From 1635d9171ccfca38509b37f70bb498bb62b603db Mon Sep 17 00:00:00 2001
From: Kip Macy <kmacy@FreeBSD.org>
Date: Wed, 17 Dec 2008 04:00:43 +0000
Subject: [PATCH] merge in 2 buf_ring helper routines for enqueueing and
 freeing buf_rings

---
 sys/net/if_var.h   | 27 +++++++++++++++++++++++++++
 sys/sys/buf_ring.h |  3 ++-
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index 7b2881ea03fd..6e6d2db08b8a 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -77,6 +77,7 @@ struct  ifvlantrunk;
 #ifdef _KERNEL
 #include <sys/mbuf.h>
 #include <sys/eventhandler.h>
+#include <sys/buf_ring.h>
 #endif /* _KERNEL */
 #include <sys/lock.h>		/* XXX */
 #include <sys/mutex.h>		/* XXX */
@@ -548,6 +549,32 @@ do {									\
 	IFQ_PURGE(ifq);							\
 } while (0)
 
+#ifdef _KERNEL
+static __inline int
+drbr_enqueue(struct buf_ring *br, struct mbuf *m)
+{	
+	int error = 0;
+
+	if ((error = buf_ring_enqueue(br, m)) == ENOBUFS) {
+		br->br_drops++;
+		m_freem(m);
+	}
+
+	return (error);
+}
+
+static __inline void
+drbr_free(struct buf_ring *br, struct malloc_type *type)
+{
+	struct mbuf *m;
+
+	while ((m = buf_ring_dequeue_sc(br)) != NULL)
+		m_freem(m);
+
+	buf_ring_free(br, type);
+}
+#endif
+
 /*
  * 72 was chosen below because it is the size of a TCP/IP
  * header (40) + the minimum mss (32).
diff --git a/sys/sys/buf_ring.h b/sys/sys/buf_ring.h
index 6d0cb7d542e2..efea85aa6f0b 100644
--- a/sys/sys/buf_ring.h
+++ b/sys/sys/buf_ring.h
@@ -48,10 +48,11 @@ struct buf_ring {
 	volatile uint32_t	br_prod_tail;	
 	int              	br_prod_size;
 	int              	br_prod_mask;
+	uint64_t		br_drops;
 	/*
 	 * Pad out to next L2 cache line
 	 */
-	uint64_t	  	_pad0[14];
+	uint64_t	  	_pad0[13];
 
 	volatile uint32_t	br_cons_head;
 	volatile uint32_t	br_cons_tail;