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
ttm_bo_cmp_rb_tree_items(struct ttm_buffer_object * a,struct ttm_buffer_object * b)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
ttm_bo_vm_lookup_rb(struct ttm_bo_device * bdev,unsigned long page_start,unsigned long num_pages)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
ttm_bo_vm_fault(vm_object_t vm_obj,vm_ooffset_t offset,int prot,vm_page_t * mres)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, oldm;
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 oldm = *mres;
117 if (oldm != NULL) {
118 vm_page_lock(oldm);
119 vm_page_remove(oldm);
120 vm_page_unlock(oldm);
121 *mres = NULL;
122 } else
123 oldm = NULL;
124 retry:
125 VM_OBJECT_WUNLOCK(vm_obj);
126 m = NULL;
127
128 reserve:
129 ret = ttm_bo_reserve(bo, false, false, false, 0);
130 if (unlikely(ret != 0)) {
131 if (ret == -EBUSY) {
132 kern_yield(0);
133 goto reserve;
134 }
135 }
136
137 if (bdev->driver->fault_reserve_notify) {
138 ret = bdev->driver->fault_reserve_notify(bo);
139 switch (ret) {
140 case 0:
141 break;
142 case -EBUSY:
143 case -ERESTARTSYS:
144 case -EINTR:
145 kern_yield(0);
146 goto reserve;
147 default:
148 retval = VM_PAGER_ERROR;
149 goto out_unlock;
150 }
151 }
152
153 /*
154 * Wait for buffer data in transit, due to a pipelined
155 * move.
156 */
157
158 mtx_lock(&bdev->fence_lock);
159 if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
160 /*
161 * Here, the behavior differs between Linux and FreeBSD.
162 *
163 * On Linux, the wait is interruptible (3rd argument to
164 * ttm_bo_wait). There must be some mechanism to resume
165 * page fault handling, once the signal is processed.
166 *
167 * On FreeBSD, the wait is uninteruptible. This is not a
168 * problem as we can't end up with an unkillable process
169 * here, because the wait will eventually time out.
170 *
171 * An example of this situation is the Xorg process
172 * which uses SIGALRM internally. The signal could
173 * interrupt the wait, causing the page fault to fail
174 * and the process to receive SIGSEGV.
175 */
176 ret = ttm_bo_wait(bo, false, false, false);
177 mtx_unlock(&bdev->fence_lock);
178 if (unlikely(ret != 0)) {
179 retval = VM_PAGER_ERROR;
180 goto out_unlock;
181 }
182 } else
183 mtx_unlock(&bdev->fence_lock);
184
185 ret = ttm_mem_io_lock(man, true);
186 if (unlikely(ret != 0)) {
187 retval = VM_PAGER_ERROR;
188 goto out_unlock;
189 }
190 ret = ttm_mem_io_reserve_vm(bo);
191 if (unlikely(ret != 0)) {
192 retval = VM_PAGER_ERROR;
193 goto out_io_unlock;
194 }
195
196 /*
197 * Strictly, we're not allowed to modify vma->vm_page_prot here,
198 * since the mmap_sem is only held in read mode. However, we
199 * modify only the caching bits of vma->vm_page_prot and
200 * consider those bits protected by
201 * the bo->mutex, as we should be the only writers.
202 * There shouldn't really be any readers of these bits except
203 * within vm_insert_mixed()? fork?
204 *
205 * TODO: Add a list of vmas to the bo, and change the
206 * vma->vm_page_prot when the object changes caching policy, with
207 * the correct locks held.
208 */
209 if (!bo->mem.bus.is_iomem) {
210 /* Allocate all page at once, most common usage */
211 ttm = bo->ttm;
212 if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
213 retval = VM_PAGER_ERROR;
214 goto out_io_unlock;
215 }
216 }
217
218 if (bo->mem.bus.is_iomem) {
219 m = PHYS_TO_VM_PAGE(bo->mem.bus.base + bo->mem.bus.offset +
220 offset);
221 KASSERT((m->flags & PG_FICTITIOUS) != 0,
222 ("physical address %#jx not fictitious",
223 (uintmax_t)(bo->mem.bus.base + bo->mem.bus.offset
224 + offset)));
225 pmap_page_set_memattr(m, ttm_io_prot(bo->mem.placement));
226 } else {
227 ttm = bo->ttm;
228 m = ttm->pages[OFF_TO_IDX(offset)];
229 if (unlikely(!m)) {
230 retval = VM_PAGER_ERROR;
231 goto out_io_unlock;
232 }
233 pmap_page_set_memattr(m,
234 (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
235 VM_MEMATTR_WRITE_BACK : ttm_io_prot(bo->mem.placement));
236 }
237
238 VM_OBJECT_WLOCK(vm_obj);
239 if (vm_page_busied(m)) {
240 vm_page_lock(m);
241 VM_OBJECT_WUNLOCK(vm_obj);
242 vm_page_busy_sleep(m, "ttmpbs");
243 VM_OBJECT_WLOCK(vm_obj);
244 ttm_mem_io_unlock(man);
245 ttm_bo_unreserve(bo);
246 goto retry;
247 }
248 m1 = vm_page_lookup(vm_obj, OFF_TO_IDX(offset));
249 if (m1 == NULL) {
250 if (vm_page_insert(m, vm_obj, OFF_TO_IDX(offset))) {
251 VM_OBJECT_WUNLOCK(vm_obj);
252 VM_WAIT;
253 VM_OBJECT_WLOCK(vm_obj);
254 ttm_mem_io_unlock(man);
255 ttm_bo_unreserve(bo);
256 goto retry;
257 }
258 } else {
259 KASSERT(m == m1,
260 ("inconsistent insert bo %p m %p m1 %p offset %jx",
261 bo, m, m1, (uintmax_t)offset));
262 }
263 m->valid = VM_PAGE_BITS_ALL;
264 *mres = m;
265 vm_page_xbusy(m);
266
267 if (oldm != NULL) {
268 vm_page_lock(oldm);
269 vm_page_free(oldm);
270 vm_page_unlock(oldm);
271 }
272
273 out_io_unlock1:
274 ttm_mem_io_unlock(man);
275 out_unlock1:
276 ttm_bo_unreserve(bo);
277 vm_object_pip_wakeup(vm_obj);
278 return (retval);
279
280 out_io_unlock:
281 VM_OBJECT_WLOCK(vm_obj);
282 goto out_io_unlock1;
283
284 out_unlock:
285 VM_OBJECT_WLOCK(vm_obj);
286 goto out_unlock1;
287 }
288
289 static int
ttm_bo_vm_ctor(void * handle,vm_ooffset_t size,vm_prot_t prot,vm_ooffset_t foff,struct ucred * cred,u_short * color)290 ttm_bo_vm_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
291 vm_ooffset_t foff, struct ucred *cred, u_short *color)
292 {
293
294 /*
295 * On Linux, a reference to the buffer object is acquired here.
296 * The reason is that this function is not called when the
297 * mmap() is initialized, but only when a process forks for
298 * instance. Therefore on Linux, the reference on the bo is
299 * acquired either in ttm_bo_mmap() or ttm_bo_vm_open(). It's
300 * then released in ttm_bo_vm_close().
301 *
302 * Here, this function is called during mmap() intialization.
303 * Thus, the reference acquired in ttm_bo_mmap_single() is
304 * sufficient.
305 */
306
307 *color = 0;
308 return (0);
309 }
310
311 static void
ttm_bo_vm_dtor(void * handle)312 ttm_bo_vm_dtor(void *handle)
313 {
314 struct ttm_buffer_object *bo = handle;
315
316 ttm_bo_unref(&bo);
317 }
318
319 static struct cdev_pager_ops ttm_pager_ops = {
320 .cdev_pg_fault = ttm_bo_vm_fault,
321 .cdev_pg_ctor = ttm_bo_vm_ctor,
322 .cdev_pg_dtor = ttm_bo_vm_dtor
323 };
324
325 int
ttm_bo_mmap_single(struct ttm_bo_device * bdev,vm_ooffset_t * offset,vm_size_t size,struct vm_object ** obj_res,int nprot)326 ttm_bo_mmap_single(struct ttm_bo_device *bdev, vm_ooffset_t *offset, vm_size_t size,
327 struct vm_object **obj_res, int nprot)
328 {
329 struct ttm_bo_driver *driver;
330 struct ttm_buffer_object *bo;
331 struct vm_object *vm_obj;
332 int ret;
333
334 rw_wlock(&bdev->vm_lock);
335 bo = ttm_bo_vm_lookup_rb(bdev, OFF_TO_IDX(*offset), OFF_TO_IDX(size));
336 if (likely(bo != NULL))
337 refcount_acquire(&bo->kref);
338 rw_wunlock(&bdev->vm_lock);
339
340 if (unlikely(bo == NULL)) {
341 printf("[TTM] Could not find buffer object to map\n");
342 return (-EINVAL);
343 }
344
345 driver = bo->bdev->driver;
346 if (unlikely(!driver->verify_access)) {
347 ret = -EPERM;
348 goto out_unref;
349 }
350 ret = driver->verify_access(bo);
351 if (unlikely(ret != 0))
352 goto out_unref;
353
354 vm_obj = cdev_pager_allocate(bo, OBJT_MGTDEVICE, &ttm_pager_ops,
355 size, nprot, 0, curthread->td_ucred);
356 if (vm_obj == NULL) {
357 ret = -EINVAL;
358 goto out_unref;
359 }
360 /*
361 * Note: We're transferring the bo reference to vm_obj->handle here.
362 */
363 *offset = 0;
364 *obj_res = vm_obj;
365 return 0;
366 out_unref:
367 ttm_bo_unref(&bo);
368 return ret;
369 }
370
371 void
ttm_bo_release_mmap(struct ttm_buffer_object * bo)372 ttm_bo_release_mmap(struct ttm_buffer_object *bo)
373 {
374 vm_object_t vm_obj;
375 vm_page_t m;
376 int i;
377
378 vm_obj = cdev_pager_lookup(bo);
379 if (vm_obj == NULL)
380 return;
381
382 VM_OBJECT_WLOCK(vm_obj);
383 retry:
384 for (i = 0; i < bo->num_pages; i++) {
385 m = vm_page_lookup(vm_obj, i);
386 if (m == NULL)
387 continue;
388 if (vm_page_sleep_if_busy(m, "ttm_unm"))
389 goto retry;
390 cdev_pager_free_page(vm_obj, m);
391 }
392 VM_OBJECT_WUNLOCK(vm_obj);
393
394 vm_object_deallocate(vm_obj);
395 }
396
397 #if 0
398 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
399 {
400 if (vma->vm_pgoff != 0)
401 return -EACCES;
402
403 vma->vm_ops = &ttm_bo_vm_ops;
404 vma->vm_private_data = ttm_bo_reference(bo);
405 vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
406 return 0;
407 }
408
409 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
410 const char __user *wbuf, char __user *rbuf, size_t count,
411 loff_t *f_pos, bool write)
412 {
413 struct ttm_buffer_object *bo;
414 struct ttm_bo_driver *driver;
415 struct ttm_bo_kmap_obj map;
416 unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
417 unsigned long kmap_offset;
418 unsigned long kmap_end;
419 unsigned long kmap_num;
420 size_t io_size;
421 unsigned int page_offset;
422 char *virtual;
423 int ret;
424 bool no_wait = false;
425 bool dummy;
426
427 read_lock(&bdev->vm_lock);
428 bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
429 if (likely(bo != NULL))
430 ttm_bo_reference(bo);
431 read_unlock(&bdev->vm_lock);
432
433 if (unlikely(bo == NULL))
434 return -EFAULT;
435
436 driver = bo->bdev->driver;
437 if (unlikely(!driver->verify_access)) {
438 ret = -EPERM;
439 goto out_unref;
440 }
441
442 ret = driver->verify_access(bo, filp);
443 if (unlikely(ret != 0))
444 goto out_unref;
445
446 kmap_offset = dev_offset - bo->vm_node->start;
447 if (unlikely(kmap_offset >= bo->num_pages)) {
448 ret = -EFBIG;
449 goto out_unref;
450 }
451
452 page_offset = *f_pos & ~PAGE_MASK;
453 io_size = bo->num_pages - kmap_offset;
454 io_size = (io_size << PAGE_SHIFT) - page_offset;
455 if (count < io_size)
456 io_size = count;
457
458 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
459 kmap_num = kmap_end - kmap_offset + 1;
460
461 ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
462
463 switch (ret) {
464 case 0:
465 break;
466 case -EBUSY:
467 ret = -EAGAIN;
468 goto out_unref;
469 default:
470 goto out_unref;
471 }
472
473 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
474 if (unlikely(ret != 0)) {
475 ttm_bo_unreserve(bo);
476 goto out_unref;
477 }
478
479 virtual = ttm_kmap_obj_virtual(&map, &dummy);
480 virtual += page_offset;
481
482 if (write)
483 ret = copy_from_user(virtual, wbuf, io_size);
484 else
485 ret = copy_to_user(rbuf, virtual, io_size);
486
487 ttm_bo_kunmap(&map);
488 ttm_bo_unreserve(bo);
489 ttm_bo_unref(&bo);
490
491 if (unlikely(ret != 0))
492 return -EFBIG;
493
494 *f_pos += io_size;
495
496 return io_size;
497 out_unref:
498 ttm_bo_unref(&bo);
499 return ret;
500 }
501
502 ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf,
503 char __user *rbuf, size_t count, loff_t *f_pos,
504 bool write)
505 {
506 struct ttm_bo_kmap_obj map;
507 unsigned long kmap_offset;
508 unsigned long kmap_end;
509 unsigned long kmap_num;
510 size_t io_size;
511 unsigned int page_offset;
512 char *virtual;
513 int ret;
514 bool no_wait = false;
515 bool dummy;
516
517 kmap_offset = (*f_pos >> PAGE_SHIFT);
518 if (unlikely(kmap_offset >= bo->num_pages))
519 return -EFBIG;
520
521 page_offset = *f_pos & ~PAGE_MASK;
522 io_size = bo->num_pages - kmap_offset;
523 io_size = (io_size << PAGE_SHIFT) - page_offset;
524 if (count < io_size)
525 io_size = count;
526
527 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
528 kmap_num = kmap_end - kmap_offset + 1;
529
530 ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
531
532 switch (ret) {
533 case 0:
534 break;
535 case -EBUSY:
536 return -EAGAIN;
537 default:
538 return ret;
539 }
540
541 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
542 if (unlikely(ret != 0)) {
543 ttm_bo_unreserve(bo);
544 return ret;
545 }
546
547 virtual = ttm_kmap_obj_virtual(&map, &dummy);
548 virtual += page_offset;
549
550 if (write)
551 ret = copy_from_user(virtual, wbuf, io_size);
552 else
553 ret = copy_to_user(rbuf, virtual, io_size);
554
555 ttm_bo_kunmap(&map);
556 ttm_bo_unreserve(bo);
557 ttm_bo_unref(&bo);
558
559 if (unlikely(ret != 0))
560 return ret;
561
562 *f_pos += io_size;
563
564 return io_size;
565 }
566 #endif
567