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_H_ 36#define _NET_NETISR_H_ 37 38/* 39 * The netisr (network interrupt service routine) provides a deferred 40 * execution evironment in which (generally inbound) network processing can 41 * take place. Protocols register handlers which will be executed directly, 42 * or via deferred dispatch, depending on the circumstances. 43 * 44 * Historically, this was implemented by the BSD software ISR facility; it is 45 * now implemented via a software ithread (SWI). 46 */ 47 48/* 49 * Protocol numbers, which are encoded in monitoring applications and kernel 50 * modules. Internally, these are used in bit shift operations so must have 51 * a value 0 < proto < 32; we currently further limit at compile-time to 16 52 * for array-sizing purposes. 53 */ 54#define NETISR_IP 1 55#define NETISR_IGMP 2 /* IGMPv3 output queue */ 56#define NETISR_ROUTE 3 /* routing socket */ 57#define NETISR_ARP 4 /* same as AF_LINK */ 58#define NETISR_ETHER 5 /* ethernet input */ 59#define NETISR_IPV6 6 60#define NETISR_EPAIR 8 /* if_epair(4) */ 61#define NETISR_IP_DIRECT 9 /* direct-dispatch IPv4 */ 62#define NETISR_IPV6_DIRECT 10 /* direct-dispatch IPv6 */ 63 64/* 65 * Protocol ordering and affinity policy constants. See the detailed 66 * discussion of policies later in the file. 67 */ 68#define NETISR_POLICY_SOURCE 1 /* Maintain source ordering. */ 69#define NETISR_POLICY_FLOW 2 /* Maintain flow ordering. */ 70#define NETISR_POLICY_CPU 3 /* Protocol determines CPU placement. */ 71 72/* 73 * Protocol dispatch policy constants; selects whether and when direct 74 * dispatch is permitted. 75 */ 76#define NETISR_DISPATCH_DEFAULT 0 /* Use global default. */ 77#define NETISR_DISPATCH_DEFERRED 1 /* Always defer dispatch. */ 78#define NETISR_DISPATCH_HYBRID 2 /* Allow hybrid dispatch. */ 79#define NETISR_DISPATCH_DIRECT 3 /* Always direct dispatch. */ 80 81/* 82 * Monitoring data structures, exported by sysctl(2). 83 * 84 * Three sysctls are defined. First, a per-protocol structure exported by 85 * net.isr.proto. 86 */ 87#define NETISR_NAMEMAXLEN 32 88struct sysctl_netisr_proto { 89 u_int snp_version; /* Length of struct. */ 90 char snp_name[NETISR_NAMEMAXLEN]; /* nh_name */ 91 u_int snp_proto; /* nh_proto */ 92 u_int snp_qlimit; /* nh_qlimit */ 93 u_int snp_policy; /* nh_policy */ 94 u_int snp_flags; /* Various flags. */ 95 u_int snp_dispatch; /* Dispatch policy. */ 96 u_int _snp_ispare[6]; 97}; 98 99/* 100 * Flags for sysctl_netisr_proto.snp_flags. 101 */ 102#define NETISR_SNP_FLAGS_M2FLOW 0x00000001 /* nh_m2flow */ 103#define NETISR_SNP_FLAGS_M2CPUID 0x00000002 /* nh_m2cpuid */ 104#define NETISR_SNP_FLAGS_DRAINEDCPU 0x00000004 /* nh_drainedcpu */ 105 106/* 107 * Next, a structure per-workstream, with per-protocol data, exported as 108 * net.isr.workstream. 109 */ 110struct sysctl_netisr_workstream { 111 u_int snws_version; /* Length of struct. */ 112 u_int snws_flags; /* Various flags. */ 113 u_int snws_wsid; /* Workstream ID. */ 114 u_int snws_cpu; /* nws_cpu */ 115 u_int _snws_ispare[12]; 116}; 117 118/* 119 * Flags for sysctl_netisr_workstream.snws_flags 120 */ 121#define NETISR_SNWS_FLAGS_INTR 0x00000001 /* nws_intr_event */ 122 123/* 124 * Finally, a per-workstream-per-protocol structure, exported as 125 * net.isr.work. 126 */ 127struct sysctl_netisr_work { 128 u_int snw_version; /* Length of struct. */ 129 u_int snw_wsid; /* Workstream ID. */ 130 u_int snw_proto; /* Protocol number. */ 131 u_int snw_len; /* nw_len */ 132 u_int snw_watermark; /* nw_watermark */ 133 u_int _snw_ispare[3]; 134 135 uint64_t snw_dispatched; /* nw_dispatched */ 136 uint64_t snw_hybrid_dispatched; /* nw_hybrid_dispatched */ 137 uint64_t snw_qdrops; /* nw_qdrops */ 138 uint64_t snw_queued; /* nw_queued */ 139 uint64_t snw_handled; /* nw_handled */ 140 141 uint64_t _snw_llspare[7]; 142}; 143 144#ifdef _KERNEL 145 146/*- 147 * Protocols express ordering constraints and affinity preferences by 148 * implementing one or neither of nh_m2flow and nh_m2cpuid, which are used by 149 * netisr to determine which per-CPU workstream to assign mbufs to. 150 * 151 * The following policies may be used by protocols: 152 * 153 * NETISR_POLICY_SOURCE - netisr should maintain source ordering without 154 * advice from the protocol. netisr will ignore any 155 * flow IDs present on the mbuf for the purposes of 156 * work placement. 157 * 158 * NETISR_POLICY_FLOW - netisr should maintain flow ordering as defined by 159 * the mbuf header flow ID field. If the protocol 160 * implements nh_m2flow, then netisr will query the 161 * protocol in the event that the mbuf doesn't have a 162 * flow ID, falling back on source ordering. 163 * 164 * NETISR_POLICY_CPU - netisr will delegate all work placement decisions to 165 * the protocol, querying nh_m2cpuid for each packet. 166 * 167 * Protocols might make decisions about work placement based on an existing 168 * calculated flow ID on the mbuf, such as one provided in hardware, the 169 * receive interface pointed to by the mbuf (if any), the optional source 170 * identifier passed at some dispatch points, or even parse packet headers to 171 * calculate a flow. Both protocol handlers may return a new mbuf pointer 172 * for the chain, or NULL if the packet proves invalid or m_pullup() fails. 173 * 174 * XXXRW: If we eventually support dynamic reconfiguration, there should be 175 * protocol handlers to notify them of CPU configuration changes so that they 176 * can rebalance work. 177 */ 178struct mbuf; 179typedef void netisr_handler_t(struct mbuf *m); 180typedef struct mbuf *netisr_m2cpuid_t(struct mbuf *m, uintptr_t source, 181 u_int *cpuid); 182typedef struct mbuf *netisr_m2flow_t(struct mbuf *m, uintptr_t source); 183typedef void netisr_drainedcpu_t(u_int cpuid); 184 185#define NETISR_CPUID_NONE ((u_int)-1) /* No affinity returned. */ 186 187/* 188 * Data structure describing a protocol handler. 189 */ 190struct netisr_handler { 191 const char *nh_name; /* Character string protocol name. */ 192 netisr_handler_t *nh_handler; /* Protocol handler. */ 193 netisr_m2flow_t *nh_m2flow; /* Query flow for untagged packet. */ 194 netisr_m2cpuid_t *nh_m2cpuid; /* Query CPU to process mbuf on. */ 195 netisr_drainedcpu_t *nh_drainedcpu; /* Callback when drained a queue. */ 196 u_int nh_proto; /* Integer protocol ID. */ 197 u_int nh_qlimit; /* Maximum per-CPU queue depth. */ 198 u_int nh_policy; /* Work placement policy. */ 199 u_int nh_dispatch; /* Dispatch policy. */ 200 u_int nh_ispare[4]; /* For future use. */ 201 void *nh_pspare[4]; /* For future use. */ 202}; 203 204/* 205 * Register, unregister, and other netisr handler management functions. 206 */ 207void netisr_clearqdrops(const struct netisr_handler *nhp); 208void netisr_getqdrops(const struct netisr_handler *nhp, 209 u_int64_t *qdropsp); 210void netisr_getqlimit(const struct netisr_handler *nhp, u_int *qlimitp); 211void netisr_register(const struct netisr_handler *nhp); 212int netisr_setqlimit(const struct netisr_handler *nhp, u_int qlimit); 213void netisr_unregister(const struct netisr_handler *nhp); 214#ifdef VIMAGE 215void netisr_register_vnet(const struct netisr_handler *nhp); 216void netisr_unregister_vnet(const struct netisr_handler *nhp); 217#endif 218 219/* 220 * Process a packet destined for a protocol, and attempt direct dispatch. 221 * Supplemental source ordering information can be passed using the _src 222 * variant. 223 */ 224int netisr_dispatch(u_int proto, struct mbuf *m); 225int netisr_dispatch_src(u_int proto, uintptr_t source, struct mbuf *m); 226int netisr_queue(u_int proto, struct mbuf *m); 227int netisr_queue_src(u_int proto, uintptr_t source, struct mbuf *m); 228 229/* 230 * Provide a default implementation of "map an ID to a CPU ID". 231 */ 232u_int netisr_default_flow2cpu(u_int flowid); 233 234/* 235 * Utility routines to return the number of CPUs participting in netisr, and 236 * to return a mapping from a number to a CPU ID that can be used with the 237 * scheduler. 238 */ 239u_int netisr_get_cpucount(void); 240u_int netisr_get_cpuid(u_int cpunumber); 241 242/* 243 * Interfaces between DEVICE_POLLING and netisr. 244 */ 245void netisr_sched_poll(void); 246void netisr_poll(void); 247void netisr_pollmore(void); 248 249#endif /* !_KERNEL */ 250#endif /* !_NET_NETISR_H_ */ 251