net/caif/cfctrl.c

   1 /*
   2  * Copyright (C) ST-Ericsson AB 2010
   3  * Author:      Sjur Brendeland/sjur.brandeland@stericsson.com
   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 <net/caif/caif_layer.h>
  13 #include <net/caif/cfpkt.h>
  14 #include <net/caif/cfctrl.h>
  15
  16 #define container_obj(layr) container_of(layr, struct cfctrl, serv.layer)
  17 #define UTILITY_NAME_LENGTH 16
  18 #define CFPKT_CTRL_PKT_LEN 20
  19
  20
  21 #ifdef CAIF_NO_LOOP
  22 static int handle_loop(struct cfctrl *ctrl,
  23                               int cmd, struct cfpkt *pkt){
  24         return -1;
  25 }
  26 #else
  27 static int handle_loop(struct cfctrl *ctrl,
  28                 int cmd, struct cfpkt *pkt);
  29 #endif
  30 static int cfctrl_recv(struct cflayer *layr, struct cfpkt *pkt);
  31 static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
  32                            int phyid);
  33
  34
  35 struct cflayer *cfctrl_create(void)
  36 {
  37         struct dev_info dev_info;
  38         struct cfctrl *this =
  39                 kmalloc(sizeof(struct cfctrl), GFP_ATOMIC);
  40         if (!this) {
  41                 pr_warn("Out of memory\n");
  42                 return NULL;
  43         }
  44         caif_assert(offsetof(struct cfctrl, serv.layer) == 0);
  45         memset(&dev_info, 0, sizeof(dev_info));
  46         dev_info.id = 0xff;
  47         memset(this, 0, sizeof(*this));
  48         cfsrvl_init(&this->serv, 0, &dev_info, false);
  49         atomic_set(&this->req_seq_no, 1);
  50         atomic_set(&this->rsp_seq_no, 1);
  51         this->serv.layer.receive = cfctrl_recv;
  52         sprintf(this->serv.layer.name, "ctrl");
  53         this->serv.layer.ctrlcmd = cfctrl_ctrlcmd;
  54         spin_lock_init(&this->loop_linkid_lock);
  55         spin_lock_init(&this->info_list_lock);
  56         INIT_LIST_HEAD(&this->list);
  57         this->loop_linkid = 1;
  58         return &this->serv.layer;
  59 }
  60
  61 static bool param_eq(struct cfctrl_link_param *p1, struct cfctrl_link_param *p2)
  62 {
  63         bool eq =
  64             p1->linktype == p2->linktype &&
  65             p1->priority == p2->priority &&
  66             p1->phyid == p2->phyid &&
  67             p1->endpoint == p2->endpoint && p1->chtype == p2->chtype;
  68
  69         if (!eq)
  70                 return false;
  71
  72         switch (p1->linktype) {
  73         case CFCTRL_SRV_VEI:
  74                 return true;
  75         case CFCTRL_SRV_DATAGRAM:
  76                 return p1->u.datagram.connid == p2->u.datagram.connid;
  77         case CFCTRL_SRV_RFM:
  78                 return
  79                     p1->u.rfm.connid == p2->u.rfm.connid &&
  80                     strcmp(p1->u.rfm.volume, p2->u.rfm.volume) == 0;
  81         case CFCTRL_SRV_UTIL:
  82                 return
  83                     p1->u.utility.fifosize_kb == p2->u.utility.fifosize_kb
  84                     && p1->u.utility.fifosize_bufs ==
  85                     p2->u.utility.fifosize_bufs
  86                     && strcmp(p1->u.utility.name, p2->u.utility.name) == 0
  87                     && p1->u.utility.paramlen == p2->u.utility.paramlen
  88                     && memcmp(p1->u.utility.params, p2->u.utility.params,
  89                               p1->u.utility.paramlen) == 0;
  90
  91         case CFCTRL_SRV_VIDEO:
  92                 return p1->u.video.connid == p2->u.video.connid;
  93         case CFCTRL_SRV_DBG:
  94                 return true;
  95         case CFCTRL_SRV_DECM:
  96                 return false;
  97         default:
  98                 return false;
  99         }
 100         return false;
 101 }
 102
 103 bool cfctrl_req_eq(struct cfctrl_request_info *r1,
 104                    struct cfctrl_request_info *r2)
 105 {
 106         if (r1->cmd != r2->cmd)
 107                 return false;
 108         if (r1->cmd == CFCTRL_CMD_LINK_SETUP)
 109                 return param_eq(&r1->param, &r2->param);
 110         else
 111                 return r1->channel_id == r2->channel_id;
 112 }
 113
 114 /* Insert request at the end */
 115 void cfctrl_insert_req(struct cfctrl *ctrl,
 116                               struct cfctrl_request_info *req)
 117 {
 118         spin_lock(&ctrl->info_list_lock);
 119         atomic_inc(&ctrl->req_seq_no);
 120         req->sequence_no = atomic_read(&ctrl->req_seq_no);
 121         list_add_tail(&req->list, &ctrl->list);
 122         spin_unlock(&ctrl->info_list_lock);
 123 }
 124
 125 /* Compare and remove request */
 126 struct cfctrl_request_info *cfctrl_remove_req(struct cfctrl *ctrl,
 127                                               struct cfctrl_request_info *req)
 128 {
 129         struct cfctrl_request_info *p, *tmp, *first;
 130
 131         spin_lock(&ctrl->info_list_lock);
 132         first = list_first_entry(&ctrl->list, struct cfctrl_request_info, list);
 133
 134         list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
 135                 if (cfctrl_req_eq(req, p)) {
 136                         if (p != first)
 137                                 pr_warn("Requests are not received in order\n");
 138
 139                         atomic_set(&ctrl->rsp_seq_no,
 140                                          p->sequence_no);
 141                         list_del(&p->list);
 142                         goto out;
 143                 }
 144         }
 145         p = NULL;
 146 out:
 147         spin_unlock(&ctrl->info_list_lock);
 148         return p;
 149 }
 150
 151 struct cfctrl_rsp *cfctrl_get_respfuncs(struct cflayer *layer)
 152 {
 153         struct cfctrl *this = container_obj(layer);
 154         return &this->res;
 155 }
 156
 157 void cfctrl_set_dnlayer(struct cflayer *this, struct cflayer *dn)
 158 {
 159         this->dn = dn;
 160 }
 161
 162 void cfctrl_set_uplayer(struct cflayer *this, struct cflayer *up)
 163 {
 164         this->up = up;
 165 }
 166
 167 static void init_info(struct caif_payload_info *info, struct cfctrl *cfctrl)
 168 {
 169         info->hdr_len = 0;
 170         info->channel_id = cfctrl->serv.layer.id;
 171         info->dev_info = &cfctrl->serv.dev_info;
 172 }
 173
 174 void cfctrl_enum_req(struct cflayer *layer, u8 physlinkid)
 175 {
 176         struct cfctrl *cfctrl = container_obj(layer);
 177         int ret;
 178         struct cfpkt *pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
 179         if (!pkt) {
 180                 pr_warn("Out of memory\n");
 181                 return;
 182         }
 183         caif_assert(offsetof(struct cfctrl, serv.layer) == 0);
 184         init_info(cfpkt_info(pkt), cfctrl);
 185         cfpkt_info(pkt)->dev_info->id = physlinkid;
 186         cfctrl->serv.dev_info.id = physlinkid;
 187         cfpkt_addbdy(pkt, CFCTRL_CMD_ENUM);
 188         cfpkt_addbdy(pkt, physlinkid);
 189         ret =
 190             cfctrl->serv.layer.dn->transmit(cfctrl->serv.layer.dn, pkt);
 191         if (ret < 0) {
 192                 pr_err("Could not transmit enum message\n");
 193                 cfpkt_destroy(pkt);
 194         }
 195 }
 196
 197 int cfctrl_linkup_request(struct cflayer *layer,
 198                            struct cfctrl_link_param *param,
 199                            struct cflayer *user_layer)
 200 {
 201         struct cfctrl *cfctrl = container_obj(layer);
 202         u32 tmp32;
 203         u16 tmp16;
 204         u8 tmp8;
 205         struct cfctrl_request_info *req;
 206         int ret;
 207         char utility_name[16];
 208         struct cfpkt *pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
 209         if (!pkt) {
 210                 pr_warn("Out of memory\n");
 211                 return -ENOMEM;
 212         }
 213         cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_SETUP);
 214         cfpkt_addbdy(pkt, (param->chtype << 4) + param->linktype);
 215         cfpkt_addbdy(pkt, (param->priority << 3) + param->phyid);
 216         cfpkt_addbdy(pkt, param->endpoint & 0x03);
 217
 218         switch (param->linktype) {
 219         case CFCTRL_SRV_VEI:
 220                 break;
 221         case CFCTRL_SRV_VIDEO:
 222                 cfpkt_addbdy(pkt, (u8) param->u.video.connid);
 223                 break;
 224         case CFCTRL_SRV_DBG:
 225                 break;
 226         case CFCTRL_SRV_DATAGRAM:
 227                 tmp32 = cpu_to_le32(param->u.datagram.connid);
 228                 cfpkt_add_body(pkt, &tmp32, 4);
 229                 break;
 230         case CFCTRL_SRV_RFM:
 231                 /* Construct a frame, convert DatagramConnectionID to network
 232                  * format long and copy it out...
 233                  */
 234                 tmp32 = cpu_to_le32(param->u.rfm.connid);
 235                 cfpkt_add_body(pkt, &tmp32, 4);
 236                 /* Add volume name, including zero termination... */
 237                 cfpkt_add_body(pkt, param->u.rfm.volume,
 238                                strlen(param->u.rfm.volume) + 1);
 239                 break;
 240         case CFCTRL_SRV_UTIL:
 241                 tmp16 = cpu_to_le16(param->u.utility.fifosize_kb);
 242                 cfpkt_add_body(pkt, &tmp16, 2);
 243                 tmp16 = cpu_to_le16(param->u.utility.fifosize_bufs);
 244                 cfpkt_add_body(pkt, &tmp16, 2);
 245                 memset(utility_name, 0, sizeof(utility_name));
 246                 strncpy(utility_name, param->u.utility.name,
 247                         UTILITY_NAME_LENGTH - 1);
 248                 cfpkt_add_body(pkt, utility_name, UTILITY_NAME_LENGTH);
 249                 tmp8 = param->u.utility.paramlen;
 250                 cfpkt_add_body(pkt, &tmp8, 1);
 251                 cfpkt_add_body(pkt, param->u.utility.params,
 252                                param->u.utility.paramlen);
 253                 break;
 254         default:
 255                 pr_warn("Request setup of bad link type = %d\n",
 256                         param->linktype);
 257                 return -EINVAL;
 258         }
 259         req = kzalloc(sizeof(*req), GFP_KERNEL);
 260         if (!req) {
 261                 pr_warn("Out of memory\n");
 262                 return -ENOMEM;
 263         }
 264         req->client_layer = user_layer;
 265         req->cmd = CFCTRL_CMD_LINK_SETUP;
 266         req->param = *param;
 267         cfctrl_insert_req(cfctrl, req);
 268         init_info(cfpkt_info(pkt), cfctrl);
 269         /*
 270          * NOTE:Always send linkup and linkdown request on the same
 271          *      device as the payload. Otherwise old queued up payload
 272          *      might arrive with the newly allocated channel ID.
 273          */
 274         cfpkt_info(pkt)->dev_info->id = param->phyid;
 275         ret =
 276             cfctrl->serv.layer.dn->transmit(cfctrl->serv.layer.dn, pkt);
 277         if (ret < 0) {
 278                 pr_err("Could not transmit linksetup request\n");
 279                 cfpkt_destroy(pkt);
 280                 return -ENODEV;
 281         }
 282         return 0;
 283 }
 284
 285 int cfctrl_linkdown_req(struct cflayer *layer, u8 channelid,
 286                                 struct cflayer *client)
 287 {
 288         int ret;
 289         struct cfctrl *cfctrl = container_obj(layer);
 290         struct cfpkt *pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
 291         if (!pkt) {
 292                 pr_warn("Out of memory\n");
 293                 return -ENOMEM;
 294         }
 295         cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_DESTROY);
 296         cfpkt_addbdy(pkt, channelid);
 297         init_info(cfpkt_info(pkt), cfctrl);
 298         ret =
 299             cfctrl->serv.layer.dn->transmit(cfctrl->serv.layer.dn, pkt);
 300         if (ret < 0) {
 301                 pr_err("Could not transmit link-down request\n");
 302                 cfpkt_destroy(pkt);
 303         }
 304         return ret;
 305 }
 306
 307 void cfctrl_sleep_req(struct cflayer *layer)
 308 {
 309         int ret;
 310         struct cfctrl *cfctrl = container_obj(layer);
 311         struct cfpkt *pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
 312         if (!pkt) {
 313                 pr_warn("Out of memory\n");
 314                 return;
 315         }
 316         cfpkt_addbdy(pkt, CFCTRL_CMD_SLEEP);
 317         init_info(cfpkt_info(pkt), cfctrl);
 318         ret =
 319             cfctrl->serv.layer.dn->transmit(cfctrl->serv.layer.dn, pkt);
 320         if (ret < 0)
 321                 cfpkt_destroy(pkt);
 322 }
 323
 324 void cfctrl_wake_req(struct cflayer *layer)
 325 {
 326         int ret;
 327         struct cfctrl *cfctrl = container_obj(layer);
 328         struct cfpkt *pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
 329         if (!pkt) {
 330                 pr_warn("Out of memory\n");
 331                 return;
 332         }
 333         cfpkt_addbdy(pkt, CFCTRL_CMD_WAKE);
 334         init_info(cfpkt_info(pkt), cfctrl);
 335         ret =
 336             cfctrl->serv.layer.dn->transmit(cfctrl->serv.layer.dn, pkt);
 337         if (ret < 0)
 338                 cfpkt_destroy(pkt);
 339 }
 340
 341 void cfctrl_getstartreason_req(struct cflayer *layer)
 342 {
 343         int ret;
 344         struct cfctrl *cfctrl = container_obj(layer);
 345         struct cfpkt *pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
 346         if (!pkt) {
 347                 pr_warn("Out of memory\n");
 348                 return;
 349         }
 350         cfpkt_addbdy(pkt, CFCTRL_CMD_START_REASON);
 351         init_info(cfpkt_info(pkt), cfctrl);
 352         ret =
 353             cfctrl->serv.layer.dn->transmit(cfctrl->serv.layer.dn, pkt);
 354         if (ret < 0)
 355                 cfpkt_destroy(pkt);
 356 }
 357
 358
 359 void cfctrl_cancel_req(struct cflayer *layr, struct cflayer *adap_layer)
 360 {
 361         struct cfctrl_request_info *p, *tmp;
 362         struct cfctrl *ctrl = container_obj(layr);
 363         spin_lock(&ctrl->info_list_lock);
 364         pr_warn("enter\n");
 365
 366         list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
 367                 if (p->client_layer == adap_layer) {
 368                         pr_warn("cancel req :%d\n", p->sequence_no);
 369                         list_del(&p->list);
 370                         kfree(p);
 371                 }
 372         }
 373
 374         spin_unlock(&ctrl->info_list_lock);
 375 }
 376
 377 static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
 378 {
 379         u8 cmdrsp;
 380         u8 cmd;
 381         int ret = -1;
 382         u16 tmp16;
 383         u8 len;
 384         u8 param[255];
 385         u8 linkid;
 386         struct cfctrl *cfctrl = container_obj(layer);
 387         struct cfctrl_request_info rsp, *req;
 388
 389
 390         cfpkt_extr_head(pkt, &cmdrsp, 1);
 391         cmd = cmdrsp & CFCTRL_CMD_MASK;
 392         if (cmd != CFCTRL_CMD_LINK_ERR
 393             && CFCTRL_RSP_BIT != (CFCTRL_RSP_BIT & cmdrsp)) {
 394                 if (handle_loop(cfctrl, cmd, pkt) != 0)
 395                         cmdrsp |= CFCTRL_ERR_BIT;
 396         }
 397
 398         switch (cmd) {
 399         case CFCTRL_CMD_LINK_SETUP:
 400                 {
 401                         enum cfctrl_srv serv;
 402                         enum cfctrl_srv servtype;
 403                         u8 endpoint;
 404                         u8 physlinkid;
 405                         u8 prio;
 406                         u8 tmp;
 407                         u32 tmp32;
 408                         u8 *cp;
 409                         int i;
 410                         struct cfctrl_link_param linkparam;
 411                         memset(&linkparam, 0, sizeof(linkparam));
 412
 413                         cfpkt_extr_head(pkt, &tmp, 1);
 414
 415                         serv = tmp & CFCTRL_SRV_MASK;
 416                         linkparam.linktype = serv;
 417
 418                         servtype = tmp >> 4;
 419                         linkparam.chtype = servtype;
 420
 421                         cfpkt_extr_head(pkt, &tmp, 1);
 422                         physlinkid = tmp & 0x07;
 423                         prio = tmp >> 3;
 424
 425                         linkparam.priority = prio;
 426                         linkparam.phyid = physlinkid;
 427                         cfpkt_extr_head(pkt, &endpoint, 1);
 428                         linkparam.endpoint = endpoint & 0x03;
 429
 430                         switch (serv) {
 431                         case CFCTRL_SRV_VEI:
 432                         case CFCTRL_SRV_DBG:
 433                                 if (CFCTRL_ERR_BIT & cmdrsp)
 434                                         break;
 435                                 /* Link ID */
 436                                 cfpkt_extr_head(pkt, &linkid, 1);
 437                                 break;
 438                         case CFCTRL_SRV_VIDEO:
 439                                 cfpkt_extr_head(pkt, &tmp, 1);
 440                                 linkparam.u.video.connid = tmp;
 441                                 if (CFCTRL_ERR_BIT & cmdrsp)
 442                                         break;
 443                                 /* Link ID */
 444                                 cfpkt_extr_head(pkt, &linkid, 1);
 445                                 break;
 446
 447                         case CFCTRL_SRV_DATAGRAM:
 448                                 cfpkt_extr_head(pkt, &tmp32, 4);
 449                                 linkparam.u.datagram.connid =
 450                                     le32_to_cpu(tmp32);
 451                                 if (CFCTRL_ERR_BIT & cmdrsp)
 452                                         break;
 453                                 /* Link ID */
 454                                 cfpkt_extr_head(pkt, &linkid, 1);
 455                                 break;
 456                         case CFCTRL_SRV_RFM:
 457                                 /* Construct a frame, convert
 458                                  * DatagramConnectionID
 459                                  * to network format long and copy it out...
 460                                  */
 461                                 cfpkt_extr_head(pkt, &tmp32, 4);
 462                                 linkparam.u.rfm.connid =
 463                                   le32_to_cpu(tmp32);
 464                                 cp = (u8 *) linkparam.u.rfm.volume;
 465                                 for (cfpkt_extr_head(pkt, &tmp, 1);
 466                                      cfpkt_more(pkt) && tmp != '\0';
 467                                      cfpkt_extr_head(pkt, &tmp, 1))
 468                                         *cp++ = tmp;
 469                                 *cp = '\0';
 470
 471                                 if (CFCTRL_ERR_BIT & cmdrsp)
 472                                         break;
 473                                 /* Link ID */
 474                                 cfpkt_extr_head(pkt, &linkid, 1);
 475
 476                                 break;
 477                         case CFCTRL_SRV_UTIL:
 478                                 /* Construct a frame, convert
 479                                  * DatagramConnectionID
 480                                  * to network format long and copy it out...
 481                                  */
 482                                 /* Fifosize KB */
 483                                 cfpkt_extr_head(pkt, &tmp16, 2);
 484                                 linkparam.u.utility.fifosize_kb =
 485                                     le16_to_cpu(tmp16);
 486                                 /* Fifosize bufs */
 487                                 cfpkt_extr_head(pkt, &tmp16, 2);
 488                                 linkparam.u.utility.fifosize_bufs =
 489                                     le16_to_cpu(tmp16);
 490                                 /* name */
 491                                 cp = (u8 *) linkparam.u.utility.name;
 492                                 caif_assert(sizeof(linkparam.u.utility.name)
 493                                              >= UTILITY_NAME_LENGTH);
 494                                 for (i = 0;
 495                                      i < UTILITY_NAME_LENGTH
 496                                      && cfpkt_more(pkt); i++) {
 497                                         cfpkt_extr_head(pkt, &tmp, 1);
 498                                         *cp++ = tmp;
 499                                 }
 500                                 /* Length */
 501                                 cfpkt_extr_head(pkt, &len, 1);
 502                                 linkparam.u.utility.paramlen = len;
 503                                 /* Param Data */
 504                                 cp = linkparam.u.utility.params;
 505                                 while (cfpkt_more(pkt) && len--) {
 506                                         cfpkt_extr_head(pkt, &tmp, 1);
 507                                         *cp++ = tmp;
 508                                 }
 509                                 if (CFCTRL_ERR_BIT & cmdrsp)
 510                                         break;
 511                                 /* Link ID */
 512                                 cfpkt_extr_head(pkt, &linkid, 1);
 513                                 /* Length */
 514                                 cfpkt_extr_head(pkt, &len, 1);
 515                                 /* Param Data */
 516                                 cfpkt_extr_head(pkt, &param, len);
 517                                 break;
 518                         default:
 519                                 pr_warn("Request setup - invalid link type (%d)\n",
 520                                         serv);
 521                                 goto error;
 522                         }
 523
 524                         rsp.cmd = cmd;
 525                         rsp.param = linkparam;
 526                         req = cfctrl_remove_req(cfctrl, &rsp);
 527
 528                         if (CFCTRL_ERR_BIT == (CFCTRL_ERR_BIT & cmdrsp) ||
 529                                 cfpkt_erroneous(pkt)) {
 530                                 pr_err("Invalid O/E bit or parse error on CAIF control channel\n");
 531                                 cfctrl->res.reject_rsp(cfctrl->serv.layer.up,
 532                                                        0,
 533                                                        req ? req->client_layer
 534                                                        : NULL);
 535                         } else {
 536                                 cfctrl->res.linksetup_rsp(cfctrl->serv.
 537                                                           layer.up, linkid,
 538                                                           serv, physlinkid,
 539                                                           req ? req->
 540                                                           client_layer : NULL);
 541                         }
 542
 543                         if (req != NULL)
 544                                 kfree(req);
 545                 }
 546                 break;
 547         case CFCTRL_CMD_LINK_DESTROY:
 548                 cfpkt_extr_head(pkt, &linkid, 1);
 549                 cfctrl->res.linkdestroy_rsp(cfctrl->serv.layer.up, linkid);
 550                 break;
 551         case CFCTRL_CMD_LINK_ERR:
 552                 pr_err("Frame Error Indication received\n");
 553                 cfctrl->res.linkerror_ind();
 554                 break;
 555         case CFCTRL_CMD_ENUM:
 556                 cfctrl->res.enum_rsp();
 557                 break;
 558         case CFCTRL_CMD_SLEEP:
 559                 cfctrl->res.sleep_rsp();
 560                 break;
 561         case CFCTRL_CMD_WAKE:
 562                 cfctrl->res.wake_rsp();
 563                 break;
 564         case CFCTRL_CMD_LINK_RECONF:
 565                 cfctrl->res.restart_rsp();
 566                 break;
 567         case CFCTRL_CMD_RADIO_SET:
 568                 cfctrl->res.radioset_rsp();
 569                 break;
 570         default:
 571                 pr_err("Unrecognized Control Frame\n");
 572                 goto error;
 573                 break;
 574         }
 575         ret = 0;
 576 error:
 577         cfpkt_destroy(pkt);
 578         return ret;
 579 }
 580
 581 static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
 582                         int phyid)
 583 {
 584         struct cfctrl *this = container_obj(layr);
 585         switch (ctrl) {
 586         case _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND:
 587         case CAIF_CTRLCMD_FLOW_OFF_IND:
 588                 spin_lock(&this->info_list_lock);
 589                 if (!list_empty(&this->list)) {
 590                         pr_debug("Received flow off in control layer\n");
 591                 }
 592                 spin_unlock(&this->info_list_lock);
 593                 break;
 594         default:
 595                 break;
 596         }
 597 }
 598
 599 #ifndef CAIF_NO_LOOP
 600 static int handle_loop(struct cfctrl *ctrl, int cmd, struct cfpkt *pkt)
 601 {
 602         static int last_linkid;
 603         u8 linkid, linktype, tmp;
 604         switch (cmd) {
 605         case CFCTRL_CMD_LINK_SETUP:
 606                 spin_lock(&ctrl->loop_linkid_lock);
 607                 for (linkid = last_linkid + 1; linkid < 255; linkid++)
 608                         if (!ctrl->loop_linkused[linkid])
 609                                 goto found;
 610                 for (linkid = last_linkid - 1; linkid > 0; linkid--)
 611                         if (!ctrl->loop_linkused[linkid])
 612                                 goto found;
 613                 spin_unlock(&ctrl->loop_linkid_lock);
 614                 pr_err("Out of link-ids\n");
 615                 return -EINVAL;
 616 found:
 617                 if (!ctrl->loop_linkused[linkid])
 618                         ctrl->loop_linkused[linkid] = 1;
 619
 620                 last_linkid = linkid;
 621
 622                 cfpkt_add_trail(pkt, &linkid, 1);
 623                 spin_unlock(&ctrl->loop_linkid_lock);
 624                 cfpkt_peek_head(pkt, &linktype, 1);
 625                 if (linktype ==  CFCTRL_SRV_UTIL) {
 626                         tmp = 0x01;
 627                         cfpkt_add_trail(pkt, &tmp, 1);
 628                         cfpkt_add_trail(pkt, &tmp, 1);
 629                 }
 630                 break;
 631
 632         case CFCTRL_CMD_LINK_DESTROY:
 633                 spin_lock(&ctrl->loop_linkid_lock);
 634                 cfpkt_peek_head(pkt, &linkid, 1);
 635                 ctrl->loop_linkused[linkid] = 0;
 636                 spin_unlock(&ctrl->loop_linkid_lock);
 637                 break;
 638         default:
 639                 break;
 640         }
 641         return 0;
 642 }
 643 #endif