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 <drm/drmP.h> 43 #include <dev/drm/ttm/ttm_module.h> 44 #include <dev/drm/ttm/ttm_bo_driver.h> 45 #include <dev/drm/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 /* 154 * Here, the behavior differs between Linux and FreeBSD. 155 * 156 * On Linux, the wait is interruptible (3rd argument to 157 * ttm_bo_wait). There must be some mechanism to resume 158 * page fault handling, once the signal is processed. 159 * 160 * On FreeBSD, the wait is uninteruptible. This is not a 161 * problem as we can't end up with an unkillable process 162 * here, because the wait will eventually time out. 163 * 164 * An example of this situation is the Xorg process 165 * which uses SIGALRM internally. The signal could 166 * interrupt the wait, causing the page fault to fail 167 * and the process to receive SIGSEGV. 168 */ 169 ret = ttm_bo_wait(bo, false, false, false); 170 lockmgr(&bdev->fence_lock, LK_RELEASE); 171 if (unlikely(ret != 0)) { 172 retval = VM_PAGER_ERROR; 173 goto out_unlock; 174 } 175 } else 176 lockmgr(&bdev->fence_lock, LK_RELEASE); 177 178 ret = ttm_mem_io_lock(man, true); 179 if (unlikely(ret != 0)) { 180 retval = VM_PAGER_ERROR; 181 goto out_unlock; 182 } 183 ret = ttm_mem_io_reserve_vm(bo); 184 if (unlikely(ret != 0)) { 185 retval = VM_PAGER_ERROR; 186 goto out_io_unlock; 187 } 188 189 /* 190 * Strictly, we're not allowed to modify vma->vm_page_prot here, 191 * since the mmap_sem is only held in read mode. However, we 192 * modify only the caching bits of vma->vm_page_prot and 193 * consider those bits protected by 194 * the bo->mutex, as we should be the only writers. 195 * There shouldn't really be any readers of these bits except 196 * within vm_insert_mixed()? fork? 197 * 198 * TODO: Add a list of vmas to the bo, and change the 199 * vma->vm_page_prot when the object changes caching policy, with 200 * the correct locks held. 201 */ 202 if (!bo->mem.bus.is_iomem) { 203 /* Allocate all page at once, most common usage */ 204 ttm = bo->ttm; 205 if (ttm->bdev->driver->ttm_tt_populate(ttm)) { 206 retval = VM_PAGER_ERROR; 207 goto out_io_unlock; 208 } 209 } 210 211 if (bo->mem.bus.is_iomem) { 212 m = vm_phys_fictitious_to_vm_page(bo->mem.bus.base + 213 bo->mem.bus.offset + offset); 214 pmap_page_set_memattr(m, ttm_io_prot(bo->mem.placement)); 215 } else { 216 ttm = bo->ttm; 217 m = ttm->pages[OFF_TO_IDX(offset)]; 218 if (unlikely(!m)) { 219 retval = VM_PAGER_ERROR; 220 goto out_io_unlock; 221 } 222 pmap_page_set_memattr(m, 223 (bo->mem.placement & TTM_PL_FLAG_CACHED) ? 224 VM_MEMATTR_WRITE_BACK : ttm_io_prot(bo->mem.placement)); 225 } 226 227 VM_OBJECT_WLOCK(vm_obj); 228 if ((m->flags & PG_BUSY) != 0) { 229 #if 0 230 vm_page_sleep(m, "ttmpbs"); 231 #endif 232 ttm_mem_io_unlock(man); 233 ttm_bo_unreserve(bo); 234 goto retry; 235 } 236 m->valid = VM_PAGE_BITS_ALL; 237 *mres = m; 238 m1 = vm_page_lookup(vm_obj, OFF_TO_IDX(offset)); 239 if (m1 == NULL) { 240 vm_page_insert(m, vm_obj, OFF_TO_IDX(offset)); 241 } else { 242 KASSERT(m == m1, 243 ("inconsistent insert bo %p m %p m1 %p offset %jx", 244 bo, m, m1, (uintmax_t)offset)); 245 } 246 vm_page_busy_try(m, FALSE); 247 248 if (oldm != NULL) { 249 vm_page_free(oldm); 250 } 251 252 out_io_unlock1: 253 ttm_mem_io_unlock(man); 254 out_unlock1: 255 ttm_bo_unreserve(bo); 256 vm_object_pip_wakeup(vm_obj); 257 return (retval); 258 259 out_io_unlock: 260 VM_OBJECT_WLOCK(vm_obj); 261 goto out_io_unlock1; 262 263 out_unlock: 264 VM_OBJECT_WLOCK(vm_obj); 265 goto out_unlock1; 266 } 267 268 static int 269 ttm_bo_vm_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 270 vm_ooffset_t foff, struct ucred *cred, u_short *color) 271 { 272 273 /* 274 * On Linux, a reference to the buffer object is acquired here. 275 * The reason is that this function is not called when the 276 * mmap() is initialized, but only when a process forks for 277 * instance. Therefore on Linux, the reference on the bo is 278 * acquired either in ttm_bo_mmap() or ttm_bo_vm_open(). It's 279 * then released in ttm_bo_vm_close(). 280 * 281 * Here, this function is called during mmap() intialization. 282 * Thus, the reference acquired in ttm_bo_mmap_single() is 283 * sufficient. 284 */ 285 286 *color = 0; 287 return (0); 288 } 289 290 static void 291 ttm_bo_vm_dtor(void *handle) 292 { 293 struct ttm_buffer_object *bo = handle; 294 295 ttm_bo_unref(&bo); 296 } 297 298 static struct cdev_pager_ops ttm_pager_ops = { 299 .cdev_pg_fault = ttm_bo_vm_fault, 300 .cdev_pg_ctor = ttm_bo_vm_ctor, 301 .cdev_pg_dtor = ttm_bo_vm_dtor 302 }; 303 304 int 305 ttm_bo_mmap_single(struct ttm_bo_device *bdev, vm_ooffset_t *offset, vm_size_t size, 306 struct vm_object **obj_res, int nprot) 307 { 308 struct ttm_bo_driver *driver; 309 struct ttm_buffer_object *bo; 310 struct vm_object *vm_obj; 311 int ret; 312 313 lockmgr(&bdev->vm_lock, LK_EXCLUSIVE); 314 bo = ttm_bo_vm_lookup_rb(bdev, OFF_TO_IDX(*offset), OFF_TO_IDX(size)); 315 if (likely(bo != NULL)) 316 refcount_acquire(&bo->kref); 317 lockmgr(&bdev->vm_lock, LK_RELEASE); 318 319 if (unlikely(bo == NULL)) { 320 kprintf("[TTM] Could not find buffer object to map\n"); 321 return (EINVAL); 322 } 323 324 driver = bo->bdev->driver; 325 if (unlikely(!driver->verify_access)) { 326 ret = EPERM; 327 goto out_unref; 328 } 329 ret = -driver->verify_access(bo); 330 if (unlikely(ret != 0)) 331 goto out_unref; 332 333 vm_obj = cdev_pager_allocate(bo, OBJT_MGTDEVICE, &ttm_pager_ops, 334 size, nprot, 0, curthread->td_ucred); 335 if (vm_obj == NULL) { 336 ret = EINVAL; 337 goto out_unref; 338 } 339 /* 340 * Note: We're transferring the bo reference to vm_obj->handle here. 341 */ 342 *offset = 0; 343 *obj_res = vm_obj; 344 return 0; 345 out_unref: 346 ttm_bo_unref(&bo); 347 return ret; 348 } 349 350 void 351 ttm_bo_release_mmap(struct ttm_buffer_object *bo) 352 { 353 vm_object_t vm_obj; 354 vm_page_t m; 355 int i; 356 357 vm_obj = cdev_pager_lookup(bo); 358 if (vm_obj == NULL) 359 return; 360 361 VM_OBJECT_WLOCK(vm_obj); 362 for (i = 0; i < bo->num_pages; i++) { 363 m = vm_page_lookup_busy_wait(vm_obj, i, TRUE, "ttm_unm"); 364 if (m == NULL) 365 continue; 366 cdev_pager_free_page(vm_obj, m); 367 } 368 VM_OBJECT_WUNLOCK(vm_obj); 369 370 vm_object_deallocate(vm_obj); 371 } 372 373 #if 0 374 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo) 375 { 376 if (vma->vm_pgoff != 0) 377 return -EACCES; 378 379 vma->vm_ops = &ttm_bo_vm_ops; 380 vma->vm_private_data = ttm_bo_reference(bo); 381 vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND; 382 return 0; 383 } 384 385 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp, 386 const char __user *wbuf, char __user *rbuf, size_t count, 387 loff_t *f_pos, bool write) 388 { 389 struct ttm_buffer_object *bo; 390 struct ttm_bo_driver *driver; 391 struct ttm_bo_kmap_obj map; 392 unsigned long dev_offset = (*f_pos >> PAGE_SHIFT); 393 unsigned long kmap_offset; 394 unsigned long kmap_end; 395 unsigned long kmap_num; 396 size_t io_size; 397 unsigned int page_offset; 398 char *virtual; 399 int ret; 400 bool no_wait = false; 401 bool dummy; 402 403 read_lock(&bdev->vm_lock); 404 bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1); 405 if (likely(bo != NULL)) 406 ttm_bo_reference(bo); 407 read_unlock(&bdev->vm_lock); 408 409 if (unlikely(bo == NULL)) 410 return -EFAULT; 411 412 driver = bo->bdev->driver; 413 if (unlikely(!driver->verify_access)) { 414 ret = -EPERM; 415 goto out_unref; 416 } 417 418 ret = driver->verify_access(bo, filp); 419 if (unlikely(ret != 0)) 420 goto out_unref; 421 422 kmap_offset = dev_offset - bo->vm_node->start; 423 if (unlikely(kmap_offset >= bo->num_pages)) { 424 ret = -EFBIG; 425 goto out_unref; 426 } 427 428 page_offset = *f_pos & ~PAGE_MASK; 429 io_size = bo->num_pages - kmap_offset; 430 io_size = (io_size << PAGE_SHIFT) - page_offset; 431 if (count < io_size) 432 io_size = count; 433 434 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT; 435 kmap_num = kmap_end - kmap_offset + 1; 436 437 ret = ttm_bo_reserve(bo, true, no_wait, false, 0); 438 439 switch (ret) { 440 case 0: 441 break; 442 case -EBUSY: 443 ret = -EAGAIN; 444 goto out_unref; 445 default: 446 goto out_unref; 447 } 448 449 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map); 450 if (unlikely(ret != 0)) { 451 ttm_bo_unreserve(bo); 452 goto out_unref; 453 } 454 455 virtual = ttm_kmap_obj_virtual(&map, &dummy); 456 virtual += page_offset; 457 458 if (write) 459 ret = copy_from_user(virtual, wbuf, io_size); 460 else 461 ret = copy_to_user(rbuf, virtual, io_size); 462 463 ttm_bo_kunmap(&map); 464 ttm_bo_unreserve(bo); 465 ttm_bo_unref(&bo); 466 467 if (unlikely(ret != 0)) 468 return -EFBIG; 469 470 *f_pos += io_size; 471 472 return io_size; 473 out_unref: 474 ttm_bo_unref(&bo); 475 return ret; 476 } 477 478 ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf, 479 char __user *rbuf, size_t count, loff_t *f_pos, 480 bool write) 481 { 482 struct ttm_bo_kmap_obj map; 483 unsigned long kmap_offset; 484 unsigned long kmap_end; 485 unsigned long kmap_num; 486 size_t io_size; 487 unsigned int page_offset; 488 char *virtual; 489 int ret; 490 bool no_wait = false; 491 bool dummy; 492 493 kmap_offset = (*f_pos >> PAGE_SHIFT); 494 if (unlikely(kmap_offset >= bo->num_pages)) 495 return -EFBIG; 496 497 page_offset = *f_pos & ~PAGE_MASK; 498 io_size = bo->num_pages - kmap_offset; 499 io_size = (io_size << PAGE_SHIFT) - page_offset; 500 if (count < io_size) 501 io_size = count; 502 503 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT; 504 kmap_num = kmap_end - kmap_offset + 1; 505 506 ret = ttm_bo_reserve(bo, true, no_wait, false, 0); 507 508 switch (ret) { 509 case 0: 510 break; 511 case -EBUSY: 512 return -EAGAIN; 513 default: 514 return ret; 515 } 516 517 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map); 518 if (unlikely(ret != 0)) { 519 ttm_bo_unreserve(bo); 520 return ret; 521 } 522 523 virtual = ttm_kmap_obj_virtual(&map, &dummy); 524 virtual += page_offset; 525 526 if (write) 527 ret = copy_from_user(virtual, wbuf, io_size); 528 else 529 ret = copy_to_user(rbuf, virtual, io_size); 530 531 ttm_bo_kunmap(&map); 532 ttm_bo_unreserve(bo); 533 ttm_bo_unref(&bo); 534 535 if (unlikely(ret != 0)) 536 return ret; 537 538 *f_pos += io_size; 539 540 return io_size; 541 } 542 #endif 543