netisr.h revision 204199
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: head/sys/net/netisr.h 204199 2010-02-22 15:03:16Z 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 80struct 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 0x00000003 /* nh_drainedcpu */ 96 97/* 98 * Next, a structure per-workstream, with per-protocol data, exported as 99 * net.isr.workstream. 100 */ 101struct 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 */ 118struct 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 */ 169struct mbuf; 170typedef void netisr_handler_t (struct mbuf *m); 171typedef struct mbuf *netisr_m2cpuid_t(struct mbuf *m, uintptr_t source, 172 u_int *cpuid); 173typedef struct mbuf *netisr_m2flow_t(struct mbuf *m, uintptr_t source); 174typedef void netisr_drainedcpu_t(u_int cpuid); 175 176/* 177 * Data structure describing a protocol handler. 178 */ 179struct 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 */ 195void netisr_clearqdrops(const struct netisr_handler *nhp); 196void netisr_getqdrops(const struct netisr_handler *nhp, 197 u_int64_t *qdropsp); 198void netisr_getqlimit(const struct netisr_handler *nhp, u_int *qlimitp); 199void netisr_register(const struct netisr_handler *nhp); 200int netisr_setqlimit(const struct netisr_handler *nhp, u_int qlimit); 201void 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 */ 208int netisr_dispatch(u_int proto, struct mbuf *m); 209int netisr_dispatch_src(u_int proto, uintptr_t source, struct mbuf *m); 210int netisr_queue(u_int proto, struct mbuf *m); 211int 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 */ 216u_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 */ 223u_int netisr_get_cpucount(void); 224u_int netisr_get_cpuid(u_int cpunumber); 225 226/* 227 * Interfaces between DEVICE_POLLING and netisr. 228 */ 229void netisr_sched_poll(void); 230void netisr_poll(void); 231void netisr_pollmore(void); 232 233#endif /* !_KERNEL */ 234#endif /* !_NET_NETISR_H_ */ 235