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 RB_FOREACH(bo, ttm_bo_device_buffer_objects, &bdev->addr_space_rb) { 80 cur_offset = bo->vm_node->start; 81 if (page_start >= cur_offset) { 82 best_bo = bo; 83 if (page_start == cur_offset) 84 break; 85 } 86 } 87 88 if (unlikely(best_bo == NULL)) 89 return NULL; 90 91 if (unlikely((best_bo->vm_node->start + best_bo->num_pages) < 92 (page_start + num_pages))) 93 return NULL; 94 95 return best_bo; 96 } 97 98 static int 99 ttm_bo_vm_fault(vm_object_t vm_obj, vm_ooffset_t offset, 100 int prot, vm_page_t *mres) 101 { 102 103 struct ttm_buffer_object *bo = vm_obj->handle; 104 struct ttm_bo_device *bdev = bo->bdev; 105 struct ttm_tt *ttm = NULL; 106 vm_page_t m, m1, oldm; 107 int ret; 108 int retval = VM_PAGER_OK; 109 struct ttm_mem_type_manager *man = 110 &bdev->man[bo->mem.mem_type]; 111 112 vm_object_pip_add(vm_obj, 1); 113 oldm = *mres; 114 if (oldm != NULL) { 115 vm_page_lock(oldm); 116 vm_page_remove(oldm); 117 vm_page_unlock(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 kern_yield(0); 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 kern_yield(0); 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 = 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 (vm_page_busied(m)) { 233 vm_page_lock(m); 234 VM_OBJECT_WUNLOCK(vm_obj); 235 vm_page_busy_sleep(m, "ttmpbs"); 236 VM_OBJECT_WLOCK(vm_obj); 237 ttm_mem_io_unlock(man); 238 ttm_bo_unreserve(bo); 239 goto retry; 240 } 241 m1 = vm_page_lookup(vm_obj, OFF_TO_IDX(offset)); 242 if (m1 == NULL) { 243 if (vm_page_insert(m, vm_obj, OFF_TO_IDX(offset))) { 244 VM_OBJECT_WUNLOCK(vm_obj); 245 VM_WAIT; 246 VM_OBJECT_WLOCK(vm_obj); 247 ttm_mem_io_unlock(man); 248 ttm_bo_unreserve(bo); 249 goto retry; 250 } 251 } else { 252 KASSERT(m == m1, 253 ("inconsistent insert bo %p m %p m1 %p offset %jx", 254 bo, m, m1, (uintmax_t)offset)); 255 } 256 m->valid = VM_PAGE_BITS_ALL; 257 *mres = m; 258 vm_page_xbusy(m); 259 260 if (oldm != NULL) { 261 vm_page_lock(oldm); 262 vm_page_free(oldm); 263 vm_page_unlock(oldm); 264 } 265 266 out_io_unlock1: 267 ttm_mem_io_unlock(man); 268 out_unlock1: 269 ttm_bo_unreserve(bo); 270 vm_object_pip_wakeup(vm_obj); 271 return (retval); 272 273 out_io_unlock: 274 VM_OBJECT_WLOCK(vm_obj); 275 goto out_io_unlock1; 276 277 out_unlock: 278 VM_OBJECT_WLOCK(vm_obj); 279 goto out_unlock1; 280 } 281 282 static int 283 ttm_bo_vm_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 284 vm_ooffset_t foff, struct ucred *cred, u_short *color) 285 { 286 287 /* 288 * On Linux, a reference to the buffer object is acquired here. 289 * The reason is that this function is not called when the 290 * mmap() is initialized, but only when a process forks for 291 * instance. Therefore on Linux, the reference on the bo is 292 * acquired either in ttm_bo_mmap() or ttm_bo_vm_open(). It's 293 * then released in ttm_bo_vm_close(). 294 * 295 * Here, this function is called during mmap() intialization. 296 * Thus, the reference acquired in ttm_bo_mmap_single() is 297 * sufficient. 298 */ 299 300 *color = 0; 301 return (0); 302 } 303 304 static void 305 ttm_bo_vm_dtor(void *handle) 306 { 307 struct ttm_buffer_object *bo = handle; 308 309 ttm_bo_unref(&bo); 310 } 311 312 static struct cdev_pager_ops ttm_pager_ops = { 313 .cdev_pg_fault = ttm_bo_vm_fault, 314 .cdev_pg_ctor = ttm_bo_vm_ctor, 315 .cdev_pg_dtor = ttm_bo_vm_dtor 316 }; 317 318 int 319 ttm_bo_mmap_single(struct ttm_bo_device *bdev, vm_ooffset_t *offset, vm_size_t size, 320 struct vm_object **obj_res, int nprot) 321 { 322 struct ttm_bo_driver *driver; 323 struct ttm_buffer_object *bo; 324 struct vm_object *vm_obj; 325 int ret; 326 327 rw_wlock(&bdev->vm_lock); 328 bo = ttm_bo_vm_lookup_rb(bdev, OFF_TO_IDX(*offset), OFF_TO_IDX(size)); 329 if (likely(bo != NULL)) 330 refcount_acquire(&bo->kref); 331 rw_wunlock(&bdev->vm_lock); 332 333 if (unlikely(bo == NULL)) { 334 printf("[TTM] Could not find buffer object to map\n"); 335 return (EINVAL); 336 } 337 338 driver = bo->bdev->driver; 339 if (unlikely(!driver->verify_access)) { 340 ret = EPERM; 341 goto out_unref; 342 } 343 ret = -driver->verify_access(bo); 344 if (unlikely(ret != 0)) 345 goto out_unref; 346 347 vm_obj = cdev_pager_allocate(bo, OBJT_MGTDEVICE, &ttm_pager_ops, 348 size, nprot, 0, curthread->td_ucred); 349 if (vm_obj == NULL) { 350 ret = EINVAL; 351 goto out_unref; 352 } 353 /* 354 * Note: We're transferring the bo reference to vm_obj->handle here. 355 */ 356 *offset = 0; 357 *obj_res = vm_obj; 358 return 0; 359 out_unref: 360 ttm_bo_unref(&bo); 361 return ret; 362 } 363 364 void 365 ttm_bo_release_mmap(struct ttm_buffer_object *bo) 366 { 367 vm_object_t vm_obj; 368 vm_page_t m; 369 int i; 370 371 vm_obj = cdev_pager_lookup(bo); 372 if (vm_obj == NULL) 373 return; 374 375 VM_OBJECT_WLOCK(vm_obj); 376 retry: 377 for (i = 0; i < bo->num_pages; i++) { 378 m = vm_page_lookup(vm_obj, i); 379 if (m == NULL) 380 continue; 381 if (vm_page_sleep_if_busy(m, "ttm_unm")) 382 goto retry; 383 cdev_pager_free_page(vm_obj, m); 384 } 385 VM_OBJECT_WUNLOCK(vm_obj); 386 387 vm_object_deallocate(vm_obj); 388 } 389 390 #if 0 391 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo) 392 { 393 if (vma->vm_pgoff != 0) 394 return -EACCES; 395 396 vma->vm_ops = &ttm_bo_vm_ops; 397 vma->vm_private_data = ttm_bo_reference(bo); 398 vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND; 399 return 0; 400 } 401 402 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp, 403 const char __user *wbuf, char __user *rbuf, size_t count, 404 loff_t *f_pos, bool write) 405 { 406 struct ttm_buffer_object *bo; 407 struct ttm_bo_driver *driver; 408 struct ttm_bo_kmap_obj map; 409 unsigned long dev_offset = (*f_pos >> PAGE_SHIFT); 410 unsigned long kmap_offset; 411 unsigned long kmap_end; 412 unsigned long kmap_num; 413 size_t io_size; 414 unsigned int page_offset; 415 char *virtual; 416 int ret; 417 bool no_wait = false; 418 bool dummy; 419 420 read_lock(&bdev->vm_lock); 421 bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1); 422 if (likely(bo != NULL)) 423 ttm_bo_reference(bo); 424 read_unlock(&bdev->vm_lock); 425 426 if (unlikely(bo == NULL)) 427 return -EFAULT; 428 429 driver = bo->bdev->driver; 430 if (unlikely(!driver->verify_access)) { 431 ret = -EPERM; 432 goto out_unref; 433 } 434 435 ret = driver->verify_access(bo, filp); 436 if (unlikely(ret != 0)) 437 goto out_unref; 438 439 kmap_offset = dev_offset - bo->vm_node->start; 440 if (unlikely(kmap_offset >= bo->num_pages)) { 441 ret = -EFBIG; 442 goto out_unref; 443 } 444 445 page_offset = *f_pos & ~PAGE_MASK; 446 io_size = bo->num_pages - kmap_offset; 447 io_size = (io_size << PAGE_SHIFT) - page_offset; 448 if (count < io_size) 449 io_size = count; 450 451 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT; 452 kmap_num = kmap_end - kmap_offset + 1; 453 454 ret = ttm_bo_reserve(bo, true, no_wait, false, 0); 455 456 switch (ret) { 457 case 0: 458 break; 459 case -EBUSY: 460 ret = -EAGAIN; 461 goto out_unref; 462 default: 463 goto out_unref; 464 } 465 466 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map); 467 if (unlikely(ret != 0)) { 468 ttm_bo_unreserve(bo); 469 goto out_unref; 470 } 471 472 virtual = ttm_kmap_obj_virtual(&map, &dummy); 473 virtual += page_offset; 474 475 if (write) 476 ret = copy_from_user(virtual, wbuf, io_size); 477 else 478 ret = copy_to_user(rbuf, virtual, io_size); 479 480 ttm_bo_kunmap(&map); 481 ttm_bo_unreserve(bo); 482 ttm_bo_unref(&bo); 483 484 if (unlikely(ret != 0)) 485 return -EFBIG; 486 487 *f_pos += io_size; 488 489 return io_size; 490 out_unref: 491 ttm_bo_unref(&bo); 492 return ret; 493 } 494 495 ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf, 496 char __user *rbuf, size_t count, loff_t *f_pos, 497 bool write) 498 { 499 struct ttm_bo_kmap_obj map; 500 unsigned long kmap_offset; 501 unsigned long kmap_end; 502 unsigned long kmap_num; 503 size_t io_size; 504 unsigned int page_offset; 505 char *virtual; 506 int ret; 507 bool no_wait = false; 508 bool dummy; 509 510 kmap_offset = (*f_pos >> PAGE_SHIFT); 511 if (unlikely(kmap_offset >= bo->num_pages)) 512 return -EFBIG; 513 514 page_offset = *f_pos & ~PAGE_MASK; 515 io_size = bo->num_pages - kmap_offset; 516 io_size = (io_size << PAGE_SHIFT) - page_offset; 517 if (count < io_size) 518 io_size = count; 519 520 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT; 521 kmap_num = kmap_end - kmap_offset + 1; 522 523 ret = ttm_bo_reserve(bo, true, no_wait, false, 0); 524 525 switch (ret) { 526 case 0: 527 break; 528 case -EBUSY: 529 return -EAGAIN; 530 default: 531 return ret; 532 } 533 534 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map); 535 if (unlikely(ret != 0)) { 536 ttm_bo_unreserve(bo); 537 return ret; 538 } 539 540 virtual = ttm_kmap_obj_virtual(&map, &dummy); 541 virtual += page_offset; 542 543 if (write) 544 ret = copy_from_user(virtual, wbuf, io_size); 545 else 546 ret = copy_to_user(rbuf, virtual, io_size); 547 548 ttm_bo_kunmap(&map); 549 ttm_bo_unreserve(bo); 550 ttm_bo_unref(&bo); 551 552 if (unlikely(ret != 0)) 553 return ret; 554 555 *f_pos += io_size; 556 557 return io_size; 558 } 559 #endif 560