text: /**************************************************************************
  
  Copyright (c) 2007-2008, Chelsio Inc.
  All rights reserved.
  
  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions are met:
  
   1. Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.
  
   2. Neither the name of the Chelsio Corporation nor the names of its
      contributors may be used to endorse or promote products derived from
      this software without specific prior written permission.
  
  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  POSSIBILITY OF SUCH DAMAGE.
  
  $FreeBSD: soc2013/dpl/head/sys/dev/cxgb/sys/mbufq.h 183105 2008-09-16 02:03:28Z kmacy $
  
  ***************************************************************************/
  
  #ifndef CXGB_MBUFQ_H_
  #define CXGB_MBUFQ_H_
  
  struct mbuf_head {
  	struct mbuf *head;
  	struct mbuf *tail;
  	uint32_t     qlen;
  	uint32_t     qsize;
  	struct mtx   lock;
  };
  
  static __inline void
  mbufq_init(struct mbuf_head *l)
  {
  	l->head = l->tail = NULL;
  	l->qlen = l->qsize = 0;
  }
  
  static __inline int
  mbufq_empty(struct mbuf_head *l)
  {
  	return (l->head == NULL);
  }
  
  static __inline int
  mbufq_len(struct mbuf_head *l)
  {
  	return (l->qlen);
  }
  
  static __inline int
  mbufq_size(struct mbuf_head *l)
  {
  	return (l->qsize);
  }
  
  static __inline int
  mbufq_head_size(struct mbuf_head *l)
  {
  	return (l->head ? l->head->m_pkthdr.len : 0);
  }
  
  static __inline void
  mbufq_tail(struct mbuf_head *l, struct mbuf *m)
  {
  	l->qlen++;
  	if (l->head == NULL)
  		l->head = m;
  	else
  		l->tail->m_nextpkt = m;
  	l->tail = m;
  	l->qsize += m->m_pkthdr.len;
  }
  
  static __inline struct mbuf *
  mbufq_dequeue(struct mbuf_head *l)
  {
  	struct mbuf *m;
  
  	m = l->head;
  	if (m) {
  		if (m == l->tail) 
  			l->head = l->tail = NULL;
  		else
  			l->head = m->m_nextpkt;
  		m->m_nextpkt = NULL;
  		l->qlen--;
  		l->qsize -= m->m_pkthdr.len;
  	}
  
  	return (m);
  }
  
  static __inline struct mbuf *
  mbufq_peek(const struct mbuf_head *l)
  {
  	return (l->head);
  }
  
  static __inline void
  mbufq_append(struct mbuf_head *a, struct mbuf_head *b)
  {
  	if (a->tail) 
  		a->tail->m_nextpkt = b->head;
  	if (b->tail)
  		a->tail = b->tail;
  	a->qlen += b->qlen;
  	a->qsize += b->qsize;
  	
  	
  }
  #endif  /* CXGB_MBUFQ_H_ */
  