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; 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 if (*mres != NULL) { 117 vm_page_lock(*mres); 118 vm_page_remove(*mres); 119 vm_page_unlock(*mres); 120 } 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 kern_yield(PRI_USER); 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 -ERESTARTSYS: 141 case -EINTR: 142 kern_yield(PRI_USER); 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 mtx_lock(&bdev->fence_lock); 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 mtx_unlock(&bdev->fence_lock); 175 if (unlikely(ret != 0)) { 176 retval = VM_PAGER_ERROR; 177 goto out_unlock; 178 } 179 } else 180 mtx_unlock(&bdev->fence_lock); 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 = PHYS_TO_VM_PAGE(bo->mem.bus.base + bo->mem.bus.offset + 217 offset); 218 KASSERT((m->flags & PG_FICTITIOUS) != 0, 219 ("physical address %#jx not fictitious", 220 (uintmax_t)(bo->mem.bus.base + bo->mem.bus.offset 221 + offset))); 222 pmap_page_set_memattr(m, ttm_io_prot(bo->mem.placement)); 223 } else { 224 ttm = bo->ttm; 225 m = ttm->pages[OFF_TO_IDX(offset)]; 226 if (unlikely(!m)) { 227 retval = VM_PAGER_ERROR; 228 goto out_io_unlock; 229 } 230 pmap_page_set_memattr(m, 231 (bo->mem.placement & TTM_PL_FLAG_CACHED) ? 232 VM_MEMATTR_WRITE_BACK : ttm_io_prot(bo->mem.placement)); 233 } 234 235 VM_OBJECT_WLOCK(vm_obj); 236 if (vm_page_busied(m)) { 237 vm_page_lock(m); 238 VM_OBJECT_WUNLOCK(vm_obj); 239 vm_page_busy_sleep(m, "ttmpbs", false); 240 VM_OBJECT_WLOCK(vm_obj); 241 ttm_mem_io_unlock(man); 242 ttm_bo_unreserve(bo); 243 goto retry; 244 } 245 m1 = vm_page_lookup(vm_obj, OFF_TO_IDX(offset)); 246 if (m1 == NULL) { 247 if (vm_page_insert(m, vm_obj, OFF_TO_IDX(offset))) { 248 VM_OBJECT_WUNLOCK(vm_obj); 249 vm_wait(vm_obj); 250 VM_OBJECT_WLOCK(vm_obj); 251 ttm_mem_io_unlock(man); 252 ttm_bo_unreserve(bo); 253 goto retry; 254 } 255 } else { 256 KASSERT(m == m1, 257 ("inconsistent insert bo %p m %p m1 %p offset %jx", 258 bo, m, m1, (uintmax_t)offset)); 259 } 260 m->valid = VM_PAGE_BITS_ALL; 261 vm_page_xbusy(m); 262 if (*mres != NULL) { 263 KASSERT(*mres != m, ("losing %p %p", *mres, m)); 264 vm_page_lock(*mres); 265 vm_page_free(*mres); 266 vm_page_unlock(*mres); 267 } 268 *mres = m; 269 270 out_io_unlock1: 271 ttm_mem_io_unlock(man); 272 out_unlock1: 273 ttm_bo_unreserve(bo); 274 vm_object_pip_wakeup(vm_obj); 275 return (retval); 276 277 out_io_unlock: 278 VM_OBJECT_WLOCK(vm_obj); 279 goto out_io_unlock1; 280 281 out_unlock: 282 VM_OBJECT_WLOCK(vm_obj); 283 goto out_unlock1; 284 } 285 286 static int 287 ttm_bo_vm_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 288 vm_ooffset_t foff, struct ucred *cred, u_short *color) 289 { 290 291 /* 292 * On Linux, a reference to the buffer object is acquired here. 293 * The reason is that this function is not called when the 294 * mmap() is initialized, but only when a process forks for 295 * instance. Therefore on Linux, the reference on the bo is 296 * acquired either in ttm_bo_mmap() or ttm_bo_vm_open(). It's 297 * then released in ttm_bo_vm_close(). 298 * 299 * Here, this function is called during mmap() initialization. 300 * Thus, the reference acquired in ttm_bo_mmap_single() is 301 * sufficient. 302 */ 303 304 *color = 0; 305 return (0); 306 } 307 308 static void 309 ttm_bo_vm_dtor(void *handle) 310 { 311 struct ttm_buffer_object *bo = handle; 312 313 ttm_bo_unref(&bo); 314 } 315 316 static struct cdev_pager_ops ttm_pager_ops = { 317 .cdev_pg_fault = ttm_bo_vm_fault, 318 .cdev_pg_ctor = ttm_bo_vm_ctor, 319 .cdev_pg_dtor = ttm_bo_vm_dtor 320 }; 321 322 int 323 ttm_bo_mmap_single(struct ttm_bo_device *bdev, vm_ooffset_t *offset, vm_size_t size, 324 struct vm_object **obj_res, int nprot) 325 { 326 struct ttm_bo_driver *driver; 327 struct ttm_buffer_object *bo; 328 struct vm_object *vm_obj; 329 int ret; 330 331 rw_wlock(&bdev->vm_lock); 332 bo = ttm_bo_vm_lookup_rb(bdev, OFF_TO_IDX(*offset), OFF_TO_IDX(size)); 333 if (likely(bo != NULL)) 334 refcount_acquire(&bo->kref); 335 rw_wunlock(&bdev->vm_lock); 336 337 if (unlikely(bo == NULL)) { 338 printf("[TTM] Could not find buffer object to map\n"); 339 return (-EINVAL); 340 } 341 342 driver = bo->bdev->driver; 343 if (unlikely(!driver->verify_access)) { 344 ret = -EPERM; 345 goto out_unref; 346 } 347 ret = driver->verify_access(bo); 348 if (unlikely(ret != 0)) 349 goto out_unref; 350 351 vm_obj = cdev_pager_allocate(bo, OBJT_MGTDEVICE, &ttm_pager_ops, 352 size, nprot, 0, curthread->td_ucred); 353 if (vm_obj == NULL) { 354 ret = -EINVAL; 355 goto out_unref; 356 } 357 /* 358 * Note: We're transferring the bo reference to vm_obj->handle here. 359 */ 360 *offset = 0; 361 *obj_res = vm_obj; 362 return 0; 363 out_unref: 364 ttm_bo_unref(&bo); 365 return ret; 366 } 367 368 void 369 ttm_bo_release_mmap(struct ttm_buffer_object *bo) 370 { 371 vm_object_t vm_obj; 372 vm_page_t m; 373 int i; 374 375 vm_obj = cdev_pager_lookup(bo); 376 if (vm_obj == NULL) 377 return; 378 379 VM_OBJECT_WLOCK(vm_obj); 380 retry: 381 for (i = 0; i < bo->num_pages; i++) { 382 m = vm_page_lookup(vm_obj, i); 383 if (m == NULL) 384 continue; 385 if (vm_page_sleep_if_busy(m, "ttm_unm")) 386 goto retry; 387 cdev_pager_free_page(vm_obj, m); 388 } 389 VM_OBJECT_WUNLOCK(vm_obj); 390 391 vm_object_deallocate(vm_obj); 392 } 393 394 #if 0 395 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo) 396 { 397 if (vma->vm_pgoff != 0) 398 return -EACCES; 399 400 vma->vm_ops = &ttm_bo_vm_ops; 401 vma->vm_private_data = ttm_bo_reference(bo); 402 vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND; 403 return 0; 404 } 405 406 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp, 407 const char __user *wbuf, char __user *rbuf, size_t count, 408 loff_t *f_pos, bool write) 409 { 410 struct ttm_buffer_object *bo; 411 struct ttm_bo_driver *driver; 412 struct ttm_bo_kmap_obj map; 413 unsigned long dev_offset = (*f_pos >> PAGE_SHIFT); 414 unsigned long kmap_offset; 415 unsigned long kmap_end; 416 unsigned long kmap_num; 417 size_t io_size; 418 unsigned int page_offset; 419 char *virtual; 420 int ret; 421 bool no_wait = false; 422 bool dummy; 423 424 read_lock(&bdev->vm_lock); 425 bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1); 426 if (likely(bo != NULL)) 427 ttm_bo_reference(bo); 428 read_unlock(&bdev->vm_lock); 429 430 if (unlikely(bo == NULL)) 431 return -EFAULT; 432 433 driver = bo->bdev->driver; 434 if (unlikely(!driver->verify_access)) { 435 ret = -EPERM; 436 goto out_unref; 437 } 438 439 ret = driver->verify_access(bo, filp); 440 if (unlikely(ret != 0)) 441 goto out_unref; 442 443 kmap_offset = dev_offset - bo->vm_node->start; 444 if (unlikely(kmap_offset >= bo->num_pages)) { 445 ret = -EFBIG; 446 goto out_unref; 447 } 448 449 page_offset = *f_pos & ~PAGE_MASK; 450 io_size = bo->num_pages - kmap_offset; 451 io_size = (io_size << PAGE_SHIFT) - page_offset; 452 if (count < io_size) 453 io_size = count; 454 455 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT; 456 kmap_num = kmap_end - kmap_offset + 1; 457 458 ret = ttm_bo_reserve(bo, true, no_wait, false, 0); 459 460 switch (ret) { 461 case 0: 462 break; 463 case -EBUSY: 464 ret = -EAGAIN; 465 goto out_unref; 466 default: 467 goto out_unref; 468 } 469 470 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map); 471 if (unlikely(ret != 0)) { 472 ttm_bo_unreserve(bo); 473 goto out_unref; 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 -EFBIG; 490 491 *f_pos += io_size; 492 493 return io_size; 494 out_unref: 495 ttm_bo_unref(&bo); 496 return ret; 497 } 498 499 ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf, 500 char __user *rbuf, size_t count, loff_t *f_pos, 501 bool write) 502 { 503 struct ttm_bo_kmap_obj map; 504 unsigned long kmap_offset; 505 unsigned long kmap_end; 506 unsigned long kmap_num; 507 size_t io_size; 508 unsigned int page_offset; 509 char *virtual; 510 int ret; 511 bool no_wait = false; 512 bool dummy; 513 514 kmap_offset = (*f_pos >> PAGE_SHIFT); 515 if (unlikely(kmap_offset >= bo->num_pages)) 516 return -EFBIG; 517 518 page_offset = *f_pos & ~PAGE_MASK; 519 io_size = bo->num_pages - kmap_offset; 520 io_size = (io_size << PAGE_SHIFT) - page_offset; 521 if (count < io_size) 522 io_size = count; 523 524 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT; 525 kmap_num = kmap_end - kmap_offset + 1; 526 527 ret = ttm_bo_reserve(bo, true, no_wait, false, 0); 528 529 switch (ret) { 530 case 0: 531 break; 532 case -EBUSY: 533 return -EAGAIN; 534 default: 535 return ret; 536 } 537 538 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map); 539 if (unlikely(ret != 0)) { 540 ttm_bo_unreserve(bo); 541 return ret; 542 } 543 544 virtual = ttm_kmap_obj_virtual(&map, &dummy); 545 virtual += page_offset; 546 547 if (write) 548 ret = copy_from_user(virtual, wbuf, io_size); 549 else 550 ret = copy_to_user(rbuf, virtual, io_size); 551 552 ttm_bo_kunmap(&map); 553 ttm_bo_unreserve(bo); 554 ttm_bo_unref(&bo); 555 556 if (unlikely(ret != 0)) 557 return ret; 558 559 *f_pos += io_size; 560 561 return io_size; 562 } 563 #endif 564