xref: /freebsd/sys/net/netisr_internal.h (revision 41059135ce931c0f1014a999ffabc6bc470ce856)
1 /*-
2  * Copyright (c) 2007-2009 Robert N. M. Watson
3  * Copyright (c) 2010-2011 Juniper Networks, Inc.
4  * All rights reserved.
5  *
6  * This software was developed by Robert N. M. Watson under contract
7  * to Juniper Networks, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  * $FreeBSD$
31  */
32 
33 #ifndef _NET_NETISR_INTERNAL_H_
34 #define	_NET_NETISR_INTERNAL_H_
35 
36 #ifndef _WANT_NETISR_INTERNAL
37 #error "no user-serviceable parts inside"
38 #endif
39 
40 /*
41  * These definitions are private to the netisr implementation, but provided
42  * here for use by post-mortem crashdump analysis tools.  They should not be
43  * used in any other context as they can and will change.  Public definitions
44  * may be found in netisr.h.
45  */
46 
47 #ifndef _KERNEL
48 typedef void *netisr_handler_t;
49 typedef void *netisr_m2flow_t;
50 typedef void *netisr_m2cpuid_t;
51 typedef void *netisr_drainedcpu_t;
52 #endif
53 
54 /*
55  * Each protocol is described by a struct netisr_proto, which holds all
56  * global per-protocol information.  This data structure is set up by
57  * netisr_register(), and derived from the public struct netisr_handler.
58  */
59 struct netisr_proto {
60 	const char	*np_name;	/* Character string protocol name. */
61 	netisr_handler_t *np_handler;	/* Protocol handler. */
62 	netisr_m2flow_t	*np_m2flow;	/* Query flow for untagged packet. */
63 	netisr_m2cpuid_t *np_m2cpuid;	/* Query CPU to process packet on. */
64 	netisr_drainedcpu_t *np_drainedcpu; /* Callback when drained a queue. */
65 	u_int		 np_qlimit;	/* Maximum per-CPU queue depth. */
66 	u_int		 np_policy;	/* Work placement policy. */
67 	u_int		 np_dispatch;	/* Work dispatch policy. */
68 };
69 
70 #define	NETISR_MAXPROT	16		/* Compile-time limit. */
71 
72 /*
73  * Protocol-specific work for each workstream is described by struct
74  * netisr_work.  Each work descriptor consists of an mbuf queue and
75  * statistics.
76  */
77 struct netisr_work {
78 	/*
79 	 * Packet queue, linked by m_nextpkt.
80 	 */
81 	struct mbuf	*nw_head;
82 	struct mbuf	*nw_tail;
83 	u_int		 nw_len;
84 	u_int		 nw_qlimit;
85 	u_int		 nw_watermark;
86 
87 	/*
88 	 * Statistics -- written unlocked, but mostly from curcpu.
89 	 */
90 	u_int64_t	 nw_dispatched; /* Number of direct dispatches. */
91 	u_int64_t	 nw_hybrid_dispatched; /* "" hybrid dispatches. */
92 	u_int64_t	 nw_qdrops;	/* "" drops. */
93 	u_int64_t	 nw_queued;	/* "" enqueues. */
94 	u_int64_t	 nw_handled;	/* "" handled in worker. */
95 };
96 
97 /*
98  * Workstreams hold a queue of ordered work across each protocol, and are
99  * described by netisr_workstream.  Each workstream is associated with a
100  * worker thread, which in turn is pinned to a CPU.  Work associated with a
101  * workstream can be processd in other threads during direct dispatch;
102  * concurrent processing is prevented by the NWS_RUNNING flag, which
103  * indicates that a thread is already processing the work queue.  It is
104  * important to prevent a directly dispatched packet from "skipping ahead" of
105  * work already in the workstream queue.
106  */
107 struct netisr_workstream {
108 	struct intr_event *nws_intr_event;	/* Handler for stream. */
109 	void		*nws_swi_cookie;	/* swi(9) cookie for stream. */
110 	struct mtx	 nws_mtx;		/* Synchronize work. */
111 	u_int		 nws_cpu;		/* CPU pinning. */
112 	u_int		 nws_flags;		/* Wakeup flags. */
113 	u_int		 nws_pendingbits;	/* Scheduled protocols. */
114 
115 	/*
116 	 * Each protocol has per-workstream data.
117 	 */
118 	struct netisr_work	nws_work[NETISR_MAXPROT];
119 } __aligned(CACHE_LINE_SIZE);
120 
121 /*
122  * Per-workstream flags.
123  */
124 #define	NWS_RUNNING	0x00000001	/* Currently running in a thread. */
125 #define	NWS_DISPATCHING	0x00000002	/* Currently being direct-dispatched. */
126 #define	NWS_SCHEDULED	0x00000004	/* Signal issued. */
127 
128 #endif /* !_NET_NETISR_INTERNAL_H_ */
129