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