xref: /openbmc/linux/drivers/gpu/drm/radeon/radeon_mn.c (revision e8f6f3b4)
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 König <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 
39 struct 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		objects;
54 };
55 
56 /**
57  * radeon_mn_destroy - destroy the rmn
58  *
59  * @work: previously sheduled work item
60  *
61  * Lazy destroys the notifier from a work item
62  */
63 static void radeon_mn_destroy(struct work_struct *work)
64 {
65 	struct radeon_mn *rmn = container_of(work, struct radeon_mn, work);
66 	struct radeon_device *rdev = rmn->rdev;
67 	struct radeon_bo *bo, *next;
68 
69 	mutex_lock(&rdev->mn_lock);
70 	mutex_lock(&rmn->lock);
71 	hash_del(&rmn->node);
72 	rbtree_postorder_for_each_entry_safe(bo, next, &rmn->objects, mn_it.rb) {
73 		interval_tree_remove(&bo->mn_it, &rmn->objects);
74 		bo->mn = NULL;
75 	}
76 	mutex_unlock(&rmn->lock);
77 	mutex_unlock(&rdev->mn_lock);
78 	mmu_notifier_unregister(&rmn->mn, rmn->mm);
79 	kfree(rmn);
80 }
81 
82 /**
83  * radeon_mn_release - callback to notify about mm destruction
84  *
85  * @mn: our notifier
86  * @mn: the mm this callback is about
87  *
88  * Shedule a work item to lazy destroy our notifier.
89  */
90 static void radeon_mn_release(struct mmu_notifier *mn,
91 			      struct mm_struct *mm)
92 {
93 	struct radeon_mn *rmn = container_of(mn, struct radeon_mn, mn);
94 	INIT_WORK(&rmn->work, radeon_mn_destroy);
95 	schedule_work(&rmn->work);
96 }
97 
98 /**
99  * radeon_mn_invalidate_range_start - callback to notify about mm change
100  *
101  * @mn: our notifier
102  * @mn: the mm this callback is about
103  * @start: start of updated range
104  * @end: end of updated range
105  *
106  * We block for all BOs between start and end to be idle and
107  * unmap them by move them into system domain again.
108  */
109 static void radeon_mn_invalidate_range_start(struct mmu_notifier *mn,
110 					     struct mm_struct *mm,
111 					     unsigned long start,
112 					     unsigned long end)
113 {
114 	struct radeon_mn *rmn = container_of(mn, struct radeon_mn, mn);
115 	struct interval_tree_node *it;
116 
117 	/* notification is exclusive, but interval is inclusive */
118 	end -= 1;
119 
120 	mutex_lock(&rmn->lock);
121 
122 	it = interval_tree_iter_first(&rmn->objects, start, end);
123 	while (it) {
124 		struct radeon_bo *bo;
125 		struct fence *fence;
126 		int r;
127 
128 		bo = container_of(it, struct radeon_bo, mn_it);
129 		it = interval_tree_iter_next(it, start, end);
130 
131 		r = radeon_bo_reserve(bo, true);
132 		if (r) {
133 			DRM_ERROR("(%d) failed to reserve user bo\n", r);
134 			continue;
135 		}
136 
137 		fence = reservation_object_get_excl(bo->tbo.resv);
138 		if (fence) {
139 			r = radeon_fence_wait((struct radeon_fence *)fence, false);
140 			if (r)
141 				DRM_ERROR("(%d) failed to wait for user bo\n", r);
142 		}
143 
144 		radeon_ttm_placement_from_domain(bo, RADEON_GEM_DOMAIN_CPU);
145 		r = ttm_bo_validate(&bo->tbo, &bo->placement, false, false);
146 		if (r)
147 			DRM_ERROR("(%d) failed to validate user bo\n", r);
148 
149 		radeon_bo_unreserve(bo);
150 	}
151 
152 	mutex_unlock(&rmn->lock);
153 }
154 
155 static const struct mmu_notifier_ops radeon_mn_ops = {
156 	.release = radeon_mn_release,
157 	.invalidate_range_start = radeon_mn_invalidate_range_start,
158 };
159 
160 /**
161  * radeon_mn_get - create notifier context
162  *
163  * @rdev: radeon device pointer
164  *
165  * Creates a notifier context for current->mm.
166  */
167 static struct radeon_mn *radeon_mn_get(struct radeon_device *rdev)
168 {
169 	struct mm_struct *mm = current->mm;
170 	struct radeon_mn *rmn;
171 	int r;
172 
173 	down_write(&mm->mmap_sem);
174 	mutex_lock(&rdev->mn_lock);
175 
176 	hash_for_each_possible(rdev->mn_hash, rmn, node, (unsigned long)mm)
177 		if (rmn->mm == mm)
178 			goto release_locks;
179 
180 	rmn = kzalloc(sizeof(*rmn), GFP_KERNEL);
181 	if (!rmn) {
182 		rmn = ERR_PTR(-ENOMEM);
183 		goto release_locks;
184 	}
185 
186 	rmn->rdev = rdev;
187 	rmn->mm = mm;
188 	rmn->mn.ops = &radeon_mn_ops;
189 	mutex_init(&rmn->lock);
190 	rmn->objects = RB_ROOT;
191 
192 	r = __mmu_notifier_register(&rmn->mn, mm);
193 	if (r)
194 		goto free_rmn;
195 
196 	hash_add(rdev->mn_hash, &rmn->node, (unsigned long)mm);
197 
198 release_locks:
199 	mutex_unlock(&rdev->mn_lock);
200 	up_write(&mm->mmap_sem);
201 
202 	return rmn;
203 
204 free_rmn:
205 	mutex_unlock(&rdev->mn_lock);
206 	up_write(&mm->mmap_sem);
207 	kfree(rmn);
208 
209 	return ERR_PTR(r);
210 }
211 
212 /**
213  * radeon_mn_register - register a BO for notifier updates
214  *
215  * @bo: radeon buffer object
216  * @addr: userptr addr we should monitor
217  *
218  * Registers an MMU notifier for the given BO at the specified address.
219  * Returns 0 on success, -ERRNO if anything goes wrong.
220  */
221 int radeon_mn_register(struct radeon_bo *bo, unsigned long addr)
222 {
223 	unsigned long end = addr + radeon_bo_size(bo) - 1;
224 	struct radeon_device *rdev = bo->rdev;
225 	struct radeon_mn *rmn;
226 	struct interval_tree_node *it;
227 
228 	rmn = radeon_mn_get(rdev);
229 	if (IS_ERR(rmn))
230 		return PTR_ERR(rmn);
231 
232 	mutex_lock(&rmn->lock);
233 
234 	it = interval_tree_iter_first(&rmn->objects, addr, end);
235 	if (it) {
236 		mutex_unlock(&rmn->lock);
237 		return -EEXIST;
238 	}
239 
240 	bo->mn = rmn;
241 	bo->mn_it.start = addr;
242 	bo->mn_it.last = end;
243 	interval_tree_insert(&bo->mn_it, &rmn->objects);
244 
245 	mutex_unlock(&rmn->lock);
246 
247 	return 0;
248 }
249 
250 /**
251  * radeon_mn_unregister - unregister a BO for notifier updates
252  *
253  * @bo: radeon buffer object
254  *
255  * Remove any registration of MMU notifier updates from the buffer object.
256  */
257 void radeon_mn_unregister(struct radeon_bo *bo)
258 {
259 	struct radeon_device *rdev = bo->rdev;
260 	struct radeon_mn *rmn;
261 
262 	mutex_lock(&rdev->mn_lock);
263 	rmn = bo->mn;
264 	if (rmn == NULL) {
265 		mutex_unlock(&rdev->mn_lock);
266 		return;
267 	}
268 
269 	mutex_lock(&rmn->lock);
270 	interval_tree_remove(&bo->mn_it, &rmn->objects);
271 	bo->mn = NULL;
272 	mutex_unlock(&rmn->lock);
273 	mutex_unlock(&rdev->mn_lock);
274 }
275