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 51#define TTM_BO_VM_NUM_PREFAULT 16 52 53RB_GENERATE(ttm_bo_device_buffer_objects, ttm_buffer_object, vm_rb, 54 ttm_bo_cmp_rb_tree_items); 55 56int 57ttm_bo_cmp_rb_tree_items(struct ttm_buffer_object *a, 58 struct ttm_buffer_object *b) 59{ 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 70static struct ttm_buffer_object *ttm_bo_vm_lookup_rb(struct ttm_bo_device *bdev, 71 unsigned long page_start, 72 unsigned long num_pages) 73{ 74 unsigned long cur_offset; 75 struct ttm_buffer_object *bo; 76 struct ttm_buffer_object *best_bo = NULL; 77 78 bo = RB_ROOT(&bdev->addr_space_rb); 79 while (bo != NULL) { 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 bo = RB_RIGHT(bo, vm_rb); 86 } else 87 bo = RB_LEFT(bo, vm_rb); 88 } 89 90 if (unlikely(best_bo == NULL)) 91 return NULL; 92 93 if (unlikely((best_bo->vm_node->start + best_bo->num_pages) < 94 (page_start + num_pages))) 95 return NULL; 96 97 return best_bo; 98} 99 100static int 101ttm_bo_vm_fault(vm_object_t vm_obj, vm_ooffset_t offset, 102 int prot, vm_page_t *mres) 103{ 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_lock(oldm); 118 vm_page_remove(oldm); 119 vm_page_unlock(oldm); 120 *mres = NULL; 121 } else 122 oldm = NULL; 123retry: 124 VM_OBJECT_UNLOCK(vm_obj); 125 m = NULL; 126 127reserve: 128 ret = ttm_bo_reserve(bo, false, false, false, 0); 129 if (unlikely(ret != 0)) { 130 if (ret == -EBUSY) { 131 kern_yield(0); 132 goto reserve; 133 } 134 } 135 136 if (bdev->driver->fault_reserve_notify) { 137 ret = bdev->driver->fault_reserve_notify(bo); 138 switch (ret) { 139 case 0: 140 break; 141 case -EBUSY: 142 case -ERESTART: 143 case -EINTR: 144 kern_yield(0); 145 goto reserve; 146 default: 147 retval = VM_PAGER_ERROR; 148 goto out_unlock; 149 } 150 } 151 152 /* 153 * Wait for buffer data in transit, due to a pipelined 154 * move. 155 */ 156 157 mtx_lock(&bdev->fence_lock); 158 if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) { 159 /* 160 * Here, the behavior differs between Linux and FreeBSD. 161 * 162 * On Linux, the wait is interruptible (3rd argument to 163 * ttm_bo_wait). There must be some mechanism to resume 164 * page fault handling, once the signal is processed. 165 * 166 * On FreeBSD, the wait is uninteruptible. This is not a 167 * problem as we can't end up with an unkillable process 168 * here, because the wait will eventually time out. 169 * 170 * An example of this situation is the Xorg process 171 * which uses SIGALRM internally. The signal could 172 * interrupt the wait, causing the page fault to fail 173 * and the process to receive SIGSEGV. 174 */ 175 ret = ttm_bo_wait(bo, false, false, false); 176 mtx_unlock(&bdev->fence_lock); 177 if (unlikely(ret != 0)) { 178 retval = VM_PAGER_ERROR; 179 goto out_unlock; 180 } 181 } else 182 mtx_unlock(&bdev->fence_lock); 183 184 ret = ttm_mem_io_lock(man, true); 185 if (unlikely(ret != 0)) { 186 retval = VM_PAGER_ERROR; 187 goto out_unlock; 188 } 189 ret = ttm_mem_io_reserve_vm(bo); 190 if (unlikely(ret != 0)) { 191 retval = VM_PAGER_ERROR; 192 goto out_io_unlock; 193 } 194 195 /* 196 * Strictly, we're not allowed to modify vma->vm_page_prot here, 197 * since the mmap_sem is only held in read mode. However, we 198 * modify only the caching bits of vma->vm_page_prot and 199 * consider those bits protected by 200 * the bo->mutex, as we should be the only writers. 201 * There shouldn't really be any readers of these bits except 202 * within vm_insert_mixed()? fork? 203 * 204 * TODO: Add a list of vmas to the bo, and change the 205 * vma->vm_page_prot when the object changes caching policy, with 206 * the correct locks held. 207 */ 208 if (!bo->mem.bus.is_iomem) { 209 /* Allocate all page at once, most common usage */ 210 ttm = bo->ttm; 211 if (ttm->bdev->driver->ttm_tt_populate(ttm)) { 212 retval = VM_PAGER_ERROR; 213 goto out_io_unlock; 214 } 215 } 216 217 if (bo->mem.bus.is_iomem) { 218 m = vm_phys_fictitious_to_vm_page(bo->mem.bus.base + 219 bo->mem.bus.offset + offset); 220 pmap_page_set_memattr(m, ttm_io_prot(bo->mem.placement)); 221 } else { 222 ttm = bo->ttm; 223 m = ttm->pages[OFF_TO_IDX(offset)]; 224 if (unlikely(!m)) { 225 retval = VM_PAGER_ERROR; 226 goto out_io_unlock; 227 } 228 pmap_page_set_memattr(m, 229 (bo->mem.placement & TTM_PL_FLAG_CACHED) ? 230 VM_MEMATTR_WRITE_BACK : ttm_io_prot(bo->mem.placement)); 231 } 232 233 VM_OBJECT_LOCK(vm_obj); 234 if ((m->flags & VPO_BUSY) != 0) { 235 vm_page_sleep(m, "ttmpbs"); 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(m); 251 252 if (oldm != NULL) { 253 vm_page_lock(oldm); 254 vm_page_free(oldm); 255 vm_page_unlock(oldm); 256 } 257 258out_io_unlock1: 259 ttm_mem_io_unlock(man); 260out_unlock1: 261 ttm_bo_unreserve(bo); 262 vm_object_pip_wakeup(vm_obj); 263 return (retval); 264 265out_io_unlock: 266 VM_OBJECT_LOCK(vm_obj); 267 goto out_io_unlock1; 268 269out_unlock: 270 VM_OBJECT_LOCK(vm_obj); 271 goto out_unlock1; 272} 273 274static int 275ttm_bo_vm_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 276 vm_ooffset_t foff, struct ucred *cred, u_short *color) 277{ 278 279 /* 280 * On Linux, a reference to the buffer object is acquired here. 281 * The reason is that this function is not called when the 282 * mmap() is initialized, but only when a process forks for 283 * instance. Therefore on Linux, the reference on the bo is 284 * acquired either in ttm_bo_mmap() or ttm_bo_vm_open(). It's 285 * then released in ttm_bo_vm_close(). 286 * 287 * Here, this function is called during mmap() intialization. 288 * Thus, the reference acquired in ttm_bo_mmap_single() is 289 * sufficient. 290 */ 291 292 *color = 0; 293 return (0); 294} 295 296static void 297ttm_bo_vm_dtor(void *handle) 298{ 299 struct ttm_buffer_object *bo = handle; 300 301 ttm_bo_unref(&bo); 302} 303 304static struct cdev_pager_ops ttm_pager_ops = { 305 .cdev_pg_fault = ttm_bo_vm_fault, 306 .cdev_pg_ctor = ttm_bo_vm_ctor, 307 .cdev_pg_dtor = ttm_bo_vm_dtor 308}; 309 310int 311ttm_bo_mmap_single(struct ttm_bo_device *bdev, vm_ooffset_t *offset, vm_size_t size, 312 struct vm_object **obj_res, int nprot) 313{ 314 struct ttm_bo_driver *driver; 315 struct ttm_buffer_object *bo; 316 struct vm_object *vm_obj; 317 int ret; 318 319 rw_wlock(&bdev->vm_lock); 320 bo = ttm_bo_vm_lookup_rb(bdev, OFF_TO_IDX(*offset), OFF_TO_IDX(size)); 321 if (likely(bo != NULL)) 322 refcount_acquire(&bo->kref); 323 rw_wunlock(&bdev->vm_lock); 324 325 if (unlikely(bo == NULL)) { 326 printf("[TTM] Could not find buffer object to map\n"); 327 return (EINVAL); 328 } 329 330 driver = bo->bdev->driver; 331 if (unlikely(!driver->verify_access)) { 332 ret = EPERM; 333 goto out_unref; 334 } 335 ret = -driver->verify_access(bo); 336 if (unlikely(ret != 0)) 337 goto out_unref; 338 339 vm_obj = cdev_pager_allocate(bo, OBJT_MGTDEVICE, &ttm_pager_ops, 340 size, nprot, 0, curthread->td_ucred); 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; 351out_unref: 352 ttm_bo_unref(&bo); 353 return ret; 354} 355 356void 357ttm_bo_release_mmap(struct ttm_buffer_object *bo) 358{ 359 vm_object_t vm_obj; 360 vm_page_t m; 361 int i; 362 363 vm_obj = cdev_pager_lookup(bo); 364 if (vm_obj == NULL) 365 return; 366 367 VM_OBJECT_LOCK(vm_obj); 368retry: 369 for (i = 0; i < bo->num_pages; i++) { 370 m = vm_page_lookup(vm_obj, i); 371 if (m == NULL) 372 continue; 373 if (vm_page_sleep_if_busy(m, true, "ttm_unm")) 374 goto retry; 375 cdev_pager_free_page(vm_obj, m); 376 } 377 VM_OBJECT_UNLOCK(vm_obj); 378 379 vm_object_deallocate(vm_obj); 380} 381 382#if 0 383int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo) 384{ 385 if (vma->vm_pgoff != 0) 386 return -EACCES; 387 388 vma->vm_ops = &ttm_bo_vm_ops; 389 vma->vm_private_data = ttm_bo_reference(bo); 390 vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND; 391 return 0; 392} 393 394ssize_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 read_lock(&bdev->vm_lock); 413 bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1); 414 if (likely(bo != NULL)) 415 ttm_bo_reference(bo); 416 read_unlock(&bdev->vm_lock); 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; 482out_unref: 483 ttm_bo_unref(&bo); 484 return ret; 485} 486 487ssize_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