/*-
 * 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_INTERNAL_H_
#define _NET_NETISR_INTERNAL_H_

#ifndef _WANT_NETISR_INTERNAL
#error "no user-serviceable parts inside"
#endif

/*
 * These definitions are private to the netisr implementation, but provided
 * here for use by post-mortem crashdump analysis tools.  They should not be
 * used in any other context as they can and will change.  Public definitions
 * may be found in netisr.h.
 */

#ifndef _KERNEL
typedef void *netisr_handler_t;
typedef void *netisr_m2flow_t;
typedef void *netisr_m2cpuid_t;
typedef void *netisr_drainedcpu_t;
#endif

/*
 * Each protocol is described by a struct netisr_proto, which holds all
 * global per-protocol information.  This data structure is set up by
 * netisr_register(), and derived from the public struct netisr_handler.
 */
struct netisr_proto {
        const char      *np_name;       /* Character string protocol name. */
        netisr_handler_t *np_handler;   /* Protocol handler. */
        netisr_m2flow_t *np_m2flow;     /* Query flow for untagged packet. */
        netisr_m2cpuid_t *np_m2cpuid;   /* Query CPU to process packet on. */
        netisr_drainedcpu_t *np_drainedcpu; /* Callback when drained a queue. */
        u_int            np_qlimit;     /* Maximum per-CPU queue depth. */
        u_int            np_policy;     /* Work placement policy. */
        u_int            np_dispatch;   /* Work dispatch policy. */
};

#define NETISR_MAXPROT  16              /* Compile-time limit. */

/*
 * Protocol-specific work for each workstream is described by struct
 * netisr_work.  Each work descriptor consists of an mbuf queue and
 * statistics.
 */
struct netisr_work {
        /*
         * Packet queue, linked by m_nextpkt.
         */
        struct mbuf     *nw_head;
        struct mbuf     *nw_tail;
        u_int            nw_len;
        u_int            nw_qlimit;
        u_int            nw_watermark;

        /*
         * Statistics -- written unlocked, but mostly from curcpu.
         */
        u_int64_t        nw_dispatched; /* Number of direct dispatches. */
        u_int64_t        nw_hybrid_dispatched; /* "" hybrid dispatches. */
        u_int64_t        nw_qdrops;     /* "" drops. */
        u_int64_t        nw_queued;     /* "" enqueues. */
        u_int64_t        nw_handled;    /* "" handled in worker. */
};

/*
 * Workstreams hold a queue of ordered work across each protocol, and are
 * described by netisr_workstream.  Each workstream is associated with a
 * worker thread, which in turn is pinned to a CPU.  Work associated with a
 * workstream can be processd in other threads during direct dispatch;
 * concurrent processing is prevented by the NWS_RUNNING flag, which
 * indicates that a thread is already processing the work queue.  It is
 * important to prevent a directly dispatched packet from "skipping ahead" of
 * work already in the workstream queue.
 */
struct netisr_workstream {
        struct intr_event *nws_intr_event;      /* Handler for stream. */
        void            *nws_swi_cookie;        /* swi(9) cookie for stream. */
        struct mtx       nws_mtx;               /* Synchronize work. */
        u_int            nws_cpu;               /* CPU pinning. */
        u_int            nws_flags;             /* Wakeup flags. */
        u_int            nws_pendingbits;       /* Scheduled protocols. */

        /*
         * Each protocol has per-workstream data.
         */
        struct netisr_work      nws_work[NETISR_MAXPROT];
} __aligned(CACHE_LINE_SIZE);

/*
 * Per-workstream flags.
 */
#define NWS_RUNNING     0x00000001      /* Currently running in a thread. */
#define NWS_DISPATCHING 0x00000002      /* Currently being direct-dispatched. */
#define NWS_SCHEDULED   0x00000004      /* Signal issued. */

#endif /* !_NET_NETISR_INTERNAL_H_ */