1/*
2 * Copyright 2014 Advanced Micro Devices, Inc.
3 * All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sub license, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
16 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
17 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
18 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
19 * USE OR OTHER DEALINGS IN THE SOFTWARE.
20 *
21 * The above copyright notice and this permission notice (including the
22 * next paragraph) shall be included in all copies or substantial portions
23 * of the Software.
24 *
25 */
26/*
27 * Authors:
28 * Christian K├Ânig <christian.koenig@amd.com>
29 */
30
31#include <linux/firmware.h>
32#include <linux/module.h>
33#include <linux/mmu_notifier.h>
34#include <drm/drmP.h>
35#include <drm/drm.h>
36
37#include "radeon.h"
38
39struct radeon_mn {
40 /* constant after initialisation */
41 struct radeon_device *rdev;
42 struct mm_struct *mm;
43 struct mmu_notifier mn;
44
45 /* only used on destruction */
46 struct work_struct work;
47
48 /* protected by rdev->mn_lock */
49 struct hlist_node node;
50
51 /* objects protected by lock */
52 struct mutex lock;
53 struct rb_root_cached objects;
54};
55
56struct radeon_mn_node {
57 struct interval_tree_node it;
58 struct list_head bos;
59};
60
61/**
62 * radeon_mn_destroy - destroy the rmn
63 *
64 * @work: previously sheduled work item
65 *
66 * Lazy destroys the notifier from a work item
67 */
68static void radeon_mn_destroy(struct work_struct *work)
69{
70 struct radeon_mn *rmn = container_of(work, struct radeon_mn, work);
71 struct radeon_device *rdev = rmn->rdev;
72 struct radeon_mn_node *node, *next_node;
73 struct radeon_bo *bo, *next_bo;
74
75 mutex_lock(&rdev->mn_lock);
76 mutex_lock(&rmn->lock);
77 hash_del(&rmn->node);
78 rbtree_postorder_for_each_entry_safe(node, next_node,
79 &rmn->objects.rb_root, it.rb) {
80
81 interval_tree_remove(&node->it, &rmn->objects);
82 list_for_each_entry_safe(bo, next_bo, &node->bos, mn_list) {
83 bo->mn = NULL;
84 list_del_init(&bo->mn_list);
85 }
86 kfree(node);
87 }
88 mutex_unlock(&rmn->lock);
89 mutex_unlock(&rdev->mn_lock);
90 mmu_notifier_unregister(&rmn->mn, rmn->mm);
91 kfree(rmn);
92}
93
94/**
95 * radeon_mn_release - callback to notify about mm destruction
96 *
97 * @mn: our notifier
98 * @mn: the mm this callback is about
99 *
100 * Shedule a work item to lazy destroy our notifier.
101 */
102static void radeon_mn_release(struct mmu_notifier *mn,
103 struct mm_struct *mm)
104{
105 struct radeon_mn *rmn = container_of(mn, struct radeon_mn, mn);
106 INIT_WORK(&rmn->work, radeon_mn_destroy);
107 schedule_work(&rmn->work);
108}
109
110/**
111 * radeon_mn_invalidate_range_start - callback to notify about mm change
112 *
113 * @mn: our notifier
114 * @mn: the mm this callback is about
115 * @start: start of updated range
116 * @end: end of updated range
117 *
118 * We block for all BOs between start and end to be idle and
119 * unmap them by move them into system domain again.
120 */
121static int radeon_mn_invalidate_range_start(struct mmu_notifier *mn,
122 const struct mmu_notifier_range *range)
123{
124 struct radeon_mn *rmn = container_of(mn, struct radeon_mn, mn);
125 struct ttm_operation_ctx ctx = { false, false };
126 struct interval_tree_node *it;
127 unsigned long end;
128 int ret = 0;
129
130 /* notification is exclusive, but interval is inclusive */
131 end = range->end - 1;
132
133 /* TODO we should be able to split locking for interval tree and
134 * the tear down.
135 */
136 if (range->blockable)
137 mutex_lock(&rmn->lock);
138 else if (!mutex_trylock(&rmn->lock))
139 return -EAGAIN;
140
141 it = interval_tree_iter_first(&rmn->objects, range->start, end);
142 while (it) {
143 struct radeon_mn_node *node;
144 struct radeon_bo *bo;
145 long r;
146
147 if (!range->blockable) {
148 ret = -EAGAIN;
149 goto out_unlock;
150 }
151
152 node = container_of(it, struct radeon_mn_node, it);
153 it = interval_tree_iter_next(it, range->start, end);
154
155 list_for_each_entry(bo, &node->bos, mn_list) {
156
157 if (!bo->tbo.ttm || bo->tbo.ttm->state != tt_bound)
158 continue;
159
160 r = radeon_bo_reserve(bo, true);
161 if (r) {
162 DRM_ERROR("(%ld) failed to reserve user bo\n", r);
163 continue;
164 }
165
166 r = reservation_object_wait_timeout_rcu(bo->tbo.resv,
167 true, false, MAX_SCHEDULE_TIMEOUT);
168 if (r <= 0)
169 DRM_ERROR("(%ld) failed to wait for user bo\n", r);
170
171 radeon_ttm_placement_from_domain(bo, RADEON_GEM_DOMAIN_CPU);
172 r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
173 if (r)
174 DRM_ERROR("(%ld) failed to validate user bo\n", r);
175
176 radeon_bo_unreserve(bo);
177 }
178 }
179
180out_unlock:
181 mutex_unlock(&rmn->lock);
182
183 return ret;
184}
185
186static const struct mmu_notifier_ops radeon_mn_ops = {
187 .release = radeon_mn_release,
188 .invalidate_range_start = radeon_mn_invalidate_range_start,
189};
190
191/**
192 * radeon_mn_get - create notifier context
193 *
194 * @rdev: radeon device pointer
195 *
196 * Creates a notifier context for current->mm.
197 */
198static struct radeon_mn *radeon_mn_get(struct radeon_device *rdev)
199{
200 struct mm_struct *mm = current->mm;
201 struct radeon_mn *rmn;
202 int r;
203
204 if (down_write_killable(&mm->mmap_sem))
205 return ERR_PTR(-EINTR);
206
207 mutex_lock(&rdev->mn_lock);
208
209 hash_for_each_possible(rdev->mn_hash, rmn, node, (unsigned long)mm)
210 if (rmn->mm == mm)
211 goto release_locks;
212
213 rmn = kzalloc(sizeof(*rmn), GFP_KERNEL);
214 if (!rmn) {
215 rmn = ERR_PTR(-ENOMEM);
216 goto release_locks;
217 }
218
219 rmn->rdev = rdev;
220 rmn->mm = mm;
221 rmn->mn.ops = &radeon_mn_ops;
222 mutex_init(&rmn->lock);
223 rmn->objects = RB_ROOT_CACHED;
224
225 r = __mmu_notifier_register(&rmn->mn, mm);
226 if (r)
227 goto free_rmn;
228
229 hash_add(rdev->mn_hash, &rmn->node, (unsigned long)mm);
230
231release_locks:
232 mutex_unlock(&rdev->mn_lock);
233 up_write(&mm->mmap_sem);
234
235 return rmn;
236
237free_rmn:
238 mutex_unlock(&rdev->mn_lock);
239 up_write(&mm->mmap_sem);
240 kfree(rmn);
241
242 return ERR_PTR(r);
243}
244
245/**
246 * radeon_mn_register - register a BO for notifier updates
247 *
248 * @bo: radeon buffer object
249 * @addr: userptr addr we should monitor
250 *
251 * Registers an MMU notifier for the given BO at the specified address.
252 * Returns 0 on success, -ERRNO if anything goes wrong.
253 */
254int radeon_mn_register(struct radeon_bo *bo, unsigned long addr)
255{
256 unsigned long end = addr + radeon_bo_size(bo) - 1;
257 struct radeon_device *rdev = bo->rdev;
258 struct radeon_mn *rmn;
259 struct radeon_mn_node *node = NULL;
260 struct list_head bos;
261 struct interval_tree_node *it;
262
263 rmn = radeon_mn_get(rdev);
264 if (IS_ERR(rmn))
265 return PTR_ERR(rmn);
266
267 INIT_LIST_HEAD(&bos);
268
269 mutex_lock(&rmn->lock);
270
271 while ((it = interval_tree_iter_first(&rmn->objects, addr, end))) {
272 kfree(node);
273 node = container_of(it, struct radeon_mn_node, it);
274 interval_tree_remove(&node->it, &rmn->objects);
275 addr = min(it->start, addr);
276 end = max(it->last, end);
277 list_splice(&node->bos, &bos);
278 }
279
280 if (!node) {
281 node = kmalloc(sizeof(struct radeon_mn_node), GFP_KERNEL);
282 if (!node) {
283 mutex_unlock(&rmn->lock);
284 return -ENOMEM;
285 }
286 }
287
288 bo->mn = rmn;
289
290 node->it.start = addr;
291 node->it.last = end;
292 INIT_LIST_HEAD(&node->bos);
293 list_splice(&bos, &node->bos);
294 list_add(&bo->mn_list, &node->bos);
295
296 interval_tree_insert(&node->it, &rmn->objects);
297
298 mutex_unlock(&rmn->lock);
299
300 return 0;
301}
302
303/**
304 * radeon_mn_unregister - unregister a BO for notifier updates
305 *
306 * @bo: radeon buffer object
307 *
308 * Remove any registration of MMU notifier updates from the buffer object.
309 */
310void radeon_mn_unregister(struct radeon_bo *bo)
311{
312 struct radeon_device *rdev = bo->rdev;
313 struct radeon_mn *rmn;
314 struct list_head *head;
315
316 mutex_lock(&rdev->mn_lock);
317 rmn = bo->mn;
318 if (rmn == NULL) {
319 mutex_unlock(&rdev->mn_lock);
320 return;
321 }
322
323 mutex_lock(&rmn->lock);
324 /* save the next list entry for later */
325 head = bo->mn_list.next;
326
327 bo->mn = NULL;
328 list_del(&bo->mn_list);
329
330 if (list_empty(head)) {
331 struct radeon_mn_node *node;
332 node = container_of(head, struct radeon_mn_node, bos);
333 interval_tree_remove(&node->it, &rmn->objects);
334 kfree(node);
335 }
336
337 mutex_unlock(&rmn->lock);
338 mutex_unlock(&rdev->mn_lock);
339}
340