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_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 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 ttm_operation_ctx ctx = { false, false };
128	struct interval_tree_node *it;
129
130	/* notification is exclusive, but interval is inclusive */
131	end -= 1;
132
133	mutex_lock(&rmn->lock);
134
135	it = interval_tree_iter_first(&rmn->objects, start, end);
136	while (it) {
137		struct radeon_mn_node *node;
138		struct radeon_bo *bo;
139		long r;
140
141		node = container_of(it, struct radeon_mn_node, it);
142		it = interval_tree_iter_next(it, start, end);
143
144		list_for_each_entry(bo, &node->bos, mn_list) {
145
146			if (!bo->tbo.ttm || bo->tbo.ttm->state != tt_bound)
147				continue;
148
149			r = radeon_bo_reserve(bo, true);
150			if (r) {
151				DRM_ERROR("(%ld) failed to reserve user bo\n", r);
152				continue;
153			}
154
155			r = reservation_object_wait_timeout_rcu(bo->tbo.resv,
156				true, false, MAX_SCHEDULE_TIMEOUT);
157			if (r <= 0)
158				DRM_ERROR("(%ld) failed to wait for user bo\n", r);
159
160			radeon_ttm_placement_from_domain(bo, RADEON_GEM_DOMAIN_CPU);
161			r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
162			if (r)
163				DRM_ERROR("(%ld) failed to validate user bo\n", r);
164
165			radeon_bo_unreserve(bo);
166		}
167	}
168	
169	mutex_unlock(&rmn->lock);
170}
171
172static const struct mmu_notifier_ops radeon_mn_ops = {
173	.release = radeon_mn_release,
174	.invalidate_range_start = radeon_mn_invalidate_range_start,
175};
176
177/**
178 * radeon_mn_get - create notifier context
179 *
180 * @rdev: radeon device pointer
181 *
182 * Creates a notifier context for current->mm.
183 */
184static struct radeon_mn *radeon_mn_get(struct radeon_device *rdev)
185{
186	struct mm_struct *mm = current->mm;
187	struct radeon_mn *rmn;
188	int r;
189
190	if (down_write_killable(&mm->mmap_sem))
191		return ERR_PTR(-EINTR);
192
193	mutex_lock(&rdev->mn_lock);
194
195	hash_for_each_possible(rdev->mn_hash, rmn, node, (unsigned long)mm)
196		if (rmn->mm == mm)
197			goto release_locks;
198
199	rmn = kzalloc(sizeof(*rmn), GFP_KERNEL);
200	if (!rmn) {
201		rmn = ERR_PTR(-ENOMEM);
202		goto release_locks;
203	}
204
205	rmn->rdev = rdev;
206	rmn->mm = mm;
207	rmn->mn.ops = &radeon_mn_ops;
208	mutex_init(&rmn->lock);
209	rmn->objects = RB_ROOT_CACHED;
210	
211	r = __mmu_notifier_register(&rmn->mn, mm);
212	if (r)
213		goto free_rmn;
214
215	hash_add(rdev->mn_hash, &rmn->node, (unsigned long)mm);
216
217release_locks:
218	mutex_unlock(&rdev->mn_lock);
219	up_write(&mm->mmap_sem);
220
221	return rmn;
222
223free_rmn:
224	mutex_unlock(&rdev->mn_lock);
225	up_write(&mm->mmap_sem);
226	kfree(rmn);
227
228	return ERR_PTR(r);
229}
230
231/**
232 * radeon_mn_register - register a BO for notifier updates
233 *
234 * @bo: radeon buffer object
235 * @addr: userptr addr we should monitor
236 *
237 * Registers an MMU notifier for the given BO at the specified address.
238 * Returns 0 on success, -ERRNO if anything goes wrong.
239 */
240int radeon_mn_register(struct radeon_bo *bo, unsigned long addr)
241{
242	unsigned long end = addr + radeon_bo_size(bo) - 1;
243	struct radeon_device *rdev = bo->rdev;
244	struct radeon_mn *rmn;
245	struct radeon_mn_node *node = NULL;
246	struct list_head bos;
247	struct interval_tree_node *it;
248
249	rmn = radeon_mn_get(rdev);
250	if (IS_ERR(rmn))
251		return PTR_ERR(rmn);
252
253	INIT_LIST_HEAD(&bos);
254
255	mutex_lock(&rmn->lock);
256
257	while ((it = interval_tree_iter_first(&rmn->objects, addr, end))) {
258		kfree(node);
259		node = container_of(it, struct radeon_mn_node, it);
260		interval_tree_remove(&node->it, &rmn->objects);
261		addr = min(it->start, addr);
262		end = max(it->last, end);
263		list_splice(&node->bos, &bos);
264	}
265
266	if (!node) {
267		node = kmalloc(sizeof(struct radeon_mn_node), GFP_KERNEL);
268		if (!node) {
269			mutex_unlock(&rmn->lock);
270			return -ENOMEM;
271		}
272	}
273
274	bo->mn = rmn;
275
276	node->it.start = addr;
277	node->it.last = end;
278	INIT_LIST_HEAD(&node->bos);
279	list_splice(&bos, &node->bos);
280	list_add(&bo->mn_list, &node->bos);
281
282	interval_tree_insert(&node->it, &rmn->objects);
283
284	mutex_unlock(&rmn->lock);
285
286	return 0;
287}
288
289/**
290 * radeon_mn_unregister - unregister a BO for notifier updates
291 *
292 * @bo: radeon buffer object
293 *
294 * Remove any registration of MMU notifier updates from the buffer object.
295 */
296void radeon_mn_unregister(struct radeon_bo *bo)
297{
298	struct radeon_device *rdev = bo->rdev;
299	struct radeon_mn *rmn;
300	struct list_head *head;
301
302	mutex_lock(&rdev->mn_lock);
303	rmn = bo->mn;
304	if (rmn == NULL) {
305		mutex_unlock(&rdev->mn_lock);
306		return;
307	}
308
309	mutex_lock(&rmn->lock);
310	/* save the next list entry for later */
311	head = bo->mn_list.next;
312
313	bo->mn = NULL;
314	list_del(&bo->mn_list);
315
316	if (list_empty(head)) {
317		struct radeon_mn_node *node;
318		node = container_of(head, struct radeon_mn_node, bos);
319		interval_tree_remove(&node->it, &rmn->objects);
320		kfree(node);
321	}
322
323	mutex_unlock(&rmn->lock);
324	mutex_unlock(&rdev->mn_lock);
325}