[thirdparty/linux.git] / sound / sound_core.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *	Sound core.  This file is composed of two parts.  sound_class
 *	which is common to both OSS and ALSA and OSS sound core which
 *	is used OSS or emulation of it.
 */

/*
 * First, the common part.
 */
#include <linux/module.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/kdev_t.h>
#include <linux/major.h>
#include <sound/core.h>

#ifdef CONFIG_SOUND_OSS_CORE
static int __init init_oss_soundcore(void);
static void cleanup_oss_soundcore(void);
#else
static inline int init_oss_soundcore(void)	{ return 0; }
static inline void cleanup_oss_soundcore(void)	{ }
#endif

MODULE_DESCRIPTION("Core sound module");
MODULE_AUTHOR("Alan Cox");
MODULE_LICENSE("GPL");

static char *sound_devnode(const struct device *dev, umode_t *mode)
{
	if (MAJOR(dev->devt) == SOUND_MAJOR)
		return NULL;
	return kasprintf(GFP_KERNEL, "snd/%s", dev_name(dev));
}

const struct class sound_class = {
	.name = "sound",
	.devnode = sound_devnode,
};
EXPORT_SYMBOL(sound_class);

static int __init init_soundcore(void)
{
	int rc;

	rc = init_oss_soundcore();
	if (rc)
		return rc;

	rc = class_register(&sound_class);
	if (rc) {
		cleanup_oss_soundcore();
		return rc;
	}

	return 0;
}

static void __exit cleanup_soundcore(void)
{
	cleanup_oss_soundcore();
	class_unregister(&sound_class);
}

subsys_initcall(init_soundcore);
module_exit(cleanup_soundcore);


#ifdef CONFIG_SOUND_OSS_CORE
/*
 *	OSS sound core handling. Breaks out sound functions to submodules
 *	
 *	Author:		Alan Cox <alan@lxorguk.ukuu.org.uk>
 *
 *	Fixes:
 *
 *                         --------------------
 * 
 *	Top level handler for the sound subsystem. Various devices can
 *	plug into this. The fact they don't all go via OSS doesn't mean 
 *	they don't have to implement the OSS API. There is a lot of logic
 *	to keeping much of the OSS weight out of the code in a compatibility
 *	module, but it's up to the driver to rember to load it...
 *
 *	The code provides a set of functions for registration of devices
 *	by type. This is done rather than providing a single call so that
 *	we can hide any future changes in the internals (eg when we go to
 *	32bit dev_t) from the modules and their interface.
 *
 *	Secondly we need to allocate the dsp, dsp16 and audio devices as
 *	one. Thus we misuse the chains a bit to simplify this.
 *
 *	Thirdly to make it more fun and for 2.3.x and above we do all
 *	of this using fine grained locking.
 *
 *	FIXME: we have to resolve modules and fine grained load/unload
 *	locking at some point in 2.3.x.
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sound.h>
#include <linux/kmod.h>

#define SOUND_STEP 16

struct sound_unit
{
	int unit_minor;
	const struct file_operations *unit_fops;
	struct sound_unit *next;
	char name[32];
};

/*
 * By default, OSS sound_core claims full legacy minor range (0-255)
 * of SOUND_MAJOR to trap open attempts to any sound minor and
 * requests modules using custom sound-slot/service-* module aliases.
 * The only benefit of doing this is allowing use of custom module
 * aliases instead of the standard char-major-* ones.  This behavior
 * prevents alternative OSS implementation and is scheduled to be
 * removed.
 *
 * CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss kernel
 * parameter are added to allow distros and developers to try and
 * switch to alternative implementations without needing to rebuild
 * the kernel in the meantime.  If preclaim_oss is non-zero, the
 * kernel will behave the same as before.  All SOUND_MAJOR minors are
 * preclaimed and the custom module aliases along with standard chrdev
 * ones are emitted if a missing device is opened.  If preclaim_oss is
 * zero, sound_core only grabs what's actually in use and for missing
 * devices only the standard chrdev aliases are requested.
 *
 * All these clutters are scheduled to be removed along with
 * sound-slot/service-* module aliases.
 */
static int preclaim_oss = IS_ENABLED(CONFIG_SOUND_OSS_CORE_PRECLAIM);

module_param(preclaim_oss, int, 0444);

static int soundcore_open(struct inode *, struct file *);

static const struct file_operations soundcore_fops =
{
	/* We must have an owner or the module locking fails */
	.owner	= THIS_MODULE,
	.open	= soundcore_open,
	.llseek = noop_llseek,
};

/*
 *	Low level list operator. Scan the ordered list, find a hole and
 *	join into it. Called with the lock asserted
 */

static int __sound_insert_unit(struct sound_unit * s, struct sound_unit **list, const struct file_operations *fops, int index, int low, int top)
{
	int n=low;

	if (index < 0) {	/* first free */

		while (*list && (*list)->unit_minor<n)
			list=&((*list)->next);

		while(n<top)
		{
			/* Found a hole ? */
			if(*list==NULL || (*list)->unit_minor>n)
				break;
			list=&((*list)->next);
			n+=SOUND_STEP;
		}

		if(n>=top)
			return -ENOENT;
	} else {
		n = low+(index*16);
		while (*list) {
			if ((*list)->unit_minor==n)
				return -EBUSY;
			if ((*list)->unit_minor>n)
				break;
			list=&((*list)->next);
		}
	}	
		
	/*
	 *	Fill it in
	 */
	 
	s->unit_minor=n;
	s->unit_fops=fops;
	
	/*
	 *	Link it
	 */
	 
	s->next=*list;
	*list=s;
	
	
	return n;
}

/*
 *	Remove a node from the chain. Called with the lock asserted
 */
 
static struct sound_unit *__sound_remove_unit(struct sound_unit **list, int unit)
{
	while(*list)
	{
		struct sound_unit *p=*list;
		if(p->unit_minor==unit)
		{
			*list=p->next;
			return p;
		}
		list=&(p->next);
	}
	printk(KERN_ERR "Sound device %d went missing!\n", unit);
	return NULL;
}

/*
 *	This lock guards the sound loader list.
 */

static DEFINE_SPINLOCK(sound_loader_lock);

/*
 *	Allocate the controlling structure and add it to the sound driver
 *	list. Acquires locks as needed
 */

static int sound_insert_unit(struct sound_unit **list, const struct file_operations *fops, int index, int low, int top, const char *name, umode_t mode, struct device *dev)
{
	struct sound_unit *s = kmalloc(sizeof(*s), GFP_KERNEL);
	int r;

	if (!s)
		return -ENOMEM;

	spin_lock(&sound_loader_lock);
retry:
	r = __sound_insert_unit(s, list, fops, index, low, top);
	spin_unlock(&sound_loader_lock);
	
	if (r < 0)
		goto fail;
	else if (r < SOUND_STEP)
		sprintf(s->name, "sound/%s", name);
	else
		sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP);

	if (!preclaim_oss) {
		/*
		 * Something else might have grabbed the minor.  If
		 * first free slot is requested, rescan with @low set
		 * to the next unit; otherwise, -EBUSY.
		 */
		r = __register_chrdev(SOUND_MAJOR, s->unit_minor, 1, s->name,
				      &soundcore_fops);
		if (r < 0) {
			spin_lock(&sound_loader_lock);
			__sound_remove_unit(list, s->unit_minor);
			if (index < 0) {
				low = s->unit_minor + SOUND_STEP;
				goto retry;
			}
			spin_unlock(&sound_loader_lock);
			r = -EBUSY;
			goto fail;
		}
	}

	device_create(&sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
		      NULL, "%s", s->name+6);
	return s->unit_minor;

fail:
	kfree(s);
	return r;
}

/*
 *	Remove a unit. Acquires locks as needed. The drivers MUST have
 *	completed the removal before their file operations become
 *	invalid.
 */
 	
static void sound_remove_unit(struct sound_unit **list, int unit)
{
	struct sound_unit *p;

	spin_lock(&sound_loader_lock);
	p = __sound_remove_unit(list, unit);
	spin_unlock(&sound_loader_lock);
	if (p) {
		if (!preclaim_oss)
			__unregister_chrdev(SOUND_MAJOR, p->unit_minor, 1,
					    p->name);
		device_destroy(&sound_class, MKDEV(SOUND_MAJOR, p->unit_minor));
		kfree(p);
	}
}

/*
 *	Allocations
 *
 *	0	*16		Mixers
 *	1	*8		Sequencers
 *	2	*16		Midi
 *	3	*16		DSP
 *	4	*16		SunDSP
 *	5	*16		DSP16
 *	6	--		sndstat (obsolete)
 *	7	*16		unused
 *	8	--		alternate sequencer (see above)
 *	9	*16		raw synthesizer access
 *	10	*16		unused
 *	11	*16		unused
 *	12	*16		unused
 *	13	*16		unused
 *	14	*16		unused
 *	15	*16		unused
 */

static struct sound_unit *chains[SOUND_STEP];

/**
 *	register_sound_special_device - register a special sound node
 *	@fops: File operations for the driver
 *	@unit: Unit number to allocate
 *      @dev: device pointer
 *
 *	Allocate a special sound device by minor number from the sound
 *	subsystem.
 *
 *	Return: The allocated number is returned on success. On failure,
 *	a negative error code is returned.
 */
 
int register_sound_special_device(const struct file_operations *fops, int unit,
				  struct device *dev)
{
	const int chain = unit % SOUND_STEP;
	int max_unit = 256;
	const char *name;
	char _name[16];

	switch (chain) {
	    case 0:
		name = "mixer";
		break;
	    case 1:
		name = "sequencer";
		if (unit >= SOUND_STEP)
			goto __unknown;
		max_unit = unit + 1;
		break;
	    case 2:
		name = "midi";
		break;
	    case 3:
		name = "dsp";
		break;
	    case 4:
		name = "audio";
		break;
	    case 5:
		name = "dspW";
		break;
	    case 8:
		name = "sequencer2";
		if (unit >= SOUND_STEP)
			goto __unknown;
		max_unit = unit + 1;
		break;
	    case 9:
		name = "dmmidi";
		break;
	    case 10:
		name = "dmfm";
		break;
	    case 12:
		name = "adsp";
		break;
	    case 13:
		name = "amidi";
		break;
	    case 14:
		name = "admmidi";
		break;
	    default:
	    	{
		    __unknown:
			sprintf(_name, "unknown%d", chain);
		    	if (unit >= SOUND_STEP)
		    		strcat(_name, "-");
		    	name = _name;
		}
		break;
	}
	return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit,
				 name, 0600, dev);
}
 
EXPORT_SYMBOL(register_sound_special_device);

int register_sound_special(const struct file_operations *fops, int unit)
{
	return register_sound_special_device(fops, unit, NULL);
}

EXPORT_SYMBOL(register_sound_special);

/**
 *	register_sound_mixer - register a mixer device
 *	@fops: File operations for the driver
 *	@dev: Unit number to allocate
 *
 *	Allocate a mixer device. Unit is the number of the mixer requested.
 *	Pass -1 to request the next free mixer unit.
 *
 *	Return: On success, the allocated number is returned. On failure,
 *	a negative error code is returned.
 */

int register_sound_mixer(const struct file_operations *fops, int dev)
{
	return sound_insert_unit(&chains[0], fops, dev, 0, 128,
				 "mixer", 0600, NULL);
}

EXPORT_SYMBOL(register_sound_mixer);

/*
 *	DSP's are registered as a triple. Register only one and cheat
 *	in open - see below.
 */
 
/**
 *	register_sound_dsp - register a DSP device
 *	@fops: File operations for the driver
 *	@dev: Unit number to allocate
 *
 *	Allocate a DSP device. Unit is the number of the DSP requested.
 *	Pass -1 to request the next free DSP unit.
 *
 *	This function allocates both the audio and dsp device entries together
 *	and will always allocate them as a matching pair - eg dsp3/audio3
 *
 *	Return: On success, the allocated number is returned. On failure,
 *	a negative error code is returned.
 */

int register_sound_dsp(const struct file_operations *fops, int dev)
{
	return sound_insert_unit(&chains[3], fops, dev, 3, 131,
				 "dsp", 0600, NULL);
}

EXPORT_SYMBOL(register_sound_dsp);

/**
 *	unregister_sound_special - unregister a special sound device
 *	@unit: unit number to allocate
 *
 *	Release a sound device that was allocated with
 *	register_sound_special(). The unit passed is the return value from
 *	the register function.
 */


void unregister_sound_special(int unit)
{
	sound_remove_unit(&chains[unit % SOUND_STEP], unit);
}
 
EXPORT_SYMBOL(unregister_sound_special);

/**
 *	unregister_sound_mixer - unregister a mixer
 *	@unit: unit number to allocate
 *
 *	Release a sound device that was allocated with register_sound_mixer().
 *	The unit passed is the return value from the register function.
 */

void unregister_sound_mixer(int unit)
{
	sound_remove_unit(&chains[0], unit);
}

EXPORT_SYMBOL(unregister_sound_mixer);

/**
 *	unregister_sound_dsp - unregister a DSP device
 *	@unit: unit number to allocate
 *
 *	Release a sound device that was allocated with register_sound_dsp().
 *	The unit passed is the return value from the register function.
 *
 *	Both of the allocated units are released together automatically.
 */

void unregister_sound_dsp(int unit)
{
	sound_remove_unit(&chains[3], unit);
}


EXPORT_SYMBOL(unregister_sound_dsp);

static struct sound_unit *__look_for_unit(int chain, int unit)
{
	struct sound_unit *s;
	
	s=chains[chain];
	while(s && s->unit_minor <= unit)
	{
		if(s->unit_minor==unit)
			return s;
		s=s->next;
	}
	return NULL;
}

static int soundcore_open(struct inode *inode, struct file *file)
{
	int chain;
	int unit = iminor(inode);
	struct sound_unit *s;
	const struct file_operations *new_fops = NULL;

	chain=unit&0x0F;
	if(chain==4 || chain==5)	/* dsp/audio/dsp16 */
	{
		unit&=0xF0;
		unit|=3;
		chain=3;
	}
	
	spin_lock(&sound_loader_lock);
	s = __look_for_unit(chain, unit);
	if (s)
		new_fops = fops_get(s->unit_fops);
	if (preclaim_oss && !new_fops) {
		spin_unlock(&sound_loader_lock);

		/*
		 *  Please, don't change this order or code.
		 *  For ALSA slot means soundcard and OSS emulation code
		 *  comes as add-on modules which aren't depend on
		 *  ALSA toplevel modules for soundcards, thus we need
		 *  load them at first.	  [Jaroslav Kysela <perex@jcu.cz>]
		 */
		request_module("sound-slot-%i", unit>>4);
		request_module("sound-service-%i-%i", unit>>4, chain);

		/*
		 * sound-slot/service-* module aliases are scheduled
		 * for removal in favor of the standard char-major-*
		 * module aliases.  For the time being, generate both
		 * the legacy and standard module aliases to ease
		 * transition.
		 */
		if (request_module("char-major-%d-%d", SOUND_MAJOR, unit) > 0)
			request_module("char-major-%d", SOUND_MAJOR);

		spin_lock(&sound_loader_lock);
		s = __look_for_unit(chain, unit);
		if (s)
			new_fops = fops_get(s->unit_fops);
	}
	spin_unlock(&sound_loader_lock);

	if (!new_fops)
		return -ENODEV;

	/*
	 * We rely upon the fact that we can't be unloaded while the
	 * subdriver is there.
	 */
	replace_fops(file, new_fops);

	if (!file->f_op->open)
		return -ENODEV;

	return file->f_op->open(inode, file);
}

MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);

static void cleanup_oss_soundcore(void)
{
	/* We have nothing to really do here - we know the lists must be
	   empty */
	unregister_chrdev(SOUND_MAJOR, "sound");
}

static int __init init_oss_soundcore(void)
{
	if (preclaim_oss &&
	    register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops) < 0) {
		printk(KERN_ERR "soundcore: sound device already in use.\n");
		return -EBUSY;
	}

	return 0;
}

#endif /* CONFIG_SOUND_OSS_CORE */
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4	2	/*
d886e87c TH	3	* Sound core. This file is composed of two parts. sound_class
	4	* which is common to both OSS and ALSA and OSS sound core which
	5	* is used OSS or emulation of it.
	6	*/
	7
	8	/*
	9	* First, the common part.
	10	*/
	11	#include <linux/module.h>
	12	#include <linux/device.h>
	13	#include <linux/err.h>
954a973c KS	14	#include <linux/kdev_t.h>
954a973c KS	15	#include <linux/major.h>
3d1ee379	16	#include <sound/core.h>
d886e87c TH	17
	18	#ifdef CONFIG_SOUND_OSS_CORE
	19	static int __init init_oss_soundcore(void);
de30d36b	20	static void cleanup_oss_soundcore(void);
d886e87c TH	21	#else
	22	static inline int init_oss_soundcore(void) { return 0; }
	23	static inline void cleanup_oss_soundcore(void) { }
	24	#endif
	25
d886e87c TH	26	MODULE_DESCRIPTION("Core sound module");
	27	MODULE_AUTHOR("Alan Cox");
	28	MODULE_LICENSE("GPL");
	29
ff62b8e6	30	static char sound_devnode(const struct device dev, umode_t *mode)
7a9d56f6	31	{
954a973c KS	32	if (MAJOR(dev->devt) == SOUND_MAJOR)
954a973c KS	33	return NULL;
7a9d56f6 KS	34	return kasprintf(GFP_KERNEL, "snd/%s", dev_name(dev));
	35	}
	36
8d0cf150 IO	37	const struct class sound_class = {
	38	.name = "sound",
	39	.devnode = sound_devnode,
	40	};
	41	EXPORT_SYMBOL(sound_class);
	42
d886e87c TH	43	static int __init init_soundcore(void)
	44	{
	45	int rc;
	46
	47	rc = init_oss_soundcore();
	48	if (rc)
	49	return rc;
	50
8d0cf150 IO	51	rc = class_register(&sound_class);
8d0cf150 IO	52	if (rc) {
d886e87c	53	cleanup_oss_soundcore();
8d0cf150	54	return rc;
d886e87c TH	55	}
	56
	57	return 0;
	58	}
	59
	60	static void __exit cleanup_soundcore(void)
	61	{
	62	cleanup_oss_soundcore();
8d0cf150	63	class_unregister(&sound_class);
d886e87c TH	64	}
d886e87c TH	65
c181a13a	66	subsys_initcall(init_soundcore);
d886e87c TH	67	module_exit(cleanup_soundcore);
	68
	69
	70	#ifdef CONFIG_SOUND_OSS_CORE
	71	/*
	72	* OSS sound core handling. Breaks out sound functions to submodules
1da177e4	73	*
2f1e593d	74	* Author: Alan Cox <alan@lxorguk.ukuu.org.uk>
1da177e4 LT	75	*
	76	* Fixes:
	77	*
1da177e4 LT	78	* --------------------
	79	*
	80	* Top level handler for the sound subsystem. Various devices can
	81	* plug into this. The fact they don't all go via OSS doesn't mean
	82	* they don't have to implement the OSS API. There is a lot of logic
	83	* to keeping much of the OSS weight out of the code in a compatibility
	84	* module, but it's up to the driver to rember to load it...
	85	*
	86	* The code provides a set of functions for registration of devices
	87	* by type. This is done rather than providing a single call so that
	88	* we can hide any future changes in the internals (eg when we go to
	89	* 32bit dev_t) from the modules and their interface.
	90	*
	91	* Secondly we need to allocate the dsp, dsp16 and audio devices as
	92	* one. Thus we misuse the chains a bit to simplify this.
	93	*
	94	* Thirdly to make it more fun and for 2.3.x and above we do all
	95	* of this using fine grained locking.
	96	*
	97	* FIXME: we have to resolve modules and fine grained load/unload
	98	* locking at some point in 2.3.x.
	99	*/
	100
1da177e4 LT	101	#include <linux/init.h>
	102	#include <linux/slab.h>
	103	#include <linux/types.h>
	104	#include <linux/kernel.h>
1da177e4	105	#include <linux/sound.h>
1da177e4	106	#include <linux/kmod.h>
1da177e4 LT	107
	108	#define SOUND_STEP 16
	109
1da177e4 LT	110	struct sound_unit
	111	{
	112	int unit_minor;
99ac48f5	113	const struct file_operations *unit_fops;
1da177e4 LT	114	struct sound_unit *next;
	115	char name[32];
	116	};
	117
93fe4483 TH	118	/*
	119	* By default, OSS sound_core claims full legacy minor range (0-255)
	120	* of SOUND_MAJOR to trap open attempts to any sound minor and
	121	* requests modules using custom sound-slot/service-* module aliases.
	122	* The only benefit of doing this is allowing use of custom module
	123	* aliases instead of the standard char-major-* ones. This behavior
	124	* prevents alternative OSS implementation and is scheduled to be
	125	* removed.
	126	*
	127	* CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss kernel
	128	* parameter are added to allow distros and developers to try and
	129	* switch to alternative implementations without needing to rebuild
	130	* the kernel in the meantime. If preclaim_oss is non-zero, the
	131	* kernel will behave the same as before. All SOUND_MAJOR minors are
	132	* preclaimed and the custom module aliases along with standard chrdev
	133	* ones are emitted if a missing device is opened. If preclaim_oss is
	134	* zero, sound_core only grabs what's actually in use and for missing
	135	* devices only the standard chrdev aliases are requested.
	136	*
	137	* All these clutters are scheduled to be removed along with
8f6e6041	138	* sound-slot/service-* module aliases.
93fe4483	139	*/
d248b277	140	static int preclaim_oss = IS_ENABLED(CONFIG_SOUND_OSS_CORE_PRECLAIM);
93fe4483 TH	141
	142	module_param(preclaim_oss, int, 0444);
	143
	144	static int soundcore_open(struct inode , struct file );
	145
	146	static const struct file_operations soundcore_fops =
	147	{
	148	/* We must have an owner or the module locking fails */
	149	.owner = THIS_MODULE,
	150	.open = soundcore_open,
6038f373	151	.llseek = noop_llseek,
93fe4483 TH	152	};
93fe4483 TH	153
1da177e4 LT	154	/*
	155	* Low level list operator. Scan the ordered list, find a hole and
	156	* join into it. Called with the lock asserted
	157	*/
	158
99ac48f5	159	static int __sound_insert_unit(struct sound_unit * s, struct sound_unit *list, const struct file_operations fops, int index, int low, int top)
1da177e4 LT	160	{
	161	int n=low;
	162
	163	if (index < 0) { /* first free */
	164
	165	while (list && (list)->unit_minor<n)
	166	list=&((*list)->next);
	167
	168	while(n<top)
	169	{
	170	/* Found a hole ? */
	171	if(list==NULL \|\| (list)->unit_minor>n)
	172	break;
	173	list=&((*list)->next);
	174	n+=SOUND_STEP;
	175	}
	176
	177	if(n>=top)
	178	return -ENOENT;
	179	} else {
	180	n = low+(index*16);
	181	while (*list) {
	182	if ((*list)->unit_minor==n)
	183	return -EBUSY;
	184	if ((*list)->unit_minor>n)
	185	break;
	186	list=&((*list)->next);
	187	}
	188	}
	189
	190	/*
	191	* Fill it in
	192	*/
	193
	194	s->unit_minor=n;
	195	s->unit_fops=fops;
	196
	197	/*
	198	* Link it
	199	*/
	200
	201	s->next=*list;
	202	*list=s;
	203
	204
	205	return n;
	206	}
	207
	208	/*
	209	* Remove a node from the chain. Called with the lock asserted
	210	*/
	211
	212	static struct sound_unit __sound_remove_unit(struct sound_unit *list, int unit)
	213	{
	214	while(*list)
	215	{
	216	struct sound_unit p=list;
	217	if(p->unit_minor==unit)
	218	{
	219	*list=p->next;
	220	return p;
	221	}
	222	list=&(p->next);
	223	}
224	printk(KERN_ERR "Sound device %d went missing!\n", unit);
225	return NULL;
226	}
227
228	/*
229	* This lock guards the sound loader list.
230	*/
231
232	static DEFINE_SPINLOCK(sound_loader_lock);
233
234	/*
235	* Allocate the controlling structure and add it to the sound driver
236	* list. Acquires locks as needed
237	*/
238
99ac48f5	239	static int sound_insert_unit(struct sound_unit *list, const struct file_operations fops, int index, int low, int top, const char name, umode_t mode, struct device dev)
1da177e4 LT	240	{
	241	struct sound_unit s = kmalloc(sizeof(s), GFP_KERNEL);
	242	int r;
	243
	244	if (!s)
	245	return -ENOMEM;
93fe4483	246
1da177e4	247	spin_lock(&sound_loader_lock);
93fe4483	248	retry:
1da177e4 LT	249	r = __sound_insert_unit(s, list, fops, index, low, top);
	250	spin_unlock(&sound_loader_lock);
	251
	252	if (r < 0)
	253	goto fail;
	254	else if (r < SOUND_STEP)
	255	sprintf(s->name, "sound/%s", name);
	256	else
	257	sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP);
	258
93fe4483 TH	259	if (!preclaim_oss) {
	260	/*
	261	* Something else might have grabbed the minor. If
	262	* first free slot is requested, rescan with @low set
	263	* to the next unit; otherwise, -EBUSY.
	264	*/
	265	r = __register_chrdev(SOUND_MAJOR, s->unit_minor, 1, s->name,
	266	&soundcore_fops);
	267	if (r < 0) {
	268	spin_lock(&sound_loader_lock);
	269	__sound_remove_unit(list, s->unit_minor);
	270	if (index < 0) {
	271	low = s->unit_minor + SOUND_STEP;
	272	goto retry;
	273	}
	274	spin_unlock(&sound_loader_lock);
c7cd7c74 WW	275	r = -EBUSY;
c7cd7c74 WW	276	goto fail;
93fe4483 TH	277	}
	278	}
	279
8d0cf150	280	device_create(&sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
02aa2a37	281	NULL, "%s", s->name+6);
93fe4483	282	return s->unit_minor;
1da177e4	283
93fe4483	284	fail:
1da177e4 LT	285	kfree(s);
	286	return r;
	287	}
	288
	289	/*
	290	* Remove a unit. Acquires locks as needed. The drivers MUST have
	291	* completed the removal before their file operations become
	292	* invalid.
	293	*/
	294
	295	static void sound_remove_unit(struct sound_unit **list, int unit)
	296	{
	297	struct sound_unit *p;
	298
	299	spin_lock(&sound_loader_lock);
	300	p = __sound_remove_unit(list, unit);
	301	spin_unlock(&sound_loader_lock);
	302	if (p) {
93fe4483 TH	303	if (!preclaim_oss)
	304	__unregister_chrdev(SOUND_MAJOR, p->unit_minor, 1,
	305	p->name);
8d0cf150	306	device_destroy(&sound_class, MKDEV(SOUND_MAJOR, p->unit_minor));
1da177e4 LT	307	kfree(p);
	308	}
	309	}
	310
	311	/*
	312	* Allocations
	313	*
	314	* 0 *16 Mixers
	315	* 1 *8 Sequencers
	316	* 2 *16 Midi
	317	* 3 *16 DSP
	318	* 4 *16 SunDSP
	319	* 5 *16 DSP16
	320	* 6 -- sndstat (obsolete)
	321	* 7 *16 unused
	322	* 8 -- alternate sequencer (see above)
	323	* 9 *16 raw synthesizer access
	324	* 10 *16 unused
	325	* 11 *16 unused
	326	* 12 *16 unused
	327	* 13 *16 unused
	328	* 14 *16 unused
	329	* 15 *16 unused
	330	*/
	331
	332	static struct sound_unit *chains[SOUND_STEP];
	333
	334	/**
d568121c	335	* register_sound_special_device - register a special sound node
1da177e4 LT	336	* @fops: File operations for the driver
1da177e4 LT	337	* @unit: Unit number to allocate
d568121c	338	* @dev: device pointer
1da177e4 LT	339	*
1da177e4 LT	340	* Allocate a special sound device by minor number from the sound
eb7c06e8 YB	341	* subsystem.
	342	*
	343	* Return: The allocated number is returned on success. On failure,
1da177e4 LT	344	* a negative error code is returned.
	345	*/
	346
99ac48f5	347	int register_sound_special_device(const struct file_operations *fops, int unit,
d568121c	348	struct device *dev)
1da177e4 LT	349	{
1da177e4 LT	350	const int chain = unit % SOUND_STEP;
2abb8017	351	int max_unit = 256;
1da177e4 LT	352	const char *name;
	353	char _name[16];
	354
	355	switch (chain) {
	356	case 0:
	357	name = "mixer";
	358	break;
	359	case 1:
	360	name = "sequencer";
	361	if (unit >= SOUND_STEP)
	362	goto __unknown;
	363	max_unit = unit + 1;
	364	break;
	365	case 2:
	366	name = "midi";
	367	break;
	368	case 3:
	369	name = "dsp";
	370	break;
	371	case 4:
	372	name = "audio";
	373	break;
848669da TI	374	case 5:
	375	name = "dspW";
	376	break;
1da177e4 LT	377	case 8:
	378	name = "sequencer2";
	379	if (unit >= SOUND_STEP)
	380	goto __unknown;
	381	max_unit = unit + 1;
	382	break;
	383	case 9:
	384	name = "dmmidi";
	385	break;
	386	case 10:
	387	name = "dmfm";
	388	break;
	389	case 12:
	390	name = "adsp";
	391	break;
	392	case 13:
	393	name = "amidi";
	394	break;
	395	case 14:
	396	name = "admmidi";
	397	break;
	398	default:
	399	{
	400	__unknown:
	401	sprintf(_name, "unknown%d", chain);
	402	if (unit >= SOUND_STEP)
	403	strcat(_name, "-");
	404	name = _name;
	405	}
	406	break;
	407	}
	408	return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit,
6a73cf46	409	name, 0600, dev);
1da177e4 LT	410	}
1da177e4 LT	411
d568121c TI	412	EXPORT_SYMBOL(register_sound_special_device);
d568121c TI	413
99ac48f5	414	int register_sound_special(const struct file_operations *fops, int unit)
d568121c TI	415	{
	416	return register_sound_special_device(fops, unit, NULL);
	417	}
	418
1da177e4 LT	419	EXPORT_SYMBOL(register_sound_special);
	420
	421	/**
	422	* register_sound_mixer - register a mixer device
	423	* @fops: File operations for the driver
	424	* @dev: Unit number to allocate
	425	*
	426	* Allocate a mixer device. Unit is the number of the mixer requested.
eb7c06e8 YB	427	* Pass -1 to request the next free mixer unit.
	428	*
	429	* Return: On success, the allocated number is returned. On failure,
	430	* a negative error code is returned.
1da177e4 LT	431	*/
1da177e4 LT	432
99ac48f5	433	int register_sound_mixer(const struct file_operations *fops, int dev)
1da177e4 LT	434	{
1da177e4 LT	435	return sound_insert_unit(&chains[0], fops, dev, 0, 128,
6a73cf46	436	"mixer", 0600, NULL);
1da177e4 LT	437	}
	438
	439	EXPORT_SYMBOL(register_sound_mixer);
	440
1da177e4 LT	441	/*
	442	* DSP's are registered as a triple. Register only one and cheat
	443	* in open - see below.
	444	*/
	445
	446	/**
	447	* register_sound_dsp - register a DSP device
	448	* @fops: File operations for the driver
	449	* @dev: Unit number to allocate
	450	*
	451	* Allocate a DSP device. Unit is the number of the DSP requested.
eb7c06e8	452	* Pass -1 to request the next free DSP unit.
1da177e4 LT	453	*
	454	* This function allocates both the audio and dsp device entries together
	455	* and will always allocate them as a matching pair - eg dsp3/audio3
eb7c06e8 YB	456	*
	457	* Return: On success, the allocated number is returned. On failure,
	458	* a negative error code is returned.
1da177e4 LT	459	*/
1da177e4 LT	460
99ac48f5	461	int register_sound_dsp(const struct file_operations *fops, int dev)
1da177e4 LT	462	{
1da177e4 LT	463	return sound_insert_unit(&chains[3], fops, dev, 3, 131,
6a73cf46	464	"dsp", 0600, NULL);
1da177e4 LT	465	}
	466
	467	EXPORT_SYMBOL(register_sound_dsp);
	468
1da177e4 LT	469	/**
	470	* unregister_sound_special - unregister a special sound device
	471	* @unit: unit number to allocate
	472	*
	473	* Release a sound device that was allocated with
	474	* register_sound_special(). The unit passed is the return value from
	475	* the register function.
	476	*/
	477
	478
	479	void unregister_sound_special(int unit)
	480	{
	481	sound_remove_unit(&chains[unit % SOUND_STEP], unit);
	482	}
	483
	484	EXPORT_SYMBOL(unregister_sound_special);
	485
	486	/**
	487	* unregister_sound_mixer - unregister a mixer
	488	* @unit: unit number to allocate
	489	*
	490	* Release a sound device that was allocated with register_sound_mixer().
	491	* The unit passed is the return value from the register function.
	492	*/
	493
	494	void unregister_sound_mixer(int unit)
	495	{
	496	sound_remove_unit(&chains[0], unit);
	497	}
	498
	499	EXPORT_SYMBOL(unregister_sound_mixer);
	500
1da177e4 LT	501	/**
	502	* unregister_sound_dsp - unregister a DSP device
	503	* @unit: unit number to allocate
	504	*
	505	* Release a sound device that was allocated with register_sound_dsp().
	506	* The unit passed is the return value from the register function.
	507	*
	508	* Both of the allocated units are released together automatically.
	509	*/
	510
	511	void unregister_sound_dsp(int unit)
	512	{
a39c4ad1	513	sound_remove_unit(&chains[3], unit);
1da177e4 LT	514	}
	515
	516
	517	EXPORT_SYMBOL(unregister_sound_dsp);
	518
1da177e4 LT	519	static struct sound_unit *__look_for_unit(int chain, int unit)
	520	{
	521	struct sound_unit *s;
	522
	523	s=chains[chain];
	524	while(s && s->unit_minor <= unit)
	525	{
	526	if(s->unit_minor==unit)
	527	return s;
	528	s=s->next;
	529	}
	530	return NULL;
	531	}
	532
a39c4ad1	533	static int soundcore_open(struct inode inode, struct file file)
1da177e4 LT	534	{
	535	int chain;
	536	int unit = iminor(inode);
	537	struct sound_unit *s;
99ac48f5	538	const struct file_operations *new_fops = NULL;
1da177e4 LT	539
	540	chain=unit&0x0F;
	541	if(chain==4 \|\| chain==5) /* dsp/audio/dsp16 */
	542	{
	543	unit&=0xF0;
	544	unit\|=3;
	545	chain=3;
	546	}
	547
	548	spin_lock(&sound_loader_lock);
	549	s = __look_for_unit(chain, unit);
	550	if (s)
	551	new_fops = fops_get(s->unit_fops);
93fe4483	552	if (preclaim_oss && !new_fops) {
1da177e4	553	spin_unlock(&sound_loader_lock);
0a848680	554
1da177e4 LT	555	/*
	556	* Please, don't change this order or code.
	557	* For ALSA slot means soundcard and OSS emulation code
	558	* comes as add-on modules which aren't depend on
	559	* ALSA toplevel modules for soundcards, thus we need
	560	* load them at first. [Jaroslav Kysela <perex@jcu.cz>]
	561	*/
	562	request_module("sound-slot-%i", unit>>4);
	563	request_module("sound-service-%i-%i", unit>>4, chain);
0a848680 TH	564
	565	/*
	566	* sound-slot/service-* module aliases are scheduled
	567	* for removal in favor of the standard char-major-*
	568	* module aliases. For the time being, generate both
	569	* the legacy and standard module aliases to ease
	570	* transition.
	571	*/
	572	if (request_module("char-major-%d-%d", SOUND_MAJOR, unit) > 0)
	573	request_module("char-major-%d", SOUND_MAJOR);
	574
1da177e4 LT	575	spin_lock(&sound_loader_lock);
	576	s = __look_for_unit(chain, unit);
	577	if (s)
	578	new_fops = fops_get(s->unit_fops);
	579	}
e84f9e57	580	spin_unlock(&sound_loader_lock);
171d9f7d	581
e52b78f8 MT	582	if (!new_fops)
e52b78f8 MT	583	return -ENODEV;
171d9f7d	584
e52b78f8 MT	585	/*
	586	* We rely upon the fact that we can't be unloaded while the
	587	* subdriver is there.
	588	*/
	589	replace_fops(file, new_fops);
	590
	591	if (!file->f_op->open)
	592	return -ENODEV;
	593
	594	return file->f_op->open(inode, file);
1da177e4 LT	595	}
1da177e4 LT	596
1da177e4 LT	597	MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);
1da177e4 LT	598
de30d36b	599	static void cleanup_oss_soundcore(void)
1da177e4 LT	600	{
	601	/* We have nothing to really do here - we know the lists must be
	602	empty */
	603	unregister_chrdev(SOUND_MAJOR, "sound");
1da177e4 LT	604	}
1da177e4 LT	605
d886e87c	606	static int __init init_oss_soundcore(void)
1da177e4	607	{
93fe4483	608	if (preclaim_oss &&
cb68429d	609	register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops) < 0) {
1da177e4 LT	610	printk(KERN_ERR "soundcore: sound device already in use.\n");
	611	return -EBUSY;
	612	}
1da177e4 LT	613
	614	return 0;
	615	}
	616
d886e87c	617	#endif /* CONFIG_SOUND_OSS_CORE */