1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Misc and compatibility things
4  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5  */
6 
7 #include <linux/init.h>
8 #include <linux/export.h>
9 #include <linux/moduleparam.h>
10 #include <linux/time.h>
11 #include <linux/slab.h>
12 #include <linux/ioport.h>
13 #include <linux/fs.h>
14 #include <sound/core.h>
15 
16 #ifdef CONFIG_SND_DEBUG
17 
18 #ifdef CONFIG_SND_DEBUG_VERBOSE
19 #define DEFAULT_DEBUG_LEVEL	2
20 #else
21 #define DEFAULT_DEBUG_LEVEL	1
22 #endif
23 
24 static int debug = DEFAULT_DEBUG_LEVEL;
25 module_param(debug, int, 0644);
26 MODULE_PARM_DESC(debug, "Debug level (0 = disable)");
27 
28 #endif /* CONFIG_SND_DEBUG */
29 
release_and_free_resource(struct resource * res)30 void release_and_free_resource(struct resource *res)
31 {
32 	if (res) {
33 		release_resource(res);
34 		kfree(res);
35 	}
36 }
37 EXPORT_SYMBOL(release_and_free_resource);
38 
39 #ifdef CONFIG_SND_VERBOSE_PRINTK
40 /* strip the leading path if the given path is absolute */
sanity_file_name(const char * path)41 static const char *sanity_file_name(const char *path)
42 {
43 	if (*path == '/')
44 		return strrchr(path, '/') + 1;
45 	else
46 		return path;
47 }
48 #endif
49 
50 #if defined(CONFIG_SND_DEBUG) || defined(CONFIG_SND_VERBOSE_PRINTK)
__snd_printk(unsigned int level,const char * path,int line,const char * format,...)51 void __snd_printk(unsigned int level, const char *path, int line,
52 		  const char *format, ...)
53 {
54 	va_list args;
55 #ifdef CONFIG_SND_VERBOSE_PRINTK
56 	int kern_level;
57 	struct va_format vaf;
58 	char verbose_fmt[] = KERN_DEFAULT "ALSA %s:%d %pV";
59 	bool level_found = false;
60 #endif
61 
62 #ifdef CONFIG_SND_DEBUG
63 	if (debug < level)
64 		return;
65 #endif
66 
67 	va_start(args, format);
68 #ifdef CONFIG_SND_VERBOSE_PRINTK
69 	vaf.fmt = format;
70 	vaf.va = &args;
71 
72 	while ((kern_level = printk_get_level(vaf.fmt)) != 0) {
73 		const char *end_of_header = printk_skip_level(vaf.fmt);
74 
75 		/* Ignore KERN_CONT. We print filename:line for each piece. */
76 		if (kern_level >= '0' && kern_level <= '7') {
77 			memcpy(verbose_fmt, vaf.fmt, end_of_header - vaf.fmt);
78 			level_found = true;
79 		}
80 
81 		vaf.fmt = end_of_header;
82 	}
83 
84 	if (!level_found && level)
85 		memcpy(verbose_fmt, KERN_DEBUG, sizeof(KERN_DEBUG) - 1);
86 
87 	printk(verbose_fmt, sanity_file_name(path), line, &vaf);
88 #else
89 	vprintk(format, args);
90 #endif
91 	va_end(args);
92 }
93 EXPORT_SYMBOL_GPL(__snd_printk);
94 #endif
95 
96 #ifdef CONFIG_PCI
97 #include <linux/pci.h>
98 /**
99  * snd_pci_quirk_lookup_id - look up a PCI SSID quirk list
100  * @vendor: PCI SSV id
101  * @device: PCI SSD id
102  * @list: quirk list, terminated by a null entry
103  *
104  * Look through the given quirk list and finds a matching entry
105  * with the same PCI SSID.  When subdevice is 0, all subdevice
106  * values may match.
107  *
108  * Returns the matched entry pointer, or NULL if nothing matched.
109  */
110 const struct snd_pci_quirk *
snd_pci_quirk_lookup_id(u16 vendor,u16 device,const struct snd_pci_quirk * list)111 snd_pci_quirk_lookup_id(u16 vendor, u16 device,
112 			const struct snd_pci_quirk *list)
113 {
114 	const struct snd_pci_quirk *q;
115 
116 	for (q = list; q->subvendor || q->subdevice; q++) {
117 		if (q->subvendor != vendor)
118 			continue;
119 		if (!q->subdevice ||
120 		    (device & q->subdevice_mask) == q->subdevice)
121 			return q;
122 	}
123 	return NULL;
124 }
125 EXPORT_SYMBOL(snd_pci_quirk_lookup_id);
126 
127 /**
128  * snd_pci_quirk_lookup - look up a PCI SSID quirk list
129  * @pci: pci_dev handle
130  * @list: quirk list, terminated by a null entry
131  *
132  * Look through the given quirk list and finds a matching entry
133  * with the same PCI SSID.  When subdevice is 0, all subdevice
134  * values may match.
135  *
136  * Returns the matched entry pointer, or NULL if nothing matched.
137  */
138 const struct snd_pci_quirk *
snd_pci_quirk_lookup(struct pci_dev * pci,const struct snd_pci_quirk * list)139 snd_pci_quirk_lookup(struct pci_dev *pci, const struct snd_pci_quirk *list)
140 {
141 	if (!pci)
142 		return NULL;
143 	return snd_pci_quirk_lookup_id(pci->subsystem_vendor,
144 				       pci->subsystem_device,
145 				       list);
146 }
147 EXPORT_SYMBOL(snd_pci_quirk_lookup);
148 #endif
149 
150 /*
151  * Deferred async signal helpers
152  *
153  * Below are a few helper functions to wrap the async signal handling
154  * in the deferred work.  The main purpose is to avoid the messy deadlock
155  * around tasklist_lock and co at the kill_fasync() invocation.
156  * fasync_helper() and kill_fasync() are replaced with snd_fasync_helper()
157  * and snd_kill_fasync(), respectively.  In addition, snd_fasync_free() has
158  * to be called at releasing the relevant file object.
159  */
160 struct snd_fasync {
161 	struct fasync_struct *fasync;
162 	int signal;
163 	int poll;
164 	int on;
165 	struct list_head list;
166 };
167 
168 static DEFINE_SPINLOCK(snd_fasync_lock);
169 static LIST_HEAD(snd_fasync_list);
170 
snd_fasync_work_fn(struct work_struct * work)171 static void snd_fasync_work_fn(struct work_struct *work)
172 {
173 	struct snd_fasync *fasync;
174 
175 	spin_lock_irq(&snd_fasync_lock);
176 	while (!list_empty(&snd_fasync_list)) {
177 		fasync = list_first_entry(&snd_fasync_list, struct snd_fasync, list);
178 		list_del_init(&fasync->list);
179 		spin_unlock_irq(&snd_fasync_lock);
180 		if (fasync->on)
181 			kill_fasync(&fasync->fasync, fasync->signal, fasync->poll);
182 		spin_lock_irq(&snd_fasync_lock);
183 	}
184 	spin_unlock_irq(&snd_fasync_lock);
185 }
186 
187 static DECLARE_WORK(snd_fasync_work, snd_fasync_work_fn);
188 
snd_fasync_helper(int fd,struct file * file,int on,struct snd_fasync ** fasyncp)189 int snd_fasync_helper(int fd, struct file *file, int on,
190 		      struct snd_fasync **fasyncp)
191 {
192 	struct snd_fasync *fasync = NULL;
193 
194 	if (on) {
195 		fasync = kzalloc(sizeof(*fasync), GFP_KERNEL);
196 		if (!fasync)
197 			return -ENOMEM;
198 		INIT_LIST_HEAD(&fasync->list);
199 	}
200 
201 	spin_lock_irq(&snd_fasync_lock);
202 	if (*fasyncp) {
203 		kfree(fasync);
204 		fasync = *fasyncp;
205 	} else {
206 		if (!fasync) {
207 			spin_unlock_irq(&snd_fasync_lock);
208 			return 0;
209 		}
210 		*fasyncp = fasync;
211 	}
212 	fasync->on = on;
213 	spin_unlock_irq(&snd_fasync_lock);
214 	return fasync_helper(fd, file, on, &fasync->fasync);
215 }
216 EXPORT_SYMBOL_GPL(snd_fasync_helper);
217 
snd_kill_fasync(struct snd_fasync * fasync,int signal,int poll)218 void snd_kill_fasync(struct snd_fasync *fasync, int signal, int poll)
219 {
220 	unsigned long flags;
221 
222 	if (!fasync || !fasync->on)
223 		return;
224 	spin_lock_irqsave(&snd_fasync_lock, flags);
225 	fasync->signal = signal;
226 	fasync->poll = poll;
227 	list_move(&fasync->list, &snd_fasync_list);
228 	schedule_work(&snd_fasync_work);
229 	spin_unlock_irqrestore(&snd_fasync_lock, flags);
230 }
231 EXPORT_SYMBOL_GPL(snd_kill_fasync);
232 
snd_fasync_free(struct snd_fasync * fasync)233 void snd_fasync_free(struct snd_fasync *fasync)
234 {
235 	if (!fasync)
236 		return;
237 	fasync->on = 0;
238 	flush_work(&snd_fasync_work);
239 	kfree(fasync);
240 }
241 EXPORT_SYMBOL_GPL(snd_fasync_free);
242