Release 4.7 drivers/media/dvb-core/dvb_ringbuffer.c

/*
 *
 * dvb_ringbuffer.c: ring buffer implementation for the dvb driver
 *
 * Copyright (C) 2003 Oliver Endriss
 * Copyright (C) 2004 Andrew de Quincey
 *
 * based on code originally found in av7110.c & dvb_ci.c:
 * Copyright (C) 1999-2003 Ralph  Metzler
 *                       & Marcus Metzler for convergence integrated media GmbH
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1
 * 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser 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 <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <asm/uaccess.h>

#include "dvb_ringbuffer.h"


#define PKT_READY 0

#define PKT_DISPOSED 1




void dvb_ringbuffer_init(struct dvb_ringbuffer *rbuf, void *data, size_t len)
{
	rbuf->pread=rbuf->pwrite=0;
	rbuf->data=data;
	rbuf->size=len;
	rbuf->error=0;

	init_waitqueue_head(&rbuf->queue);

	spin_lock_init(&(rbuf->lock));
}



Contributors
Person
Tokens
Prop
Commits
CommitProp
alan cox
alan cox
55
87.30%
1
33.33%
andreas oberritter
andreas oberritter
6
9.52%
1
33.33%
michael hunold
michael hunold
2
3.17%
1
33.33%
Total
63
100.00%
3
100.00%



int dvb_ringbuffer_empty(struct dvb_ringbuffer *rbuf)
{
	return (rbuf->pread==rbuf->pwrite);
}



Contributors
Person
Tokens
Prop
Commits
CommitProp
alan cox
alan cox
19
90.48%
1
50.00%
michael hunold
michael hunold
2
9.52%
1
50.00%
Total
21
100.00%
2
100.00%



ssize_t dvb_ringbuffer_free(struct dvb_ringbuffer *rbuf)
{
	ssize_t free;

	free = rbuf->pread - rbuf->pwrite;
	if (free <= 0)
		free += rbuf->size;
	return free-1;
}



Contributors
Person
Tokens
Prop
Commits
CommitProp
alan cox
alan cox
38
95.00%
1
50.00%
michael hunold
michael hunold
2
5.00%
1
50.00%
Total
40
100.00%
2
100.00%



ssize_t dvb_ringbuffer_avail(struct dvb_ringbuffer *rbuf)
{
	ssize_t avail;

	avail = rbuf->pwrite - rbuf->pread;
	if (avail < 0)
		avail += rbuf->size;
	return avail;
}



Contributors
Person
Tokens
Prop
Commits
CommitProp
alan cox
alan cox
36
94.74%
1
50.00%
michael hunold
michael hunold
2
5.26%
1
50.00%
Total
38
100.00%
2
100.00%



void dvb_ringbuffer_flush(struct dvb_ringbuffer *rbuf)
{
	rbuf->pread = rbuf->pwrite;
	rbuf->error = 0;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
alan cox
alan cox
16
66.67%
1
33.33%
andreas oberritter
andreas oberritter
6
25.00%
1
33.33%
michael hunold
michael hunold
2
8.33%
1
33.33%
Total
24
100.00%
3
100.00%


EXPORT_SYMBOL(dvb_ringbuffer_flush);



void dvb_ringbuffer_reset(struct dvb_ringbuffer *rbuf)
{
	rbuf->pread = rbuf->pwrite = 0;
	rbuf->error = 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
andrea odetti* (same as mario rossi)
andrea odetti* (same as mario rossi)
26
100.00%
1
100.00%
Total
26
100.00%
1
100.00%



void dvb_ringbuffer_flush_spinlock_wakeup(struct dvb_ringbuffer *rbuf)
{
	unsigned long flags;

	spin_lock_irqsave(&rbuf->lock, flags);
	dvb_ringbuffer_flush(rbuf);
	spin_unlock_irqrestore(&rbuf->lock, flags);

	wake_up(&rbuf->queue);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
alan cox
alan cox
45
95.74%
1
50.00%
michael hunold
michael hunold
2
4.26%
1
50.00%
Total
47
100.00%
2
100.00%



ssize_t dvb_ringbuffer_read_user(struct dvb_ringbuffer *rbuf, u8 __user *buf, size_t len)
{
	size_t todo = len;
	size_t split;

	split = (rbuf->pread + len > rbuf->size) ? rbuf->size - rbuf->pread : 0;
	if (split > 0) {
		if (copy_to_user(buf, rbuf->data+rbuf->pread, split))
			return -EFAULT;
		buf += split;
		todo -= split;
		rbuf->pread = 0;
	}
	if (copy_to_user(buf, rbuf->data+rbuf->pread, todo))
		return -EFAULT;

	rbuf->pread = (rbuf->pread + todo) % rbuf->size;

	return len;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
alan cox
alan cox
89
66.92%
1
33.33%
al viro
al viro
42
31.58%
1
33.33%
michael hunold
michael hunold
2
1.50%
1
33.33%
Total
133
100.00%
3
100.00%



void dvb_ringbuffer_read(struct dvb_ringbuffer *rbuf, u8 *buf, size_t len)
{
	size_t todo = len;
	size_t split;

	split = (rbuf->pread + len > rbuf->size) ? rbuf->size - rbuf->pread : 0;
	if (split > 0) {
		memcpy(buf, rbuf->data+rbuf->pread, split);
		buf += split;
		todo -= split;
		rbuf->pread = 0;
	}
	memcpy(buf, rbuf->data+rbuf->pread, todo);

	rbuf->pread = (rbuf->pread + todo) % rbuf->size;
}


Contributors
Person
Tokens
Prop
Commits
CommitProp
al viro
al viro
63
53.85%
1
33.33%
alan cox
alan cox
53
45.30%
1
33.33%
andrew morton
andrew morton
1
0.85%
1
33.33%
Total
117
100.00%
3
100.00%



ssize_t dvb_ringbuffer_write(struct dvb_ringbuffer *rbuf, const u8 *buf, size_t len)
{
	size_t todo = len;
	size_t split;

	split = (rbuf->pwrite + len > rbuf->size) ? rbuf->size - rbuf->pwrite : 0;

	if (split > 0) {
		memcpy(rbuf->data+rbuf->pwrite, buf, split);
		buf += split;
		todo -= split;
		rbuf->pwrite = 0;
	}
	memcpy(rbuf->data+rbuf->pwrite, buf, todo);
	rbuf->pwrite = (rbuf->pwrite + todo) % rbuf->size;

	return len;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
alan cox
alan cox
118
97.52%
1
33.33%
michael hunold
michael hunold
2
1.65%
1
33.33%
andrew morton
andrew morton
1
0.83%
1
33.33%
Total
121
100.00%
3
100.00%



ssize_t dvb_ringbuffer_write_user(struct dvb_ringbuffer *rbuf,
				  const u8 __user *buf, size_t len)
{
	int status;
	size_t todo = len;
	size_t split;

	split = (rbuf->pwrite + len > rbuf->size) ? rbuf->size - rbuf->pwrite : 0;

	if (split > 0) {
		status = copy_from_user(rbuf->data+rbuf->pwrite, buf, split);
		if (status)
			return len - todo;
		buf += split;
		todo -= split;
		rbuf->pwrite = 0;
	}
	status = copy_from_user(rbuf->data+rbuf->pwrite, buf, todo);
	if (status)
		return len - todo;
	rbuf->pwrite = (rbuf->pwrite + todo) % rbuf->size;

	return len;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
mauro carvalho chehab
mauro carvalho chehab
147
100.00%
1
100.00%
Total
147
100.00%
1
100.00%



ssize_t dvb_ringbuffer_pkt_write(struct dvb_ringbuffer *rbuf, u8* buf, size_t len)
{
	int status;
	ssize_t oldpwrite = rbuf->pwrite;

	DVB_RINGBUFFER_WRITE_BYTE(rbuf, len >> 8);
	DVB_RINGBUFFER_WRITE_BYTE(rbuf, len & 0xff);
	DVB_RINGBUFFER_WRITE_BYTE(rbuf, PKT_READY);
	status = dvb_ringbuffer_write(rbuf, buf, len);

	if (status < 0) rbuf->pwrite = oldpwrite;
	return status;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
michael hunold
michael hunold
78
100.00%
1
100.00%
Total
78
100.00%
1
100.00%



ssize_t dvb_ringbuffer_pkt_read_user(struct dvb_ringbuffer *rbuf, size_t idx,
				int offset, u8 __user *buf, size_t len)
{
	size_t todo;
	size_t split;
	size_t pktlen;

	pktlen = rbuf->data[idx] << 8;
	pktlen |= rbuf->data[(idx + 1) % rbuf->size];
	if (offset > pktlen) return -EINVAL;
	if ((offset + len) > pktlen) len = pktlen - offset;

	idx = (idx + DVB_RINGBUFFER_PKTHDRSIZE + offset) % rbuf->size;
	todo = len;
	split = ((idx + len) > rbuf->size) ? rbuf->size - idx : 0;
	if (split > 0) {
		if (copy_to_user(buf, rbuf->data+idx, split))
			return -EFAULT;
		buf += split;
		todo -= split;
		idx = 0;
	}
	if (copy_to_user(buf, rbuf->data+idx, todo))
		return -EFAULT;

	return len;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
michael hunold
michael hunold
163
86.70%
1
50.00%
al viro
al viro
25
13.30%
1
50.00%
Total
188
100.00%
2
100.00%



ssize_t dvb_ringbuffer_pkt_read(struct dvb_ringbuffer *rbuf, size_t idx,
				int offset, u8* buf, size_t len)
{
	size_t todo;
	size_t split;
	size_t pktlen;

	pktlen = rbuf->data[idx] << 8;
	pktlen |= rbuf->data[(idx + 1) % rbuf->size];
	if (offset > pktlen) return -EINVAL;
	if ((offset + len) > pktlen) len = pktlen - offset;

	idx = (idx + DVB_RINGBUFFER_PKTHDRSIZE + offset) % rbuf->size;
	todo = len;
	split = ((idx + len) > rbuf->size) ? rbuf->size - idx : 0;
	if (split > 0) {
		memcpy(buf, rbuf->data+idx, split);
		buf += split;
		todo -= split;
		idx = 0;
	}
	memcpy(buf, rbuf->data+idx, todo);
	return len;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
al viro
al viro
137
78.29%
1
50.00%
michael hunold
michael hunold
38
21.71%
1
50.00%
Total
175
100.00%
2
100.00%



void dvb_ringbuffer_pkt_dispose(struct dvb_ringbuffer *rbuf, size_t idx)
{
	size_t pktlen;

	rbuf->data[(idx + 2) % rbuf->size] = PKT_DISPOSED;

	// clean up disposed packets
	while(dvb_ringbuffer_avail(rbuf) > DVB_RINGBUFFER_PKTHDRSIZE) {
		if (DVB_RINGBUFFER_PEEK(rbuf, 2) == PKT_DISPOSED) {
			pktlen = DVB_RINGBUFFER_PEEK(rbuf, 0) << 8;
			pktlen |= DVB_RINGBUFFER_PEEK(rbuf, 1);
			DVB_RINGBUFFER_SKIP(rbuf, pktlen + DVB_RINGBUFFER_PKTHDRSIZE);
		} else {
			// first packet is not disposed, so we stop cleaning now
			break;
		}
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
michael hunold
michael hunold
92
100.00%
1
100.00%
Total
92
100.00%
1
100.00%



ssize_t dvb_ringbuffer_pkt_next(struct dvb_ringbuffer *rbuf, size_t idx, size_t* pktlen)
{
	int consumed;
	int curpktlen;
	int curpktstatus;

	if (idx == -1) {
	       idx = rbuf->pread;
	} else {
		curpktlen = rbuf->data[idx] << 8;
		curpktlen |= rbuf->data[(idx + 1) % rbuf->size];
		idx = (idx + curpktlen + DVB_RINGBUFFER_PKTHDRSIZE) % rbuf->size;
	}

	consumed = (idx - rbuf->pread) % rbuf->size;

	while((dvb_ringbuffer_avail(rbuf) - consumed) > DVB_RINGBUFFER_PKTHDRSIZE) {

		curpktlen = rbuf->data[idx] << 8;
		curpktlen |= rbuf->data[(idx + 1) % rbuf->size];
		curpktstatus = rbuf->data[(idx + 2) % rbuf->size];

		if (curpktstatus == PKT_READY) {
			*pktlen = curpktlen;
			return idx;
		}

		consumed += curpktlen + DVB_RINGBUFFER_PKTHDRSIZE;
		idx = (idx + curpktlen + DVB_RINGBUFFER_PKTHDRSIZE) % rbuf->size;
	}

	// no packets available
	return -1;
}



Contributors
Person
Tokens
Prop
Commits
CommitProp
michael hunold
michael hunold
201
100.00%
1
100.00%
Total
201
100.00%
1
100.00%


EXPORT_SYMBOL(dvb_ringbuffer_init);

EXPORT_SYMBOL(dvb_ringbuffer_empty);

EXPORT_SYMBOL(dvb_ringbuffer_free);

EXPORT_SYMBOL(dvb_ringbuffer_avail);

EXPORT_SYMBOL(dvb_ringbuffer_flush_spinlock_wakeup);

EXPORT_SYMBOL(dvb_ringbuffer_read_user);

EXPORT_SYMBOL(dvb_ringbuffer_read);

EXPORT_SYMBOL(dvb_ringbuffer_write);

EXPORT_SYMBOL(dvb_ringbuffer_write_user);
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
michael hunold
michael hunold
607
38.15%
3
25.00%
alan cox
alan cox
507
31.87%
1
8.33%
al viro
al viro
272
17.10%
1
8.33%
mauro carvalho chehab
mauro carvalho chehab
152
9.55%
1
8.33%
andrea odetti* (same as mario rossi)
andrea odetti* (same as mario rossi)
26
1.63%
1
8.33%
andreas oberritter
andreas oberritter
12
0.75%
1
8.33%
andrew morton
andrew morton
9
0.57%
2
16.67%
oliver endriss
oliver endriss
5
0.31%
1
8.33%
johannes stezenbach
johannes stezenbach
1
0.06%
1
8.33%
Total
1591
100.00%
12
100.00%
  
Directory: drivers/media/dvb-core

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.