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
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 */
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)
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 >= '' && 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 *
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 *
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
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
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
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
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
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