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Diffstat (limited to 'sys/net/netisr.h')
| -rw-r--r-- | sys/net/netisr.h | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/sys/net/netisr.h b/sys/net/netisr.h new file mode 100644 index 000000000000..c5b335bb94b2 --- /dev/null +++ b/sys/net/netisr.h @@ -0,0 +1,247 @@ +/*- + * 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_ */ |