 int ret; 315 316 *obj_res = NULL; 317 318 lockmgr(&bdev->vm_lock, LK_EXCLUSIVE); 319 bo = ttm_bo_vm_lookup_rb(bdev, OFF_TO_IDX(*offset), OFF_TO_IDX(size)); 320 if (likely(bo != NULL)) 321 kref_get(&bo->kref); 322 lockmgr(&bdev->vm_lock, LK_RELEASE); 323 324 if (unlikely(bo == NULL)) { 325 kprintf("[TTM] Could not find buffer object to map\n"); 326 return (EINVAL); 327 } 328 329 driver = bo->bdev->driver; 330 if (unlikely(!driver->verify_access)) { 331 ret = EPERM; 332 goto out_unref; 333 } 334 ret = -driver->verify_access(bo); 335 if (unlikely(ret != 0)) 336 goto out_unref; 337 338 vm_obj = cdev_pager_allocate(bo, OBJT_MGTDEVICE, &ttm_pager_ops, 339 size, nprot, 0, curthread->td_ucred); 340 341 if (vm_obj == NULL) { 342 ret = EINVAL; 343 goto out_unref; 344 } 345 /* 346 * Note: We're transferring the bo reference to vm_obj->handle here. 347 */ 348 *offset = 0; 349 *obj_res = vm_obj; 350 return 0; 351 out_unref: 352 ttm_bo_unref(&bo); 353 return ret; 354 } 355 EXPORT_SYMBOL(ttm_bo_mmap); 356 357 void 358 ttm_bo_release_mmap(struct ttm_buffer_object *bo) 359 { 360 vm_object_t vm_obj; 361 vm_page_t m; 362 int i; 363 364 vm_obj = cdev_pager_lookup(bo); 365 if (vm_obj == NULL) 366 return; 367 368 VM_OBJECT_WLOCK(vm_obj); 369 for (i = 0; i < bo->num_pages; i++) { 370 m = vm_page_lookup_busy_wait(vm_obj, i, TRUE, "ttm_unm"); 371 if (m == NULL) 372 continue; 373 cdev_pager_free_page(vm_obj, m); 374 } 375 VM_OBJECT_WUNLOCK(vm_obj); 376 377 vm_object_deallocate(vm_obj); 378 } 379 380 #if 0 381 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo) 382 { 383 if (vma->vm_pgoff != 0) 384 return -EACCES; 385 386 vma->vm_ops = &ttm_bo_vm_ops; 387 vma->vm_private_data = ttm_bo_reference(bo); 388 vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND; 389 return 0; 390 } 391 EXPORT_SYMBOL(ttm_fbdev_mmap); 392 393 394 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp, 395 const char __user *wbuf, char __user *rbuf, size_t count, 396 loff_t *f_pos, bool write) 397 { 398 struct ttm_buffer_object *bo; 399 struct ttm_bo_driver *driver; 400 struct ttm_bo_kmap_obj map; 401 unsigned long dev_offset = (*f_pos >> PAGE_SHIFT); 402 unsigned long kmap_offset; 403 unsigned long kmap_end; 404 unsigned long kmap_num; 405 size_t io_size; 406 unsigned int page_offset; 407 char *virtual; 408 int ret; 409 bool no_wait = false; 410 bool dummy; 411 412 lockmgr(&bdev->vm_lock, LK_EXCLUSIVE); 413 bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1); 414 if (likely(bo != NULL)) 415 ttm_bo_reference(bo); 416 lockmgr(&bdev->vm_lock, LK_RELEASE); 417 418 if (unlikely(bo == NULL)) 419 return -EFAULT; 420 421 driver = bo->bdev->driver; 422 if (unlikely(!driver->verify_access)) { 423 ret = -EPERM; 424 goto out_unref; 425 } 426 427 ret = driver->verify_access(bo, filp); 428 if (unlikely(ret != 0)) 429 goto out_unref; 430 431 kmap_offset = dev_offset - bo->vm_node->start; 432 if (unlikely(kmap_offset >= bo->num_pages)) { 433 ret = -EFBIG; 434 goto out_unref; 435 } 436 437 page_offset = *f_pos & ~PAGE_MASK; 438 io_size = bo->num_pages - kmap_offset; 439 io_size = (io_size << PAGE_SHIFT) - page_offset; 440 if (count < io_size) 441 io_size = count; 442 443 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT; 444 kmap_num = kmap_end - kmap_offset + 1; 445 446 ret = ttm_bo_reserve(bo, true, no_wait, false, 0); 447 448 switch (ret) { 449 case 0: 450 break; 451 case -EBUSY: 452 ret = -EAGAIN; 453 goto out_unref; 454 default: 455 goto out_unref; 456 } 457 458 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map); 459 if (unlikely(ret != 0)) { 460 ttm_bo_unreserve(bo); 461 goto out_unref; 462 } 463 464 virtual = ttm_kmap_obj_virtual(&map, &dummy); 465 virtual += page_offset; 466 467 if (write) 468 ret = copy_from_user(virtual, wbuf, io_size); 469 else 470 ret = copy_to_user(rbuf, virtual, io_size); 471 472 ttm_bo_kunmap(&map); 473 ttm_bo_unreserve(bo); 474 ttm_bo_unref(&bo); 475 476 if (unlikely(ret != 0)) 477 return -EFBIG; 478 479 *f_pos += io_size; 480 481 return io_size; 482 out_unref: 483 ttm_bo_unref(&bo); 484 return ret; 485 } 486 487 ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf, 488 char __user *rbuf, size_t count, loff_t *f_pos, 489 bool write) 490 { 491 struct ttm_bo_kmap_obj map; 492 unsigned long kmap_offset; 493 unsigned long kmap_end; 494 unsigned long kmap_num; 495 size_t io_size; 496 unsigned int page_offset; 497 char *virtual; 498 int ret; 499 bool no_wait = false; 500 bool dummy; 501 502 kmap_offset = (*f_pos >> PAGE_SHIFT); 503 if (unlikely(kmap_offset >= bo->num_pages)) 504 return -EFBIG; 505 506 page_offset = *f_pos & ~PAGE_MASK; 507 io_size = bo->num_pages - kmap_offset; 508 io_size = (io_size << PAGE_SHIFT) - page_offset; 509 if (count < io_size) 510 io_size = count; 511 512 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT; 513 kmap_num = kmap_end - kmap_offset + 1; 514 515 ret = ttm_bo_reserve(bo, true, no_wait, false, 0); 516 517 switch (ret) { 518 case 0: 519 break; 520 case -EBUSY: 521 return -EAGAIN; 522 default: 523 return ret; 524 } 525 526 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map); 527 if (unlikely(ret != 0)) { 528 ttm_bo_unreserve(bo); 529 return ret; 530 } 531 532 virtual = ttm_kmap_obj_virtual(&map, &dummy); 533 virtual += page_offset; 534 535 if (write) 536 ret = copy_from_user(virtual, wbuf, io_size); 537 else 538 ret = copy_to_user(rbuf, virtual, io_size); 539 540 ttm_bo_kunmap(&map); 541 ttm_bo_unreserve(bo); 542 ttm_bo_unref(&bo); 543 544 if (unlikely(ret != 0)) 545 return ret; 546 547 *f_pos += io_size; 548 549 return io_size; 550 } 551 #endif 552