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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Misc and compatibility things4 * 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 16void release_and_free_resource(struct resource *res)17{18 if (res) {19 release_resource(res);20 kfree(res);21 }22}23EXPORT_SYMBOL(release_and_free_resource);24 25#ifdef CONFIG_PCI26#include <linux/pci.h>27/**28 * snd_pci_quirk_lookup_id - look up a PCI SSID quirk list29 * @vendor: PCI SSV id30 * @device: PCI SSD id31 * @list: quirk list, terminated by a null entry32 *33 * Look through the given quirk list and finds a matching entry34 * with the same PCI SSID. When subdevice is 0, all subdevice35 * values may match.36 *37 * Returns the matched entry pointer, or NULL if nothing matched.38 */39const struct snd_pci_quirk *40snd_pci_quirk_lookup_id(u16 vendor, u16 device,41 const struct snd_pci_quirk *list)42{43 const struct snd_pci_quirk *q;44 45 for (q = list; q->subvendor || q->subdevice; q++) {46 if (q->subvendor != vendor)47 continue;48 if (!q->subdevice ||49 (device & q->subdevice_mask) == q->subdevice)50 return q;51 }52 return NULL;53}54EXPORT_SYMBOL(snd_pci_quirk_lookup_id);55 56/**57 * snd_pci_quirk_lookup - look up a PCI SSID quirk list58 * @pci: pci_dev handle59 * @list: quirk list, terminated by a null entry60 *61 * Look through the given quirk list and finds a matching entry62 * with the same PCI SSID. When subdevice is 0, all subdevice63 * values may match.64 *65 * Returns the matched entry pointer, or NULL if nothing matched.66 */67const struct snd_pci_quirk *68snd_pci_quirk_lookup(struct pci_dev *pci, const struct snd_pci_quirk *list)69{70 if (!pci)71 return NULL;72 return snd_pci_quirk_lookup_id(pci->subsystem_vendor,73 pci->subsystem_device,74 list);75}76EXPORT_SYMBOL(snd_pci_quirk_lookup);77#endif78 79/*80 * Deferred async signal helpers81 *82 * Below are a few helper functions to wrap the async signal handling83 * in the deferred work. The main purpose is to avoid the messy deadlock84 * around tasklist_lock and co at the kill_fasync() invocation.85 * fasync_helper() and kill_fasync() are replaced with snd_fasync_helper()86 * and snd_kill_fasync(), respectively. In addition, snd_fasync_free() has87 * to be called at releasing the relevant file object.88 */89struct snd_fasync {90 struct fasync_struct *fasync;91 int signal;92 int poll;93 int on;94 struct list_head list;95};96 97static DEFINE_SPINLOCK(snd_fasync_lock);98static LIST_HEAD(snd_fasync_list);99 100static void snd_fasync_work_fn(struct work_struct *work)101{102 struct snd_fasync *fasync;103 104 spin_lock_irq(&snd_fasync_lock);105 while (!list_empty(&snd_fasync_list)) {106 fasync = list_first_entry(&snd_fasync_list, struct snd_fasync, list);107 list_del_init(&fasync->list);108 spin_unlock_irq(&snd_fasync_lock);109 if (fasync->on)110 kill_fasync(&fasync->fasync, fasync->signal, fasync->poll);111 spin_lock_irq(&snd_fasync_lock);112 }113 spin_unlock_irq(&snd_fasync_lock);114}115 116static DECLARE_WORK(snd_fasync_work, snd_fasync_work_fn);117 118int snd_fasync_helper(int fd, struct file *file, int on,119 struct snd_fasync **fasyncp)120{121 struct snd_fasync *fasync = NULL;122 123 if (on) {124 fasync = kzalloc(sizeof(*fasync), GFP_KERNEL);125 if (!fasync)126 return -ENOMEM;127 INIT_LIST_HEAD(&fasync->list);128 }129 130 spin_lock_irq(&snd_fasync_lock);131 if (*fasyncp) {132 kfree(fasync);133 fasync = *fasyncp;134 } else {135 if (!fasync) {136 spin_unlock_irq(&snd_fasync_lock);137 return 0;138 }139 *fasyncp = fasync;140 }141 fasync->on = on;142 spin_unlock_irq(&snd_fasync_lock);143 return fasync_helper(fd, file, on, &fasync->fasync);144}145EXPORT_SYMBOL_GPL(snd_fasync_helper);146 147void snd_kill_fasync(struct snd_fasync *fasync, int signal, int poll)148{149 unsigned long flags;150 151 if (!fasync || !fasync->on)152 return;153 spin_lock_irqsave(&snd_fasync_lock, flags);154 fasync->signal = signal;155 fasync->poll = poll;156 list_move(&fasync->list, &snd_fasync_list);157 schedule_work(&snd_fasync_work);158 spin_unlock_irqrestore(&snd_fasync_lock, flags);159}160EXPORT_SYMBOL_GPL(snd_kill_fasync);161 162void snd_fasync_free(struct snd_fasync *fasync)163{164 if (!fasync)165 return;166 fasync->on = 0;167 flush_work(&snd_fasync_work);168 kfree(fasync);169}170EXPORT_SYMBOL_GPL(snd_fasync_free);171