/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2007-2009 Robert N. M. Watson * Copyright (c) 2010-2011 Juniper Networks, Inc. * All rights reserved. * * This software was developed by Robert N. M. Watson under contract * to Juniper Networks, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef _NET_NETISR_H_ #define _NET_NETISR_H_ /* * The netisr (network interrupt service routine) provides a deferred * execution evironment in which (generally inbound) network processing can * take place. Protocols register handlers which will be executed directly, * or via deferred dispatch, depending on the circumstances. * * Historically, this was implemented by the BSD software ISR facility; it is * now implemented via a software ithread (SWI). */ /* * Protocol numbers, which are encoded in monitoring applications and kernel * modules. Internally, these are used in bit shift operations so must have * a value 0 < proto < 32; we currently further limit at compile-time to 16 * for array-sizing purposes. */ #define NETISR_IP 1 #define NETISR_IGMP 2 /* IGMPv3 output queue */ #define NETISR_ROUTE 3 /* routing socket */ #define NETISR_ARP 4 /* same as AF_LINK */ #define NETISR_ETHER 5 /* ethernet input */ #define NETISR_IPV6 6 #define NETISR_IP_DIRECT 9 /* direct-dispatch IPv4 */ #define NETISR_IPV6_DIRECT 10 /* direct-dispatch IPv6 */ /* * Protocol ordering and affinity policy constants. See the detailed * discussion of policies later in the file. */ #define NETISR_POLICY_SOURCE 1 /* Maintain source ordering. */ #define NETISR_POLICY_FLOW 2 /* Maintain flow ordering. */ #define NETISR_POLICY_CPU 3 /* Protocol determines CPU placement. */ /* * Protocol dispatch policy constants; selects whether and when direct * dispatch is permitted. */ #define NETISR_DISPATCH_DEFAULT 0 /* Use global default. */ #define NETISR_DISPATCH_DEFERRED 1 /* Always defer dispatch. */ #define NETISR_DISPATCH_HYBRID 2 /* Allow hybrid dispatch. */ #define NETISR_DISPATCH_DIRECT 3 /* Always direct dispatch. */ /* * Monitoring data structures, exported by sysctl(2). * * Three sysctls are defined. First, a per-protocol structure exported by * net.isr.proto. */ #define NETISR_NAMEMAXLEN 32 struct sysctl_netisr_proto { u_int snp_version; /* Length of struct. */ char snp_name[NETISR_NAMEMAXLEN]; /* nh_name */ u_int snp_proto; /* nh_proto */ u_int snp_qlimit; /* nh_qlimit */ u_int snp_policy; /* nh_policy */ u_int snp_flags; /* Various flags. */ u_int snp_dispatch; /* Dispatch policy. */ u_int _snp_ispare[6]; }; /* * Flags for sysctl_netisr_proto.snp_flags. */ #define NETISR_SNP_FLAGS_M2FLOW 0x00000001 /* nh_m2flow */ #define NETISR_SNP_FLAGS_M2CPUID 0x00000002 /* nh_m2cpuid */ #define NETISR_SNP_FLAGS_DRAINEDCPU 0x00000004 /* nh_drainedcpu */ /* * Next, a structure per-workstream, with per-protocol data, exported as * net.isr.workstream. */ struct sysctl_netisr_workstream { u_int snws_version; /* Length of struct. */ u_int snws_flags; /* Various flags. */ u_int snws_wsid; /* Workstream ID. */ u_int snws_cpu; /* nws_cpu */ u_int _snws_ispare[12]; }; /* * Flags for sysctl_netisr_workstream.snws_flags */ #define NETISR_SNWS_FLAGS_INTR 0x00000001 /* nws_intr_event */ /* * Finally, a per-workstream-per-protocol structure, exported as * net.isr.work. */ struct sysctl_netisr_work { u_int snw_version; /* Length of struct. */ u_int snw_wsid; /* Workstream ID. */ u_int snw_proto; /* Protocol number. */ u_int snw_len; /* nw_len */ u_int snw_watermark; /* nw_watermark */ u_int _snw_ispare[3]; uint64_t snw_dispatched; /* nw_dispatched */ uint64_t snw_hybrid_dispatched; /* nw_hybrid_dispatched */ uint64_t snw_qdrops; /* nw_qdrops */ uint64_t snw_queued; /* nw_queued */ uint64_t snw_handled; /* nw_handled */ uint64_t _snw_llspare[7]; }; #ifdef _KERNEL /*- * Protocols express ordering constraints and affinity preferences by * implementing one or neither of nh_m2flow and nh_m2cpuid, which are used by * netisr to determine which per-CPU workstream to assign mbufs to. * * The following policies may be used by protocols: * * NETISR_POLICY_SOURCE - netisr should maintain source ordering without * advice from the protocol. netisr will ignore any * flow IDs present on the mbuf for the purposes of * work placement. * * NETISR_POLICY_FLOW - netisr should maintain flow ordering as defined by * the mbuf header flow ID field. If the protocol * implements nh_m2flow, then netisr will query the * protocol in the event that the mbuf doesn't have a * flow ID, falling back on source ordering. * * NETISR_POLICY_CPU - netisr will delegate all work placement decisions to * the protocol, querying nh_m2cpuid for each packet. * * Protocols might make decisions about work placement based on an existing * calculated flow ID on the mbuf, such as one provided in hardware, the * receive interface pointed to by the mbuf (if any), the optional source * identifier passed at some dispatch points, or even parse packet headers to * calculate a flow. Both protocol handlers may return a new mbuf pointer * for the chain, or NULL if the packet proves invalid or m_pullup() fails. * * XXXRW: If we eventually support dynamic reconfiguration, there should be * protocol handlers to notify them of CPU configuration changes so that they * can rebalance work. */ struct mbuf; typedef void netisr_handler_t(struct mbuf *m); typedef struct mbuf *netisr_m2cpuid_t(struct mbuf *m, uintptr_t source, u_int *cpuid); typedef struct mbuf *netisr_m2flow_t(struct mbuf *m, uintptr_t source); typedef void netisr_drainedcpu_t(u_int cpuid); #define NETISR_CPUID_NONE ((u_int)-1) /* No affinity returned. */ /* * Data structure describing a protocol handler. */ struct netisr_handler { const char *nh_name; /* Character string protocol name. */ netisr_handler_t *nh_handler; /* Protocol handler. */ netisr_m2flow_t *nh_m2flow; /* Query flow for untagged packet. */ netisr_m2cpuid_t *nh_m2cpuid; /* Query CPU to process mbuf on. */ netisr_drainedcpu_t *nh_drainedcpu; /* Callback when drained a queue. */ u_int nh_proto; /* Integer protocol ID. */ u_int nh_qlimit; /* Maximum per-CPU queue depth. */ u_int nh_policy; /* Work placement policy. */ u_int nh_dispatch; /* Dispatch policy. */ u_int nh_ispare[4]; /* For future use. */ void *nh_pspare[4]; /* For future use. */ }; /* * Register, unregister, and other netisr handler management functions. */ void netisr_clearqdrops(const struct netisr_handler *nhp); void netisr_getqdrops(const struct netisr_handler *nhp, u_int64_t *qdropsp); void netisr_getqlimit(const struct netisr_handler *nhp, u_int *qlimitp); void netisr_register(const struct netisr_handler *nhp); int netisr_setqlimit(const struct netisr_handler *nhp, u_int qlimit); void netisr_unregister(const struct netisr_handler *nhp); #ifdef VIMAGE void netisr_register_vnet(const struct netisr_handler *nhp); void netisr_unregister_vnet(const struct netisr_handler *nhp); #endif /* * Process a packet destined for a protocol, and attempt direct dispatch. * Supplemental source ordering information can be passed using the _src * variant. */ int netisr_dispatch(u_int proto, struct mbuf *m); int netisr_dispatch_src(u_int proto, uintptr_t source, struct mbuf *m); int netisr_queue(u_int proto, struct mbuf *m); int netisr_queue_src(u_int proto, uintptr_t source, struct mbuf *m); /* * Provide a default implementation of "map an ID to a CPU ID". */ u_int netisr_default_flow2cpu(u_int flowid); /* * Utility routines to return the number of CPUs participting in netisr, and * to return a mapping from a number to a CPU ID that can be used with the * scheduler. */ u_int netisr_get_cpucount(void); u_int netisr_get_cpuid(u_int cpunumber); /* * Interfaces between DEVICE_POLLING and netisr. */ void netisr_sched_poll(void); void netisr_poll(void); void netisr_pollmore(void); #endif /* !_KERNEL */ #endif /* !_NET_NETISR_H_ */
