/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2012, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * lnet/lnet/lib-msg.c
 *
 * Message decoding, parsing and finalizing routines
 */

#define DEBUG_SUBSYSTEM S_LNET

#include "../../include/linux/lnet/lib-lnet.h"

void
lnet_build_unlink_event(lnet_libmd_t *md, lnet_event_t *ev)
{
        memset(ev, 0, sizeof(*ev));

        ev->status   = 0;
        ev->unlinked = 1;
        ev->type     = LNET_EVENT_UNLINK;
        lnet_md_deconstruct(md, &ev->md);
        lnet_md2handle(&ev->md_handle, md);
}

/*
 * Don't need any lock, must be called after lnet_commit_md
 */
void
lnet_build_msg_event(lnet_msg_t *msg, lnet_event_kind_t ev_type)
{
        lnet_hdr_t *hdr = &msg->msg_hdr;
        lnet_event_t *ev  = &msg->msg_ev;

        LASSERT(!msg->msg_routing);

        ev->type = ev_type;

        if (ev_type == LNET_EVENT_SEND) {
                /* event for active message */
                ev->target.nid    = le64_to_cpu(hdr->dest_nid);
                ev->target.pid    = le32_to_cpu(hdr->dest_pid);
                ev->initiator.nid = LNET_NID_ANY;
                ev->initiator.pid = the_lnet.ln_pid;
                ev->sender        = LNET_NID_ANY;
        } else {
                /* event for passive message */
                ev->target.pid    = hdr->dest_pid;
                ev->target.nid    = hdr->dest_nid;
                ev->initiator.pid = hdr->src_pid;
                ev->initiator.nid = hdr->src_nid;
                ev->rlength       = hdr->payload_length;
                ev->sender        = msg->msg_from;
                ev->mlength       = msg->msg_wanted;
                ev->offset        = msg->msg_offset;
        }

        switch (ev_type) {
        default:
                LBUG();

        case LNET_EVENT_PUT: /* passive PUT */
                ev->pt_index   = hdr->msg.put.ptl_index;
                ev->match_bits = hdr->msg.put.match_bits;
                ev->hdr_data   = hdr->msg.put.hdr_data;
                return;

        case LNET_EVENT_GET: /* passive GET */
                ev->pt_index   = hdr->msg.get.ptl_index;
                ev->match_bits = hdr->msg.get.match_bits;
                ev->hdr_data   = 0;
                return;

        case LNET_EVENT_ACK: /* ACK */
                ev->match_bits = hdr->msg.ack.match_bits;
                ev->mlength    = hdr->msg.ack.mlength;
                return;

        case LNET_EVENT_REPLY: /* REPLY */
                return;

        case LNET_EVENT_SEND: /* active message */
                if (msg->msg_type == LNET_MSG_PUT) {
                        ev->pt_index   = le32_to_cpu(hdr->msg.put.ptl_index);
                        ev->match_bits = le64_to_cpu(hdr->msg.put.match_bits);
                        ev->offset     = le32_to_cpu(hdr->msg.put.offset);
                        ev->mlength    =
                        ev->rlength    = le32_to_cpu(hdr->payload_length);
                        ev->hdr_data   = le64_to_cpu(hdr->msg.put.hdr_data);

                } else {
                        LASSERT(msg->msg_type == LNET_MSG_GET);
                        ev->pt_index   = le32_to_cpu(hdr->msg.get.ptl_index);
                        ev->match_bits = le64_to_cpu(hdr->msg.get.match_bits);
                        ev->mlength    =
                        ev->rlength    = le32_to_cpu(hdr->msg.get.sink_length);
                        ev->offset     = le32_to_cpu(hdr->msg.get.src_offset);
                        ev->hdr_data   = 0;
                }
                return;
        }
}

void
lnet_msg_commit(lnet_msg_t *msg, int cpt)
{
        struct lnet_msg_container *container = the_lnet.ln_msg_containers[cpt];
        lnet_counters_t *counters  = the_lnet.ln_counters[cpt];

        /* routed message can be committed for both receiving and sending */
        LASSERT(!msg->msg_tx_committed);

        if (msg->msg_sending) {
                LASSERT(!msg->msg_receiving);

                msg->msg_tx_cpt = cpt;
                msg->msg_tx_committed = 1;
                if (msg->msg_rx_committed) { /* routed message REPLY */
                        LASSERT(msg->msg_onactivelist);
                        return;
                }
        } else {
                LASSERT(!msg->msg_sending);
                msg->msg_rx_cpt = cpt;
                msg->msg_rx_committed = 1;
        }

        LASSERT(!msg->msg_onactivelist);
        msg->msg_onactivelist = 1;
        list_add(&msg->msg_activelist, &container->msc_active);

        counters->msgs_alloc++;
        if (counters->msgs_alloc > counters->msgs_max)
                counters->msgs_max = counters->msgs_alloc;
}

static void
lnet_msg_decommit_tx(lnet_msg_t *msg, int status)
{
        lnet_counters_t *counters;
        lnet_event_t *ev = &msg->msg_ev;

        LASSERT(msg->msg_tx_committed);
        if (status)
                goto out;

        counters = the_lnet.ln_counters[msg->msg_tx_cpt];
        switch (ev->type) {
        default: /* routed message */
                LASSERT(msg->msg_routing);
                LASSERT(msg->msg_rx_committed);
                LASSERT(!ev->type);

                counters->route_length += msg->msg_len;
                counters->route_count++;
                goto out;

        case LNET_EVENT_PUT:
                /* should have been decommitted */
                LASSERT(!msg->msg_rx_committed);
                /* overwritten while sending ACK */
                LASSERT(msg->msg_type == LNET_MSG_ACK);
                msg->msg_type = LNET_MSG_PUT; /* fix type */
                break;

        case LNET_EVENT_SEND:
                LASSERT(!msg->msg_rx_committed);
                if (msg->msg_type == LNET_MSG_PUT)
                        counters->send_length += msg->msg_len;
                break;

        case LNET_EVENT_GET:
                LASSERT(msg->msg_rx_committed);
                /*
                 * overwritten while sending reply, we should never be
                 * here for optimized GET
                 */
                LASSERT(msg->msg_type == LNET_MSG_REPLY);
                msg->msg_type = LNET_MSG_GET; /* fix type */
                break;
        }

        counters->send_count++;
 out:
        lnet_return_tx_credits_locked(msg);
        msg->msg_tx_committed = 0;
}

static void
lnet_msg_decommit_rx(lnet_msg_t *msg, int status)
{
        lnet_counters_t *counters;
        lnet_event_t *ev = &msg->msg_ev;

        LASSERT(!msg->msg_tx_committed); /* decommitted or never committed */
        LASSERT(msg->msg_rx_committed);

        if (status)
                goto out;

        counters = the_lnet.ln_counters[msg->msg_rx_cpt];
        switch (ev->type) {
        default:
                LASSERT(!ev->type);
                LASSERT(msg->msg_routing);
                goto out;

        case LNET_EVENT_ACK:
                LASSERT(msg->msg_type == LNET_MSG_ACK);
                break;

        case LNET_EVENT_GET:
                /*
                 * type is "REPLY" if it's an optimized GET on passive side,
                 * because optimized GET will never be committed for sending,
                 * so message type wouldn't be changed back to "GET" by
                 * lnet_msg_decommit_tx(), see details in lnet_parse_get()
                 */
                LASSERT(msg->msg_type == LNET_MSG_REPLY ||
                        msg->msg_type == LNET_MSG_GET);
                counters->send_length += msg->msg_wanted;
                break;

        case LNET_EVENT_PUT:
                LASSERT(msg->msg_type == LNET_MSG_PUT);
                break;

        case LNET_EVENT_REPLY:
                /*
                 * type is "GET" if it's an optimized GET on active side,
                 * see details in lnet_create_reply_msg()
                 */
                LASSERT(msg->msg_type == LNET_MSG_GET ||
                        msg->msg_type == LNET_MSG_REPLY);
                break;
        }

        counters->recv_count++;
        if (ev->type == LNET_EVENT_PUT || ev->type == LNET_EVENT_REPLY)
                counters->recv_length += msg->msg_wanted;

 out:
        lnet_return_rx_credits_locked(msg);
        msg->msg_rx_committed = 0;
}

void
lnet_msg_decommit(lnet_msg_t *msg, int cpt, int status)
{
        int cpt2 = cpt;

        LASSERT(msg->msg_tx_committed || msg->msg_rx_committed);
        LASSERT(msg->msg_onactivelist);

        if (msg->msg_tx_committed) { /* always decommit for sending first */
                LASSERT(cpt == msg->msg_tx_cpt);
                lnet_msg_decommit_tx(msg, status);
        }

        if (msg->msg_rx_committed) {
                /* forwarding msg committed for both receiving and sending */
                if (cpt != msg->msg_rx_cpt) {
                        lnet_net_unlock(cpt);
                        cpt2 = msg->msg_rx_cpt;
                        lnet_net_lock(cpt2);
                }
                lnet_msg_decommit_rx(msg, status);
        }

        list_del(&msg->msg_activelist);
        msg->msg_onactivelist = 0;

        the_lnet.ln_counters[cpt2]->msgs_alloc--;

        if (cpt2 != cpt) {
                lnet_net_unlock(cpt2);
                lnet_net_lock(cpt);
        }
}

void
lnet_msg_attach_md(lnet_msg_t *msg, lnet_libmd_t *md,
                   unsigned int offset, unsigned int mlen)
{
        /* NB: @offset and @len are only useful for receiving */
        /*
         * Here, we attach the MD on lnet_msg and mark it busy and
         * decrementing its threshold. Come what may, the lnet_msg "owns"
         * the MD until a call to lnet_msg_detach_md or lnet_finalize()
         * signals completion.
         */
        LASSERT(!msg->msg_routing);

        msg->msg_md = md;
        if (msg->msg_receiving) { /* committed for receiving */
                msg->msg_offset = offset;
                msg->msg_wanted = mlen;
        }

        md->md_refcount++;
        if (md->md_threshold != LNET_MD_THRESH_INF) {
                LASSERT(md->md_threshold > 0);
                md->md_threshold--;
        }

        /* build umd in event */
        lnet_md2handle(&msg->msg_ev.md_handle, md);
        lnet_md_deconstruct(md, &msg->msg_ev.md);
}

void
lnet_msg_detach_md(lnet_msg_t *msg, int status)
{
        lnet_libmd_t *md = msg->msg_md;
        int unlink;

        /* Now it's safe to drop my caller's ref */
        md->md_refcount--;
        LASSERT(md->md_refcount >= 0);

        unlink = lnet_md_unlinkable(md);
        if (md->md_eq) {
                msg->msg_ev.status   = status;
                msg->msg_ev.unlinked = unlink;
                lnet_eq_enqueue_event(md->md_eq, &msg->msg_ev);
        }

        if (unlink)
                lnet_md_unlink(md);

        msg->msg_md = NULL;
}

static int
lnet_complete_msg_locked(lnet_msg_t *msg, int cpt)
{
        lnet_handle_wire_t ack_wmd;
        int rc;
        int status = msg->msg_ev.status;

        LASSERT(msg->msg_onactivelist);

        if (!status && msg->msg_ack) {
                /* Only send an ACK if the PUT completed successfully */

                lnet_msg_decommit(msg, cpt, 0);

                msg->msg_ack = 0;
                lnet_net_unlock(cpt);

                LASSERT(msg->msg_ev.type == LNET_EVENT_PUT);
                LASSERT(!msg->msg_routing);

                ack_wmd = msg->msg_hdr.msg.put.ack_wmd;

                lnet_prep_send(msg, LNET_MSG_ACK, msg->msg_ev.initiator, 0, 0);

                msg->msg_hdr.msg.ack.dst_wmd = ack_wmd;
                msg->msg_hdr.msg.ack.match_bits = msg->msg_ev.match_bits;
                msg->msg_hdr.msg.ack.mlength = cpu_to_le32(msg->msg_ev.mlength);

                /*
                 * NB: we probably want to use NID of msg::msg_from as 3rd
                 * parameter (router NID) if it's routed message
                 */
                rc = lnet_send(msg->msg_ev.target.nid, msg, LNET_NID_ANY);

                lnet_net_lock(cpt);
                /*
                 * NB: message is committed for sending, we should return
                 * on success because LND will finalize this message later.
                 *
                 * Also, there is possibility that message is committed for
                 * sending and also failed before delivering to LND,
                 * i.e: ENOMEM, in that case we can't fall through either
                 * because CPT for sending can be different with CPT for
                 * receiving, so we should return back to lnet_finalize()
                 * to make sure we are locking the correct partition.
                 */
                return rc;

        } else if (!status &&   /* OK so far */
                   (msg->msg_routing && !msg->msg_sending)) {
                /* not forwarded */
                LASSERT(!msg->msg_receiving);   /* called back recv already */
                lnet_net_unlock(cpt);

                rc = lnet_send(LNET_NID_ANY, msg, LNET_NID_ANY);

                lnet_net_lock(cpt);
                /*
                 * NB: message is committed for sending, we should return
                 * on success because LND will finalize this message later.
                 *
                 * Also, there is possibility that message is committed for
                 * sending and also failed before delivering to LND,
                 * i.e: ENOMEM, in that case we can't fall through either:
                 * - The rule is message must decommit for sending first if
                 *   the it's committed for both sending and receiving
                 * - CPT for sending can be different with CPT for receiving,
                 *   so we should return back to lnet_finalize() to make
                 *   sure we are locking the correct partition.
                 */
                return rc;
        }

        lnet_msg_decommit(msg, cpt, status);
        lnet_msg_free(msg);
        return 0;
}

void
lnet_finalize(lnet_ni_t *ni, lnet_msg_t *msg, int status)
{
        struct lnet_msg_container *container;
        int my_slot;
        int cpt;
        int rc;
        int i;

        LASSERT(!in_interrupt());

        if (!msg)
                return;
#if 0
        CDEBUG(D_WARNING, "%s msg->%s Flags:%s%s%s%s%s%s%s%s%s%s%s txp %s rxp %s\n",
               lnet_msgtyp2str(msg->msg_type), libcfs_id2str(msg->msg_target),
               msg->msg_target_is_router ? "t" : "",
               msg->msg_routing ? "X" : "",
               msg->msg_ack ? "A" : "",
               msg->msg_sending ? "S" : "",
               msg->msg_receiving ? "R" : "",
               msg->msg_delayed ? "d" : "",
               msg->msg_txcredit ? "C" : "",
               msg->msg_peertxcredit ? "c" : "",
               msg->msg_rtrcredit ? "F" : "",
               msg->msg_peerrtrcredit ? "f" : "",
               msg->msg_onactivelist ? "!" : "",
               !msg->msg_txpeer ? "<none>" : libcfs_nid2str(msg->msg_txpeer->lp_nid),
               !msg->msg_rxpeer ? "<none>" : libcfs_nid2str(msg->msg_rxpeer->lp_nid));
#endif
        msg->msg_ev.status = status;

        if (msg->msg_md) {
                cpt = lnet_cpt_of_cookie(msg->msg_md->md_lh.lh_cookie);

                lnet_res_lock(cpt);
                lnet_msg_detach_md(msg, status);
                lnet_res_unlock(cpt);
        }

 again:
        rc = 0;
        if (!msg->msg_tx_committed && !msg->msg_rx_committed) {
                /* not committed to network yet */
                LASSERT(!msg->msg_onactivelist);
                lnet_msg_free(msg);
                return;
        }

        /*
         * NB: routed message can be committed for both receiving and sending,
         * we should finalize in LIFO order and keep counters correct.
         * (finalize sending first then finalize receiving)
         */
        cpt = msg->msg_tx_committed ? msg->msg_tx_cpt : msg->msg_rx_cpt;
        lnet_net_lock(cpt);

        container = the_lnet.ln_msg_containers[cpt];
        list_add_tail(&msg->msg_list, &container->msc_finalizing);

        /*
         * Recursion breaker.  Don't complete the message here if I am (or
         * enough other threads are) already completing messages
         */
        my_slot = -1;
        for (i = 0; i < container->msc_nfinalizers; i++) {
                if (container->msc_finalizers[i] == current)
                        break;

                if (my_slot < 0 && !container->msc_finalizers[i])
                        my_slot = i;
        }

        if (i < container->msc_nfinalizers || my_slot < 0) {
                lnet_net_unlock(cpt);
                return;
        }

        container->msc_finalizers[my_slot] = current;

        while (!list_empty(&container->msc_finalizing)) {
                msg = list_entry(container->msc_finalizing.next,
                                 lnet_msg_t, msg_list);

                list_del(&msg->msg_list);

                /*
                 * NB drops and regains the lnet lock if it actually does
                 * anything, so my finalizing friends can chomp along too
                 */
                rc = lnet_complete_msg_locked(msg, cpt);
                if (rc)
                        break;
        }

        if (unlikely(!list_empty(&the_lnet.ln_delay_rules))) {
                lnet_net_unlock(cpt);
                lnet_delay_rule_check();
                lnet_net_lock(cpt);
        }

        container->msc_finalizers[my_slot] = NULL;
        lnet_net_unlock(cpt);

        if (rc)
                goto again;
}
EXPORT_SYMBOL(lnet_finalize);

void
lnet_msg_container_cleanup(struct lnet_msg_container *container)
{
        int count = 0;

        if (!container->msc_init)
                return;

        while (!list_empty(&container->msc_active)) {
                lnet_msg_t *msg = list_entry(container->msc_active.next,
                                             lnet_msg_t, msg_activelist);

                LASSERT(msg->msg_onactivelist);
                msg->msg_onactivelist = 0;
                list_del(&msg->msg_activelist);
                lnet_msg_free(msg);
                count++;
        }

        if (count > 0)
                CERROR("%d active msg on exit\n", count);

        if (container->msc_finalizers) {
                LIBCFS_FREE(container->msc_finalizers,
                            container->msc_nfinalizers *
                            sizeof(*container->msc_finalizers));
                container->msc_finalizers = NULL;
        }
        container->msc_init = 0;
}

int
lnet_msg_container_setup(struct lnet_msg_container *container, int cpt)
{
        container->msc_init = 1;

        INIT_LIST_HEAD(&container->msc_active);
        INIT_LIST_HEAD(&container->msc_finalizing);

        /* number of CPUs */
        container->msc_nfinalizers = cfs_cpt_weight(lnet_cpt_table(), cpt);

        LIBCFS_CPT_ALLOC(container->msc_finalizers, lnet_cpt_table(), cpt,
                         container->msc_nfinalizers *
                         sizeof(*container->msc_finalizers));

        if (!container->msc_finalizers) {
                CERROR("Failed to allocate message finalizers\n");
                lnet_msg_container_cleanup(container);
                return -ENOMEM;
        }

        return 0;
}

void
lnet_msg_containers_destroy(void)
{
        struct lnet_msg_container *container;
        int i;

        if (!the_lnet.ln_msg_containers)
                return;

        cfs_percpt_for_each(container, i, the_lnet.ln_msg_containers)
                lnet_msg_container_cleanup(container);

        cfs_percpt_free(the_lnet.ln_msg_containers);
        the_lnet.ln_msg_containers = NULL;
}

int
lnet_msg_containers_create(void)
{
        struct lnet_msg_container *container;
        int rc;
        int i;

        the_lnet.ln_msg_containers = cfs_percpt_alloc(lnet_cpt_table(),
                                                      sizeof(*container));

        if (!the_lnet.ln_msg_containers) {
                CERROR("Failed to allocate cpu-partition data for network\n");
                return -ENOMEM;
        }

        cfs_percpt_for_each(container, i, the_lnet.ln_msg_containers) {
                rc = lnet_msg_container_setup(container, i);
                if (rc) {
                        lnet_msg_containers_destroy();
                        return rc;
                }
        }

        return 0;
}