xref: /freebsd/sys/net/netisr_internal.h (revision 389e4940069316fe667ffa263fa7d6390d0a960f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2007-2009 Robert N. M. Watson
5  * Copyright (c) 2010-2011 Juniper Networks, Inc.
6  * All rights reserved.
7  *
8  * This software was developed by Robert N. M. Watson under contract
9  * to Juniper Networks, Inc.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  * $FreeBSD$
33  */
34 
35 #ifndef _NET_NETISR_INTERNAL_H_
36 #define	_NET_NETISR_INTERNAL_H_
37 
38 #ifndef _WANT_NETISR_INTERNAL
39 #error "no user-serviceable parts inside"
40 #endif
41 
42 /*
43  * These definitions are private to the netisr implementation, but provided
44  * here for use by post-mortem crashdump analysis tools.  They should not be
45  * used in any other context as they can and will change.  Public definitions
46  * may be found in netisr.h.
47  */
48 
49 #ifndef _KERNEL
50 typedef void *netisr_handler_t;
51 typedef void *netisr_m2flow_t;
52 typedef void *netisr_m2cpuid_t;
53 typedef void *netisr_drainedcpu_t;
54 #endif
55 
56 /*
57  * Each protocol is described by a struct netisr_proto, which holds all
58  * global per-protocol information.  This data structure is set up by
59  * netisr_register(), and derived from the public struct netisr_handler.
60  */
61 struct netisr_proto {
62 	const char	*np_name;	/* Character string protocol name. */
63 	netisr_handler_t *np_handler;	/* Protocol handler. */
64 	netisr_m2flow_t	*np_m2flow;	/* Query flow for untagged packet. */
65 	netisr_m2cpuid_t *np_m2cpuid;	/* Query CPU to process packet on. */
66 	netisr_drainedcpu_t *np_drainedcpu; /* Callback when drained a queue. */
67 	u_int		 np_qlimit;	/* Maximum per-CPU queue depth. */
68 	u_int		 np_policy;	/* Work placement policy. */
69 	u_int		 np_dispatch;	/* Work dispatch policy. */
70 };
71 
72 #define	NETISR_MAXPROT	16		/* Compile-time limit. */
73 
74 /*
75  * Protocol-specific work for each workstream is described by struct
76  * netisr_work.  Each work descriptor consists of an mbuf queue and
77  * statistics.
78  */
79 struct netisr_work {
80 	/*
81 	 * Packet queue, linked by m_nextpkt.
82 	 */
83 	struct mbuf	*nw_head;
84 	struct mbuf	*nw_tail;
85 	u_int		 nw_len;
86 	u_int		 nw_qlimit;
87 	u_int		 nw_watermark;
88 
89 	/*
90 	 * Statistics -- written unlocked, but mostly from curcpu.
91 	 */
92 	u_int64_t	 nw_dispatched; /* Number of direct dispatches. */
93 	u_int64_t	 nw_hybrid_dispatched; /* "" hybrid dispatches. */
94 	u_int64_t	 nw_qdrops;	/* "" drops. */
95 	u_int64_t	 nw_queued;	/* "" enqueues. */
96 	u_int64_t	 nw_handled;	/* "" handled in worker. */
97 };
98 
99 /*
100  * Workstreams hold a queue of ordered work across each protocol, and are
101  * described by netisr_workstream.  Each workstream is associated with a
102  * worker thread, which in turn is pinned to a CPU.  Work associated with a
103  * workstream can be processd in other threads during direct dispatch;
104  * concurrent processing is prevented by the NWS_RUNNING flag, which
105  * indicates that a thread is already processing the work queue.  It is
106  * important to prevent a directly dispatched packet from "skipping ahead" of
107  * work already in the workstream queue.
108  */
109 struct netisr_workstream {
110 	struct intr_event *nws_intr_event;	/* Handler for stream. */
111 	void		*nws_swi_cookie;	/* swi(9) cookie for stream. */
112 	struct mtx	 nws_mtx;		/* Synchronize work. */
113 	u_int		 nws_cpu;		/* CPU pinning. */
114 	u_int		 nws_flags;		/* Wakeup flags. */
115 	u_int		 nws_pendingbits;	/* Scheduled protocols. */
116 
117 	/*
118 	 * Each protocol has per-workstream data.
119 	 */
120 	struct netisr_work	nws_work[NETISR_MAXPROT];
121 } __aligned(CACHE_LINE_SIZE);
122 
123 /*
124  * Per-workstream flags.
125  */
126 #define	NWS_RUNNING	0x00000001	/* Currently running in a thread. */
127 #define	NWS_DISPATCHING	0x00000002	/* Currently being direct-dispatched. */
128 #define	NWS_SCHEDULED	0x00000004	/* Signal issued. */
129 
130 #endif /* !_NET_NETISR_INTERNAL_H_ */
131