FreeBSD/Linux Kernel Cross Reference
sys/net/netisr.h
1 /*-
2 * Copyright (c) 2007-2009 Robert N. M. Watson
3 * Copyright (c) 2010 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: releng/8.4/sys/net/netisr.h 217449 2011-01-15 19:02:08Z rwatson $
31 */
32
33 #ifndef _NET_NETISR_H_
34 #define _NET_NETISR_H_
35
36 /*
37 * The netisr (network interrupt service routine) provides a deferred
38 * execution evironment in which (generally inbound) network processing can
39 * take place. Protocols register handlers which will be executed directly,
40 * or via deferred dispatch, depending on the circumstances.
41 *
42 * Historically, this was implemented by the BSD software ISR facility; it is
43 * now implemented via a software ithread (SWI).
44 */
45
46 /*
47 * Protocol numbers, which are encoded in monitoring applications and kernel
48 * modules. Internally, these are used in bit shift operations so must have
49 * a value 0 < proto < 32; we currently further limit at compile-time to 16
50 * for array-sizing purposes.
51 */
52 #define NETISR_IP 1
53 #define NETISR_IGMP 2 /* IGMPv3 output queue */
54 #define NETISR_ROUTE 3 /* routing socket */
55 #define NETISR_AARP 4 /* Appletalk ARP */
56 #define NETISR_ATALK2 5 /* Appletalk phase 2 */
57 #define NETISR_ATALK1 6 /* Appletalk phase 1 */
58 #define NETISR_ARP 7 /* same as AF_LINK */
59 #define NETISR_IPX 8 /* same as AF_IPX */
60 #define NETISR_ETHER 9 /* ethernet input */
61 #define NETISR_IPV6 10
62 #define NETISR_NATM 11
63 #define NETISR_EPAIR 12 /* if_epair(4) */
64
65 /*
66 * Protocol ordering and affinity policy constants. See the detailed
67 * discussion of policies later in the file.
68 */
69 #define NETISR_POLICY_SOURCE 1 /* Maintain source ordering. */
70 #define NETISR_POLICY_FLOW 2 /* Maintain flow ordering. */
71 #define NETISR_POLICY_CPU 3 /* Protocol determines CPU placement. */
72
73 /*
74 * Monitoring data structures, exported by sysctl(2).
75 *
76 * Three sysctls are defined. First, a per-protocol structure exported by
77 * net.isr.proto.
78 */
79 #define NETISR_NAMEMAXLEN 32
80 struct sysctl_netisr_proto {
81 u_int snp_version; /* Length of struct. */
82 char snp_name[NETISR_NAMEMAXLEN]; /* nh_name */
83 u_int snp_proto; /* nh_proto */
84 u_int snp_qlimit; /* nh_qlimit */
85 u_int snp_policy; /* nh_policy */
86 u_int snp_flags; /* Various flags. */
87 u_int _snp_ispare[7];
88 };
89
90 /*
91 * Flags for sysctl_netisr_proto.snp_flags.
92 */
93 #define NETISR_SNP_FLAGS_M2FLOW 0x00000001 /* nh_m2flow */
94 #define NETISR_SNP_FLAGS_M2CPUID 0x00000002 /* nh_m2cpuid */
95 #define NETISR_SNP_FLAGS_DRAINEDCPU 0x00000004 /* nh_drainedcpu */
96
97 /*
98 * Next, a structure per-workstream, with per-protocol data, exported as
99 * net.isr.workstream.
100 */
101 struct sysctl_netisr_workstream {
102 u_int snws_version; /* Length of struct. */
103 u_int snws_flags; /* Various flags. */
104 u_int snws_wsid; /* Workstream ID. */
105 u_int snws_cpu; /* nws_cpu */
106 u_int _snws_ispare[12];
107 };
108
109 /*
110 * Flags for sysctl_netisr_workstream.snws_flags
111 */
112 #define NETISR_SNWS_FLAGS_INTR 0x00000001 /* nws_intr_event */
113
114 /*
115 * Finally, a per-workstream-per-protocol structure, exported as
116 * net.isr.work.
117 */
118 struct sysctl_netisr_work {
119 u_int snw_version; /* Length of struct. */
120 u_int snw_wsid; /* Workstream ID. */
121 u_int snw_proto; /* Protocol number. */
122 u_int snw_len; /* nw_len */
123 u_int snw_watermark; /* nw_watermark */
124 u_int _snw_ispare[3];
125
126 uint64_t snw_dispatched; /* nw_dispatched */
127 uint64_t snw_hybrid_dispatched; /* nw_hybrid_dispatched */
128 uint64_t snw_qdrops; /* nw_qdrops */
129 uint64_t snw_queued; /* nw_queued */
130 uint64_t snw_handled; /* nw_handled */
131
132 uint64_t _snw_llspare[7];
133 };
134
135 #ifdef _KERNEL
136
137 /*-
138 * Protocols express ordering constraints and affinity preferences by
139 * implementing one or neither of nh_m2flow and nh_m2cpuid, which are used by
140 * netisr to determine which per-CPU workstream to assign mbufs to.
141 *
142 * The following policies may be used by protocols:
143 *
144 * NETISR_POLICY_SOURCE - netisr should maintain source ordering without
145 * advice from the protocol. netisr will ignore any
146 * flow IDs present on the mbuf for the purposes of
147 * work placement.
148 *
149 * NETISR_POLICY_FLOW - netisr should maintain flow ordering as defined by
150 * the mbuf header flow ID field. If the protocol
151 * implements nh_m2flow, then netisr will query the
152 * protocol in the event that the mbuf doesn't have a
153 * flow ID, falling back on source ordering.
154 *
155 * NETISR_POLICY_CPU - netisr will delegate all work placement decisions to
156 * the protocol, querying nh_m2cpuid for each packet.
157 *
158 * Protocols might make decisions about work placement based on an existing
159 * calculated flow ID on the mbuf, such as one provided in hardware, the
160 * receive interface pointed to by the mbuf (if any), the optional source
161 * identifier passed at some dispatch points, or even parse packet headers to
162 * calculate a flow. Both protocol handlers may return a new mbuf pointer
163 * for the chain, or NULL if the packet proves invalid or m_pullup() fails.
164 *
165 * XXXRW: If we eventually support dynamic reconfiguration, there should be
166 * protocol handlers to notify them of CPU configuration changes so that they
167 * can rebalance work.
168 */
169 struct mbuf;
170 typedef void netisr_handler_t(struct mbuf *m);
171 typedef struct mbuf *netisr_m2cpuid_t(struct mbuf *m, uintptr_t source,
172 u_int *cpuid);
173 typedef struct mbuf *netisr_m2flow_t(struct mbuf *m, uintptr_t source);
174 typedef void netisr_drainedcpu_t(u_int cpuid);
175
176 /*
177 * Data structure describing a protocol handler.
178 */
179 struct netisr_handler {
180 const char *nh_name; /* Character string protocol name. */
181 netisr_handler_t *nh_handler; /* Protocol handler. */
182 netisr_m2flow_t *nh_m2flow; /* Query flow for untagged packet. */
183 netisr_m2cpuid_t *nh_m2cpuid; /* Query CPU to process mbuf on. */
184 netisr_drainedcpu_t *nh_drainedcpu; /* Callback when drained a queue. */
185 u_int nh_proto; /* Integer protocol ID. */
186 u_int nh_qlimit; /* Maximum per-CPU queue depth. */
187 u_int nh_policy; /* Work placement policy. */
188 u_int nh_ispare[5]; /* For future use. */
189 void *nh_pspare[4]; /* For future use. */
190 };
191
192 /*
193 * Register, unregister, and other netisr handler management functions.
194 */
195 void netisr_clearqdrops(const struct netisr_handler *nhp);
196 void netisr_getqdrops(const struct netisr_handler *nhp,
197 u_int64_t *qdropsp);
198 void netisr_getqlimit(const struct netisr_handler *nhp, u_int *qlimitp);
199 void netisr_register(const struct netisr_handler *nhp);
200 int netisr_setqlimit(const struct netisr_handler *nhp, u_int qlimit);
201 void netisr_unregister(const struct netisr_handler *nhp);
202
203 /*
204 * Process a packet destined for a protocol, and attempt direct dispatch.
205 * Supplemental source ordering information can be passed using the _src
206 * variant.
207 */
208 int netisr_dispatch(u_int proto, struct mbuf *m);
209 int netisr_dispatch_src(u_int proto, uintptr_t source, struct mbuf *m);
210 int netisr_queue(u_int proto, struct mbuf *m);
211 int netisr_queue_src(u_int proto, uintptr_t source, struct mbuf *m);
212
213 /*
214 * Provide a default implementation of "map an ID to a CPU ID".
215 */
216 u_int netisr_default_flow2cpu(u_int flowid);
217
218 /*
219 * Utility routines to return the number of CPUs participting in netisr, and
220 * to return a mapping from a number to a CPU ID that can be used with the
221 * scheduler.
222 */
223 u_int netisr_get_cpucount(void);
224 u_int netisr_get_cpuid(u_int cpunumber);
225
226 /*
227 * Interfaces between DEVICE_POLLING and netisr.
228 */
229 void netisr_sched_poll(void);
230 void netisr_poll(void);
231 void netisr_pollmore(void);
232
233 #endif /* !_KERNEL */
234 #endif /* !_NET_NETISR_H_ */
Cache object: 7305b06d4029058a093589761c37254e
|