[linux-2.6-block.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/smp_lock.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 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)
{
	unsigned long u = 0;
	int found = 0;
	unsigned char *cp, valbuf[128];
	long base = 10;
	hysdn_card *card = (hysdn_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 */
	cp = valbuf;
	if ((count > 2) && (valbuf[0] == '0') && (valbuf[1] == 'x')) {
		cp += 2;	/* pointer after hex modifier */
		base = 16;
	}
	/* scan the input for debug flags */
	while (*cp) {
		if ((*cp >= '0') && (*cp <= '9')) {
			found = 1;
			u *= base;	/* adjust to next digit */
			u += *cp++ - '0';
			continue;
		}
		if (base != 16)
			break;	/* end of number */

		if ((*cp >= 'a') && (*cp <= 'f')) {
			found = 1;
			u *= base;	/* adjust to next digit */
			u += *cp++ - 'a' + 10;
			continue;
		}
		break;		/* terminated */
	}

	if (found) {
		card->debug_flags = u;	/* remember debug flags */
		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;

	lock_kernel();
	card = card_root;
	while (card) {
		pd = card->proclog;
		if (pd->log == PDE(ino))
			break;
		card = card->next;	/* search next entry */
	}
	if (!card) {
		unlock_kernel();
		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 ! */
		unlock_kernel();
		return (-EPERM);	/* no permission this time */
	}
	unlock_kernel();
	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;
	unsigned long flags;
	spinlock_t hysdn_lock = SPIN_LOCK_UNLOCKED;

	lock_kernel();
	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;
		spin_lock_irqsave(&hysdn_lock, flags);
		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;
		}
		spin_unlock_irqrestore(&hysdn_lock, flags);

		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 */
	unlock_kernel();

	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 =
{
	.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);
		if ((pd->log = create_proc_entry(pd->log_name, S_IFREG | S_IRUGO | S_IWUSR, hysdn_proc_entry)) != NULL) {
		        pd->log->proc_fops = &log_fops; 
		        pd->log->owner = THIS_MODULE;
		}

		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>
1da177e4 LT	16	#include <linux/smp_lock.h>
	17
	18	#include "hysdn_defs.h"
	19
	20	/* the proc subdir for the interface is defined in the procconf module */
	21	extern struct proc_dir_entry *hysdn_proc_entry;
	22
aade0e82 AB	23	static void put_log_buffer(hysdn_card * card, char *cp);
aade0e82 AB	24
1da177e4 LT	25	/*************************************************/
	26	/* structure keeping ascii log for device output */
	27	/*************************************************/
	28	struct log_data {
	29	struct log_data *next;
c721bcce	30	unsigned long usage_cnt;/* number of files still to work */
1da177e4 LT	31	void proc_ctrl; / pointer to own control procdata structure */
	32	char log_start[2]; /* log string start (final len aligned by size) */
	33	};
	34
	35	/**********************************************/
	36	/* structure holding proc entrys for one card */
	37	/**********************************************/
	38	struct procdata {
	39	struct proc_dir_entry log; / log entry */
	40	char log_name[15]; /* log filename */
	41	struct log_data log_head, log_tail; /* head and tail for queue */
	42	int if_used; /* open count for interface */
	43	int volatile del_lock; /* lock for delete operations */
c721bcce	44	unsigned char logtmp[LOG_MAX_LINELEN];
1da177e4 LT	45	wait_queue_head_t rd_queue;
	46	};
	47
	48
	49	/**********************************************/
	50	/* log function for cards error log interface */
	51	/**********************************************/
	52	void
	53	hysdn_card_errlog(hysdn_card * card, tErrLogEntry * logp, int maxsize)
	54	{
	55	char buf[ERRLOG_TEXT_SIZE + 40];
	56
	57	sprintf(buf, "LOG 0x%08lX 0x%08lX : %s\n", logp->ulErrType, logp->ulErrSubtype, logp->ucText);
	58	put_log_buffer(card, buf); /* output the string */
	59	} /* hysdn_card_errlog */
	60
	61	/***************************************************/
	62	/* Log function using format specifiers for output */
	63	/***************************************************/
	64	void
	65	hysdn_addlog(hysdn_card * card, char *fmt,...)
	66	{
	67	struct procdata *pd = card->proclog;
	68	char *cp;
	69	va_list args;
	70
	71	if (!pd)
	72	return; /* log structure non existent */
	73
	74	cp = pd->logtmp;
	75	cp += sprintf(cp, "HYSDN: card %d ", card->myid);
	76
	77	va_start(args, fmt);
	78	cp += vsprintf(cp, fmt, args);
	79	va_end(args);
	80	*cp++ = '\n';
	81	*cp = 0;
	82
	83	if (card->debug_flags & DEB_OUT_SYSLOG)
	84	printk(KERN_INFO "%s", pd->logtmp);
	85	else
	86	put_log_buffer(card, pd->logtmp);
	87
	88	} /* hysdn_addlog */
	89
	90	/********************************************/
	91	/* put an log buffer into the log queue. */
	92	/* This buffer will be kept until all files */
	93	/* opened for read got the contents. */
	94	/* Flushes buffers not longer in use. */
	95	/********************************************/
aade0e82	96	static void
1da177e4 LT	97	put_log_buffer(hysdn_card * card, char *cp)
	98	{
	99	struct log_data *ib;
	100	struct procdata *pd = card->proclog;
	101	int i;
	102	unsigned long flags;
	103
	104	if (!pd)
	105	return;
	106	if (!cp)
	107	return;
	108	if (!*cp)
	109	return;
	110	if (pd->if_used <= 0)
	111	return; /* no open file for read */
	112
5cbded58	113	if (!(ib = kmalloc(sizeof(struct log_data) + strlen(cp), GFP_ATOMIC)))
1da177e4 LT	114	return; /* no memory */
	115	strcpy(ib->log_start, cp); /* set output string */
	116	ib->next = NULL;
	117	ib->proc_ctrl = pd; /* point to own control structure */
0d9ba869	118	spin_lock_irqsave(&card->hysdn_lock, flags);
1da177e4 LT	119	ib->usage_cnt = pd->if_used;
	120	if (!pd->log_head)
	121	pd->log_head = ib; /* new head */
	122	else
	123	pd->log_tail->next = ib; /* follows existing messages */
	124	pd->log_tail = ib; /* new tail */
	125	i = pd->del_lock++; /* get lock state */
0d9ba869	126	spin_unlock_irqrestore(&card->hysdn_lock, flags);
1da177e4 LT	127
	128	/* delete old entrys */
	129	if (!i)
	130	while (pd->log_head->next) {
	131	if ((pd->log_head->usage_cnt <= 0) &&
	132	(pd->log_head->next->usage_cnt <= 0)) {
	133	ib = pd->log_head;
	134	pd->log_head = pd->log_head->next;
	135	kfree(ib);
	136	} else
	137	break;
	138	} /* pd->log_head->next */
	139	pd->del_lock--; /* release lock level */
	140	wake_up_interruptible(&(pd->rd_queue)); /* announce new entry */
	141	} /* put_log_buffer */
	142
	143
	144	/******************************/
	145	/* file operations and tables */
	146	/******************************/
	147
	148	/****************************************/
	149	/* write log file -> set log level bits */
	150	/****************************************/
	151	static ssize_t
	152	hysdn_log_write(struct file file, const char __user buf, size_t count, loff_t * off)
	153	{
c721bcce	154	unsigned long u = 0;
1da177e4	155	int found = 0;
c721bcce	156	unsigned char *cp, valbuf[128];
1da177e4 LT	157	long base = 10;
	158	hysdn_card card = (hysdn_card ) file->private_data;
	159
	160	if (count > (sizeof(valbuf) - 1))
	161	count = sizeof(valbuf) - 1; /* limit length */
	162	if (copy_from_user(valbuf, buf, count))
	163	return (-EFAULT); /* copy failed */
	164
	165	valbuf[count] = 0; /* terminating 0 */
	166	cp = valbuf;
	167	if ((count > 2) && (valbuf[0] == '0') && (valbuf[1] == 'x')) {
	168	cp += 2; /* pointer after hex modifier */
	169	base = 16;
	170	}
	171	/* scan the input for debug flags */
	172	while (*cp) {
	173	if ((cp >= '0') && (cp <= '9')) {
	174	found = 1;
	175	u = base; / adjust to next digit */
	176	u += *cp++ - '0';
	177	continue;
	178	}
	179	if (base != 16)
	180	break; /* end of number */
	181
	182	if ((cp >= 'a') && (cp <= 'f')) {
	183	found = 1;
	184	u = base; / adjust to next digit */
	185	u += *cp++ - 'a' + 10;
	186	continue;
	187	}
	188	break; /* terminated */
	189	}
	190
	191	if (found) {
	192	card->debug_flags = u; /* remember debug flags */
	193	hysdn_addlog(card, "debug set to 0x%lx", card->debug_flags);
	194	}
	195	return (count);
	196	} /* hysdn_log_write */
	197
	198	/******************/
	199	/* read log file */
	200	/******************/
	201	static ssize_t
	202	hysdn_log_read(struct file file, char __user buf, size_t count, loff_t * off)
	203	{
	204	struct log_data *inf;
	205	int len;
4482dfad	206	struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
1da177e4 LT	207	struct procdata *pd = NULL;
	208	hysdn_card *card;
	209
	210	if (!((struct log_data *) file->private_data)) {
	211	if (file->f_flags & O_NONBLOCK)
	212	return (-EAGAIN);
	213
	214	/* sorry, but we need to search the card */
	215	card = card_root;
	216	while (card) {
	217	pd = card->proclog;
	218	if (pd->log == pde)
	219	break;
	220	card = card->next; /* search next entry */
	221	}
	222	if (card)
	223	interruptible_sleep_on(&(pd->rd_queue));
	224	else
	225	return (-EAGAIN);
	226
	227	}
	228	if (!(inf = ((struct log_data *) file->private_data)))
	229	return (0);
	230
	231	inf->usage_cnt--; /* new usage count */
	232	file->private_data = &inf->next; /* next structure */
	233	if ((len = strlen(inf->log_start)) <= count) {
	234	if (copy_to_user(buf, inf->log_start, len))
	235	return -EFAULT;
	236	*off += len;
	237	return (len);
	238	}
	239	return (0);
	240	} /* hysdn_log_read */
	241
	242	/******************/
	243	/* open log file */
	244	/******************/
	245	static int
	246	hysdn_log_open(struct inode ino, struct file filep)
	247	{
	248	hysdn_card *card;
	249	struct procdata *pd = NULL;
c721bcce	250	unsigned long flags;
1da177e4 LT	251
	252	lock_kernel();
	253	card = card_root;
	254	while (card) {
	255	pd = card->proclog;
	256	if (pd->log == PDE(ino))
	257	break;
	258	card = card->next; /* search next entry */
	259	}
	260	if (!card) {
	261	unlock_kernel();
	262	return (-ENODEV); /* device is unknown/invalid */
	263	}
	264	filep->private_data = card; /* remember our own card */
	265
	266	if ((filep->f_mode & (FMODE_READ \| FMODE_WRITE)) == FMODE_WRITE) {
	267	/* write only access -> write log level only */
	268	} else if ((filep->f_mode & (FMODE_READ \| FMODE_WRITE)) == FMODE_READ) {
	269
	270	/* read access -> log/debug read */
0d9ba869	271	spin_lock_irqsave(&card->hysdn_lock, flags);
1da177e4 LT	272	pd->if_used++;
	273	if (pd->log_head)
	274	filep->private_data = &pd->log_tail->next;
	275	else
	276	filep->private_data = &pd->log_head;
0d9ba869	277	spin_unlock_irqrestore(&card->hysdn_lock, flags);
1da177e4 LT	278	} else { /* simultaneous read/write access forbidden ! */
	279	unlock_kernel();
	280	return (-EPERM); /* no permission this time */
	281	}
	282	unlock_kernel();
	283	return nonseekable_open(ino, filep);
	284	} /* hysdn_log_open */
	285
	286	/*******************************************************************************/
	287	/* close a cardlog file. If the file has been opened for exclusive write it is */
	288	/* assumed as pof data input and the pof loader is noticed about. */
	289	/* Otherwise file is handled as log output. In this case the interface usage */
	290	/* count is decremented and all buffers are noticed of closing. If this file */
	291	/* was the last one to be closed, all buffers are freed. */
	292	/*******************************************************************************/
	293	static int
	294	hysdn_log_close(struct inode ino, struct file filep)
	295	{
	296	struct log_data *inf;
	297	struct procdata *pd;
	298	hysdn_card *card;
	299	int retval = 0;
	300	unsigned long flags;
0d9ba869	301	spinlock_t hysdn_lock = SPIN_LOCK_UNLOCKED;
1da177e4 LT	302
	303	lock_kernel();
	304	if ((filep->f_mode & (FMODE_READ \| FMODE_WRITE)) == FMODE_WRITE) {
	305	/* write only access -> write debug level written */
	306	retval = 0; /* success */
	307	} else {
	308	/* read access -> log/debug read, mark one further file as closed */
	309
	310	pd = NULL;
0d9ba869	311	spin_lock_irqsave(&hysdn_lock, flags);
1da177e4 LT	312	inf = ((struct log_data ) filep->private_data); / get first log entry */
	313	if (inf)
	314	pd = (struct procdata ) inf->proc_ctrl; / still entries there */
	315	else {
	316	/* no info available -> search card */
	317	card = card_root;
	318	while (card) {
	319	pd = card->proclog;
	320	if (pd->log == PDE(ino))
	321	break;
	322	card = card->next; /* search next entry */
	323	}
	324	if (card)
	325	pd = card->proclog; /* pointer to procfs log */
	326	}
	327	if (pd)
	328	pd->if_used--; /* decrement interface usage count by one */
	329
	330	while (inf) {
	331	inf->usage_cnt--; /* decrement usage count for buffers */
	332	inf = inf->next;
	333	}
0d9ba869	334	spin_unlock_irqrestore(&hysdn_lock, flags);
1da177e4 LT	335
	336	if (pd)
	337	if (pd->if_used <= 0) /* delete buffers if last file closed */
	338	while (pd->log_head) {
	339	inf = pd->log_head;
	340	pd->log_head = pd->log_head->next;
	341	kfree(inf);
	342	}
	343	} /* read access */
	344	unlock_kernel();
	345
	346	return (retval);
	347	} /* hysdn_log_close */
	348
	349	/*************************************************/
	350	/* select/poll routine to be able using select() */
	351	/*************************************************/
	352	static unsigned int
	353	hysdn_log_poll(struct file file, poll_table wait)
	354	{
	355	unsigned int mask = 0;
4482dfad	356	struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
1da177e4 LT	357	hysdn_card *card;
	358	struct procdata *pd = NULL;
	359
	360	if ((file->f_mode & (FMODE_READ \| FMODE_WRITE)) == FMODE_WRITE)
	361	return (mask); /* no polling for write supported */
	362
	363	/* we need to search the card */
	364	card = card_root;
	365	while (card) {
	366	pd = card->proclog;
	367	if (pd->log == pde)
	368	break;
	369	card = card->next; /* search next entry */
	370	}
	371	if (!card)
	372	return (mask); /* card not found */
	373
	374	poll_wait(file, &(pd->rd_queue), wait);
	375
	376	if (((struct log_data *) file->private_data))
	377	mask \|= POLLIN \| POLLRDNORM;
	378
	379	return mask;
	380	} /* hysdn_log_poll */
	381
	382	/**************************************************/
	383	/* table for log filesystem functions defined above. */
	384	/**************************************************/
2b8693c0	385	static const struct file_operations log_fops =
1da177e4 LT	386	{
	387	.llseek = no_llseek,
	388	.read = hysdn_log_read,
	389	.write = hysdn_log_write,
	390	.poll = hysdn_log_poll,
	391	.open = hysdn_log_open,
	392	.release = hysdn_log_close,
	393	};
	394
	395
	396	/***********************************************************************************/
	397	/* hysdn_proclog_init is called when the module is loaded after creating the cards */
	398	/* conf files. */
	399	/***********************************************************************************/
	400	int
	401	hysdn_proclog_init(hysdn_card * card)
	402	{
	403	struct procdata *pd;
	404
	405	/* create a cardlog proc entry */
	406
41f96935	407	if ((pd = kzalloc(sizeof(struct procdata), GFP_KERNEL)) != NULL) {
1da177e4 LT	408	sprintf(pd->log_name, "%s%d", PROC_LOG_BASENAME, card->myid);
	409	if ((pd->log = create_proc_entry(pd->log_name, S_IFREG \| S_IRUGO \| S_IWUSR, hysdn_proc_entry)) != NULL) {
	410	pd->log->proc_fops = &log_fops;
	411	pd->log->owner = THIS_MODULE;
	412	}
	413
	414	init_waitqueue_head(&(pd->rd_queue));
	415
	416	card->proclog = (void ) pd; / remember procfs structure */
	417	}
	418	return (0);
	419	} /* hysdn_proclog_init */
	420
	421	/************************************************************************************/
	422	/* hysdn_proclog_release is called when the module is unloaded and before the cards */
	423	/* conf file is released */
	424	/* The module counter is assumed to be 0 ! */
	425	/************************************************************************************/
	426	void
	427	hysdn_proclog_release(hysdn_card * card)
	428	{
	429	struct procdata *pd;
	430
	431	if ((pd = (struct procdata *) card->proclog) != NULL) {
	432	if (pd->log)
	433	remove_proc_entry(pd->log_name, hysdn_proc_entry);
	434	kfree(pd); /* release memory */
	435	card->proclog = NULL;
	436	}
	437	} /* hysdn_proclog_release */