// 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> void release_and_free_resource(struct resource *res){	if (res) {		release_resource(res);		kfree(res);	}}EXPORT_SYMBOL(release_and_free_resource); #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->subdevice; 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;	int signal, poll; 	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);		if (!fasync->on)			continue;		signal = fasync->signal;		poll = fasync->poll;		spin_unlock_irq(&snd_fasync_lock);		kill_fasync(&fasync->fasync, signal, 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_obj(*fasync);		if (!fasync)			return -ENOMEM;		INIT_LIST_HEAD(&fasync->list);	} 	scoped_guard(spinlock_irq, &snd_fasync_lock) {		if (*fasyncp) {			kfree(fasync);			fasync = *fasyncp;		} else {			if (!fasync)				return 0;			*fasyncp = fasync;		}		fasync->on = on;	}	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){	if (!fasync)		return;	guard(spinlock_irqsave)(&snd_fasync_lock);	if (!fasync->on)		return;	fasync->signal = signal;	fasync->poll = poll;	list_move(&fasync->list, &snd_fasync_list);	schedule_work(&snd_fasync_work);}EXPORT_SYMBOL_GPL(snd_kill_fasync); void snd_fasync_free(struct snd_fasync *fasync){	if (!fasync)		return; 	scoped_guard(spinlock_irq, &snd_fasync_lock) {		fasync->on = 0;		list_del_init(&fasync->list);	} 	flush_work(&snd_fasync_work);	kfree(fasync);}EXPORT_SYMBOL_GPL(snd_fasync_free); /* * generic refcount helper */ void snd_refcount_init(struct snd_refcount *ref){	atomic_set(&ref->count, 0);	init_waitqueue_head(&ref->waiter);}EXPORT_SYMBOL_GPL(snd_refcount_init); void snd_refcount_put(struct snd_refcount *ref){	if (atomic_dec_and_test(&ref->count))		wake_up(&ref->waiter);}EXPORT_SYMBOL_GPL(snd_refcount_put); void snd_refcount_sync(struct snd_refcount *ref){	wait_event(ref->waiter, !atomic_read(&ref->count));}EXPORT_SYMBOL_GPL(snd_refcount_sync);