358 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			358 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* $Id: hysdn_proclog.c,v 1.9.6.3 2001/09/23 22:24:54 kai Exp $
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 *
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 * Linux driver for HYSDN cards, /proc/net filesystem log functions.
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 *
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 * Author    Werner Cornelius (werner@titro.de) for Hypercope GmbH
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 * Copyright 1999 by Werner Cornelius (werner@titro.de)
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 *
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 * This software may be used and distributed according to the terms
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 * of the GNU General Public License, incorporated herein by reference.
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 *
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 */
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#include <linux/module.h>
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#include <linux/poll.h>
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#include <linux/proc_fs.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/mutex.h>
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#include <linux/kernel.h>
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#include "hysdn_defs.h"
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/* the proc subdir for the interface is defined in the procconf module */
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extern struct proc_dir_entry *hysdn_proc_entry;
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static DEFINE_MUTEX(hysdn_log_mutex);
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static void put_log_buffer(hysdn_card *card, char *cp);
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/*************************************************/
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/* structure keeping ascii log for device output */
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/*************************************************/
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struct log_data {
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	struct log_data *next;
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	unsigned long usage_cnt;/* number of files still to work */
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	void *proc_ctrl;	/* pointer to own control procdata structure */
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	char log_start[2];	/* log string start (final len aligned by size) */
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};
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/**********************************************/
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/* structure holding proc entrys for one card */
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/**********************************************/
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struct procdata {
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	struct proc_dir_entry *log;	/* log entry */
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	char log_name[15];	/* log filename */
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	struct log_data *log_head, *log_tail;	/* head and tail for queue */
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	int if_used;		/* open count for interface */
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	unsigned char logtmp[LOG_MAX_LINELEN];
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	wait_queue_head_t rd_queue;
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};
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/**********************************************/
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/* log function for cards error log interface */
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/**********************************************/
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void
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hysdn_card_errlog(hysdn_card *card, tErrLogEntry *logp, int maxsize)
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{
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	char buf[ERRLOG_TEXT_SIZE + 40];
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	sprintf(buf, "LOG 0x%08lX 0x%08lX : %s\n", logp->ulErrType, logp->ulErrSubtype, logp->ucText);
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	put_log_buffer(card, buf);	/* output the string */
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}				/* hysdn_card_errlog */
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/***************************************************/
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/* Log function using format specifiers for output */
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/***************************************************/
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void
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hysdn_addlog(hysdn_card *card, char *fmt, ...)
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{
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	struct procdata *pd = card->proclog;
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	char *cp;
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	va_list args;
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	if (!pd)
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		return;		/* log structure non existent */
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	cp = pd->logtmp;
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	cp += sprintf(cp, "HYSDN: card %d ", card->myid);
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	va_start(args, fmt);
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	cp += vsprintf(cp, fmt, args);
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	va_end(args);
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	*cp++ = '\n';
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	*cp = 0;
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	if (card->debug_flags & DEB_OUT_SYSLOG)
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		printk(KERN_INFO "%s", pd->logtmp);
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	else
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		put_log_buffer(card, pd->logtmp);
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}				/* hysdn_addlog */
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/********************************************/
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/* put an log buffer into the log queue.    */
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/* This buffer will be kept until all files */
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/* opened for read got the contents.        */
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/* Flushes buffers not longer in use.       */
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/********************************************/
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static void
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put_log_buffer(hysdn_card *card, char *cp)
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{
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	struct log_data *ib;
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	struct procdata *pd = card->proclog;
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	unsigned long flags;
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	if (!pd)
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		return;
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	if (!cp)
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		return;
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	if (!*cp)
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		return;
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	if (pd->if_used <= 0)
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		return;		/* no open file for read */
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	if (!(ib = kmalloc(sizeof(struct log_data) + strlen(cp), GFP_ATOMIC)))
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		return;	/* no memory */
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	strcpy(ib->log_start, cp);	/* set output string */
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	ib->next = NULL;
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	ib->proc_ctrl = pd;	/* point to own control structure */
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	spin_lock_irqsave(&card->hysdn_lock, flags);
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	ib->usage_cnt = pd->if_used;
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	if (!pd->log_head)
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		pd->log_head = ib;	/* new head */
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	else
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		pd->log_tail->next = ib;	/* follows existing messages */
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	pd->log_tail = ib;	/* new tail */
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	/* delete old entrys */
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	while (pd->log_head->next) {
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		if ((pd->log_head->usage_cnt <= 0) &&
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		    (pd->log_head->next->usage_cnt <= 0)) {
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			ib = pd->log_head;
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			pd->log_head = pd->log_head->next;
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			kfree(ib);
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		} else {
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			break;
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		}
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	}		/* pd->log_head->next */
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	spin_unlock_irqrestore(&card->hysdn_lock, flags);
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	wake_up_interruptible(&(pd->rd_queue));		/* announce new entry */
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}				/* put_log_buffer */
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/******************************/
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/* file operations and tables */
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/******************************/
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/****************************************/
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/* write log file -> set log level bits */
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/****************************************/
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static ssize_t
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hysdn_log_write(struct file *file, const char __user *buf, size_t count, loff_t *off)
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{
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	int rc;
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	hysdn_card *card = file->private_data;
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	rc = kstrtoul_from_user(buf, count, 0, &card->debug_flags);
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	if (rc < 0)
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		return rc;
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	hysdn_addlog(card, "debug set to 0x%lx", card->debug_flags);
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	return (count);
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}				/* hysdn_log_write */
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/******************/
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/* read log file */
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/******************/
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static ssize_t
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hysdn_log_read(struct file *file, char __user *buf, size_t count, loff_t *off)
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{
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	struct log_data *inf;
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	int len;
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	hysdn_card *card = PDE_DATA(file_inode(file));
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	if (!(inf = *((struct log_data **) file->private_data))) {
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		struct procdata *pd = card->proclog;
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		if (file->f_flags & O_NONBLOCK)
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			return (-EAGAIN);
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		wait_event_interruptible(pd->rd_queue, (inf =
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				*((struct log_data **) file->private_data)));
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	}
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	if (!inf)
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		return (0);
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	inf->usage_cnt--;	/* new usage count */
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	file->private_data = &inf->next;	/* next structure */
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	if ((len = strlen(inf->log_start)) <= count) {
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		if (copy_to_user(buf, inf->log_start, len))
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			return -EFAULT;
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		*off += len;
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		return (len);
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	}
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	return (0);
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}				/* hysdn_log_read */
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/******************/
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/* open log file */
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/******************/
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static int
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hysdn_log_open(struct inode *ino, struct file *filep)
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{
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	hysdn_card *card = PDE_DATA(ino);
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	mutex_lock(&hysdn_log_mutex);
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	if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) {
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		/* write only access -> write log level only */
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		filep->private_data = card;	/* remember our own card */
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	} else if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
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		struct procdata *pd = card->proclog;
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		unsigned long flags;
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		/* read access -> log/debug read */
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		spin_lock_irqsave(&card->hysdn_lock, flags);
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		pd->if_used++;
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		if (pd->log_head)
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			filep->private_data = &pd->log_tail->next;
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		else
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			filep->private_data = &pd->log_head;
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		spin_unlock_irqrestore(&card->hysdn_lock, flags);
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	} else {		/* simultaneous read/write access forbidden ! */
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		mutex_unlock(&hysdn_log_mutex);
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		return (-EPERM);	/* no permission this time */
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	}
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	mutex_unlock(&hysdn_log_mutex);
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	return nonseekable_open(ino, filep);
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}				/* hysdn_log_open */
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/*******************************************************************************/
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/* close a cardlog file. If the file has been opened for exclusive write it is */
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/* assumed as pof data input and the pof loader is noticed about.              */
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/* Otherwise file is handled as log output. In this case the interface usage   */
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/* count is decremented and all buffers are noticed of closing. If this file   */
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/* was the last one to be closed, all buffers are freed.                       */
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/*******************************************************************************/
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static int
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hysdn_log_close(struct inode *ino, struct file *filep)
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{
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	struct log_data *inf;
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	struct procdata *pd;
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	hysdn_card *card;
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	int retval = 0;
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	mutex_lock(&hysdn_log_mutex);
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	if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) {
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		/* write only access -> write debug level written */
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		retval = 0;	/* success */
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	} else {
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		/* read access -> log/debug read, mark one further file as closed */
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		inf = *((struct log_data **) filep->private_data);	/* get first log entry */
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		if (inf)
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			pd = (struct procdata *) inf->proc_ctrl;	/* still entries there */
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		else {
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			/* no info available -> search card */
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			card = PDE_DATA(file_inode(filep));
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			pd = card->proclog;	/* pointer to procfs log */
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		}
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		if (pd)
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			pd->if_used--;	/* decrement interface usage count by one */
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		while (inf) {
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			inf->usage_cnt--;	/* decrement usage count for buffers */
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			inf = inf->next;
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		}
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		if (pd)
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			if (pd->if_used <= 0)	/* delete buffers if last file closed */
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				while (pd->log_head) {
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					inf = pd->log_head;
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					pd->log_head = pd->log_head->next;
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					kfree(inf);
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				}
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	}			/* read access */
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	mutex_unlock(&hysdn_log_mutex);
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	return (retval);
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}				/* hysdn_log_close */
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/*************************************************/
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/* select/poll routine to be able using select() */
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/*************************************************/
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static __poll_t
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hysdn_log_poll(struct file *file, poll_table *wait)
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{
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	__poll_t mask = 0;
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	hysdn_card *card = PDE_DATA(file_inode(file));
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	struct procdata *pd = card->proclog;
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	if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE)
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		return (mask);	/* no polling for write supported */
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	poll_wait(file, &(pd->rd_queue), wait);
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	if (*((struct log_data **) file->private_data))
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		mask |= EPOLLIN | EPOLLRDNORM;
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	return mask;
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}				/* hysdn_log_poll */
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/**************************************************/
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/* table for log filesystem functions defined above. */
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/**************************************************/
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static const struct file_operations log_fops =
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{
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	.owner		= THIS_MODULE,
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	.llseek         = no_llseek,
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	.read           = hysdn_log_read,
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	.write          = hysdn_log_write,
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	.poll           = hysdn_log_poll,
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	.open           = hysdn_log_open,
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	.release        = hysdn_log_close,
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};
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/***********************************************************************************/
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/* hysdn_proclog_init is called when the module is loaded after creating the cards */
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/* conf files.                                                                     */
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/***********************************************************************************/
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int
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hysdn_proclog_init(hysdn_card *card)
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{
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	struct procdata *pd;
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	/* create a cardlog proc entry */
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	if ((pd = kzalloc(sizeof(struct procdata), GFP_KERNEL)) != NULL) {
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		sprintf(pd->log_name, "%s%d", PROC_LOG_BASENAME, card->myid);
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		pd->log = proc_create_data(pd->log_name,
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				      S_IFREG | S_IRUGO | S_IWUSR, hysdn_proc_entry,
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				      &log_fops, card);
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		init_waitqueue_head(&(pd->rd_queue));
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		card->proclog = (void *) pd;	/* remember procfs structure */
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	}
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	return (0);
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}				/* hysdn_proclog_init */
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/************************************************************************************/
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/* hysdn_proclog_release is called when the module is unloaded and before the cards */
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/* conf file is released                                                            */
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/* The module counter is assumed to be 0 !                                          */
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/************************************************************************************/
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void
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hysdn_proclog_release(hysdn_card *card)
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{
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	struct procdata *pd;
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	if ((pd = (struct procdata *) card->proclog) != NULL) {
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		if (pd->log)
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			remove_proc_entry(pd->log_name, hysdn_proc_entry);
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		kfree(pd);	/* release memory */
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		card->proclog = NULL;
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	}
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}				/* hysdn_proclog_release */
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