// SPDX-License-Identifier: GPL-2.0-or-later
/******************************************************************************
 *
 *      (C)Copyright 1998,1999 SysKonnect,
 *      a business unit of Schneider & Koch & Co. Datensysteme GmbH.
 *
 *      See the file "skfddi.c" for further information.
 *
 *      The information in this file is provided "AS IS" without warranty.
 *
 ******************************************************************************/

/*
 * *******************************************************************
 * This SBA code implements the Synchronous Bandwidth Allocation
 * functions described in the "FDDI Synchronous Forum Implementer's
 * Agreement" dated December 1th, 1993.
 * *******************************************************************
 *
 *      PURPOSE: The purpose of this function is to control
 *               synchronous allocations on a single FDDI segment.
 *               Allocations are limited to the primary FDDI ring.
 *               The SBM provides recovery mechanisms to recover
 *               unused bandwidth also resolves T_Neg and
 *               reconfiguration changes. Many of the SBM state
 *               machine inputs are sourced by the underlying
 *               FDDI sub-system supporting the SBA application.
 *
 * *******************************************************************
 */

#include "h/types.h"
#include "h/fddi.h"
#include "h/smc.h"
#include "h/smt_p.h"


#ifndef SLIM_SMT

#ifdef ESS

#ifndef lint
#define LINT_USE(x)
#else
#define LINT_USE(x)     (x)=(x)
#endif
#define MS2BCLK(x)      ((x)*12500L)

/*
        -------------------------------------------------------------
        LOCAL VARIABLES:
        -------------------------------------------------------------
*/

static const u_short plist_raf_alc_res[] = { SMT_P0012, SMT_P320B, SMT_P320F,
                                        SMT_P3210, SMT_P0019, SMT_P001A,
                                        SMT_P001D, 0 } ;

static const u_short plist_raf_chg_req[] = { SMT_P320B, SMT_P320F, SMT_P3210,
                                        SMT_P001A, 0 } ;

static const struct fddi_addr smt_sba_da = {{0x80,0x01,0x43,0x00,0x80,0x0C}} ;
static const struct fddi_addr null_addr = {{0,0,0,0,0,0}} ;

/*
        -------------------------------------------------------------
        GLOBAL VARIABLES:
        -------------------------------------------------------------
*/


/*
        -------------------------------------------------------------
        LOCAL FUNCTIONS:
        -------------------------------------------------------------
*/

static void ess_send_response(struct s_smc *smc, struct smt_header *sm,
                              int sba_cmd);
static void ess_config_fifo(struct s_smc *smc);
static void ess_send_alc_req(struct s_smc *smc);
static void ess_send_frame(struct s_smc *smc, SMbuf *mb);

/*
        -------------------------------------------------------------
        EXTERNAL FUNCTIONS:
        -------------------------------------------------------------
*/

/*
        -------------------------------------------------------------
        PUBLIC FUNCTIONS:
        -------------------------------------------------------------
*/

void ess_timer_poll(struct s_smc *smc);
void ess_para_change(struct s_smc *smc);
int ess_raf_received_pack(struct s_smc *smc, SMbuf *mb, struct smt_header *sm,
                          int fs);
static int process_bw_alloc(struct s_smc *smc, long int payload, long int overhead);


/*
 * --------------------------------------------------------------------------
 *      End Station Support     (ESS)
 * --------------------------------------------------------------------------
 */

/*
 * evaluate the RAF frame
 */
int ess_raf_received_pack(struct s_smc *smc, SMbuf *mb, struct smt_header *sm,
                          int fs)
{
        void                    *p ;            /* universal pointer */
        struct smt_p_0016       *cmd ;          /* para: command for the ESS */
        SMbuf                   *db ;
        u_long                  msg_res_type ;  /* recource type */
        u_long                  payload, overhead ;
        int                     local ;
        int                     i ;

        /*
         * Message Processing Code
         */
         local = ((fs & L_INDICATOR) != 0) ;

        /*
         * get the resource type
         */
        if (!(p = (void *) sm_to_para(smc,sm,SMT_P0015))) {
                DB_ESS("ESS: RAF frame error, parameter type not found");
                return fs;
        }
        msg_res_type = ((struct smt_p_0015 *)p)->res_type ;

        /*
         * get the pointer to the ESS command
         */
        if (!(cmd = (struct smt_p_0016 *) sm_to_para(smc,sm,SMT_P0016))) {
                /*
                 * error in frame: para ESS command was not found
                 */
                 DB_ESS("ESS: RAF frame error, parameter command not found");
                 return fs;
        }

        DB_ESSN(2, "fc %x       ft %x", sm->smt_class, sm->smt_type);
        DB_ESSN(2, "ver %x      tran %x", sm->smt_version, sm->smt_tid);
        DB_ESSN(2, "stn_id %pM", &sm->smt_source);

        DB_ESSN(2, "infolen %x  res %lx", sm->smt_len, msg_res_type);
        DB_ESSN(2, "sbacmd %x", cmd->sba_cmd);

        /*
         * evaluate the ESS command
         */
        switch (cmd->sba_cmd) {

        /*
         * Process an ESS Allocation Request
         */
        case REQUEST_ALLOCATION :
                /*
                 * check for an RAF Request (Allocation Request)
                 */
                if (sm->smt_type == SMT_REQUEST) {
                        /*
                         * process the Allocation request only if the frame is
                         * local and no static allocation is used
                         */
                        if (!local || smc->mib.fddiESSPayload)
                                return fs;
                        
                        p = (void *) sm_to_para(smc,sm,SMT_P0019)  ;
                        for (i = 0; i < 5; i++) {
                                if (((struct smt_p_0019 *)p)->alloc_addr.a[i]) {
                                        return fs;
                                }
                        }

                        /*
                         * Note: The Application should send a LAN_LOC_FRAME.
                         *       The ESS do not send the Frame to the network!
                         */
                        smc->ess.alloc_trans_id = sm->smt_tid ;
                        DB_ESS("ESS: save Alloc Req Trans ID %x", sm->smt_tid);
                        p = (void *) sm_to_para(smc,sm,SMT_P320F) ;
                        ((struct smt_p_320f *)p)->mib_payload =
                                smc->mib.a[PATH0].fddiPATHSbaPayload ;
                        p = (void *) sm_to_para(smc,sm,SMT_P3210) ;
                        ((struct smt_p_3210 *)p)->mib_overhead =
                                smc->mib.a[PATH0].fddiPATHSbaOverhead ;
                        sm->smt_dest = smt_sba_da ;

                        if (smc->ess.local_sba_active)
                                return fs | I_INDICATOR;

                        if (!(db = smt_get_mbuf(smc)))
                                return fs;

                        db->sm_len = mb->sm_len ;
                        db->sm_off = mb->sm_off ;
                        memcpy(((char *)(db->sm_data+db->sm_off)),(char *)sm,
                                (int)db->sm_len) ;
                        dump_smt(smc,
                                (struct smt_header *)(db->sm_data+db->sm_off),
                                "RAF") ;
                        smt_send_frame(smc,db,FC_SMT_INFO,0) ;
                        return fs;
                }

                /*
                 * The RAF frame is an Allocation Response !
                 * check the parameters
                 */
                if (smt_check_para(smc,sm,plist_raf_alc_res)) {
                        DB_ESS("ESS: RAF with para problem, ignoring");
                        return fs;
                }

                /*
                 * VERIFY THE FRAME IS WELL BUILT:
                 *
                 *      1. path index = primary ring only
                 *      2. resource type = sync bw only
                 *      3. trans action id = alloc_trans_id
                 *      4. reason code = success
                 *
                 * If any are violated, discard the RAF frame
                 */
                if ((((struct smt_p_320b *)sm_to_para(smc,sm,SMT_P320B))->path_index
                        != PRIMARY_RING) ||
                        (msg_res_type != SYNC_BW) ||
                (((struct smt_p_reason *)sm_to_para(smc,sm,SMT_P0012))->rdf_reason
                        != SMT_RDF_SUCCESS) ||
                        (sm->smt_tid != smc->ess.alloc_trans_id)) {

                        DB_ESS("ESS: Allocation Response not accepted");
                        return fs;
                }

                /*
                 * Extract message parameters
                 */
                p = (void *) sm_to_para(smc,sm,SMT_P320F) ;
                if (!p) {
                        printk(KERN_ERR "ESS: sm_to_para failed");
                        return fs;
                }       
                payload = ((struct smt_p_320f *)p)->mib_payload ;
                p = (void *) sm_to_para(smc,sm,SMT_P3210) ;
                if (!p) {
                        printk(KERN_ERR "ESS: sm_to_para failed");
                        return fs;
                }       
                overhead = ((struct smt_p_3210 *)p)->mib_overhead ;

                DB_ESSN(2, "payload= %lx        overhead= %lx",
                        payload, overhead);

                /*
                 * process the bandwidth allocation
                 */
                (void)process_bw_alloc(smc,(long)payload,(long)overhead) ;

                return fs;
                /* end of Process Allocation Request */

        /*
         * Process an ESS Change Request
         */
        case CHANGE_ALLOCATION :
                /*
                 * except only replies
                 */
                if (sm->smt_type != SMT_REQUEST) {
                        DB_ESS("ESS: Do not process Change Responses");
                        return fs;
                }

                /*
                 * check the para for the Change Request
                 */
                if (smt_check_para(smc,sm,plist_raf_chg_req)) {
                        DB_ESS("ESS: RAF with para problem, ignoring");
                        return fs;
                }

                /*
                 * Verify the path index and resource
                 * type are correct. If any of
                 * these are false, don't process this
                 * change request frame.
                 */
                if ((((struct smt_p_320b *)sm_to_para(smc,sm,SMT_P320B))->path_index
                        != PRIMARY_RING) || (msg_res_type != SYNC_BW)) {
                        DB_ESS("ESS: RAF frame with para problem, ignoring");
                        return fs;
                }

                /*
                 * Extract message queue parameters
                 */
                p = (void *) sm_to_para(smc,sm,SMT_P320F) ;
                payload = ((struct smt_p_320f *)p)->mib_payload ;
                p = (void *) sm_to_para(smc,sm,SMT_P3210) ;
                overhead = ((struct smt_p_3210 *)p)->mib_overhead ;

                DB_ESSN(2, "ESS: Change Request from %pM",
                        &sm->smt_source);
                DB_ESSN(2, "payload= %lx        overhead= %lx",
                        payload, overhead);

                /*
                 * process the bandwidth allocation
                 */
                if(!process_bw_alloc(smc,(long)payload,(long)overhead))
                        return fs;

                /*
                 * send an RAF Change Reply
                 */
                ess_send_response(smc,sm,CHANGE_ALLOCATION) ;

                return fs;
                /* end of Process Change Request */

        /*
         * Process Report Response
         */
        case REPORT_ALLOCATION :
                /*
                 * except only requests
                 */
                if (sm->smt_type != SMT_REQUEST) {
                        DB_ESS("ESS: Do not process a Report Reply");
                        return fs;
                }

                DB_ESSN(2, "ESS: Report Request from %pM",
                        &sm->smt_source);

                /*
                 * verify that the resource type is sync bw only
                 */
                if (msg_res_type != SYNC_BW) {
                        DB_ESS("ESS: ignoring RAF with para problem");
                        return fs;
                }

                /*
                 * send an RAF Change Reply
                 */
                ess_send_response(smc,sm,REPORT_ALLOCATION) ;

                return fs;
                /* end of Process Report Request */

        default:
                /*
                 * error in frame
                 */
                DB_ESS("ESS: ignoring RAF with bad sba_cmd");
                break ;
        }

        return fs;
}

/*
 * determines the synchronous bandwidth, set the TSYNC register and the
 * mib variables SBAPayload, SBAOverhead and fddiMACT-NEG.
 */
static int process_bw_alloc(struct s_smc *smc, long int payload, long int overhead)
{
        /*
         * determine the synchronous bandwidth (sync_bw) in bytes per T-NEG,
         * if the payload is greater than zero.
         * For the SBAPayload and the SBAOverhead we have the following
         * unite quations
         *                    _           _
         *                   |       bytes |
         *      SBAPayload = | 8000 ------ |
         *                   |          s  |
         *                    -           -
         *                     _       _
         *                    |  bytes  |
         *      SBAOverhead = | ------  |
         *                    |  T-NEG  |
         *                     -       -
         *
         * T-NEG is described by the equation:
         *
         *                   (-) fddiMACT-NEG
         *      T-NEG =     -------------------
         *                      12500000 1/s
         *
         * The number of bytes we are able to send is the payload
         * plus the overhead.
         *
         *                        bytes    T-NEG SBAPayload 8000 bytes/s
         * sync_bw =  SBAOverhead ------ + -----------------------------
         *                        T-NEG         T-NEG
         *
         *
         *                           1
         * sync_bw =  SBAOverhead + ---- (-)fddiMACT-NEG * SBAPayload
         *                          1562
         *
         */

        /*
         * set the mib attributes fddiPATHSbaOverhead, fddiPATHSbaPayload
         */
/*      if (smt_set_obj(smc,SMT_P320F,payload,S_SET)) {
                DB_ESS("ESS: SMT does not accept the payload value");
                return FALSE;
        }
        if (smt_set_obj(smc,SMT_P3210,overhead,S_SET)) {
                DB_ESS("ESS: SMT does not accept the overhead value");
                return FALSE;
        } */

        /* premliminary */
        if (payload > MAX_PAYLOAD || overhead > 5000) {
                DB_ESS("ESS: payload / overhead not accepted");
                return FALSE;
        }

        /*
         * start the iterative allocation process if the payload or the overhead
         * are smaller than the parsed values
         */
        if (smc->mib.fddiESSPayload &&
                ((u_long)payload != smc->mib.fddiESSPayload ||
                (u_long)overhead != smc->mib.fddiESSOverhead)) {
                smc->ess.raf_act_timer_poll = TRUE ;
                smc->ess.timer_count = 0 ;
        }

        /*
         * evulate the Payload
         */
        if (payload) {
                DB_ESSN(2, "ESS: turn SMT_ST_SYNC_SERVICE bit on");
                smc->ess.sync_bw_available = TRUE ;

                smc->ess.sync_bw = overhead -
                        (long)smc->mib.m[MAC0].fddiMACT_Neg *
                        payload / 1562 ;
        }
        else {
                DB_ESSN(2, "ESS: turn SMT_ST_SYNC_SERVICE bit off");
                smc->ess.sync_bw_available = FALSE ;
                smc->ess.sync_bw = 0 ;
                overhead = 0 ;
        }

        smc->mib.a[PATH0].fddiPATHSbaPayload = payload ;
        smc->mib.a[PATH0].fddiPATHSbaOverhead = overhead ;


        DB_ESSN(2, "tsync = %lx", smc->ess.sync_bw);

        ess_config_fifo(smc) ;
        set_formac_tsync(smc,smc->ess.sync_bw) ;
        return TRUE;
}

static void ess_send_response(struct s_smc *smc, struct smt_header *sm,
                              int sba_cmd)
{
        struct smt_sba_chg      *chg ;
        SMbuf                   *mb ;
        void                    *p ;

        /*
         * get and initialize the response frame
         */
        if (sba_cmd == CHANGE_ALLOCATION) {
                if (!(mb=smt_build_frame(smc,SMT_RAF,SMT_REPLY,
                                sizeof(struct smt_sba_chg))))
                                return ;
        }
        else {
                if (!(mb=smt_build_frame(smc,SMT_RAF,SMT_REPLY,
                                sizeof(struct smt_sba_rep_res))))
                                return ;
        }

        chg = smtod(mb,struct smt_sba_chg *) ;
        chg->smt.smt_tid = sm->smt_tid ;
        chg->smt.smt_dest = sm->smt_source ;

        /* set P15 */
        chg->s_type.para.p_type = SMT_P0015 ;
        chg->s_type.para.p_len = sizeof(struct smt_p_0015) - PARA_LEN ;
        chg->s_type.res_type = SYNC_BW ;

        /* set P16 */
        chg->cmd.para.p_type = SMT_P0016 ;
        chg->cmd.para.p_len = sizeof(struct smt_p_0016) - PARA_LEN ;
        chg->cmd.sba_cmd = sba_cmd ;

        /* set P320B */
        chg->path.para.p_type = SMT_P320B ;
        chg->path.para.p_len = sizeof(struct smt_p_320b) - PARA_LEN ;
        chg->path.mib_index = SBAPATHINDEX ;
        chg->path.path_pad = 0;
        chg->path.path_index = PRIMARY_RING ;

        /* set P320F */
        chg->payload.para.p_type = SMT_P320F ;
        chg->payload.para.p_len = sizeof(struct smt_p_320f) - PARA_LEN ;
        chg->payload.mib_index = SBAPATHINDEX ;
        chg->payload.mib_payload = smc->mib.a[PATH0].fddiPATHSbaPayload ;

        /* set P3210 */
        chg->overhead.para.p_type = SMT_P3210 ;
        chg->overhead.para.p_len = sizeof(struct smt_p_3210) - PARA_LEN ;
        chg->overhead.mib_index = SBAPATHINDEX ;
        chg->overhead.mib_overhead = smc->mib.a[PATH0].fddiPATHSbaOverhead ;

        if (sba_cmd == CHANGE_ALLOCATION) {
                /* set P1A */
                chg->cat.para.p_type = SMT_P001A ;
                chg->cat.para.p_len = sizeof(struct smt_p_001a) - PARA_LEN ;
                p = (void *) sm_to_para(smc,sm,SMT_P001A) ;
                chg->cat.category = ((struct smt_p_001a *)p)->category ;
        }
        dump_smt(smc,(struct smt_header *)chg,"RAF") ;
        ess_send_frame(smc,mb) ;
}

void ess_timer_poll(struct s_smc *smc)
{
        if (!smc->ess.raf_act_timer_poll)
                return ;

        DB_ESSN(2, "ESS: timer_poll");

        smc->ess.timer_count++ ;
        if (smc->ess.timer_count == 10) {
                smc->ess.timer_count = 0 ;
                ess_send_alc_req(smc) ;
        }
}

static void ess_send_alc_req(struct s_smc *smc)
{
        struct smt_sba_alc_req *req ;
        SMbuf   *mb ;

        /*
         * send never allocation request where the requested payload and
         * overhead is zero or deallocate bandwidth when no bandwidth is
         * parsed
         */
        if (!smc->mib.fddiESSPayload) {
                smc->mib.fddiESSOverhead = 0 ;
        }
        else {
                if (!smc->mib.fddiESSOverhead)
                        smc->mib.fddiESSOverhead = DEFAULT_OV ;
        }

        if (smc->mib.fddiESSOverhead ==
                smc->mib.a[PATH0].fddiPATHSbaOverhead &&
                smc->mib.fddiESSPayload ==
                smc->mib.a[PATH0].fddiPATHSbaPayload){
                smc->ess.raf_act_timer_poll = FALSE ;
                smc->ess.timer_count = 7 ;      /* next RAF alc req after 3 s */
                return ;
        }
        
        /*
         * get and initialize the response frame
         */
        if (!(mb=smt_build_frame(smc,SMT_RAF,SMT_REQUEST,
                        sizeof(struct smt_sba_alc_req))))
                        return ;
        req = smtod(mb,struct smt_sba_alc_req *) ;
        req->smt.smt_tid = smc->ess.alloc_trans_id = smt_get_tid(smc) ;
        req->smt.smt_dest = smt_sba_da ;

        /* set P15 */
        req->s_type.para.p_type = SMT_P0015 ;
        req->s_type.para.p_len = sizeof(struct smt_p_0015) - PARA_LEN ;
        req->s_type.res_type = SYNC_BW ;

        /* set P16 */
        req->cmd.para.p_type = SMT_P0016 ;
        req->cmd.para.p_len = sizeof(struct smt_p_0016) - PARA_LEN ;
        req->cmd.sba_cmd = REQUEST_ALLOCATION ;

        /*
         * set the parameter type and parameter length of all used
         * parameters
         */

        /* set P320B */
        req->path.para.p_type = SMT_P320B ;
        req->path.para.p_len = sizeof(struct smt_p_320b) - PARA_LEN ;
        req->path.mib_index = SBAPATHINDEX ;
        req->path.path_pad = 0;
        req->path.path_index = PRIMARY_RING ;

        /* set P0017 */
        req->pl_req.para.p_type = SMT_P0017 ;
        req->pl_req.para.p_len = sizeof(struct smt_p_0017) - PARA_LEN ;
        req->pl_req.sba_pl_req = smc->mib.fddiESSPayload -
                smc->mib.a[PATH0].fddiPATHSbaPayload ;

        /* set P0018 */
        req->ov_req.para.p_type = SMT_P0018 ;
        req->ov_req.para.p_len = sizeof(struct smt_p_0018) - PARA_LEN ;
        req->ov_req.sba_ov_req = smc->mib.fddiESSOverhead -
                smc->mib.a[PATH0].fddiPATHSbaOverhead ;

        /* set P320F */
        req->payload.para.p_type = SMT_P320F ;
        req->payload.para.p_len = sizeof(struct smt_p_320f) - PARA_LEN ;
        req->payload.mib_index = SBAPATHINDEX ;
        req->payload.mib_payload = smc->mib.a[PATH0].fddiPATHSbaPayload ;

        /* set P3210 */
        req->overhead.para.p_type = SMT_P3210 ;
        req->overhead.para.p_len = sizeof(struct smt_p_3210) - PARA_LEN ;
        req->overhead.mib_index = SBAPATHINDEX ;
        req->overhead.mib_overhead = smc->mib.a[PATH0].fddiPATHSbaOverhead ;

        /* set P19 */
        req->a_addr.para.p_type = SMT_P0019 ;
        req->a_addr.para.p_len = sizeof(struct smt_p_0019) - PARA_LEN ;
        req->a_addr.sba_pad = 0;
        req->a_addr.alloc_addr = null_addr ;

        /* set P1A */
        req->cat.para.p_type = SMT_P001A ;
        req->cat.para.p_len = sizeof(struct smt_p_001a) - PARA_LEN ;
        req->cat.category = smc->mib.fddiESSCategory ;

        /* set P1B */
        req->tneg.para.p_type = SMT_P001B ;
        req->tneg.para.p_len = sizeof(struct smt_p_001b) - PARA_LEN ;
        req->tneg.max_t_neg = smc->mib.fddiESSMaxTNeg ;

        /* set P1C */
        req->segm.para.p_type = SMT_P001C ;
        req->segm.para.p_len = sizeof(struct smt_p_001c) - PARA_LEN ;
        req->segm.min_seg_siz = smc->mib.fddiESSMinSegmentSize ;

        dump_smt(smc,(struct smt_header *)req,"RAF") ;
        ess_send_frame(smc,mb) ;
}

static void ess_send_frame(struct s_smc *smc, SMbuf *mb)
{
        /*
         * check if the frame must be send to the own ESS
         */
        if (smc->ess.local_sba_active) {
                /*
                 * Send the Change Reply to the local SBA
                 */
                DB_ESS("ESS:Send to the local SBA");
                if (!smc->ess.sba_reply_pend)
                        smc->ess.sba_reply_pend = mb ;
                else {
                        DB_ESS("Frame is lost - another frame was pending");
                        smt_free_mbuf(smc,mb) ;
                }
        }
        else {
                /*
                 * Send the SBA RAF Change Reply to the network
                 */
                DB_ESS("ESS:Send to the network");
                smt_send_frame(smc,mb,FC_SMT_INFO,0) ;
        }
}

void ess_para_change(struct s_smc *smc)
{
        (void)process_bw_alloc(smc,(long)smc->mib.a[PATH0].fddiPATHSbaPayload,
                (long)smc->mib.a[PATH0].fddiPATHSbaOverhead) ;
}

static void ess_config_fifo(struct s_smc *smc)
{
        /*
         * if nothing to do exit 
         */
        if (smc->mib.a[PATH0].fddiPATHSbaPayload) {
                if (smc->hw.fp.fifo.fifo_config_mode & SYNC_TRAFFIC_ON &&
                        (smc->hw.fp.fifo.fifo_config_mode&SEND_ASYNC_AS_SYNC) ==
                        smc->mib.fddiESSSynchTxMode) {
                        return ;
                }
        }
        else {
                if (!(smc->hw.fp.fifo.fifo_config_mode & SYNC_TRAFFIC_ON)) {
                        return ;
                }
        }

        /*
         * split up the FIFO and reinitialize the queues
         */
        formac_reinit_tx(smc) ;
}

#endif /* ESS */

#endif  /* no SLIM_SMT */