summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/drm_managed.c
blob: c21c3f6230335f4a93a2c9cf0c4d2768138a72bb (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
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2020 Intel
 *
 * Based on drivers/base/devres.c
 */

#include <drm/drm_managed.h>

#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

#include <drm/drm_device.h>
#include <drm/drm_print.h>

#include "drm_internal.h"

/**
 * DOC: managed resources
 *
 * Inspired by struct &device managed resources, but tied to the lifetime of
 * struct &drm_device, which can outlive the underlying physical device, usually
 * when userspace has some open files and other handles to resources still open.
 *
 * Release actions can be added with drmm_add_action(), memory allocations can
 * be done directly with drmm_kmalloc() and the related functions. Everything
 * will be released on the final drm_dev_put() in reverse order of how the
 * release actions have been added and memory has been allocated since driver
 * loading started with devm_drm_dev_alloc().
 *
 * Note that release actions and managed memory can also be added and removed
 * during the lifetime of the driver, all the functions are fully concurrent
 * safe. But it is recommended to use managed resources only for resources that
 * change rarely, if ever, during the lifetime of the &drm_device instance.
 */

struct drmres_node {
	struct list_head	entry;
	drmres_release_t	release;
	const char		*name;
	size_t			size;
};

struct drmres {
	struct drmres_node		node;
	/*
	 * Some archs want to perform DMA into kmalloc caches
	 * and need a guaranteed alignment larger than
	 * the alignment of a 64-bit integer.
	 * Thus we use ARCH_KMALLOC_MINALIGN here and get exactly the same
	 * buffer alignment as if it was allocated by plain kmalloc().
	 */
	u8 __aligned(ARCH_KMALLOC_MINALIGN) data[];
};

static void free_dr(struct drmres *dr)
{
	kfree_const(dr->node.name);
	kfree(dr);
}

void drm_managed_release(struct drm_device *dev)
{
	struct drmres *dr, *tmp;

	drm_dbg_drmres(dev, "drmres release begin\n");
	list_for_each_entry_safe(dr, tmp, &dev->managed.resources, node.entry) {
		drm_dbg_drmres(dev, "REL %p %s (%zu bytes)\n",
			       dr, dr->node.name, dr->node.size);

		if (dr->node.release)
			dr->node.release(dev, dr->node.size ? *(void **)&dr->data : NULL);

		list_del(&dr->node.entry);
		free_dr(dr);
	}
	drm_dbg_drmres(dev, "drmres release end\n");
}

/*
 * Always inline so that kmalloc_track_caller tracks the actual interesting
 * caller outside of drm_managed.c.
 */
static __always_inline struct drmres * alloc_dr(drmres_release_t release,
						size_t size, gfp_t gfp, int nid)
{
	size_t tot_size;
	struct drmres *dr;

	/* We must catch any near-SIZE_MAX cases that could overflow. */
	if (unlikely(check_add_overflow(sizeof(*dr), size, &tot_size)))
		return NULL;

	dr = kmalloc_node_track_caller(tot_size, gfp, nid);
	if (unlikely(!dr))
		return NULL;

	memset(dr, 0, offsetof(struct drmres, data));

	INIT_LIST_HEAD(&dr->node.entry);
	dr->node.release = release;
	dr->node.size = size;

	return dr;
}

static void del_dr(struct drm_device *dev, struct drmres *dr)
{
	list_del_init(&dr->node.entry);

	drm_dbg_drmres(dev, "DEL %p %s (%lu bytes)\n",
		       dr, dr->node.name, (unsigned long) dr->node.size);
}

static void add_dr(struct drm_device *dev, struct drmres *dr)
{
	unsigned long flags;

	spin_lock_irqsave(&dev->managed.lock, flags);
	list_add(&dr->node.entry, &dev->managed.resources);
	spin_unlock_irqrestore(&dev->managed.lock, flags);

	drm_dbg_drmres(dev, "ADD %p %s (%lu bytes)\n",
		       dr, dr->node.name, (unsigned long) dr->node.size);
}

void drmm_add_final_kfree(struct drm_device *dev, void *container)
{
	WARN_ON(dev->managed.final_kfree);
	WARN_ON(dev < (struct drm_device *) container);
	WARN_ON(dev + 1 > (struct drm_device *) (container + ksize(container)));
	dev->managed.final_kfree = container;
}

int __drmm_add_action(struct drm_device *dev,
		      drmres_release_t action,
		      void *data, const char *name)
{
	struct drmres *dr;
	void **void_ptr;

	dr = alloc_dr(action, data ? sizeof(void*) : 0,
		      GFP_KERNEL | __GFP_ZERO,
		      dev_to_node(dev->dev));
	if (!dr) {
		drm_dbg_drmres(dev, "failed to add action %s for %p\n",
			       name, data);
		return -ENOMEM;
	}

	dr->node.name = kstrdup_const(name, GFP_KERNEL);
	if (data) {
		void_ptr = (void **)&dr->data;
		*void_ptr = data;
	}

	add_dr(dev, dr);

	return 0;
}
EXPORT_SYMBOL(__drmm_add_action);

int __drmm_add_action_or_reset(struct drm_device *dev,
			       drmres_release_t action,
			       void *data, const char *name)
{
	int ret;

	ret = __drmm_add_action(dev, action, data, name);
	if (ret)
		action(dev, data);

	return ret;
}
EXPORT_SYMBOL(__drmm_add_action_or_reset);

/**
 * drmm_kmalloc - &drm_device managed kmalloc()
 * @dev: DRM device
 * @size: size of the memory allocation
 * @gfp: GFP allocation flags
 *
 * This is a &drm_device managed version of kmalloc(). The allocated memory is
 * automatically freed on the final drm_dev_put(). Memory can also be freed
 * before the final drm_dev_put() by calling drmm_kfree().
 */
void *drmm_kmalloc(struct drm_device *dev, size_t size, gfp_t gfp)
{
	struct drmres *dr;

	dr = alloc_dr(NULL, size, gfp, dev_to_node(dev->dev));
	if (!dr) {
		drm_dbg_drmres(dev, "failed to allocate %zu bytes, %u flags\n",
			       size, gfp);
		return NULL;
	}
	dr->node.name = kstrdup_const("kmalloc", GFP_KERNEL);

	add_dr(dev, dr);

	return dr->data;
}
EXPORT_SYMBOL(drmm_kmalloc);

/**
 * drmm_kstrdup - &drm_device managed kstrdup()
 * @dev: DRM device
 * @s: 0-terminated string to be duplicated
 * @gfp: GFP allocation flags
 *
 * This is a &drm_device managed version of kstrdup(). The allocated memory is
 * automatically freed on the final drm_dev_put() and works exactly like a
 * memory allocation obtained by drmm_kmalloc().
 */
char *drmm_kstrdup(struct drm_device *dev, const char *s, gfp_t gfp)
{
	size_t size;
	char *buf;

	if (!s)
		return NULL;

	size = strlen(s) + 1;
	buf = drmm_kmalloc(dev, size, gfp);
	if (buf)
		memcpy(buf, s, size);
	return buf;
}
EXPORT_SYMBOL_GPL(drmm_kstrdup);

/**
 * drmm_kfree - &drm_device managed kfree()
 * @dev: DRM device
 * @data: memory allocation to be freed
 *
 * This is a &drm_device managed version of kfree() which can be used to
 * release memory allocated through drmm_kmalloc() or any of its related
 * functions before the final drm_dev_put() of @dev.
 */
void drmm_kfree(struct drm_device *dev, void *data)
{
	struct drmres *dr_match = NULL, *dr;
	unsigned long flags;

	if (!data)
		return;

	spin_lock_irqsave(&dev->managed.lock, flags);
	list_for_each_entry(dr, &dev->managed.resources, node.entry) {
		if (dr->data == data) {
			dr_match = dr;
			del_dr(dev, dr_match);
			break;
		}
	}
	spin_unlock_irqrestore(&dev->managed.lock, flags);

	if (WARN_ON(!dr_match))
		return;

	free_dr(dr_match);
}
EXPORT_SYMBOL(drmm_kfree);

void __drmm_mutex_release(struct drm_device *dev, void *res)
{
	struct mutex *lock = res;

	mutex_destroy(lock);
}
EXPORT_SYMBOL(__drmm_mutex_release);