kernel-ark/sound/core/init.c
Takashi Iwai e28563cceb [ALSA] Optimize for config without PROC_FS
Modules: HWDEP Midlevel,ALSA Core,PCM Midlevel,Timer Midlevel

Optimize the code when compiled without CONFIG_PROC_FS.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2006-01-03 12:30:02 +01:00

721 lines
19 KiB
C

/*
* Initialization routines
* Copyright (c) by Jaroslav Kysela <perex@suse.cz>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <sound/driver.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/ctype.h>
#include <linux/pci.h>
#include <linux/pm.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/info.h>
struct snd_shutdown_f_ops {
struct file_operations f_ops;
struct snd_shutdown_f_ops *next;
};
unsigned int snd_cards_lock = 0; /* locked for registering/using */
struct snd_card *snd_cards[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = NULL};
DEFINE_RWLOCK(snd_card_rwlock);
#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
#endif
#ifdef CONFIG_PROC_FS
static void snd_card_id_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
snd_iprintf(buffer, "%s\n", entry->card->id);
}
static inline int init_info_for_card(struct snd_card *card)
{
int err;
struct snd_info_entry *entry;
if ((err = snd_info_card_register(card)) < 0) {
snd_printd("unable to create card info\n");
return err;
}
if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
snd_printd("unable to create card entry\n");
return err;
}
entry->c.text.read_size = PAGE_SIZE;
entry->c.text.read = snd_card_id_read;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
entry = NULL;
}
card->proc_id = entry;
return 0;
}
#else /* !CONFIG_PROC_FS */
#define init_info_for_card(card)
#endif
static void snd_card_free_thread(void * __card);
/**
* snd_card_new - create and initialize a soundcard structure
* @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
* @xid: card identification (ASCII string)
* @module: top level module for locking
* @extra_size: allocate this extra size after the main soundcard structure
*
* Creates and initializes a soundcard structure.
*
* Returns kmallocated snd_card structure. Creates the ALSA control interface
* (which is blocked until snd_card_register function is called).
*/
struct snd_card *snd_card_new(int idx, const char *xid,
struct module *module, int extra_size)
{
struct snd_card *card;
int err;
if (extra_size < 0)
extra_size = 0;
card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
if (card == NULL)
return NULL;
if (xid) {
if (!snd_info_check_reserved_words(xid))
goto __error;
strlcpy(card->id, xid, sizeof(card->id));
}
err = 0;
write_lock(&snd_card_rwlock);
if (idx < 0) {
int idx2;
for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
if (~snd_cards_lock & idx & 1<<idx2) {
idx = idx2;
if (idx >= snd_ecards_limit)
snd_ecards_limit = idx + 1;
break;
}
} else if (idx < snd_ecards_limit) {
if (snd_cards_lock & (1 << idx))
err = -ENODEV; /* invalid */
} else if (idx < SNDRV_CARDS)
snd_ecards_limit = idx + 1; /* increase the limit */
else
err = -ENODEV;
if (idx < 0 || err < 0) {
write_unlock(&snd_card_rwlock);
snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i)\n", idx, snd_ecards_limit - 1);
goto __error;
}
snd_cards_lock |= 1 << idx; /* lock it */
write_unlock(&snd_card_rwlock);
card->number = idx;
card->module = module;
INIT_LIST_HEAD(&card->devices);
init_rwsem(&card->controls_rwsem);
rwlock_init(&card->ctl_files_rwlock);
INIT_LIST_HEAD(&card->controls);
INIT_LIST_HEAD(&card->ctl_files);
spin_lock_init(&card->files_lock);
init_waitqueue_head(&card->shutdown_sleep);
INIT_WORK(&card->free_workq, snd_card_free_thread, card);
#ifdef CONFIG_PM
init_MUTEX(&card->power_lock);
init_waitqueue_head(&card->power_sleep);
#endif
/* the control interface cannot be accessed from the user space until */
/* snd_cards_bitmask and snd_cards are set with snd_card_register */
if ((err = snd_ctl_create(card)) < 0) {
snd_printd("unable to register control minors\n");
goto __error;
}
if ((err = snd_info_card_create(card)) < 0) {
snd_printd("unable to create card info\n");
goto __error_ctl;
}
if (extra_size > 0)
card->private_data = (char *)card + sizeof(struct snd_card);
return card;
__error_ctl:
snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
__error:
kfree(card);
return NULL;
}
static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
{
return POLLERR | POLLNVAL;
}
/**
* snd_card_disconnect - disconnect all APIs from the file-operations (user space)
* @card: soundcard structure
*
* Disconnects all APIs from the file-operations (user space).
*
* Returns zero, otherwise a negative error code.
*
* Note: The current implementation replaces all active file->f_op with special
* dummy file operations (they do nothing except release).
*/
int snd_card_disconnect(struct snd_card *card)
{
struct snd_monitor_file *mfile;
struct file *file;
struct snd_shutdown_f_ops *s_f_ops;
struct file_operations *f_ops, *old_f_ops;
int err;
spin_lock(&card->files_lock);
if (card->shutdown) {
spin_unlock(&card->files_lock);
return 0;
}
card->shutdown = 1;
spin_unlock(&card->files_lock);
/* phase 1: disable fops (user space) operations for ALSA API */
write_lock(&snd_card_rwlock);
snd_cards[card->number] = NULL;
write_unlock(&snd_card_rwlock);
/* phase 2: replace file->f_op with special dummy operations */
spin_lock(&card->files_lock);
mfile = card->files;
while (mfile) {
file = mfile->file;
/* it's critical part, use endless loop */
/* we have no room to fail */
s_f_ops = kmalloc(sizeof(struct snd_shutdown_f_ops), GFP_ATOMIC);
if (s_f_ops == NULL)
panic("Atomic allocation failed for snd_shutdown_f_ops!");
f_ops = &s_f_ops->f_ops;
memset(f_ops, 0, sizeof(*f_ops));
f_ops->owner = file->f_op->owner;
f_ops->release = file->f_op->release;
f_ops->poll = snd_disconnect_poll;
s_f_ops->next = card->s_f_ops;
card->s_f_ops = s_f_ops;
f_ops = fops_get(f_ops);
old_f_ops = file->f_op;
file->f_op = f_ops; /* must be atomic */
fops_put(old_f_ops);
mfile = mfile->next;
}
spin_unlock(&card->files_lock);
/* phase 3: notify all connected devices about disconnection */
/* at this point, they cannot respond to any calls except release() */
#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
if (snd_mixer_oss_notify_callback)
snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
#endif
/* notify all devices that we are disconnected */
err = snd_device_disconnect_all(card);
if (err < 0)
snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
return 0;
}
/**
* snd_card_free - frees given soundcard structure
* @card: soundcard structure
*
* This function releases the soundcard structure and the all assigned
* devices automatically. That is, you don't have to release the devices
* by yourself.
*
* Returns zero. Frees all associated devices and frees the control
* interface associated to given soundcard.
*/
int snd_card_free(struct snd_card *card)
{
struct snd_shutdown_f_ops *s_f_ops;
if (card == NULL)
return -EINVAL;
write_lock(&snd_card_rwlock);
snd_cards[card->number] = NULL;
write_unlock(&snd_card_rwlock);
#ifdef CONFIG_PM
wake_up(&card->power_sleep);
#endif
/* wait, until all devices are ready for the free operation */
wait_event(card->shutdown_sleep, card->files == NULL);
#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
if (snd_mixer_oss_notify_callback)
snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
#endif
if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
snd_printk(KERN_ERR "unable to free all devices (pre)\n");
/* Fatal, but this situation should never occur */
}
if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
snd_printk(KERN_ERR "unable to free all devices (normal)\n");
/* Fatal, but this situation should never occur */
}
if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
snd_printk(KERN_ERR "unable to free all devices (post)\n");
/* Fatal, but this situation should never occur */
}
if (card->private_free)
card->private_free(card);
snd_info_unregister(card->proc_id);
if (snd_info_card_free(card) < 0) {
snd_printk(KERN_WARNING "unable to free card info\n");
/* Not fatal error */
}
while (card->s_f_ops) {
s_f_ops = card->s_f_ops;
card->s_f_ops = s_f_ops->next;
kfree(s_f_ops);
}
write_lock(&snd_card_rwlock);
snd_cards_lock &= ~(1 << card->number);
write_unlock(&snd_card_rwlock);
kfree(card);
return 0;
}
static void snd_card_free_thread(void * __card)
{
struct snd_card *card = __card;
struct module * module = card->module;
if (!try_module_get(module)) {
snd_printk(KERN_ERR "unable to lock toplevel module for card %i in free thread\n", card->number);
module = NULL;
}
snd_card_free(card);
module_put(module);
}
/**
* snd_card_free_in_thread - call snd_card_free() in thread
* @card: soundcard structure
*
* This function schedules the call of snd_card_free() function in a
* work queue. When all devices are released (non-busy), the work
* is woken up and calls snd_card_free().
*
* When a card can be disconnected at any time by hotplug service,
* this function should be used in disconnect (or detach) callback
* instead of calling snd_card_free() directly.
*
* Returns - zero otherwise a negative error code if the start of thread failed.
*/
int snd_card_free_in_thread(struct snd_card *card)
{
if (card->files == NULL) {
snd_card_free(card);
return 0;
}
if (schedule_work(&card->free_workq))
return 0;
snd_printk(KERN_ERR "schedule_work() failed in snd_card_free_in_thread for card %i\n", card->number);
/* try to free the structure immediately */
snd_card_free(card);
return -EFAULT;
}
static void choose_default_id(struct snd_card *card)
{
int i, len, idx_flag = 0, loops = SNDRV_CARDS;
char *id, *spos;
id = spos = card->shortname;
while (*id != '\0') {
if (*id == ' ')
spos = id + 1;
id++;
}
id = card->id;
while (*spos != '\0' && !isalnum(*spos))
spos++;
if (isdigit(*spos))
*id++ = isalpha(card->shortname[0]) ? card->shortname[0] : 'D';
while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
if (isalnum(*spos))
*id++ = *spos;
spos++;
}
*id = '\0';
id = card->id;
if (*id == '\0')
strcpy(id, "default");
while (1) {
if (loops-- == 0) {
snd_printk(KERN_ERR "unable to choose default card id (%s)\n", id);
strcpy(card->id, card->proc_root->name);
return;
}
if (!snd_info_check_reserved_words(id))
goto __change;
for (i = 0; i < snd_ecards_limit; i++) {
if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
goto __change;
}
break;
__change:
len = strlen(id);
if (idx_flag) {
if (id[len-1] != '9')
id[len-1]++;
else
id[len-1] = 'A';
} else if ((size_t)len <= sizeof(card->id) - 3) {
strcat(id, "_1");
idx_flag++;
} else {
spos = id + len - 2;
if ((size_t)len <= sizeof(card->id) - 2)
spos++;
*spos++ = '_';
*spos++ = '1';
*spos++ = '\0';
idx_flag++;
}
}
}
/**
* snd_card_register - register the soundcard
* @card: soundcard structure
*
* This function registers all the devices assigned to the soundcard.
* Until calling this, the ALSA control interface is blocked from the
* external accesses. Thus, you should call this function at the end
* of the initialization of the card.
*
* Returns zero otherwise a negative error code if the registrain failed.
*/
int snd_card_register(struct snd_card *card)
{
int err;
snd_assert(card != NULL, return -EINVAL);
if ((err = snd_device_register_all(card)) < 0)
return err;
write_lock(&snd_card_rwlock);
if (snd_cards[card->number]) {
/* already registered */
write_unlock(&snd_card_rwlock);
return 0;
}
if (card->id[0] == '\0')
choose_default_id(card);
snd_cards[card->number] = card;
write_unlock(&snd_card_rwlock);
init_info_for_card(card);
#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
if (snd_mixer_oss_notify_callback)
snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
#endif
return 0;
}
#ifdef CONFIG_PROC_FS
static struct snd_info_entry *snd_card_info_entry = NULL;
static void snd_card_info_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
int idx, count;
struct snd_card *card;
for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
read_lock(&snd_card_rwlock);
if ((card = snd_cards[idx]) != NULL) {
count++;
snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
idx,
card->id,
card->driver,
card->shortname);
snd_iprintf(buffer, " %s\n",
card->longname);
}
read_unlock(&snd_card_rwlock);
}
if (!count)
snd_iprintf(buffer, "--- no soundcards ---\n");
}
#ifdef CONFIG_SND_OSSEMUL
void snd_card_info_read_oss(struct snd_info_buffer *buffer)
{
int idx, count;
struct snd_card *card;
for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
read_lock(&snd_card_rwlock);
if ((card = snd_cards[idx]) != NULL) {
count++;
snd_iprintf(buffer, "%s\n", card->longname);
}
read_unlock(&snd_card_rwlock);
}
if (!count) {
snd_iprintf(buffer, "--- no soundcards ---\n");
}
}
#endif
#ifdef MODULE
static struct snd_info_entry *snd_card_module_info_entry;
static void snd_card_module_info_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
int idx;
struct snd_card *card;
for (idx = 0; idx < SNDRV_CARDS; idx++) {
read_lock(&snd_card_rwlock);
if ((card = snd_cards[idx]) != NULL)
snd_iprintf(buffer, "%2i %s\n",
idx, card->module->name);
read_unlock(&snd_card_rwlock);
}
}
#endif
int __init snd_card_info_init(void)
{
struct snd_info_entry *entry;
entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
if (! entry)
return -ENOMEM;
entry->c.text.read_size = PAGE_SIZE;
entry->c.text.read = snd_card_info_read;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
return -ENOMEM;
}
snd_card_info_entry = entry;
#ifdef MODULE
entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
if (entry) {
entry->c.text.read_size = PAGE_SIZE;
entry->c.text.read = snd_card_module_info_read;
if (snd_info_register(entry) < 0)
snd_info_free_entry(entry);
else
snd_card_module_info_entry = entry;
}
#endif
return 0;
}
int __exit snd_card_info_done(void)
{
snd_info_unregister(snd_card_info_entry);
#ifdef MODULE
snd_info_unregister(snd_card_module_info_entry);
#endif
return 0;
}
#endif /* CONFIG_PROC_FS */
/**
* snd_component_add - add a component string
* @card: soundcard structure
* @component: the component id string
*
* This function adds the component id string to the supported list.
* The component can be referred from the alsa-lib.
*
* Returns zero otherwise a negative error code.
*/
int snd_component_add(struct snd_card *card, const char *component)
{
char *ptr;
int len = strlen(component);
ptr = strstr(card->components, component);
if (ptr != NULL) {
if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
return 1;
}
if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
snd_BUG();
return -ENOMEM;
}
if (card->components[0] != '\0')
strcat(card->components, " ");
strcat(card->components, component);
return 0;
}
/**
* snd_card_file_add - add the file to the file list of the card
* @card: soundcard structure
* @file: file pointer
*
* This function adds the file to the file linked-list of the card.
* This linked-list is used to keep tracking the connection state,
* and to avoid the release of busy resources by hotplug.
*
* Returns zero or a negative error code.
*/
int snd_card_file_add(struct snd_card *card, struct file *file)
{
struct snd_monitor_file *mfile;
mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
if (mfile == NULL)
return -ENOMEM;
mfile->file = file;
mfile->next = NULL;
spin_lock(&card->files_lock);
if (card->shutdown) {
spin_unlock(&card->files_lock);
kfree(mfile);
return -ENODEV;
}
mfile->next = card->files;
card->files = mfile;
spin_unlock(&card->files_lock);
return 0;
}
/**
* snd_card_file_remove - remove the file from the file list
* @card: soundcard structure
* @file: file pointer
*
* This function removes the file formerly added to the card via
* snd_card_file_add() function.
* If all files are removed and the release of the card is
* scheduled, it will wake up the the thread to call snd_card_free()
* (see snd_card_free_in_thread() function).
*
* Returns zero or a negative error code.
*/
int snd_card_file_remove(struct snd_card *card, struct file *file)
{
struct snd_monitor_file *mfile, *pfile = NULL;
spin_lock(&card->files_lock);
mfile = card->files;
while (mfile) {
if (mfile->file == file) {
if (pfile)
pfile->next = mfile->next;
else
card->files = mfile->next;
break;
}
pfile = mfile;
mfile = mfile->next;
}
spin_unlock(&card->files_lock);
if (card->files == NULL)
wake_up(&card->shutdown_sleep);
if (!mfile) {
snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
return -ENOENT;
}
kfree(mfile);
return 0;
}
#ifdef CONFIG_PM
/**
* snd_power_wait - wait until the power-state is changed.
* @card: soundcard structure
* @power_state: expected power state
* @file: file structure for the O_NONBLOCK check (optional)
*
* Waits until the power-state is changed.
*
* Note: the power lock must be active before call.
*/
int snd_power_wait(struct snd_card *card, unsigned int power_state, struct file *file)
{
wait_queue_t wait;
int result = 0;
/* fastpath */
if (snd_power_get_state(card) == power_state)
return 0;
init_waitqueue_entry(&wait, current);
add_wait_queue(&card->power_sleep, &wait);
while (1) {
if (card->shutdown) {
result = -ENODEV;
break;
}
if (snd_power_get_state(card) == power_state)
break;
#if 0 /* block all devices */
if (file && (file->f_flags & O_NONBLOCK)) {
result = -EAGAIN;
break;
}
#endif
set_current_state(TASK_UNINTERRUPTIBLE);
snd_power_unlock(card);
schedule_timeout(30 * HZ);
snd_power_lock(card);
}
remove_wait_queue(&card->power_sleep, &wait);
return result;
}
#endif /* CONFIG_PM */