aboutsummaryrefslogtreecommitdiffstats
path: root/sound/core/misc.c
blob: c3f3d94b51970c372bb35f5a7ed48602b220a913 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Misc and compatibility things
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 */

#include <linux/init.h>
#include <linux/export.h>
#include <linux/moduleparam.h>
#include <linux/time.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/fs.h>
#include <sound/core.h>

#ifdef CONFIG_SND_DEBUG

#ifdef CONFIG_SND_DEBUG_VERBOSE
#define DEFAULT_DEBUG_LEVEL	2
#else
#define DEFAULT_DEBUG_LEVEL	1
#endif

static int debug = DEFAULT_DEBUG_LEVEL;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Debug level (0 = disable)");

#endif /* CONFIG_SND_DEBUG */

void release_and_free_resource(struct resource *res)
{
	if (res) {
		release_resource(res);
		kfree(res);
	}
}
EXPORT_SYMBOL(release_and_free_resource);

#ifdef CONFIG_SND_VERBOSE_PRINTK
/* strip the leading path if the given path is absolute */
static const char *sanity_file_name(const char *path)
{
	if (*path == '/')
		return strrchr(path, '/') + 1;
	else
		return path;
}
#endif

#if defined(CONFIG_SND_DEBUG) || defined(CONFIG_SND_VERBOSE_PRINTK)
void __snd_printk(unsigned int level, const char *path, int line,
		  const char *format, ...)
{
	va_list args;
#ifdef CONFIG_SND_VERBOSE_PRINTK
	int kern_level;
	struct va_format vaf;
	char verbose_fmt[] = KERN_DEFAULT "ALSA %s:%d %pV";
	bool level_found = false;
#endif

#ifdef CONFIG_SND_DEBUG
	if (debug < level)
		return;
#endif

	va_start(args, format);
#ifdef CONFIG_SND_VERBOSE_PRINTK
	vaf.fmt = format;
	vaf.va = &args;

	while ((kern_level = printk_get_level(vaf.fmt)) != 0) {
		const char *end_of_header = printk_skip_level(vaf.fmt);

		/* Ignore KERN_CONT. We print filename:line for each piece. */
		if (kern_level >= '0' && kern_level <= '7') {
			memcpy(verbose_fmt, vaf.fmt, end_of_header - vaf.fmt);
			level_found = true;
		}

		vaf.fmt = end_of_header;
	}

	if (!level_found && level)
		memcpy(verbose_fmt, KERN_DEBUG, sizeof(KERN_DEBUG) - 1);

	printk(verbose_fmt, sanity_file_name(path), line, &vaf);
#else
	vprintk(format, args);
#endif
	va_end(args);
}
EXPORT_SYMBOL_GPL(__snd_printk);
#endif

#ifdef CONFIG_PCI
#include <linux/pci.h>
/**
 * snd_pci_quirk_lookup_id - look up a PCI SSID quirk list
 * @vendor: PCI SSV id
 * @device: PCI SSD id
 * @list: quirk list, terminated by a null entry
 *
 * Look through the given quirk list and finds a matching entry
 * with the same PCI SSID.  When subdevice is 0, all subdevice
 * values may match.
 *
 * Returns the matched entry pointer, or NULL if nothing matched.
 */
const struct snd_pci_quirk *
snd_pci_quirk_lookup_id(u16 vendor, u16 device,
			const struct snd_pci_quirk *list)
{
	const struct snd_pci_quirk *q;

	for (q = list; q->subvendor; q++) {
		if (q->subvendor != vendor)
			continue;
		if (!q->subdevice ||
		    (device & q->subdevice_mask) == q->subdevice)
			return q;
	}
	return NULL;
}
EXPORT_SYMBOL(snd_pci_quirk_lookup_id);

/**
 * snd_pci_quirk_lookup - look up a PCI SSID quirk list
 * @pci: pci_dev handle
 * @list: quirk list, terminated by a null entry
 *
 * Look through the given quirk list and finds a matching entry
 * with the same PCI SSID.  When subdevice is 0, all subdevice
 * values may match.
 *
 * Returns the matched entry pointer, or NULL if nothing matched.
 */
const struct snd_pci_quirk *
snd_pci_quirk_lookup(struct pci_dev *pci, const struct snd_pci_quirk *list)
{
	if (!pci)
		return NULL;
	return snd_pci_quirk_lookup_id(pci->subsystem_vendor,
				       pci->subsystem_device,
				       list);
}
EXPORT_SYMBOL(snd_pci_quirk_lookup);
#endif

/*
 * Deferred async signal helpers
 *
 * Below are a few helper functions to wrap the async signal handling
 * in the deferred work.  The main purpose is to avoid the messy deadlock
 * around tasklist_lock and co at the kill_fasync() invocation.
 * fasync_helper() and kill_fasync() are replaced with snd_fasync_helper()
 * and snd_kill_fasync(), respectively.  In addition, snd_fasync_free() has
 * to be called at releasing the relevant file object.
 */
struct snd_fasync {
	struct fasync_struct *fasync;
	int signal;
	int poll;
	int on;
	struct list_head list;
};

static DEFINE_SPINLOCK(snd_fasync_lock);
static LIST_HEAD(snd_fasync_list);

static void snd_fasync_work_fn(struct work_struct *work)
{
	struct snd_fasync *fasync;

	spin_lock_irq(&snd_fasync_lock);
	while (!list_empty(&snd_fasync_list)) {
		fasync = list_first_entry(&snd_fasync_list, struct snd_fasync, list);
		list_del_init(&fasync->list);
		spin_unlock_irq(&snd_fasync_lock);
		if (fasync->on)
			kill_fasync(&fasync->fasync, fasync->signal, fasync->poll);
		spin_lock_irq(&snd_fasync_lock);
	}
	spin_unlock_irq(&snd_fasync_lock);
}

static DECLARE_WORK(snd_fasync_work, snd_fasync_work_fn);

int snd_fasync_helper(int fd, struct file *file, int on,
		      struct snd_fasync **fasyncp)
{
	struct snd_fasync *fasync = NULL;

	if (on) {
		fasync = kzalloc(sizeof(*fasync), GFP_KERNEL);
		if (!fasync)
			return -ENOMEM;
		INIT_LIST_HEAD(&fasync->list);
	}

	spin_lock_irq(&snd_fasync_lock);
	if (*fasyncp) {
		kfree(fasync);
		fasync = *fasyncp;
	} else {
		if (!fasync) {
			spin_unlock_irq(&snd_fasync_lock);
			return 0;
		}
		*fasyncp = fasync;
	}
	fasync->on = on;
	spin_unlock_irq(&snd_fasync_lock);
	return fasync_helper(fd, file, on, &fasync->fasync);
}
EXPORT_SYMBOL_GPL(snd_fasync_helper);

void snd_kill_fasync(struct snd_fasync *fasync, int signal, int poll)
{
	unsigned long flags;

	if (!fasync || !fasync->on)
		return;
	spin_lock_irqsave(&snd_fasync_lock, flags);
	fasync->signal = signal;
	fasync->poll = poll;
	list_move(&fasync->list, &snd_fasync_list);
	schedule_work(&snd_fasync_work);
	spin_unlock_irqrestore(&snd_fasync_lock, flags);
}
EXPORT_SYMBOL_GPL(snd_kill_fasync);

void snd_fasync_free(struct snd_fasync *fasync)
{
	if (!fasync)
		return;
	fasync->on = 0;
	flush_work(&snd_fasync_work);
	kfree(fasync);
}
EXPORT_SYMBOL_GPL(snd_fasync_free);