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
 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		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, &rmn->objects,
 79					     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 void radeon_mn_invalidate_range_start(struct mmu_notifier *mn,
122					     struct mm_struct *mm,
123					     unsigned long start,
124					     unsigned long end)
125{
126	struct radeon_mn *rmn = container_of(mn, struct radeon_mn, mn);
127	struct interval_tree_node *it;
128
129	/* notification is exclusive, but interval is inclusive */
130	end -= 1;
131
132	mutex_lock(&rmn->lock);
133
134	it = interval_tree_iter_first(&rmn->objects, start, end);
135	while (it) {
136		struct radeon_mn_node *node;
137		struct radeon_bo *bo;
138		long r;
139
140		node = container_of(it, struct radeon_mn_node, it);
141		it = interval_tree_iter_next(it, start, end);
142
143		list_for_each_entry(bo, &node->bos, mn_list) {
144
145			if (!bo->tbo.ttm || bo->tbo.ttm->state != tt_bound)
146				continue;
147
148			r = radeon_bo_reserve(bo, true);
149			if (r) {
150				DRM_ERROR("(%ld) failed to reserve user bo\n", r);
151				continue;
152			}
153
154			r = reservation_object_wait_timeout_rcu(bo->tbo.resv,
155				true, false, MAX_SCHEDULE_TIMEOUT);
156			if (r <= 0)
157				DRM_ERROR("(%ld) failed to wait for user bo\n", r);
158
159			radeon_ttm_placement_from_domain(bo, RADEON_GEM_DOMAIN_CPU);
160			r = ttm_bo_validate(&bo->tbo, &bo->placement, false, false);
161			if (r)
162				DRM_ERROR("(%ld) failed to validate user bo\n", r);
163
164			radeon_bo_unreserve(bo);
165		}
166	}
167	
168	mutex_unlock(&rmn->lock);
169}
170
171static const struct mmu_notifier_ops radeon_mn_ops = {
172	.release = radeon_mn_release,
173	.invalidate_range_start = radeon_mn_invalidate_range_start,
174};
175
176/**
177 * radeon_mn_get - create notifier context
178 *
179 * @rdev: radeon device pointer
180 *
181 * Creates a notifier context for current->mm.
182 */
183static struct radeon_mn *radeon_mn_get(struct radeon_device *rdev)
184{
185	struct mm_struct *mm = current->mm;
186	struct radeon_mn *rmn;
187	int r;
188
189	down_write(&mm->mmap_sem);
190	mutex_lock(&rdev->mn_lock);
191
192	hash_for_each_possible(rdev->mn_hash, rmn, node, (unsigned long)mm)
193		if (rmn->mm == mm)
194			goto release_locks;
195
196	rmn = kzalloc(sizeof(*rmn), GFP_KERNEL);
197	if (!rmn) {
198		rmn = ERR_PTR(-ENOMEM);
199		goto release_locks;
200	}
201
202	rmn->rdev = rdev;
203	rmn->mm = mm;
204	rmn->mn.ops = &radeon_mn_ops;
205	mutex_init(&rmn->lock);
206	rmn->objects = RB_ROOT;
207	
208	r = __mmu_notifier_register(&rmn->mn, mm);
209	if (r)
210		goto free_rmn;
211
212	hash_add(rdev->mn_hash, &rmn->node, (unsigned long)mm);
213
214release_locks:
215	mutex_unlock(&rdev->mn_lock);
216	up_write(&mm->mmap_sem);
217
218	return rmn;
219
220free_rmn:
221	mutex_unlock(&rdev->mn_lock);
222	up_write(&mm->mmap_sem);
223	kfree(rmn);
224
225	return ERR_PTR(r);
226}
227
228/**
229 * radeon_mn_register - register a BO for notifier updates
230 *
231 * @bo: radeon buffer object
232 * @addr: userptr addr we should monitor
233 *
234 * Registers an MMU notifier for the given BO at the specified address.
235 * Returns 0 on success, -ERRNO if anything goes wrong.
236 */
237int radeon_mn_register(struct radeon_bo *bo, unsigned long addr)
238{
239	unsigned long end = addr + radeon_bo_size(bo) - 1;
240	struct radeon_device *rdev = bo->rdev;
241	struct radeon_mn *rmn;
242	struct radeon_mn_node *node = NULL;
243	struct list_head bos;
244	struct interval_tree_node *it;
245
246	rmn = radeon_mn_get(rdev);
247	if (IS_ERR(rmn))
248		return PTR_ERR(rmn);
249
250	INIT_LIST_HEAD(&bos);
251
252	mutex_lock(&rmn->lock);
253
254	while ((it = interval_tree_iter_first(&rmn->objects, addr, end))) {
255		kfree(node);
256		node = container_of(it, struct radeon_mn_node, it);
257		interval_tree_remove(&node->it, &rmn->objects);
258		addr = min(it->start, addr);
259		end = max(it->last, end);
260		list_splice(&node->bos, &bos);
261	}
262
263	if (!node) {
264		node = kmalloc(sizeof(struct radeon_mn_node), GFP_KERNEL);
265		if (!node) {
266			mutex_unlock(&rmn->lock);
267			return -ENOMEM;
268		}
269	}
270
271	bo->mn = rmn;
272
273	node->it.start = addr;
274	node->it.last = end;
275	INIT_LIST_HEAD(&node->bos);
276	list_splice(&bos, &node->bos);
277	list_add(&bo->mn_list, &node->bos);
278
279	interval_tree_insert(&node->it, &rmn->objects);
280
281	mutex_unlock(&rmn->lock);
282
283	return 0;
284}
285
286/**
287 * radeon_mn_unregister - unregister a BO for notifier updates
288 *
289 * @bo: radeon buffer object
290 *
291 * Remove any registration of MMU notifier updates from the buffer object.
292 */
293void radeon_mn_unregister(struct radeon_bo *bo)
294{
295	struct radeon_device *rdev = bo->rdev;
296	struct radeon_mn *rmn;
297	struct list_head *head;
298
299	mutex_lock(&rdev->mn_lock);
300	rmn = bo->mn;
301	if (rmn == NULL) {
302		mutex_unlock(&rdev->mn_lock);
303		return;
304	}
305
306	mutex_lock(&rmn->lock);
307	/* save the next list entry for later */
308	head = bo->mn_list.next;
309
310	bo->mn = NULL;
311	list_del(&bo->mn_list);
312
313	if (list_empty(head)) {
314		struct radeon_mn_node *node;
315		node = container_of(head, struct radeon_mn_node, bos);
316		interval_tree_remove(&node->it, &rmn->objects);
317		kfree(node);
318	}
319
320	mutex_unlock(&rmn->lock);
321	mutex_unlock(&rdev->mn_lock);
322}