Changes to support crashdump analysis of netisr:

- Rename the netisr protocol registration array, 'np' to 'netisr_proto',
  in order to reduce the chances of symbol name collisions.  It remains
  statically defined, but it will be looked up by netstat(1).

- Move certain internal structure definitions from netisr.c to
  netisr_internal.h so that netstat(1) can find them.  They remain
  private, and should not be used for any other purpose (for example,
  they should not be used by kernel modules, which must instead use the
  public interfaces in netisr.h).

- Store a kernel-compiled version of NETISR_MAXPROT in the global variable
  netisr_maxprot, and export via a sysctl, so that it is available for use
  by netstat(1).  This is especially important for crashdump
  interpretation, where the size of the workstream structure is determined
  by the maximum number of protocols compiled into the kernel.

MFC after:	1 week
Sponsored by:	Juniper Networks

1 files changed, 127 insertions, 0 deletions

diff --git a/sys/net/netisr_internal.h b/sys/net/netisr_internal.h
new file mode 100644
index 0000000..40afaf1
--- /dev/null
+++ b/sys/net/netisr_internal.h
@@ -0,0 +1,127 @@
+/*-
+ * Copyright (c) 2007-2009 Robert N. M. Watson
+ * Copyright (c) 2010 Juniper Networks, Inc.
+ * All rights reserved.
+ *
+ * This software was developed by Robert N. M. Watson under contract
+ * to Juniper Networks, Inc.
+ *
+ * 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. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _NET_NETISR_INTERNAL_H_
+#define	_NET_NETISR_INTERNAL_H_
+
+#ifndef _WANT_NETISR_INTERNAL
+#error "no user-serviceable parts inside"
+#endif
+
+/*
+ * These definitions are private to the netisr implementation, but provided
+ * here for use by post-mortem crashdump analysis tools.  They should not be
+ * used in any other context as they can and will change.  Public definitions
+ * may be found in netisr.h.
+ */
+
+#ifndef _KERNEL
+typedef void *netisr_handler_t;
+typedef void *netisr_m2flow_t;
+typedef void *netisr_m2cpuid_t;
+typedef void *netisr_drainedcpu_t;
+#endif
+
+/*
+ * Each protocol is described by a struct netisr_proto, which holds all
+ * global per-protocol information.  This data structure is set up by
+ * netisr_register(), and derived from the public struct netisr_handler.
+ */
+struct netisr_proto {
+	const char	*np_name;	/* Character string protocol name. */
+	netisr_handler_t *np_handler;	/* Protocol handler. */
+	netisr_m2flow_t	*np_m2flow;	/* Query flow for untagged packet. */
+	netisr_m2cpuid_t *np_m2cpuid;	/* Query CPU to process packet on. */
+	netisr_drainedcpu_t *np_drainedcpu; /* Callback when drained a queue. */
+	u_int		 np_qlimit;	/* Maximum per-CPU queue depth. */
+	u_int		 np_policy;	/* Work placement policy. */
+};
+
+#define	NETISR_MAXPROT	16		/* Compile-time limit. */
+
+/*
+ * Protocol-specific work for each workstream is described by struct
+ * netisr_work.  Each work descriptor consists of an mbuf queue and
+ * statistics.
+ */
+struct netisr_work {
+	/*
+	 * Packet queue, linked by m_nextpkt.
+	 */
+	struct mbuf	*nw_head;
+	struct mbuf	*nw_tail;
+	u_int		 nw_len;
+	u_int		 nw_qlimit;
+	u_int		 nw_watermark;
+
+	/*
+	 * Statistics -- written unlocked, but mostly from curcpu.
+	 */
+	u_int64_t	 nw_dispatched; /* Number of direct dispatches. */
+	u_int64_t	 nw_hybrid_dispatched; /* "" hybrid dispatches. */
+	u_int64_t	 nw_qdrops;	/* "" drops. */
+	u_int64_t	 nw_queued;	/* "" enqueues. */
+	u_int64_t	 nw_handled;	/* "" handled in worker. */
+};
+
+/*
+ * Workstreams hold a queue of ordered work across each protocol, and are
+ * described by netisr_workstream.  Each workstream is associated with a
+ * worker thread, which in turn is pinned to a CPU.  Work associated with a
+ * workstream can be processd in other threads during direct dispatch;
+ * concurrent processing is prevented by the NWS_RUNNING flag, which
+ * indicates that a thread is already processing the work queue.  It is
+ * important to prevent a directly dispatched packet from "skipping ahead" of
+ * work already in the workstream queue.
+ */
+struct netisr_workstream {
+	struct intr_event *nws_intr_event;	/* Handler for stream. */
+	void		*nws_swi_cookie;	/* swi(9) cookie for stream. */
+	struct mtx	 nws_mtx;		/* Synchronize work. */
+	u_int		 nws_cpu;		/* CPU pinning. */
+	u_int		 nws_flags;		/* Wakeup flags. */
+	u_int		 nws_pendingbits;	/* Scheduled protocols. */
+
+	/*
+	 * Each protocol has per-workstream data.
+	 */
+	struct netisr_work	nws_work[NETISR_MAXPROT];
+} __aligned(CACHE_LINE_SIZE);
+
+/*
+ * Per-workstream flags.
+ */
+#define	NWS_RUNNING	0x00000001	/* Currently running in a thread. */
+#define	NWS_DISPATCHING	0x00000002	/* Currently being direct-dispatched. */
+#define	NWS_SCHEDULED	0x00000004	/* Signal issued. */
+
+#endif /* !_NET_NETISR_INTERNAL_H_ */