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