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CommitLineData
5cc9ed4b
CW
1/*
2 * Copyright © 2012-2014 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 */
24
b588c92b
ML
25#include <drm/drmP.h>
26#include <drm/i915_drm.h>
5cc9ed4b
CW
27#include "i915_drv.h"
28#include "i915_trace.h"
29#include "intel_drv.h"
30#include <linux/mmu_context.h>
31#include <linux/mmu_notifier.h>
32#include <linux/mempolicy.h>
33#include <linux/swap.h>
34
ad46cb53
CW
35struct i915_mm_struct {
36 struct mm_struct *mm;
f470b190 37 struct drm_i915_private *i915;
ad46cb53
CW
38 struct i915_mmu_notifier *mn;
39 struct hlist_node node;
40 struct kref kref;
41 struct work_struct work;
42};
43
5cc9ed4b
CW
44#if defined(CONFIG_MMU_NOTIFIER)
45#include <linux/interval_tree.h>
46
47struct i915_mmu_notifier {
48 spinlock_t lock;
49 struct hlist_node node;
50 struct mmu_notifier mn;
51 struct rb_root objects;
393afc2c 52 struct workqueue_struct *wq;
5cc9ed4b
CW
53};
54
55struct i915_mmu_object {
ad46cb53 56 struct i915_mmu_notifier *mn;
768e159f 57 struct drm_i915_gem_object *obj;
5cc9ed4b 58 struct interval_tree_node it;
ec8b0dd5 59 struct list_head link;
380996aa 60 struct work_struct work;
768e159f 61 bool attached;
5cc9ed4b
CW
62};
63
393afc2c
CW
64static void wait_rendering(struct drm_i915_gem_object *obj)
65{
8a3b3d57
CW
66 unsigned long active = __I915_BO_ACTIVE(obj);
67 int idx;
393afc2c 68
8a3b3d57
CW
69 for_each_active(active, idx)
70 i915_gem_active_wait_unlocked(&obj->last_read[idx],
ea746f36 71 0, NULL, NULL);
393afc2c
CW
72}
73
768e159f 74static void cancel_userptr(struct work_struct *work)
ec8b0dd5 75{
380996aa
CW
76 struct i915_mmu_object *mo = container_of(work, typeof(*mo), work);
77 struct drm_i915_gem_object *obj = mo->obj;
ec8b0dd5 78 struct drm_device *dev = obj->base.dev;
ec8b0dd5 79
8a3b3d57
CW
80 wait_rendering(obj);
81
ec8b0dd5
CW
82 mutex_lock(&dev->struct_mutex);
83 /* Cancel any active worker and force us to re-evaluate gup */
84 obj->userptr.work = NULL;
85
86 if (obj->pages != NULL) {
f826ee21 87 /* We are inside a kthread context and can't be interrupted */
aa653a68 88 WARN_ON(i915_gem_object_unbind(obj));
ec8b0dd5 89 WARN_ON(i915_gem_object_put_pages(obj));
ec8b0dd5
CW
90 }
91
f8c417cd 92 i915_gem_object_put(obj);
ec8b0dd5 93 mutex_unlock(&dev->struct_mutex);
ec8b0dd5
CW
94}
95
768e159f 96static void add_object(struct i915_mmu_object *mo)
ec8b0dd5 97{
768e159f
CW
98 if (mo->attached)
99 return;
ec8b0dd5 100
768e159f
CW
101 interval_tree_insert(&mo->it, &mo->mn->objects);
102 mo->attached = true;
103}
104
105static void del_object(struct i915_mmu_object *mo)
106{
107 if (!mo->attached)
108 return;
109
110 interval_tree_remove(&mo->it, &mo->mn->objects);
111 mo->attached = false;
ec8b0dd5
CW
112}
113
5cc9ed4b
CW
114static void i915_gem_userptr_mn_invalidate_range_start(struct mmu_notifier *_mn,
115 struct mm_struct *mm,
116 unsigned long start,
117 unsigned long end)
118{
380996aa
CW
119 struct i915_mmu_notifier *mn =
120 container_of(_mn, struct i915_mmu_notifier, mn);
121 struct i915_mmu_object *mo;
768e159f
CW
122 struct interval_tree_node *it;
123 LIST_HEAD(cancelled);
124
125 if (RB_EMPTY_ROOT(&mn->objects))
126 return;
380996aa
CW
127
128 /* interval ranges are inclusive, but invalidate range is exclusive */
129 end--;
130
131 spin_lock(&mn->lock);
768e159f
CW
132 it = interval_tree_iter_first(&mn->objects, start, end);
133 while (it) {
134 /* The mmu_object is released late when destroying the
135 * GEM object so it is entirely possible to gain a
136 * reference on an object in the process of being freed
137 * since our serialisation is via the spinlock and not
138 * the struct_mutex - and consequently use it after it
139 * is freed and then double free it. To prevent that
140 * use-after-free we only acquire a reference on the
141 * object if it is not in the process of being destroyed.
142 */
143 mo = container_of(it, struct i915_mmu_object, it);
144 if (kref_get_unless_zero(&mo->obj->base.refcount))
393afc2c 145 queue_work(mn->wq, &mo->work);
5cc9ed4b 146
768e159f
CW
147 list_add(&mo->link, &cancelled);
148 it = interval_tree_iter_next(it, start, end);
5cc9ed4b 149 }
768e159f
CW
150 list_for_each_entry(mo, &cancelled, link)
151 del_object(mo);
380996aa 152 spin_unlock(&mn->lock);
393afc2c
CW
153
154 flush_workqueue(mn->wq);
5cc9ed4b
CW
155}
156
157static const struct mmu_notifier_ops i915_gem_userptr_notifier = {
158 .invalidate_range_start = i915_gem_userptr_mn_invalidate_range_start,
159};
160
161static struct i915_mmu_notifier *
ad46cb53 162i915_mmu_notifier_create(struct mm_struct *mm)
5cc9ed4b 163{
ad46cb53 164 struct i915_mmu_notifier *mn;
5cc9ed4b
CW
165 int ret;
166
ad46cb53
CW
167 mn = kmalloc(sizeof(*mn), GFP_KERNEL);
168 if (mn == NULL)
5cc9ed4b
CW
169 return ERR_PTR(-ENOMEM);
170
ad46cb53
CW
171 spin_lock_init(&mn->lock);
172 mn->mn.ops = &i915_gem_userptr_notifier;
173 mn->objects = RB_ROOT;
393afc2c
CW
174 mn->wq = alloc_workqueue("i915-userptr-release", WQ_UNBOUND, 0);
175 if (mn->wq == NULL) {
176 kfree(mn);
177 return ERR_PTR(-ENOMEM);
178 }
ad46cb53
CW
179
180 /* Protected by mmap_sem (write-lock) */
181 ret = __mmu_notifier_register(&mn->mn, mm);
5cc9ed4b 182 if (ret) {
393afc2c 183 destroy_workqueue(mn->wq);
ad46cb53 184 kfree(mn);
5cc9ed4b
CW
185 return ERR_PTR(ret);
186 }
187
ad46cb53 188 return mn;
5cc9ed4b
CW
189}
190
5cc9ed4b
CW
191static void
192i915_gem_userptr_release__mmu_notifier(struct drm_i915_gem_object *obj)
193{
ad46cb53 194 struct i915_mmu_object *mo;
5cc9ed4b 195
ad46cb53
CW
196 mo = obj->userptr.mmu_object;
197 if (mo == NULL)
5cc9ed4b
CW
198 return;
199
768e159f
CW
200 spin_lock(&mo->mn->lock);
201 del_object(mo);
202 spin_unlock(&mo->mn->lock);
ad46cb53
CW
203 kfree(mo);
204
205 obj->userptr.mmu_object = NULL;
206}
207
208static struct i915_mmu_notifier *
209i915_mmu_notifier_find(struct i915_mm_struct *mm)
210{
e9681366
CW
211 struct i915_mmu_notifier *mn = mm->mn;
212
213 mn = mm->mn;
214 if (mn)
215 return mn;
216
217 down_write(&mm->mm->mmap_sem);
f470b190 218 mutex_lock(&mm->i915->mm_lock);
e9681366
CW
219 if ((mn = mm->mn) == NULL) {
220 mn = i915_mmu_notifier_create(mm->mm);
221 if (!IS_ERR(mn))
222 mm->mn = mn;
ad46cb53 223 }
f470b190 224 mutex_unlock(&mm->i915->mm_lock);
e9681366
CW
225 up_write(&mm->mm->mmap_sem);
226
227 return mn;
5cc9ed4b
CW
228}
229
230static int
231i915_gem_userptr_init__mmu_notifier(struct drm_i915_gem_object *obj,
232 unsigned flags)
233{
ad46cb53
CW
234 struct i915_mmu_notifier *mn;
235 struct i915_mmu_object *mo;
5cc9ed4b
CW
236
237 if (flags & I915_USERPTR_UNSYNCHRONIZED)
238 return capable(CAP_SYS_ADMIN) ? 0 : -EPERM;
239
ad46cb53
CW
240 if (WARN_ON(obj->userptr.mm == NULL))
241 return -EINVAL;
5cc9ed4b 242
ad46cb53
CW
243 mn = i915_mmu_notifier_find(obj->userptr.mm);
244 if (IS_ERR(mn))
245 return PTR_ERR(mn);
5cc9ed4b 246
ad46cb53
CW
247 mo = kzalloc(sizeof(*mo), GFP_KERNEL);
248 if (mo == NULL)
249 return -ENOMEM;
5cc9ed4b 250
ad46cb53 251 mo->mn = mn;
ad46cb53 252 mo->obj = obj;
768e159f
CW
253 mo->it.start = obj->userptr.ptr;
254 mo->it.last = obj->userptr.ptr + obj->base.size - 1;
255 INIT_WORK(&mo->work, cancel_userptr);
ad46cb53
CW
256
257 obj->userptr.mmu_object = mo;
5cc9ed4b 258 return 0;
ad46cb53
CW
259}
260
261static void
262i915_mmu_notifier_free(struct i915_mmu_notifier *mn,
263 struct mm_struct *mm)
264{
265 if (mn == NULL)
266 return;
5cc9ed4b 267
ad46cb53 268 mmu_notifier_unregister(&mn->mn, mm);
393afc2c 269 destroy_workqueue(mn->wq);
5cc9ed4b 270 kfree(mn);
5cc9ed4b
CW
271}
272
273#else
274
275static void
276i915_gem_userptr_release__mmu_notifier(struct drm_i915_gem_object *obj)
277{
278}
279
280static int
281i915_gem_userptr_init__mmu_notifier(struct drm_i915_gem_object *obj,
282 unsigned flags)
283{
284 if ((flags & I915_USERPTR_UNSYNCHRONIZED) == 0)
285 return -ENODEV;
286
287 if (!capable(CAP_SYS_ADMIN))
288 return -EPERM;
289
290 return 0;
291}
ad46cb53
CW
292
293static void
294i915_mmu_notifier_free(struct i915_mmu_notifier *mn,
295 struct mm_struct *mm)
296{
297}
298
5cc9ed4b
CW
299#endif
300
ad46cb53
CW
301static struct i915_mm_struct *
302__i915_mm_struct_find(struct drm_i915_private *dev_priv, struct mm_struct *real)
303{
304 struct i915_mm_struct *mm;
305
306 /* Protected by dev_priv->mm_lock */
307 hash_for_each_possible(dev_priv->mm_structs, mm, node, (unsigned long)real)
308 if (mm->mm == real)
309 return mm;
310
311 return NULL;
312}
313
314static int
315i915_gem_userptr_init__mm_struct(struct drm_i915_gem_object *obj)
316{
317 struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
318 struct i915_mm_struct *mm;
319 int ret = 0;
320
321 /* During release of the GEM object we hold the struct_mutex. This
322 * precludes us from calling mmput() at that time as that may be
323 * the last reference and so call exit_mmap(). exit_mmap() will
324 * attempt to reap the vma, and if we were holding a GTT mmap
325 * would then call drm_gem_vm_close() and attempt to reacquire
326 * the struct mutex. So in order to avoid that recursion, we have
327 * to defer releasing the mm reference until after we drop the
328 * struct_mutex, i.e. we need to schedule a worker to do the clean
329 * up.
330 */
331 mutex_lock(&dev_priv->mm_lock);
332 mm = __i915_mm_struct_find(dev_priv, current->mm);
333 if (mm == NULL) {
334 mm = kmalloc(sizeof(*mm), GFP_KERNEL);
335 if (mm == NULL) {
336 ret = -ENOMEM;
337 goto out;
338 }
339
340 kref_init(&mm->kref);
f470b190 341 mm->i915 = to_i915(obj->base.dev);
ad46cb53
CW
342
343 mm->mm = current->mm;
344 atomic_inc(&current->mm->mm_count);
345
346 mm->mn = NULL;
347
348 /* Protected by dev_priv->mm_lock */
349 hash_add(dev_priv->mm_structs,
350 &mm->node, (unsigned long)mm->mm);
351 } else
352 kref_get(&mm->kref);
353
354 obj->userptr.mm = mm;
355out:
356 mutex_unlock(&dev_priv->mm_lock);
357 return ret;
358}
359
360static void
361__i915_mm_struct_free__worker(struct work_struct *work)
362{
363 struct i915_mm_struct *mm = container_of(work, typeof(*mm), work);
364 i915_mmu_notifier_free(mm->mn, mm->mm);
365 mmdrop(mm->mm);
366 kfree(mm);
367}
368
369static void
370__i915_mm_struct_free(struct kref *kref)
371{
372 struct i915_mm_struct *mm = container_of(kref, typeof(*mm), kref);
373
374 /* Protected by dev_priv->mm_lock */
375 hash_del(&mm->node);
f470b190 376 mutex_unlock(&mm->i915->mm_lock);
ad46cb53
CW
377
378 INIT_WORK(&mm->work, __i915_mm_struct_free__worker);
379 schedule_work(&mm->work);
380}
381
382static void
383i915_gem_userptr_release__mm_struct(struct drm_i915_gem_object *obj)
384{
385 if (obj->userptr.mm == NULL)
386 return;
387
388 kref_put_mutex(&obj->userptr.mm->kref,
389 __i915_mm_struct_free,
390 &to_i915(obj->base.dev)->mm_lock);
391 obj->userptr.mm = NULL;
392}
393
5cc9ed4b
CW
394struct get_pages_work {
395 struct work_struct work;
396 struct drm_i915_gem_object *obj;
397 struct task_struct *task;
398};
399
5cc9ed4b
CW
400#if IS_ENABLED(CONFIG_SWIOTLB)
401#define swiotlb_active() swiotlb_nr_tbl()
402#else
403#define swiotlb_active() 0
404#endif
405
406static int
407st_set_pages(struct sg_table **st, struct page **pvec, int num_pages)
408{
409 struct scatterlist *sg;
410 int ret, n;
411
412 *st = kmalloc(sizeof(**st), GFP_KERNEL);
413 if (*st == NULL)
414 return -ENOMEM;
415
416 if (swiotlb_active()) {
417 ret = sg_alloc_table(*st, num_pages, GFP_KERNEL);
418 if (ret)
419 goto err;
420
421 for_each_sg((*st)->sgl, sg, num_pages, n)
422 sg_set_page(sg, pvec[n], PAGE_SIZE, 0);
423 } else {
424 ret = sg_alloc_table_from_pages(*st, pvec, num_pages,
425 0, num_pages << PAGE_SHIFT,
426 GFP_KERNEL);
427 if (ret)
428 goto err;
429 }
430
431 return 0;
432
433err:
434 kfree(*st);
435 *st = NULL;
436 return ret;
437}
438
e2273302
ID
439static int
440__i915_gem_userptr_set_pages(struct drm_i915_gem_object *obj,
441 struct page **pvec, int num_pages)
442{
443 int ret;
444
445 ret = st_set_pages(&obj->pages, pvec, num_pages);
446 if (ret)
447 return ret;
448
449 ret = i915_gem_gtt_prepare_object(obj);
450 if (ret) {
451 sg_free_table(obj->pages);
452 kfree(obj->pages);
453 obj->pages = NULL;
454 }
455
456 return ret;
457}
458
380996aa 459static int
e4b946bf
CW
460__i915_gem_userptr_set_active(struct drm_i915_gem_object *obj,
461 bool value)
462{
380996aa
CW
463 int ret = 0;
464
e4b946bf
CW
465 /* During mm_invalidate_range we need to cancel any userptr that
466 * overlaps the range being invalidated. Doing so requires the
467 * struct_mutex, and that risks recursion. In order to cause
468 * recursion, the user must alias the userptr address space with
469 * a GTT mmapping (possible with a MAP_FIXED) - then when we have
470 * to invalidate that mmaping, mm_invalidate_range is called with
471 * the userptr address *and* the struct_mutex held. To prevent that
472 * we set a flag under the i915_mmu_notifier spinlock to indicate
473 * whether this object is valid.
474 */
475#if defined(CONFIG_MMU_NOTIFIER)
476 if (obj->userptr.mmu_object == NULL)
380996aa 477 return 0;
e4b946bf
CW
478
479 spin_lock(&obj->userptr.mmu_object->mn->lock);
380996aa
CW
480 /* In order to serialise get_pages with an outstanding
481 * cancel_userptr, we must drop the struct_mutex and try again.
482 */
768e159f
CW
483 if (!value)
484 del_object(obj->userptr.mmu_object);
485 else if (!work_pending(&obj->userptr.mmu_object->work))
486 add_object(obj->userptr.mmu_object);
380996aa
CW
487 else
488 ret = -EAGAIN;
e4b946bf
CW
489 spin_unlock(&obj->userptr.mmu_object->mn->lock);
490#endif
380996aa
CW
491
492 return ret;
e4b946bf
CW
493}
494
5cc9ed4b
CW
495static void
496__i915_gem_userptr_get_pages_worker(struct work_struct *_work)
497{
498 struct get_pages_work *work = container_of(_work, typeof(*work), work);
499 struct drm_i915_gem_object *obj = work->obj;
500 struct drm_device *dev = obj->base.dev;
68d6c840 501 const int npages = obj->base.size >> PAGE_SHIFT;
5cc9ed4b
CW
502 struct page **pvec;
503 int pinned, ret;
504
505 ret = -ENOMEM;
506 pinned = 0;
507
f2a85e19 508 pvec = drm_malloc_gfp(npages, sizeof(struct page *), GFP_TEMPORARY);
5cc9ed4b 509 if (pvec != NULL) {
ad46cb53 510 struct mm_struct *mm = obj->userptr.mm->mm;
9beae1ea
LS
511 unsigned int flags = 0;
512
513 if (!obj->userptr.read_only)
514 flags |= FOLL_WRITE;
5cc9ed4b 515
40313f0c
CW
516 ret = -EFAULT;
517 if (atomic_inc_not_zero(&mm->mm_users)) {
518 down_read(&mm->mmap_sem);
519 while (pinned < npages) {
520 ret = get_user_pages_remote
521 (work->task, mm,
522 obj->userptr.ptr + pinned * PAGE_SIZE,
523 npages - pinned,
9beae1ea 524 flags,
40313f0c
CW
525 pvec + pinned, NULL);
526 if (ret < 0)
527 break;
528
529 pinned += ret;
530 }
531 up_read(&mm->mmap_sem);
532 mmput(mm);
5cc9ed4b 533 }
5cc9ed4b
CW
534 }
535
536 mutex_lock(&dev->struct_mutex);
68d6c840
CW
537 if (obj->userptr.work == &work->work) {
538 if (pinned == npages) {
539 ret = __i915_gem_userptr_set_pages(obj, pvec, npages);
540 if (ret == 0) {
541 list_add_tail(&obj->global_list,
542 &to_i915(dev)->mm.unbound_list);
543 obj->get_page.sg = obj->pages->sgl;
544 obj->get_page.last = 0;
545 pinned = 0;
546 }
5cc9ed4b 547 }
68d6c840 548 obj->userptr.work = ERR_PTR(ret);
5cc9ed4b
CW
549 }
550
5cc9ed4b 551 obj->userptr.workers--;
f8c417cd 552 i915_gem_object_put(obj);
5cc9ed4b
CW
553 mutex_unlock(&dev->struct_mutex);
554
555 release_pages(pvec, pinned, 0);
556 drm_free_large(pvec);
557
558 put_task_struct(work->task);
559 kfree(work);
560}
561
e4b946bf
CW
562static int
563__i915_gem_userptr_get_pages_schedule(struct drm_i915_gem_object *obj,
564 bool *active)
565{
566 struct get_pages_work *work;
567
568 /* Spawn a worker so that we can acquire the
569 * user pages without holding our mutex. Access
570 * to the user pages requires mmap_sem, and we have
571 * a strict lock ordering of mmap_sem, struct_mutex -
572 * we already hold struct_mutex here and so cannot
573 * call gup without encountering a lock inversion.
574 *
575 * Userspace will keep on repeating the operation
576 * (thanks to EAGAIN) until either we hit the fast
577 * path or the worker completes. If the worker is
578 * cancelled or superseded, the task is still run
579 * but the results ignored. (This leads to
580 * complications that we may have a stray object
581 * refcount that we need to be wary of when
582 * checking for existing objects during creation.)
583 * If the worker encounters an error, it reports
584 * that error back to this function through
585 * obj->userptr.work = ERR_PTR.
586 */
587 if (obj->userptr.workers >= I915_GEM_USERPTR_MAX_WORKERS)
588 return -EAGAIN;
589
590 work = kmalloc(sizeof(*work), GFP_KERNEL);
591 if (work == NULL)
592 return -ENOMEM;
593
594 obj->userptr.work = &work->work;
595 obj->userptr.workers++;
596
25dc556a 597 work->obj = i915_gem_object_get(obj);
e4b946bf
CW
598
599 work->task = current;
600 get_task_struct(work->task);
601
602 INIT_WORK(&work->work, __i915_gem_userptr_get_pages_worker);
603 schedule_work(&work->work);
604
605 *active = true;
606 return -EAGAIN;
607}
608
5cc9ed4b
CW
609static int
610i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj)
611{
612 const int num_pages = obj->base.size >> PAGE_SHIFT;
613 struct page **pvec;
614 int pinned, ret;
e4b946bf 615 bool active;
5cc9ed4b
CW
616
617 /* If userspace should engineer that these pages are replaced in
618 * the vma between us binding this page into the GTT and completion
619 * of rendering... Their loss. If they change the mapping of their
620 * pages they need to create a new bo to point to the new vma.
621 *
622 * However, that still leaves open the possibility of the vma
623 * being copied upon fork. Which falls under the same userspace
624 * synchronisation issue as a regular bo, except that this time
625 * the process may not be expecting that a particular piece of
626 * memory is tied to the GPU.
627 *
628 * Fortunately, we can hook into the mmu_notifier in order to
629 * discard the page references prior to anything nasty happening
630 * to the vma (discard or cloning) which should prevent the more
631 * egregious cases from causing harm.
632 */
364c8172
CW
633
634 if (obj->userptr.work) {
e4b946bf 635 /* active flag should still be held for the pending work */
364c8172
CW
636 if (IS_ERR(obj->userptr.work))
637 return PTR_ERR(obj->userptr.work);
638 else
639 return -EAGAIN;
640 }
e4b946bf
CW
641
642 /* Let the mmu-notifier know that we have begun and need cancellation */
380996aa
CW
643 ret = __i915_gem_userptr_set_active(obj, true);
644 if (ret)
645 return ret;
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CW
646
647 pvec = NULL;
648 pinned = 0;
ad46cb53 649 if (obj->userptr.mm->mm == current->mm) {
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650 pvec = drm_malloc_gfp(num_pages, sizeof(struct page *),
651 GFP_TEMPORARY);
5cc9ed4b 652 if (pvec == NULL) {
f2a85e19
CW
653 __i915_gem_userptr_set_active(obj, false);
654 return -ENOMEM;
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CW
655 }
656
657 pinned = __get_user_pages_fast(obj->userptr.ptr, num_pages,
658 !obj->userptr.read_only, pvec);
659 }
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660
661 active = false;
662 if (pinned < 0)
663 ret = pinned, pinned = 0;
664 else if (pinned < num_pages)
665 ret = __i915_gem_userptr_get_pages_schedule(obj, &active);
666 else
e2273302 667 ret = __i915_gem_userptr_set_pages(obj, pvec, num_pages);
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668 if (ret) {
669 __i915_gem_userptr_set_active(obj, active);
670 release_pages(pvec, pinned, 0);
5cc9ed4b 671 }
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CW
672 drm_free_large(pvec);
673 return ret;
674}
675
676static void
677i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj)
678{
85d1225e
DG
679 struct sgt_iter sgt_iter;
680 struct page *page;
5cc9ed4b
CW
681
682 BUG_ON(obj->userptr.work != NULL);
e4b946bf 683 __i915_gem_userptr_set_active(obj, false);
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684
685 if (obj->madv != I915_MADV_WILLNEED)
686 obj->dirty = 0;
687
e2273302
ID
688 i915_gem_gtt_finish_object(obj);
689
85d1225e 690 for_each_sgt_page(page, sgt_iter, obj->pages) {
5cc9ed4b
CW
691 if (obj->dirty)
692 set_page_dirty(page);
693
694 mark_page_accessed(page);
09cbfeaf 695 put_page(page);
5cc9ed4b
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696 }
697 obj->dirty = 0;
698
699 sg_free_table(obj->pages);
700 kfree(obj->pages);
701}
702
703static void
704i915_gem_userptr_release(struct drm_i915_gem_object *obj)
705{
706 i915_gem_userptr_release__mmu_notifier(obj);
ad46cb53 707 i915_gem_userptr_release__mm_struct(obj);
5cc9ed4b
CW
708}
709
710static int
711i915_gem_userptr_dmabuf_export(struct drm_i915_gem_object *obj)
712{
ad46cb53 713 if (obj->userptr.mmu_object)
5cc9ed4b
CW
714 return 0;
715
716 return i915_gem_userptr_init__mmu_notifier(obj, 0);
717}
718
719static const struct drm_i915_gem_object_ops i915_gem_userptr_ops = {
de472664 720 .flags = I915_GEM_OBJECT_HAS_STRUCT_PAGE,
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721 .get_pages = i915_gem_userptr_get_pages,
722 .put_pages = i915_gem_userptr_put_pages,
de472664 723 .dmabuf_export = i915_gem_userptr_dmabuf_export,
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724 .release = i915_gem_userptr_release,
725};
726
727/**
728 * Creates a new mm object that wraps some normal memory from the process
729 * context - user memory.
730 *
731 * We impose several restrictions upon the memory being mapped
732 * into the GPU.
733 * 1. It must be page aligned (both start/end addresses, i.e ptr and size).
ec8b0dd5 734 * 2. It must be normal system memory, not a pointer into another map of IO
5cc9ed4b 735 * space (e.g. it must not be a GTT mmapping of another object).
ec8b0dd5 736 * 3. We only allow a bo as large as we could in theory map into the GTT,
5cc9ed4b 737 * that is we limit the size to the total size of the GTT.
ec8b0dd5 738 * 4. The bo is marked as being snoopable. The backing pages are left
5cc9ed4b
CW
739 * accessible directly by the CPU, but reads and writes by the GPU may
740 * incur the cost of a snoop (unless you have an LLC architecture).
741 *
742 * Synchronisation between multiple users and the GPU is left to userspace
743 * through the normal set-domain-ioctl. The kernel will enforce that the
744 * GPU relinquishes the VMA before it is returned back to the system
745 * i.e. upon free(), munmap() or process termination. However, the userspace
746 * malloc() library may not immediately relinquish the VMA after free() and
747 * instead reuse it whilst the GPU is still reading and writing to the VMA.
748 * Caveat emptor.
749 *
750 * Also note, that the object created here is not currently a "first class"
751 * object, in that several ioctls are banned. These are the CPU access
752 * ioctls: mmap(), pwrite and pread. In practice, you are expected to use
cc917ab4
CW
753 * direct access via your pointer rather than use those ioctls. Another
754 * restriction is that we do not allow userptr surfaces to be pinned to the
755 * hardware and so we reject any attempt to create a framebuffer out of a
756 * userptr.
5cc9ed4b
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757 *
758 * If you think this is a good interface to use to pass GPU memory between
759 * drivers, please use dma-buf instead. In fact, wherever possible use
760 * dma-buf instead.
761 */
762int
763i915_gem_userptr_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
764{
5cc9ed4b
CW
765 struct drm_i915_gem_userptr *args = data;
766 struct drm_i915_gem_object *obj;
767 int ret;
768 u32 handle;
769
ca377809
TU
770 if (!HAS_LLC(dev) && !HAS_SNOOP(dev)) {
771 /* We cannot support coherent userptr objects on hw without
772 * LLC and broken snooping.
773 */
774 return -ENODEV;
775 }
776
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CW
777 if (args->flags & ~(I915_USERPTR_READ_ONLY |
778 I915_USERPTR_UNSYNCHRONIZED))
779 return -EINVAL;
780
781 if (offset_in_page(args->user_ptr | args->user_size))
782 return -EINVAL;
783
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CW
784 if (!access_ok(args->flags & I915_USERPTR_READ_ONLY ? VERIFY_READ : VERIFY_WRITE,
785 (char __user *)(unsigned long)args->user_ptr, args->user_size))
786 return -EFAULT;
787
788 if (args->flags & I915_USERPTR_READ_ONLY) {
789 /* On almost all of the current hw, we cannot tell the GPU that a
790 * page is readonly, so this is just a placeholder in the uAPI.
791 */
792 return -ENODEV;
793 }
794
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CW
795 obj = i915_gem_object_alloc(dev);
796 if (obj == NULL)
797 return -ENOMEM;
798
799 drm_gem_private_object_init(dev, &obj->base, args->user_size);
800 i915_gem_object_init(obj, &i915_gem_userptr_ops);
801 obj->cache_level = I915_CACHE_LLC;
802 obj->base.write_domain = I915_GEM_DOMAIN_CPU;
803 obj->base.read_domains = I915_GEM_DOMAIN_CPU;
804
805 obj->userptr.ptr = args->user_ptr;
806 obj->userptr.read_only = !!(args->flags & I915_USERPTR_READ_ONLY);
807
808 /* And keep a pointer to the current->mm for resolving the user pages
809 * at binding. This means that we need to hook into the mmu_notifier
810 * in order to detect if the mmu is destroyed.
811 */
ad46cb53
CW
812 ret = i915_gem_userptr_init__mm_struct(obj);
813 if (ret == 0)
5cc9ed4b
CW
814 ret = i915_gem_userptr_init__mmu_notifier(obj, args->flags);
815 if (ret == 0)
816 ret = drm_gem_handle_create(file, &obj->base, &handle);
817
818 /* drop reference from allocate - handle holds it now */
34911fd3 819 i915_gem_object_put_unlocked(obj);
5cc9ed4b
CW
820 if (ret)
821 return ret;
822
823 args->handle = handle;
824 return 0;
825}
826
72778cb2 827void i915_gem_init_userptr(struct drm_i915_private *dev_priv)
5cc9ed4b 828{
ad46cb53
CW
829 mutex_init(&dev_priv->mm_lock);
830 hash_init(dev_priv->mm_structs);
5cc9ed4b 831}