[deliverable/linux.git] / drivers / isdn / hysdn / hysdn_proclog.c

/* $Id: hysdn_proclog.c,v 1.9.6.3 2001/09/23 22:24:54 kai Exp $
 *
 * Linux driver for HYSDN cards, /proc/net filesystem log functions.
 *
 * Author    Werner Cornelius (werner@titro.de) for Hypercope GmbH
 * Copyright 1999 by Werner Cornelius (werner@titro.de)
 *
 * This software may be used and distributed according to the terms
 * of the GNU General Public License, incorporated herein by reference.
 *
 */

#include <linux/module.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/kernel.h>

#include "hysdn_defs.h"

/* the proc subdir for the interface is defined in the procconf module */
extern struct proc_dir_entry *hysdn_proc_entry;

static DEFINE_MUTEX(hysdn_log_mutex);
static void put_log_buffer(hysdn_card *card, char *cp);

/*************************************************/
/* structure keeping ascii log for device output */
/*************************************************/
struct log_data {
	struct log_data *next;
	unsigned long usage_cnt;/* number of files still to work */
	void *proc_ctrl;	/* pointer to own control procdata structure */
	char log_start[2];	/* log string start (final len aligned by size) */
};

/**********************************************/
/* structure holding proc entrys for one card */
/**********************************************/
struct procdata {
	struct proc_dir_entry *log;	/* log entry */
	char log_name[15];	/* log filename */
	struct log_data *log_head, *log_tail;	/* head and tail for queue */
	int if_used;		/* open count for interface */
	int volatile del_lock;	/* lock for delete operations */
	unsigned char logtmp[LOG_MAX_LINELEN];
	wait_queue_head_t rd_queue;
};


/**********************************************/
/* log function for cards error log interface */
/**********************************************/
void
hysdn_card_errlog(hysdn_card *card, tErrLogEntry *logp, int maxsize)
{
	char buf[ERRLOG_TEXT_SIZE + 40];

	sprintf(buf, "LOG 0x%08lX 0x%08lX : %s\n", logp->ulErrType, logp->ulErrSubtype, logp->ucText);
	put_log_buffer(card, buf);	/* output the string */
}				/* hysdn_card_errlog */

/***************************************************/
/* Log function using format specifiers for output */
/***************************************************/
void
hysdn_addlog(hysdn_card *card, char *fmt, ...)
{
	struct procdata *pd = card->proclog;
	char *cp;
	va_list args;

	if (!pd)
		return;		/* log structure non existent */

	cp = pd->logtmp;
	cp += sprintf(cp, "HYSDN: card %d ", card->myid);

	va_start(args, fmt);
	cp += vsprintf(cp, fmt, args);
	va_end(args);
	*cp++ = '\n';
	*cp = 0;

	if (card->debug_flags & DEB_OUT_SYSLOG)
		printk(KERN_INFO "%s", pd->logtmp);
	else
		put_log_buffer(card, pd->logtmp);

}				/* hysdn_addlog */

/********************************************/
/* put an log buffer into the log queue.    */
/* This buffer will be kept until all files */
/* opened for read got the contents.        */
/* Flushes buffers not longer in use.       */
/********************************************/
static void
put_log_buffer(hysdn_card *card, char *cp)
{
	struct log_data *ib;
	struct procdata *pd = card->proclog;
	int i;
	unsigned long flags;

	if (!pd)
		return;
	if (!cp)
		return;
	if (!*cp)
		return;
	if (pd->if_used <= 0)
		return;		/* no open file for read */

	if (!(ib = kmalloc(sizeof(struct log_data) + strlen(cp), GFP_ATOMIC)))
		return;	/* no memory */
	strcpy(ib->log_start, cp);	/* set output string */
	ib->next = NULL;
	ib->proc_ctrl = pd;	/* point to own control structure */
	spin_lock_irqsave(&card->hysdn_lock, flags);
	ib->usage_cnt = pd->if_used;
	if (!pd->log_head)
		pd->log_head = ib;	/* new head */
	else
		pd->log_tail->next = ib;	/* follows existing messages */
	pd->log_tail = ib;	/* new tail */
	i = pd->del_lock++;	/* get lock state */
	spin_unlock_irqrestore(&card->hysdn_lock, flags);

	/* delete old entrys */
	if (!i)
		while (pd->log_head->next) {
			if ((pd->log_head->usage_cnt <= 0) &&
			    (pd->log_head->next->usage_cnt <= 0)) {
				ib = pd->log_head;
				pd->log_head = pd->log_head->next;
				kfree(ib);
			} else
				break;
		}		/* pd->log_head->next */
	pd->del_lock--;		/* release lock level */
	wake_up_interruptible(&(pd->rd_queue));		/* announce new entry */
}				/* put_log_buffer */


/******************************/
/* file operations and tables */
/******************************/

/****************************************/
/* write log file -> set log level bits */
/****************************************/
static ssize_t
hysdn_log_write(struct file *file, const char __user *buf, size_t count, loff_t *off)
{
	int rc;
	unsigned char valbuf[128];
	hysdn_card *card = file->private_data;

	if (count > (sizeof(valbuf) - 1))
		count = sizeof(valbuf) - 1;	/* limit length */
	if (copy_from_user(valbuf, buf, count))
		return (-EFAULT);	/* copy failed */

	valbuf[count] = 0;	/* terminating 0 */

	rc = kstrtoul(valbuf, 0, &card->debug_flags);
	if (rc < 0)
		return rc;
	hysdn_addlog(card, "debug set to 0x%lx", card->debug_flags);
	return (count);
}				/* hysdn_log_write */

/******************/
/* read log file */
/******************/
static ssize_t
hysdn_log_read(struct file *file, char __user *buf, size_t count, loff_t *off)
{
	struct log_data *inf;
	int len;
	struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
	struct procdata *pd = NULL;
	hysdn_card *card;

	if (!*((struct log_data **) file->private_data)) {
		if (file->f_flags & O_NONBLOCK)
			return (-EAGAIN);

		/* sorry, but we need to search the card */
		card = card_root;
		while (card) {
			pd = card->proclog;
			if (pd->log == pde)
				break;
			card = card->next;	/* search next entry */
		}
		if (card)
			interruptible_sleep_on(&(pd->rd_queue));
		else
			return (-EAGAIN);

	}
	if (!(inf = *((struct log_data **) file->private_data)))
		return (0);

	inf->usage_cnt--;	/* new usage count */
	file->private_data = &inf->next;	/* next structure */
	if ((len = strlen(inf->log_start)) <= count) {
		if (copy_to_user(buf, inf->log_start, len))
			return -EFAULT;
		*off += len;
		return (len);
	}
	return (0);
}				/* hysdn_log_read */

/******************/
/* open log file */
/******************/
static int
hysdn_log_open(struct inode *ino, struct file *filep)
{
	hysdn_card *card;
	struct procdata *pd = NULL;
	unsigned long flags;

	mutex_lock(&hysdn_log_mutex);
	card = card_root;
	while (card) {
		pd = card->proclog;
		if (pd->log == PDE(ino))
			break;
		card = card->next;	/* search next entry */
	}
	if (!card) {
		mutex_unlock(&hysdn_log_mutex);
		return (-ENODEV);	/* device is unknown/invalid */
	}
	filep->private_data = card;	/* remember our own card */

	if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) {
		/* write only access -> write log level only */
	} else if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {

		/* read access -> log/debug read */
		spin_lock_irqsave(&card->hysdn_lock, flags);
		pd->if_used++;
		if (pd->log_head)
			filep->private_data = &pd->log_tail->next;
		else
			filep->private_data = &pd->log_head;
		spin_unlock_irqrestore(&card->hysdn_lock, flags);
	} else {		/* simultaneous read/write access forbidden ! */
		mutex_unlock(&hysdn_log_mutex);
		return (-EPERM);	/* no permission this time */
	}
	mutex_unlock(&hysdn_log_mutex);
	return nonseekable_open(ino, filep);
}				/* hysdn_log_open */

/*******************************************************************************/
/* close a cardlog file. If the file has been opened for exclusive write it is */
/* assumed as pof data input and the pof loader is noticed about.              */
/* Otherwise file is handled as log output. In this case the interface usage   */
/* count is decremented and all buffers are noticed of closing. If this file   */
/* was the last one to be closed, all buffers are freed.                       */
/*******************************************************************************/
static int
hysdn_log_close(struct inode *ino, struct file *filep)
{
	struct log_data *inf;
	struct procdata *pd;
	hysdn_card *card;
	int retval = 0;

	mutex_lock(&hysdn_log_mutex);
	if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) {
		/* write only access -> write debug level written */
		retval = 0;	/* success */
	} else {
		/* read access -> log/debug read, mark one further file as closed */

		pd = NULL;
		inf = *((struct log_data **) filep->private_data);	/* get first log entry */
		if (inf)
			pd = (struct procdata *) inf->proc_ctrl;	/* still entries there */
		else {
			/* no info available -> search card */
			card = card_root;
			while (card) {
				pd = card->proclog;
				if (pd->log == PDE(ino))
					break;
				card = card->next;	/* search next entry */
			}
			if (card)
				pd = card->proclog;	/* pointer to procfs log */
		}
		if (pd)
			pd->if_used--;	/* decrement interface usage count by one */

		while (inf) {
			inf->usage_cnt--;	/* decrement usage count for buffers */
			inf = inf->next;
		}

		if (pd)
			if (pd->if_used <= 0)	/* delete buffers if last file closed */
				while (pd->log_head) {
					inf = pd->log_head;
					pd->log_head = pd->log_head->next;
					kfree(inf);
				}
	}			/* read access */
	mutex_unlock(&hysdn_log_mutex);

	return (retval);
}				/* hysdn_log_close */

/*************************************************/
/* select/poll routine to be able using select() */
/*************************************************/
static unsigned int
hysdn_log_poll(struct file *file, poll_table *wait)
{
	unsigned int mask = 0;
	struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
	hysdn_card *card;
	struct procdata *pd = NULL;

	if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE)
		return (mask);	/* no polling for write supported */

	/* we need to search the card */
	card = card_root;
	while (card) {
		pd = card->proclog;
		if (pd->log == pde)
			break;
		card = card->next;	/* search next entry */
	}
	if (!card)
		return (mask);	/* card not found */

	poll_wait(file, &(pd->rd_queue), wait);

	if (*((struct log_data **) file->private_data))
		mask |= POLLIN | POLLRDNORM;

	return mask;
}				/* hysdn_log_poll */

/**************************************************/
/* table for log filesystem functions defined above. */
/**************************************************/
static const struct file_operations log_fops =
{
	.owner		= THIS_MODULE,
	.llseek         = no_llseek,
	.read           = hysdn_log_read,
	.write          = hysdn_log_write,
	.poll           = hysdn_log_poll,
	.open           = hysdn_log_open,
	.release        = hysdn_log_close,
};


/***********************************************************************************/
/* hysdn_proclog_init is called when the module is loaded after creating the cards */
/* conf files.                                                                     */
/***********************************************************************************/
int
hysdn_proclog_init(hysdn_card *card)
{
	struct procdata *pd;

	/* create a cardlog proc entry */

	if ((pd = kzalloc(sizeof(struct procdata), GFP_KERNEL)) != NULL) {
		sprintf(pd->log_name, "%s%d", PROC_LOG_BASENAME, card->myid);
		pd->log = proc_create(pd->log_name,
				      S_IFREG | S_IRUGO | S_IWUSR, hysdn_proc_entry,
				      &log_fops);

		init_waitqueue_head(&(pd->rd_queue));

		card->proclog = (void *) pd;	/* remember procfs structure */
	}
	return (0);
}				/* hysdn_proclog_init */

/************************************************************************************/
/* hysdn_proclog_release is called when the module is unloaded and before the cards */
/* conf file is released                                                            */
/* The module counter is assumed to be 0 !                                          */
/************************************************************************************/
void
hysdn_proclog_release(hysdn_card *card)
{
	struct procdata *pd;

	if ((pd = (struct procdata *) card->proclog) != NULL) {
		if (pd->log)
			remove_proc_entry(pd->log_name, hysdn_proc_entry);
		kfree(pd);	/* release memory */
		card->proclog = NULL;
	}
}				/* hysdn_proclog_release */
Commit	Line	Data
1da177e4 LT	1	/* $Id: hysdn_proclog.c,v 1.9.6.3 2001/09/23 22:24:54 kai Exp $
	2	*
	3	* Linux driver for HYSDN cards, /proc/net filesystem log functions.
	4	*
	5	* Author Werner Cornelius (werner@titro.de) for Hypercope GmbH
	6	* Copyright 1999 by Werner Cornelius (werner@titro.de)
	7	*
	8	* This software may be used and distributed according to the terms
	9	* of the GNU General Public License, incorporated herein by reference.
	10	*
	11	*/
	12
	13	#include <linux/module.h>
1da177e4 LT	14	#include <linux/poll.h>
1da177e4 LT	15	#include <linux/proc_fs.h>
d43c36dc	16	#include <linux/sched.h>
5a0e3ad6	17	#include <linux/slab.h>
76a64921	18	#include <linux/mutex.h>
3944ad68	19	#include <linux/kernel.h>
1da177e4 LT	20
	21	#include "hysdn_defs.h"
	22
	23	/* the proc subdir for the interface is defined in the procconf module */
	24	extern struct proc_dir_entry *hysdn_proc_entry;
	25
76a64921	26	static DEFINE_MUTEX(hysdn_log_mutex);
475be4d8	27	static void put_log_buffer(hysdn_card card, char cp);
aade0e82	28
1da177e4 LT	29	/*************************************************/
	30	/* structure keeping ascii log for device output */
	31	/*************************************************/
	32	struct log_data {
	33	struct log_data *next;
c721bcce	34	unsigned long usage_cnt;/* number of files still to work */
1da177e4 LT	35	void proc_ctrl; / pointer to own control procdata structure */
	36	char log_start[2]; /* log string start (final len aligned by size) */
	37	};
	38
	39	/**********************************************/
	40	/* structure holding proc entrys for one card */
	41	/**********************************************/
	42	struct procdata {
	43	struct proc_dir_entry log; / log entry */
	44	char log_name[15]; /* log filename */
	45	struct log_data log_head, log_tail; /* head and tail for queue */
	46	int if_used; /* open count for interface */
	47	int volatile del_lock; /* lock for delete operations */
c721bcce	48	unsigned char logtmp[LOG_MAX_LINELEN];
1da177e4 LT	49	wait_queue_head_t rd_queue;
	50	};
	51
	52
	53	/**********************************************/
	54	/* log function for cards error log interface */
	55	/**********************************************/
	56	void
475be4d8	57	hysdn_card_errlog(hysdn_card card, tErrLogEntry logp, int maxsize)
1da177e4 LT	58	{
	59	char buf[ERRLOG_TEXT_SIZE + 40];
	60
	61	sprintf(buf, "LOG 0x%08lX 0x%08lX : %s\n", logp->ulErrType, logp->ulErrSubtype, logp->ucText);
	62	put_log_buffer(card, buf); /* output the string */
	63	} /* hysdn_card_errlog */
	64
	65	/***************************************************/
	66	/* Log function using format specifiers for output */
	67	/***************************************************/
	68	void
475be4d8	69	hysdn_addlog(hysdn_card card, char fmt, ...)
1da177e4 LT	70	{
	71	struct procdata *pd = card->proclog;
	72	char *cp;
	73	va_list args;
	74
	75	if (!pd)
	76	return; /* log structure non existent */
	77
	78	cp = pd->logtmp;
	79	cp += sprintf(cp, "HYSDN: card %d ", card->myid);
	80
	81	va_start(args, fmt);
	82	cp += vsprintf(cp, fmt, args);
	83	va_end(args);
	84	*cp++ = '\n';
	85	*cp = 0;
	86
	87	if (card->debug_flags & DEB_OUT_SYSLOG)
	88	printk(KERN_INFO "%s", pd->logtmp);
	89	else
	90	put_log_buffer(card, pd->logtmp);
	91
	92	} /* hysdn_addlog */
	93
	94	/********************************************/
	95	/* put an log buffer into the log queue. */
	96	/* This buffer will be kept until all files */
	97	/* opened for read got the contents. */
	98	/* Flushes buffers not longer in use. */
	99	/********************************************/
aade0e82	100	static void
475be4d8	101	put_log_buffer(hysdn_card card, char cp)
1da177e4 LT	102	{
	103	struct log_data *ib;
	104	struct procdata *pd = card->proclog;
	105	int i;
	106	unsigned long flags;
	107
	108	if (!pd)
	109	return;
	110	if (!cp)
	111	return;
	112	if (!*cp)
	113	return;
	114	if (pd->if_used <= 0)
	115	return; /* no open file for read */
	116
5cbded58	117	if (!(ib = kmalloc(sizeof(struct log_data) + strlen(cp), GFP_ATOMIC)))
475be4d8	118	return; /* no memory */
1da177e4 LT	119	strcpy(ib->log_start, cp); /* set output string */
	120	ib->next = NULL;
	121	ib->proc_ctrl = pd; /* point to own control structure */
0d9ba869	122	spin_lock_irqsave(&card->hysdn_lock, flags);
1da177e4 LT	123	ib->usage_cnt = pd->if_used;
	124	if (!pd->log_head)
	125	pd->log_head = ib; /* new head */
	126	else
	127	pd->log_tail->next = ib; /* follows existing messages */
	128	pd->log_tail = ib; /* new tail */
	129	i = pd->del_lock++; /* get lock state */
0d9ba869	130	spin_unlock_irqrestore(&card->hysdn_lock, flags);
1da177e4 LT	131
	132	/* delete old entrys */
	133	if (!i)
	134	while (pd->log_head->next) {
	135	if ((pd->log_head->usage_cnt <= 0) &&
	136	(pd->log_head->next->usage_cnt <= 0)) {
	137	ib = pd->log_head;
	138	pd->log_head = pd->log_head->next;
	139	kfree(ib);
	140	} else
	141	break;
	142	} /* pd->log_head->next */
	143	pd->del_lock--; /* release lock level */
	144	wake_up_interruptible(&(pd->rd_queue)); /* announce new entry */
	145	} /* put_log_buffer */
	146
	147
	148	/******************************/
	149	/* file operations and tables */
	150	/******************************/
	151
	152	/****************************************/
	153	/* write log file -> set log level bits */
	154	/****************************************/
	155	static ssize_t
475be4d8	156	hysdn_log_write(struct file file, const char __user buf, size_t count, loff_t *off)
1da177e4	157	{
3944ad68 AS	158	int rc;
3944ad68 AS	159	unsigned char valbuf[128];
54cbb1ca	160	hysdn_card *card = file->private_data;
1da177e4 LT	161
	162	if (count > (sizeof(valbuf) - 1))
	163	count = sizeof(valbuf) - 1; /* limit length */
	164	if (copy_from_user(valbuf, buf, count))
	165	return (-EFAULT); /* copy failed */
	166
	167	valbuf[count] = 0; /* terminating 0 */
3944ad68	168
19eccc2b AD	169	rc = kstrtoul(valbuf, 0, &card->debug_flags);
	170	if (rc < 0)
	171	return rc;
	172	hysdn_addlog(card, "debug set to 0x%lx", card->debug_flags);
1da177e4 LT	173	return (count);
	174	} /* hysdn_log_write */
	175
	176	/******************/
	177	/* read log file */
	178	/******************/
	179	static ssize_t
475be4d8	180	hysdn_log_read(struct file file, char __user buf, size_t count, loff_t *off)
1da177e4 LT	181	{
	182	struct log_data *inf;
	183	int len;
4482dfad	184	struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
1da177e4 LT	185	struct procdata *pd = NULL;
	186	hysdn_card *card;
	187
	188	if (!((struct log_data *) file->private_data)) {
	189	if (file->f_flags & O_NONBLOCK)
	190	return (-EAGAIN);
	191
	192	/* sorry, but we need to search the card */
	193	card = card_root;
	194	while (card) {
	195	pd = card->proclog;
	196	if (pd->log == pde)
	197	break;
	198	card = card->next; /* search next entry */
	199	}
	200	if (card)
	201	interruptible_sleep_on(&(pd->rd_queue));
	202	else
	203	return (-EAGAIN);
	204
	205	}
	206	if (!(inf = ((struct log_data *) file->private_data)))
	207	return (0);
	208
	209	inf->usage_cnt--; /* new usage count */
	210	file->private_data = &inf->next; /* next structure */
	211	if ((len = strlen(inf->log_start)) <= count) {
	212	if (copy_to_user(buf, inf->log_start, len))
	213	return -EFAULT;
	214	*off += len;
	215	return (len);
	216	}
	217	return (0);
	218	} /* hysdn_log_read */
	219
	220	/******************/
	221	/* open log file */
	222	/******************/
	223	static int
	224	hysdn_log_open(struct inode ino, struct file filep)
	225	{
	226	hysdn_card *card;
	227	struct procdata *pd = NULL;
c721bcce	228	unsigned long flags;
1da177e4	229
76a64921	230	mutex_lock(&hysdn_log_mutex);
1da177e4 LT	231	card = card_root;
	232	while (card) {
	233	pd = card->proclog;
	234	if (pd->log == PDE(ino))
	235	break;
	236	card = card->next; /* search next entry */
	237	}
	238	if (!card) {
76a64921	239	mutex_unlock(&hysdn_log_mutex);
1da177e4 LT	240	return (-ENODEV); /* device is unknown/invalid */
	241	}
	242	filep->private_data = card; /* remember our own card */
	243
	244	if ((filep->f_mode & (FMODE_READ \| FMODE_WRITE)) == FMODE_WRITE) {
	245	/* write only access -> write log level only */
	246	} else if ((filep->f_mode & (FMODE_READ \| FMODE_WRITE)) == FMODE_READ) {
	247
	248	/* read access -> log/debug read */
0d9ba869	249	spin_lock_irqsave(&card->hysdn_lock, flags);
1da177e4 LT	250	pd->if_used++;
	251	if (pd->log_head)
	252	filep->private_data = &pd->log_tail->next;
	253	else
	254	filep->private_data = &pd->log_head;
0d9ba869	255	spin_unlock_irqrestore(&card->hysdn_lock, flags);
1da177e4	256	} else { /* simultaneous read/write access forbidden ! */
76a64921	257	mutex_unlock(&hysdn_log_mutex);
1da177e4 LT	258	return (-EPERM); /* no permission this time */
1da177e4 LT	259	}
76a64921	260	mutex_unlock(&hysdn_log_mutex);
1da177e4 LT	261	return nonseekable_open(ino, filep);
	262	} /* hysdn_log_open */
	263
	264	/*******************************************************************************/
	265	/* close a cardlog file. If the file has been opened for exclusive write it is */
	266	/* assumed as pof data input and the pof loader is noticed about. */
	267	/* Otherwise file is handled as log output. In this case the interface usage */
	268	/* count is decremented and all buffers are noticed of closing. If this file */
	269	/* was the last one to be closed, all buffers are freed. */
	270	/*******************************************************************************/
	271	static int
	272	hysdn_log_close(struct inode ino, struct file filep)
	273	{
	274	struct log_data *inf;
	275	struct procdata *pd;
	276	hysdn_card *card;
	277	int retval = 0;
1da177e4	278
76a64921	279	mutex_lock(&hysdn_log_mutex);
1da177e4 LT	280	if ((filep->f_mode & (FMODE_READ \| FMODE_WRITE)) == FMODE_WRITE) {
	281	/* write only access -> write debug level written */
	282	retval = 0; /* success */
	283	} else {
	284	/* read access -> log/debug read, mark one further file as closed */
	285
	286	pd = NULL;
1da177e4 LT	287	inf = ((struct log_data ) filep->private_data); / get first log entry */
	288	if (inf)
	289	pd = (struct procdata ) inf->proc_ctrl; / still entries there */
	290	else {
	291	/* no info available -> search card */
	292	card = card_root;
	293	while (card) {
	294	pd = card->proclog;
	295	if (pd->log == PDE(ino))
	296	break;
	297	card = card->next; /* search next entry */
	298	}
	299	if (card)
	300	pd = card->proclog; /* pointer to procfs log */
	301	}
	302	if (pd)
	303	pd->if_used--; /* decrement interface usage count by one */
	304
	305	while (inf) {
	306	inf->usage_cnt--; /* decrement usage count for buffers */
	307	inf = inf->next;
	308	}
1da177e4 LT	309
	310	if (pd)
	311	if (pd->if_used <= 0) /* delete buffers if last file closed */
	312	while (pd->log_head) {
	313	inf = pd->log_head;
	314	pd->log_head = pd->log_head->next;
	315	kfree(inf);
	316	}
	317	} /* read access */
76a64921	318	mutex_unlock(&hysdn_log_mutex);
1da177e4 LT	319
	320	return (retval);
	321	} /* hysdn_log_close */
	322
	323	/*************************************************/
	324	/* select/poll routine to be able using select() */
	325	/*************************************************/
	326	static unsigned int
475be4d8	327	hysdn_log_poll(struct file file, poll_table wait)
1da177e4 LT	328	{
1da177e4 LT	329	unsigned int mask = 0;
4482dfad	330	struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
1da177e4 LT	331	hysdn_card *card;
	332	struct procdata *pd = NULL;
	333
	334	if ((file->f_mode & (FMODE_READ \| FMODE_WRITE)) == FMODE_WRITE)
	335	return (mask); /* no polling for write supported */
	336
	337	/* we need to search the card */
	338	card = card_root;
	339	while (card) {
	340	pd = card->proclog;
	341	if (pd->log == pde)
	342	break;
	343	card = card->next; /* search next entry */
	344	}
	345	if (!card)
	346	return (mask); /* card not found */
	347
	348	poll_wait(file, &(pd->rd_queue), wait);
	349
	350	if (((struct log_data *) file->private_data))
	351	mask \|= POLLIN \| POLLRDNORM;
	352
	353	return mask;
	354	} /* hysdn_log_poll */
	355
	356	/**************************************************/
	357	/* table for log filesystem functions defined above. */
	358	/**************************************************/
2b8693c0	359	static const struct file_operations log_fops =
1da177e4	360	{
ac41cfd1	361	.owner = THIS_MODULE,
1da177e4 LT	362	.llseek = no_llseek,
	363	.read = hysdn_log_read,
	364	.write = hysdn_log_write,
	365	.poll = hysdn_log_poll,
	366	.open = hysdn_log_open,
475be4d8	367	.release = hysdn_log_close,
1da177e4 LT	368	};
	369
	370
	371	/***********************************************************************************/
	372	/* hysdn_proclog_init is called when the module is loaded after creating the cards */
	373	/* conf files. */
	374	/***********************************************************************************/
	375	int
475be4d8	376	hysdn_proclog_init(hysdn_card *card)
1da177e4 LT	377	{
	378	struct procdata *pd;
	379
	380	/* create a cardlog proc entry */
	381
41f96935	382	if ((pd = kzalloc(sizeof(struct procdata), GFP_KERNEL)) != NULL) {
1da177e4	383	sprintf(pd->log_name, "%s%d", PROC_LOG_BASENAME, card->myid);
ac41cfd1	384	pd->log = proc_create(pd->log_name,
475be4d8 JP	385	S_IFREG \| S_IRUGO \| S_IWUSR, hysdn_proc_entry,
475be4d8 JP	386	&log_fops);
1da177e4 LT	387
	388	init_waitqueue_head(&(pd->rd_queue));
	389
	390	card->proclog = (void ) pd; / remember procfs structure */
	391	}
	392	return (0);
	393	} /* hysdn_proclog_init */
	394
	395	/************************************************************************************/
	396	/* hysdn_proclog_release is called when the module is unloaded and before the cards */
	397	/* conf file is released */
	398	/* The module counter is assumed to be 0 ! */
	399	/************************************************************************************/
	400	void
475be4d8	401	hysdn_proclog_release(hysdn_card *card)
1da177e4 LT	402	{
	403	struct procdata *pd;
	404
	405	if ((pd = (struct procdata *) card->proclog) != NULL) {
	406	if (pd->log)
	407	remove_proc_entry(pd->log_name, hysdn_proc_entry);
	408	kfree(pd); /* release memory */
	409	card->proclog = NULL;
	410	}
	411	} /* hysdn_proclog_release */