linux/net/caif/cfctrl.c
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   1/*
   2 * Copyright (C) ST-Ericsson AB 2010
   3 * Author:      Sjur Brendeland
   4 * License terms: GNU General Public License (GPL) version 2
   5 */
   6
   7#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
   8
   9#include <linux/stddef.h>
  10#include <linux/spinlock.h>
  11#include <linux/slab.h>
  12#include <linux/pkt_sched.h>
  13#include <net/caif/caif_layer.h>
  14#include <net/caif/cfpkt.h>
  15#include <net/caif/cfctrl.h>
  16
  17#define container_obj(layr) container_of(layr, struct cfctrl, serv.layer)
  18#define UTILITY_NAME_LENGTH 16
  19#define CFPKT_CTRL_PKT_LEN 20
  20
  21#ifdef CAIF_NO_LOOP
  22static int handle_loop(struct cfctrl *ctrl,
  23                       int cmd, struct cfpkt *pkt){
  24        return -1;
  25}
  26#else
  27static int handle_loop(struct cfctrl *ctrl,
  28                       int cmd, struct cfpkt *pkt);
  29#endif
  30static int cfctrl_recv(struct cflayer *layr, struct cfpkt *pkt);
  31static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
  32                           int phyid);
  33
  34
  35struct cflayer *cfctrl_create(void)
  36{
  37        struct dev_info dev_info;
  38        struct cfctrl *this =
  39                kzalloc(sizeof(struct cfctrl), GFP_ATOMIC);
  40        if (!this)
  41                return NULL;
  42        caif_assert(offsetof(struct cfctrl, serv.layer) == 0);
  43        memset(&dev_info, 0, sizeof(dev_info));
  44        dev_info.id = 0xff;
  45        cfsrvl_init(&this->serv, 0, &dev_info, false);
  46        atomic_set(&this->req_seq_no, 1);
  47        atomic_set(&this->rsp_seq_no, 1);
  48        this->serv.layer.receive = cfctrl_recv;
  49        sprintf(this->serv.layer.name, "ctrl");
  50        this->serv.layer.ctrlcmd = cfctrl_ctrlcmd;
  51#ifndef CAIF_NO_LOOP
  52        spin_lock_init(&this->loop_linkid_lock);
  53        this->loop_linkid = 1;
  54#endif
  55        spin_lock_init(&this->info_list_lock);
  56        INIT_LIST_HEAD(&this->list);
  57        return &this->serv.layer;
  58}
  59
  60void cfctrl_remove(struct cflayer *layer)
  61{
  62        struct cfctrl_request_info *p, *tmp;
  63        struct cfctrl *ctrl = container_obj(layer);
  64
  65        spin_lock_bh(&ctrl->info_list_lock);
  66        list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
  67                list_del(&p->list);
  68                kfree(p);
  69        }
  70        spin_unlock_bh(&ctrl->info_list_lock);
  71        kfree(layer);
  72}
  73
  74static bool param_eq(const struct cfctrl_link_param *p1,
  75                     const struct cfctrl_link_param *p2)
  76{
  77        bool eq =
  78            p1->linktype == p2->linktype &&
  79            p1->priority == p2->priority &&
  80            p1->phyid == p2->phyid &&
  81            p1->endpoint == p2->endpoint && p1->chtype == p2->chtype;
  82
  83        if (!eq)
  84                return false;
  85
  86        switch (p1->linktype) {
  87        case CFCTRL_SRV_VEI:
  88                return true;
  89        case CFCTRL_SRV_DATAGRAM:
  90                return p1->u.datagram.connid == p2->u.datagram.connid;
  91        case CFCTRL_SRV_RFM:
  92                return
  93                    p1->u.rfm.connid == p2->u.rfm.connid &&
  94                    strcmp(p1->u.rfm.volume, p2->u.rfm.volume) == 0;
  95        case CFCTRL_SRV_UTIL:
  96                return
  97                    p1->u.utility.fifosize_kb == p2->u.utility.fifosize_kb
  98                    && p1->u.utility.fifosize_bufs ==
  99                    p2->u.utility.fifosize_bufs
 100                    && strcmp(p1->u.utility.name, p2->u.utility.name) == 0
 101                    && p1->u.utility.paramlen == p2->u.utility.paramlen
 102                    && memcmp(p1->u.utility.params, p2->u.utility.params,
 103                              p1->u.utility.paramlen) == 0;
 104
 105        case CFCTRL_SRV_VIDEO:
 106                return p1->u.video.connid == p2->u.video.connid;
 107        case CFCTRL_SRV_DBG:
 108                return true;
 109        case CFCTRL_SRV_DECM:
 110                return false;
 111        default:
 112                return false;
 113        }
 114        return false;
 115}
 116
 117static bool cfctrl_req_eq(const struct cfctrl_request_info *r1,
 118                          const struct cfctrl_request_info *r2)
 119{
 120        if (r1->cmd != r2->cmd)
 121                return false;
 122        if (r1->cmd == CFCTRL_CMD_LINK_SETUP)
 123                return param_eq(&r1->param, &r2->param);
 124        else
 125                return r1->channel_id == r2->channel_id;
 126}
 127
 128/* Insert request at the end */
 129static void cfctrl_insert_req(struct cfctrl *ctrl,
 130                              struct cfctrl_request_info *req)
 131{
 132        spin_lock_bh(&ctrl->info_list_lock);
 133        atomic_inc(&ctrl->req_seq_no);
 134        req->sequence_no = atomic_read(&ctrl->req_seq_no);
 135        list_add_tail(&req->list, &ctrl->list);
 136        spin_unlock_bh(&ctrl->info_list_lock);
 137}
 138
 139/* Compare and remove request */
 140static struct cfctrl_request_info *cfctrl_remove_req(struct cfctrl *ctrl,
 141                                                struct cfctrl_request_info *req)
 142{
 143        struct cfctrl_request_info *p, *tmp, *first;
 144
 145        first = list_first_entry(&ctrl->list, struct cfctrl_request_info, list);
 146
 147        list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
 148                if (cfctrl_req_eq(req, p)) {
 149                        if (p != first)
 150                                pr_warn("Requests are not received in order\n");
 151
 152                        atomic_set(&ctrl->rsp_seq_no,
 153                                         p->sequence_no);
 154                        list_del(&p->list);
 155                        goto out;
 156                }
 157        }
 158        p = NULL;
 159out:
 160        return p;
 161}
 162
 163struct cfctrl_rsp *cfctrl_get_respfuncs(struct cflayer *layer)
 164{
 165        struct cfctrl *this = container_obj(layer);
 166        return &this->res;
 167}
 168
 169static void init_info(struct caif_payload_info *info, struct cfctrl *cfctrl)
 170{
 171        info->hdr_len = 0;
 172        info->channel_id = cfctrl->serv.layer.id;
 173        info->dev_info = &cfctrl->serv.dev_info;
 174}
 175
 176void cfctrl_enum_req(struct cflayer *layer, u8 physlinkid)
 177{
 178        struct cfpkt *pkt;
 179        struct cfctrl *cfctrl = container_obj(layer);
 180        struct cflayer *dn = cfctrl->serv.layer.dn;
 181
 182        if (!dn) {
 183                pr_debug("not able to send enum request\n");
 184                return;
 185        }
 186        pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
 187        if (!pkt)
 188                return;
 189        caif_assert(offsetof(struct cfctrl, serv.layer) == 0);
 190        init_info(cfpkt_info(pkt), cfctrl);
 191        cfpkt_info(pkt)->dev_info->id = physlinkid;
 192        cfctrl->serv.dev_info.id = physlinkid;
 193        cfpkt_addbdy(pkt, CFCTRL_CMD_ENUM);
 194        cfpkt_addbdy(pkt, physlinkid);
 195        cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
 196        dn->transmit(dn, pkt);
 197}
 198
 199int cfctrl_linkup_request(struct cflayer *layer,
 200                          struct cfctrl_link_param *param,
 201                          struct cflayer *user_layer)
 202{
 203        struct cfctrl *cfctrl = container_obj(layer);
 204        u32 tmp32;
 205        u16 tmp16;
 206        u8 tmp8;
 207        struct cfctrl_request_info *req;
 208        int ret;
 209        char utility_name[16];
 210        struct cfpkt *pkt;
 211        struct cflayer *dn = cfctrl->serv.layer.dn;
 212
 213        if (!dn) {
 214                pr_debug("not able to send linkup request\n");
 215                return -ENODEV;
 216        }
 217
 218        if (cfctrl_cancel_req(layer, user_layer) > 0) {
 219                /* Slight Paranoia, check if already connecting */
 220                pr_err("Duplicate connect request for same client\n");
 221                WARN_ON(1);
 222                return -EALREADY;
 223        }
 224
 225        pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
 226        if (!pkt)
 227                return -ENOMEM;
 228        cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_SETUP);
 229        cfpkt_addbdy(pkt, (param->chtype << 4) | param->linktype);
 230        cfpkt_addbdy(pkt, (param->priority << 3) | param->phyid);
 231        cfpkt_addbdy(pkt, param->endpoint & 0x03);
 232
 233        switch (param->linktype) {
 234        case CFCTRL_SRV_VEI:
 235                break;
 236        case CFCTRL_SRV_VIDEO:
 237                cfpkt_addbdy(pkt, (u8) param->u.video.connid);
 238                break;
 239        case CFCTRL_SRV_DBG:
 240                break;
 241        case CFCTRL_SRV_DATAGRAM:
 242                tmp32 = cpu_to_le32(param->u.datagram.connid);
 243                cfpkt_add_body(pkt, &tmp32, 4);
 244                break;
 245        case CFCTRL_SRV_RFM:
 246                /* Construct a frame, convert DatagramConnectionID to network
 247                 * format long and copy it out...
 248                 */
 249                tmp32 = cpu_to_le32(param->u.rfm.connid);
 250                cfpkt_add_body(pkt, &tmp32, 4);
 251                /* Add volume name, including zero termination... */
 252                cfpkt_add_body(pkt, param->u.rfm.volume,
 253                               strlen(param->u.rfm.volume) + 1);
 254                break;
 255        case CFCTRL_SRV_UTIL:
 256                tmp16 = cpu_to_le16(param->u.utility.fifosize_kb);
 257                cfpkt_add_body(pkt, &tmp16, 2);
 258                tmp16 = cpu_to_le16(param->u.utility.fifosize_bufs);
 259                cfpkt_add_body(pkt, &tmp16, 2);
 260                memset(utility_name, 0, sizeof(utility_name));
 261                strlcpy(utility_name, param->u.utility.name,
 262                        UTILITY_NAME_LENGTH);
 263                cfpkt_add_body(pkt, utility_name, UTILITY_NAME_LENGTH);
 264                tmp8 = param->u.utility.paramlen;
 265                cfpkt_add_body(pkt, &tmp8, 1);
 266                cfpkt_add_body(pkt, param->u.utility.params,
 267                               param->u.utility.paramlen);
 268                break;
 269        default:
 270                pr_warn("Request setup of bad link type = %d\n",
 271                        param->linktype);
 272                return -EINVAL;
 273        }
 274        req = kzalloc(sizeof(*req), GFP_KERNEL);
 275        if (!req)
 276                return -ENOMEM;
 277        req->client_layer = user_layer;
 278        req->cmd = CFCTRL_CMD_LINK_SETUP;
 279        req->param = *param;
 280        cfctrl_insert_req(cfctrl, req);
 281        init_info(cfpkt_info(pkt), cfctrl);
 282        /*
 283         * NOTE:Always send linkup and linkdown request on the same
 284         *      device as the payload. Otherwise old queued up payload
 285         *      might arrive with the newly allocated channel ID.
 286         */
 287        cfpkt_info(pkt)->dev_info->id = param->phyid;
 288        cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
 289        ret =
 290            dn->transmit(dn, pkt);
 291        if (ret < 0) {
 292                int count;
 293
 294                count = cfctrl_cancel_req(&cfctrl->serv.layer,
 295                                                user_layer);
 296                if (count != 1) {
 297                        pr_err("Could not remove request (%d)", count);
 298                        return -ENODEV;
 299                }
 300        }
 301        return 0;
 302}
 303
 304int cfctrl_linkdown_req(struct cflayer *layer, u8 channelid,
 305                        struct cflayer *client)
 306{
 307        int ret;
 308        struct cfpkt *pkt;
 309        struct cfctrl *cfctrl = container_obj(layer);
 310        struct cflayer *dn = cfctrl->serv.layer.dn;
 311
 312        if (!dn) {
 313                pr_debug("not able to send link-down request\n");
 314                return -ENODEV;
 315        }
 316        pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
 317        if (!pkt)
 318                return -ENOMEM;
 319        cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_DESTROY);
 320        cfpkt_addbdy(pkt, channelid);
 321        init_info(cfpkt_info(pkt), cfctrl);
 322        cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
 323        ret =
 324            dn->transmit(dn, pkt);
 325#ifndef CAIF_NO_LOOP
 326        cfctrl->loop_linkused[channelid] = 0;
 327#endif
 328        return ret;
 329}
 330
 331int cfctrl_cancel_req(struct cflayer *layr, struct cflayer *adap_layer)
 332{
 333        struct cfctrl_request_info *p, *tmp;
 334        struct cfctrl *ctrl = container_obj(layr);
 335        int found = 0;
 336        spin_lock_bh(&ctrl->info_list_lock);
 337
 338        list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
 339                if (p->client_layer == adap_layer) {
 340                        list_del(&p->list);
 341                        kfree(p);
 342                        found++;
 343                }
 344        }
 345
 346        spin_unlock_bh(&ctrl->info_list_lock);
 347        return found;
 348}
 349
 350static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
 351{
 352        u8 cmdrsp;
 353        u8 cmd;
 354        int ret = -1;
 355        u8 len;
 356        u8 param[255];
 357        u8 linkid = 0;
 358        struct cfctrl *cfctrl = container_obj(layer);
 359        struct cfctrl_request_info rsp, *req;
 360
 361
 362        cmdrsp = cfpkt_extr_head_u8(pkt);
 363        cmd = cmdrsp & CFCTRL_CMD_MASK;
 364        if (cmd != CFCTRL_CMD_LINK_ERR
 365            && CFCTRL_RSP_BIT != (CFCTRL_RSP_BIT & cmdrsp)
 366                && CFCTRL_ERR_BIT != (CFCTRL_ERR_BIT & cmdrsp)) {
 367                if (handle_loop(cfctrl, cmd, pkt) != 0)
 368                        cmdrsp |= CFCTRL_ERR_BIT;
 369        }
 370
 371        switch (cmd) {
 372        case CFCTRL_CMD_LINK_SETUP:
 373                {
 374                        enum cfctrl_srv serv;
 375                        enum cfctrl_srv servtype;
 376                        u8 endpoint;
 377                        u8 physlinkid;
 378                        u8 prio;
 379                        u8 tmp;
 380                        u8 *cp;
 381                        int i;
 382                        struct cfctrl_link_param linkparam;
 383                        memset(&linkparam, 0, sizeof(linkparam));
 384
 385                        tmp = cfpkt_extr_head_u8(pkt);
 386
 387                        serv = tmp & CFCTRL_SRV_MASK;
 388                        linkparam.linktype = serv;
 389
 390                        servtype = tmp >> 4;
 391                        linkparam.chtype = servtype;
 392
 393                        tmp = cfpkt_extr_head_u8(pkt);
 394                        physlinkid = tmp & 0x07;
 395                        prio = tmp >> 3;
 396
 397                        linkparam.priority = prio;
 398                        linkparam.phyid = physlinkid;
 399                        endpoint = cfpkt_extr_head_u8(pkt);
 400                        linkparam.endpoint = endpoint & 0x03;
 401
 402                        switch (serv) {
 403                        case CFCTRL_SRV_VEI:
 404                        case CFCTRL_SRV_DBG:
 405                                if (CFCTRL_ERR_BIT & cmdrsp)
 406                                        break;
 407                                /* Link ID */
 408                                linkid = cfpkt_extr_head_u8(pkt);
 409                                break;
 410                        case CFCTRL_SRV_VIDEO:
 411                                tmp = cfpkt_extr_head_u8(pkt);
 412                                linkparam.u.video.connid = tmp;
 413                                if (CFCTRL_ERR_BIT & cmdrsp)
 414                                        break;
 415                                /* Link ID */
 416                                linkid = cfpkt_extr_head_u8(pkt);
 417                                break;
 418
 419                        case CFCTRL_SRV_DATAGRAM:
 420                                linkparam.u.datagram.connid =
 421                                    cfpkt_extr_head_u32(pkt);
 422                                if (CFCTRL_ERR_BIT & cmdrsp)
 423                                        break;
 424                                /* Link ID */
 425                                linkid = cfpkt_extr_head_u8(pkt);
 426                                break;
 427                        case CFCTRL_SRV_RFM:
 428                                /* Construct a frame, convert
 429                                 * DatagramConnectionID
 430                                 * to network format long and copy it out...
 431                                 */
 432                                linkparam.u.rfm.connid =
 433                                    cfpkt_extr_head_u32(pkt);
 434                                cp = (u8 *) linkparam.u.rfm.volume;
 435                                for (tmp = cfpkt_extr_head_u8(pkt);
 436                                     cfpkt_more(pkt) && tmp != '\0';
 437                                     tmp = cfpkt_extr_head_u8(pkt))
 438                                        *cp++ = tmp;
 439                                *cp = '\0';
 440
 441                                if (CFCTRL_ERR_BIT & cmdrsp)
 442                                        break;
 443                                /* Link ID */
 444                                linkid = cfpkt_extr_head_u8(pkt);
 445
 446                                break;
 447                        case CFCTRL_SRV_UTIL:
 448                                /* Construct a frame, convert
 449                                 * DatagramConnectionID
 450                                 * to network format long and copy it out...
 451                                 */
 452                                /* Fifosize KB */
 453                                linkparam.u.utility.fifosize_kb =
 454                                    cfpkt_extr_head_u16(pkt);
 455                                /* Fifosize bufs */
 456                                linkparam.u.utility.fifosize_bufs =
 457                                    cfpkt_extr_head_u16(pkt);
 458                                /* name */
 459                                cp = (u8 *) linkparam.u.utility.name;
 460                                caif_assert(sizeof(linkparam.u.utility.name)
 461                                             >= UTILITY_NAME_LENGTH);
 462                                for (i = 0;
 463                                     i < UTILITY_NAME_LENGTH
 464                                     && cfpkt_more(pkt); i++) {
 465                                        tmp = cfpkt_extr_head_u8(pkt);
 466                                        *cp++ = tmp;
 467                                }
 468                                /* Length */
 469                                len = cfpkt_extr_head_u8(pkt);
 470                                linkparam.u.utility.paramlen = len;
 471                                /* Param Data */
 472                                cp = linkparam.u.utility.params;
 473                                while (cfpkt_more(pkt) && len--) {
 474                                        tmp = cfpkt_extr_head_u8(pkt);
 475                                        *cp++ = tmp;
 476                                }
 477                                if (CFCTRL_ERR_BIT & cmdrsp)
 478                                        break;
 479                                /* Link ID */
 480                                linkid = cfpkt_extr_head_u8(pkt);
 481                                /* Length */
 482                                len = cfpkt_extr_head_u8(pkt);
 483                                /* Param Data */
 484                                cfpkt_extr_head(pkt, &param, len);
 485                                break;
 486                        default:
 487                                pr_warn("Request setup, invalid type (%d)\n",
 488                                        serv);
 489                                goto error;
 490                        }
 491
 492                        rsp.cmd = cmd;
 493                        rsp.param = linkparam;
 494                        spin_lock_bh(&cfctrl->info_list_lock);
 495                        req = cfctrl_remove_req(cfctrl, &rsp);
 496
 497                        if (CFCTRL_ERR_BIT == (CFCTRL_ERR_BIT & cmdrsp) ||
 498                                cfpkt_erroneous(pkt)) {
 499                                pr_err("Invalid O/E bit or parse error "
 500                                                "on CAIF control channel\n");
 501                                cfctrl->res.reject_rsp(cfctrl->serv.layer.up,
 502                                                       0,
 503                                                       req ? req->client_layer
 504                                                       : NULL);
 505                        } else {
 506                                cfctrl->res.linksetup_rsp(cfctrl->serv.
 507                                                          layer.up, linkid,
 508                                                          serv, physlinkid,
 509                                                          req ? req->
 510                                                          client_layer : NULL);
 511                        }
 512
 513                        kfree(req);
 514
 515                        spin_unlock_bh(&cfctrl->info_list_lock);
 516                }
 517                break;
 518        case CFCTRL_CMD_LINK_DESTROY:
 519                linkid = cfpkt_extr_head_u8(pkt);
 520                cfctrl->res.linkdestroy_rsp(cfctrl->serv.layer.up, linkid);
 521                break;
 522        case CFCTRL_CMD_LINK_ERR:
 523                pr_err("Frame Error Indication received\n");
 524                cfctrl->res.linkerror_ind();
 525                break;
 526        case CFCTRL_CMD_ENUM:
 527                cfctrl->res.enum_rsp();
 528                break;
 529        case CFCTRL_CMD_SLEEP:
 530                cfctrl->res.sleep_rsp();
 531                break;
 532        case CFCTRL_CMD_WAKE:
 533                cfctrl->res.wake_rsp();
 534                break;
 535        case CFCTRL_CMD_LINK_RECONF:
 536                cfctrl->res.restart_rsp();
 537                break;
 538        case CFCTRL_CMD_RADIO_SET:
 539                cfctrl->res.radioset_rsp();
 540                break;
 541        default:
 542                pr_err("Unrecognized Control Frame\n");
 543                goto error;
 544        }
 545        ret = 0;
 546error:
 547        cfpkt_destroy(pkt);
 548        return ret;
 549}
 550
 551static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
 552                           int phyid)
 553{
 554        struct cfctrl *this = container_obj(layr);
 555        switch (ctrl) {
 556        case _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND:
 557        case CAIF_CTRLCMD_FLOW_OFF_IND:
 558                spin_lock_bh(&this->info_list_lock);
 559                if (!list_empty(&this->list))
 560                        pr_debug("Received flow off in control layer\n");
 561                spin_unlock_bh(&this->info_list_lock);
 562                break;
 563        case _CAIF_CTRLCMD_PHYIF_DOWN_IND: {
 564                struct cfctrl_request_info *p, *tmp;
 565
 566                /* Find all connect request and report failure */
 567                spin_lock_bh(&this->info_list_lock);
 568                list_for_each_entry_safe(p, tmp, &this->list, list) {
 569                        if (p->param.phyid == phyid) {
 570                                list_del(&p->list);
 571                                p->client_layer->ctrlcmd(p->client_layer,
 572                                                CAIF_CTRLCMD_INIT_FAIL_RSP,
 573                                                phyid);
 574                                kfree(p);
 575                        }
 576                }
 577                spin_unlock_bh(&this->info_list_lock);
 578                break;
 579        }
 580        default:
 581                break;
 582        }
 583}
 584
 585#ifndef CAIF_NO_LOOP
 586static int handle_loop(struct cfctrl *ctrl, int cmd, struct cfpkt *pkt)
 587{
 588        static int last_linkid;
 589        static int dec;
 590        u8 linkid, linktype, tmp;
 591        switch (cmd) {
 592        case CFCTRL_CMD_LINK_SETUP:
 593                spin_lock_bh(&ctrl->loop_linkid_lock);
 594                if (!dec) {
 595                        for (linkid = last_linkid + 1; linkid < 254; linkid++)
 596                                if (!ctrl->loop_linkused[linkid])
 597                                        goto found;
 598                }
 599                dec = 1;
 600                for (linkid = last_linkid - 1; linkid > 1; linkid--)
 601                        if (!ctrl->loop_linkused[linkid])
 602                                goto found;
 603                spin_unlock_bh(&ctrl->loop_linkid_lock);
 604                return -1;
 605found:
 606                if (linkid < 10)
 607                        dec = 0;
 608
 609                if (!ctrl->loop_linkused[linkid])
 610                        ctrl->loop_linkused[linkid] = 1;
 611
 612                last_linkid = linkid;
 613
 614                cfpkt_add_trail(pkt, &linkid, 1);
 615                spin_unlock_bh(&ctrl->loop_linkid_lock);
 616                cfpkt_peek_head(pkt, &linktype, 1);
 617                if (linktype ==  CFCTRL_SRV_UTIL) {
 618                        tmp = 0x01;
 619                        cfpkt_add_trail(pkt, &tmp, 1);
 620                        cfpkt_add_trail(pkt, &tmp, 1);
 621                }
 622                break;
 623
 624        case CFCTRL_CMD_LINK_DESTROY:
 625                spin_lock_bh(&ctrl->loop_linkid_lock);
 626                cfpkt_peek_head(pkt, &linkid, 1);
 627                ctrl->loop_linkused[linkid] = 0;
 628                spin_unlock_bh(&ctrl->loop_linkid_lock);
 629                break;
 630        default:
 631                break;
 632        }
 633        return 0;
 634}
 635#endif
 636