aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/msm/msm_gem_shrinker.c
blob: d01f6ed1977e7e85c01714c0298bfa9793559c1b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
/*
 * Copyright (C) 2016 Red Hat
 * Author: Rob Clark <robdclark@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "msm_drv.h"
#include "msm_gem.h"

static bool mutex_is_locked_by(struct mutex *mutex, struct task_struct *task)
{
	if (!mutex_is_locked(mutex))
		return false;

#if (defined(CONFIG_SMP) || defined(CONFIG_DEBUG_MUTEXES)) && !defined(CONFIG_PREEMPT_RT_BASE)
	return mutex->owner == task;
#else
	/* Since UP may be pre-empted, we cannot assume that we own the lock */
	return false;
#endif
}

static bool msm_gem_shrinker_lock(struct drm_device *dev, bool *unlock)
{
	if (!mutex_trylock(&dev->struct_mutex)) {
		if (!mutex_is_locked_by(&dev->struct_mutex, current))
			return false;
		*unlock = false;
	} else {
		*unlock = true;
	}

	return true;
}


static unsigned long
msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
{
	struct msm_drm_private *priv =
		container_of(shrinker, struct msm_drm_private, shrinker);
	struct drm_device *dev = priv->dev;
	struct msm_gem_object *msm_obj;
	unsigned long count = 0;
	bool unlock;

	if (!msm_gem_shrinker_lock(dev, &unlock))
		return 0;

	list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
		if (is_purgeable(msm_obj))
			count += msm_obj->base.size >> PAGE_SHIFT;
	}

	if (unlock)
		mutex_unlock(&dev->struct_mutex);

	return count;
}

static unsigned long
msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
{
	struct msm_drm_private *priv =
		container_of(shrinker, struct msm_drm_private, shrinker);
	struct drm_device *dev = priv->dev;
	struct msm_gem_object *msm_obj;
	unsigned long freed = 0;
	bool unlock;

	if (!msm_gem_shrinker_lock(dev, &unlock))
		return SHRINK_STOP;

	list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
		if (freed >= sc->nr_to_scan)
			break;
		if (is_purgeable(msm_obj)) {
			msm_gem_purge(&msm_obj->base);
			freed += msm_obj->base.size >> PAGE_SHIFT;
		}
	}

	if (unlock)
		mutex_unlock(&dev->struct_mutex);

	if (freed > 0)
		pr_info_ratelimited("Purging %lu bytes\n", freed << PAGE_SHIFT);

	return freed;
}

static int
msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr)
{
	struct msm_drm_private *priv =
		container_of(nb, struct msm_drm_private, vmap_notifier);
	struct drm_device *dev = priv->dev;
	struct msm_gem_object *msm_obj;
	unsigned unmapped = 0;
	bool unlock;

	if (!msm_gem_shrinker_lock(dev, &unlock))
		return NOTIFY_DONE;

	list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
		if (is_vunmapable(msm_obj)) {
			msm_gem_vunmap(&msm_obj->base);
			/* since we don't know any better, lets bail after a few
			 * and if necessary the shrinker will be invoked again.
			 * Seems better than unmapping *everything*
			 */
			if (++unmapped >= 15)
				break;
		}
	}

	if (unlock)
		mutex_unlock(&dev->struct_mutex);

	*(unsigned long *)ptr += unmapped;

	if (unmapped > 0)
		pr_info_ratelimited("Purging %u vmaps\n", unmapped);

	return NOTIFY_DONE;
}

/**
 * msm_gem_shrinker_init - Initialize msm shrinker
 * @dev_priv: msm device
 *
 * This function registers and sets up the msm shrinker.
 */
void msm_gem_shrinker_init(struct drm_device *dev)
{
	struct msm_drm_private *priv = dev->dev_private;
	priv->shrinker.count_objects = msm_gem_shrinker_count;
	priv->shrinker.scan_objects = msm_gem_shrinker_scan;
	priv->shrinker.seeks = DEFAULT_SEEKS;
	WARN_ON(register_shrinker(&priv->shrinker));

	priv->vmap_notifier.notifier_call = msm_gem_shrinker_vmap;
	WARN_ON(register_vmap_purge_notifier(&priv->vmap_notifier));
}

/**
 * msm_gem_shrinker_cleanup - Clean up msm shrinker
 * @dev_priv: msm device
 *
 * This function unregisters the msm shrinker.
 */
void msm_gem_shrinker_cleanup(struct drm_device *dev)
{
	struct msm_drm_private *priv = dev->dev_private;
	WARN_ON(unregister_vmap_purge_notifier(&priv->vmap_notifier));
	unregister_shrinker(&priv->shrinker);
}