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 #include "opt_vm.h"
40
41 #include <dev/drm2/drmP.h>
42 #include <dev/drm2/ttm/ttm_module.h>
43 #include <dev/drm2/ttm/ttm_bo_driver.h>
44 #include <dev/drm2/ttm/ttm_placement.h>
45
46 #include <vm/vm.h>
47 #include <vm/vm_page.h>
48 #include <vm/vm_pageout.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
ttm_bo_cmp_rb_tree_items(struct ttm_buffer_object * a,struct ttm_buffer_object * b)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
ttm_bo_vm_lookup_rb(struct ttm_bo_device * bdev,unsigned long page_start,unsigned long num_pages)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 bo = RB_ROOT(&bdev->addr_space_rb);
78 while (bo != NULL) {
79 cur_offset = bo->vm_node->start;
80 if (page_start >= cur_offset) {
81 best_bo = bo;
82 if (page_start == cur_offset)
83 break;
84 bo = RB_RIGHT(bo, vm_rb);
85 } else
86 bo = RB_LEFT(bo, vm_rb);
87 }
88
89 if (unlikely(best_bo == NULL))
90 return NULL;
91
92 if (unlikely((best_bo->vm_node->start + best_bo->num_pages) <
93 (page_start + num_pages)))
94 return NULL;
95
96 return best_bo;
97 }
98
99 static int
ttm_bo_vm_fault(vm_object_t vm_obj,vm_ooffset_t offset,int prot,vm_page_t * mres)100 ttm_bo_vm_fault(vm_object_t vm_obj, vm_ooffset_t offset,
101 int prot, vm_page_t *mres)
102 {
103
104 struct ttm_buffer_object *bo = vm_obj->handle;
105 struct ttm_bo_device *bdev = bo->bdev;
106 struct ttm_tt *ttm = NULL;
107 vm_page_t m, m1;
108 int ret;
109 int retval = VM_PAGER_OK;
110 struct ttm_mem_type_manager *man =
111 &bdev->man[bo->mem.mem_type];
112
113 vm_object_pip_add(vm_obj, 1);
114 if (*mres != NULL) {
115 (void)vm_page_remove(*mres);
116 }
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 kern_yield(PRI_USER);
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 -ERESTARTSYS:
137 case -EINTR:
138 kern_yield(PRI_USER);
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 mtx_lock(&bdev->fence_lock);
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 mtx_unlock(&bdev->fence_lock);
171 if (unlikely(ret != 0)) {
172 retval = VM_PAGER_ERROR;
173 goto out_unlock;
174 }
175 } else
176 mtx_unlock(&bdev->fence_lock);
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 = PHYS_TO_VM_PAGE(bo->mem.bus.base + bo->mem.bus.offset +
213 offset);
214 KASSERT((m->flags & PG_FICTITIOUS) != 0,
215 ("physical address %#jx not fictitious",
216 (uintmax_t)(bo->mem.bus.base + bo->mem.bus.offset
217 + 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_busy_acquire(m, VM_ALLOC_WAITFAIL) == 0) {
233 ttm_mem_io_unlock(man);
234 ttm_bo_unreserve(bo);
235 goto retry;
236 }
237 m1 = vm_page_lookup(vm_obj, OFF_TO_IDX(offset));
238 /* XXX This looks like it should just be vm_page_replace? */
239 if (m1 == NULL) {
240 if (vm_page_insert(m, vm_obj, OFF_TO_IDX(offset))) {
241 vm_page_xunbusy(m);
242 VM_OBJECT_WUNLOCK(vm_obj);
243 vm_wait(vm_obj);
244 VM_OBJECT_WLOCK(vm_obj);
245 ttm_mem_io_unlock(man);
246 ttm_bo_unreserve(bo);
247 goto retry;
248 }
249 } else {
250 KASSERT(m == m1,
251 ("inconsistent insert bo %p m %p m1 %p offset %jx",
252 bo, m, m1, (uintmax_t)offset));
253 }
254 vm_page_valid(m);
255 if (*mres != NULL) {
256 KASSERT(*mres != m, ("losing %p %p", *mres, m));
257 vm_page_xunbusy(*mres);
258 vm_page_free(*mres);
259 }
260 *mres = m;
261
262 out_io_unlock1:
263 ttm_mem_io_unlock(man);
264 out_unlock1:
265 ttm_bo_unreserve(bo);
266 vm_object_pip_wakeup(vm_obj);
267 return (retval);
268
269 out_io_unlock:
270 VM_OBJECT_WLOCK(vm_obj);
271 goto out_io_unlock1;
272
273 out_unlock:
274 VM_OBJECT_WLOCK(vm_obj);
275 goto out_unlock1;
276 }
277
278 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)279 ttm_bo_vm_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
280 vm_ooffset_t foff, struct ucred *cred, u_short *color)
281 {
282
283 /*
284 * On Linux, a reference to the buffer object is acquired here.
285 * The reason is that this function is not called when the
286 * mmap() is initialized, but only when a process forks for
287 * instance. Therefore on Linux, the reference on the bo is
288 * acquired either in ttm_bo_mmap() or ttm_bo_vm_open(). It's
289 * then released in ttm_bo_vm_close().
290 *
291 * Here, this function is called during mmap() initialization.
292 * Thus, the reference acquired in ttm_bo_mmap_single() is
293 * sufficient.
294 */
295
296 *color = 0;
297 return (0);
298 }
299
300 static void
ttm_bo_vm_dtor(void * handle)301 ttm_bo_vm_dtor(void *handle)
302 {
303 struct ttm_buffer_object *bo = handle;
304
305 ttm_bo_unref(&bo);
306 }
307
308 static struct cdev_pager_ops ttm_pager_ops = {
309 .cdev_pg_fault = ttm_bo_vm_fault,
310 .cdev_pg_ctor = ttm_bo_vm_ctor,
311 .cdev_pg_dtor = ttm_bo_vm_dtor
312 };
313
314 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)315 ttm_bo_mmap_single(struct ttm_bo_device *bdev, vm_ooffset_t *offset, vm_size_t size,
316 struct vm_object **obj_res, int nprot)
317 {
318 struct ttm_bo_driver *driver;
319 struct ttm_buffer_object *bo;
320 struct vm_object *vm_obj;
321 int ret;
322
323 rw_wlock(&bdev->vm_lock);
324 bo = ttm_bo_vm_lookup_rb(bdev, OFF_TO_IDX(*offset), OFF_TO_IDX(size));
325 if (likely(bo != NULL))
326 refcount_acquire(&bo->kref);
327 rw_wunlock(&bdev->vm_lock);
328
329 if (unlikely(bo == NULL)) {
330 printf("[TTM] Could not find buffer object to map\n");
331 return (-EINVAL);
332 }
333
334 driver = bo->bdev->driver;
335 if (unlikely(!driver->verify_access)) {
336 ret = -EPERM;
337 goto out_unref;
338 }
339 ret = driver->verify_access(bo);
340 if (unlikely(ret != 0))
341 goto out_unref;
342
343 vm_obj = cdev_pager_allocate(bo, OBJT_MGTDEVICE, &ttm_pager_ops,
344 size, nprot, 0, curthread->td_ucred);
345 if (vm_obj == NULL) {
346 ret = -EINVAL;
347 goto out_unref;
348 }
349 /*
350 * Note: We're transferring the bo reference to vm_obj->handle here.
351 */
352 *offset = 0;
353 *obj_res = vm_obj;
354 return 0;
355 out_unref:
356 ttm_bo_unref(&bo);
357 return ret;
358 }
359
360 void
ttm_bo_release_mmap(struct ttm_buffer_object * bo)361 ttm_bo_release_mmap(struct ttm_buffer_object *bo)
362 {
363 vm_object_t vm_obj;
364
365 vm_obj = cdev_pager_lookup(bo);
366 if (vm_obj != NULL) {
367 cdev_mgtdev_pager_free_pages(vm_obj);
368 vm_object_deallocate(vm_obj);
369 }
370 }
371
372 #if 0
373 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
374 {
375 if (vma->vm_pgoff != 0)
376 return -EACCES;
377
378 vma->vm_ops = &ttm_bo_vm_ops;
379 vma->vm_private_data = ttm_bo_reference(bo);
380 vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
381 return 0;
382 }
383
384 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
385 const char __user *wbuf, char __user *rbuf, size_t count,
386 loff_t *f_pos, bool write)
387 {
388 struct ttm_buffer_object *bo;
389 struct ttm_bo_driver *driver;
390 struct ttm_bo_kmap_obj map;
391 unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
392 unsigned long kmap_offset;
393 unsigned long kmap_end;
394 unsigned long kmap_num;
395 size_t io_size;
396 unsigned int page_offset;
397 char *virtual;
398 int ret;
399 bool no_wait = false;
400 bool dummy;
401
402 read_lock(&bdev->vm_lock);
403 bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
404 if (likely(bo != NULL))
405 ttm_bo_reference(bo);
406 read_unlock(&bdev->vm_lock);
407
408 if (unlikely(bo == NULL))
409 return -EFAULT;
410
411 driver = bo->bdev->driver;
412 if (unlikely(!driver->verify_access)) {
413 ret = -EPERM;
414 goto out_unref;
415 }
416
417 ret = driver->verify_access(bo, filp);
418 if (unlikely(ret != 0))
419 goto out_unref;
420
421 kmap_offset = dev_offset - bo->vm_node->start;
422 if (unlikely(kmap_offset >= bo->num_pages)) {
423 ret = -EFBIG;
424 goto out_unref;
425 }
426
427 page_offset = *f_pos & ~PAGE_MASK;
428 io_size = bo->num_pages - kmap_offset;
429 io_size = (io_size << PAGE_SHIFT) - page_offset;
430 if (count < io_size)
431 io_size = count;
432
433 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
434 kmap_num = kmap_end - kmap_offset + 1;
435
436 ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
437
438 switch (ret) {
439 case 0:
440 break;
441 case -EBUSY:
442 ret = -EAGAIN;
443 goto out_unref;
444 default:
445 goto out_unref;
446 }
447
448 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
449 if (unlikely(ret != 0)) {
450 ttm_bo_unreserve(bo);
451 goto out_unref;
452 }
453
454 virtual = ttm_kmap_obj_virtual(&map, &dummy);
455 virtual += page_offset;
456
457 if (write)
458 ret = copy_from_user(virtual, wbuf, io_size);
459 else
460 ret = copy_to_user(rbuf, virtual, io_size);
461
462 ttm_bo_kunmap(&map);
463 ttm_bo_unreserve(bo);
464 ttm_bo_unref(&bo);
465
466 if (unlikely(ret != 0))
467 return -EFBIG;
468
469 *f_pos += io_size;
470
471 return io_size;
472 out_unref:
473 ttm_bo_unref(&bo);
474 return ret;
475 }
476
477 ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf,
478 char __user *rbuf, size_t count, loff_t *f_pos,
479 bool write)
480 {
481 struct ttm_bo_kmap_obj map;
482 unsigned long kmap_offset;
483 unsigned long kmap_end;
484 unsigned long kmap_num;
485 size_t io_size;
486 unsigned int page_offset;
487 char *virtual;
488 int ret;
489 bool no_wait = false;
490 bool dummy;
491
492 kmap_offset = (*f_pos >> PAGE_SHIFT);
493 if (unlikely(kmap_offset >= bo->num_pages))
494 return -EFBIG;
495
496 page_offset = *f_pos & ~PAGE_MASK;
497 io_size = bo->num_pages - kmap_offset;
498 io_size = (io_size << PAGE_SHIFT) - page_offset;
499 if (count < io_size)
500 io_size = count;
501
502 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
503 kmap_num = kmap_end - kmap_offset + 1;
504
505 ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
506
507 switch (ret) {
508 case 0:
509 break;
510 case -EBUSY:
511 return -EAGAIN;
512 default:
513 return ret;
514 }
515
516 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
517 if (unlikely(ret != 0)) {
518 ttm_bo_unreserve(bo);
519 return ret;
520 }
521
522 virtual = ttm_kmap_obj_virtual(&map, &dummy);
523 virtual += page_offset;
524
525 if (write)
526 ret = copy_from_user(virtual, wbuf, io_size);
527 else
528 ret = copy_to_user(rbuf, virtual, io_size);
529
530 ttm_bo_kunmap(&map);
531 ttm_bo_unreserve(bo);
532 ttm_bo_unref(&bo);
533
534 if (unlikely(ret != 0))
535 return ret;
536
537 *f_pos += io_size;
538
539 return io_size;
540 }
541 #endif
542