net/caif/cfcnfg.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/kernel.h>
  10 #include <linux/stddef.h>
  11 #include <linux/slab.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/module.h>
  14 #include <net/caif/caif_layer.h>
  15 #include <net/caif/cfpkt.h>
  16 #include <net/caif/cfcnfg.h>
  17 #include <net/caif/cfctrl.h>
  18 #include <net/caif/cfmuxl.h>
  19 #include <net/caif/cffrml.h>
  20 #include <net/caif/cfserl.h>
  21 #include <net/caif/cfsrvl.h>
  22 #include <net/caif/caif_dev.h>
  23
  24 #define container_obj(layr) container_of(layr, struct cfcnfg, layer)
  25
  26 /* Information about CAIF physical interfaces held by Config Module in order
  27  * to manage physical interfaces
  28  */
  29 struct cfcnfg_phyinfo {
  30         struct list_head node;
  31         bool up;
  32
  33         /* Pointer to the layer below the MUX (framing layer) */
  34         struct cflayer *frm_layer;
  35         /* Pointer to the lowest actual physical layer */
  36         struct cflayer *phy_layer;
  37         /* Unique identifier of the physical interface */
  38         unsigned int id;
  39         /* Preference of the physical in interface */
  40         enum cfcnfg_phy_preference pref;
  41
  42         /* Information about the physical device */
  43         struct dev_info dev_info;
  44
  45         /* Interface index */
  46         int ifindex;
  47
  48         /* Use Start of frame extension */
  49         bool use_stx;
  50
  51         /* Use Start of frame checksum */
  52         bool use_fcs;
  53 };
  54
  55 struct cfcnfg {
  56         struct cflayer layer;
  57         struct cflayer *ctrl;
  58         struct cflayer *mux;
  59         struct list_head phys;
  60         struct mutex lock;
  61 };
  62
  63 static void cfcnfg_linkup_rsp(struct cflayer *layer, u8 channel_id,
  64                              enum cfctrl_srv serv, u8 phyid,
  65                              struct cflayer *adapt_layer);
  66 static void cfcnfg_linkdestroy_rsp(struct cflayer *layer, u8 channel_id);
  67 static void cfcnfg_reject_rsp(struct cflayer *layer, u8 channel_id,
  68                              struct cflayer *adapt_layer);
  69 static void cfctrl_resp_func(void);
  70 static void cfctrl_enum_resp(void);
  71
  72 struct cfcnfg *cfcnfg_create(void)
  73 {
  74         struct cfcnfg *this;
  75         struct cfctrl_rsp *resp;
  76
  77         might_sleep();
  78
  79         /* Initiate this layer */
  80         this = kzalloc(sizeof(struct cfcnfg), GFP_ATOMIC);
  81         if (!this) {
  82                 pr_warn("Out of memory\n");
  83                 return NULL;
  84         }
  85         this->mux = cfmuxl_create();
  86         if (!this->mux)
  87                 goto out_of_mem;
  88         this->ctrl = cfctrl_create();
  89         if (!this->ctrl)
  90                 goto out_of_mem;
  91         /* Initiate response functions */
  92         resp = cfctrl_get_respfuncs(this->ctrl);
  93         resp->enum_rsp = cfctrl_enum_resp;
  94         resp->linkerror_ind = cfctrl_resp_func;
  95         resp->linkdestroy_rsp = cfcnfg_linkdestroy_rsp;
  96         resp->sleep_rsp = cfctrl_resp_func;
  97         resp->wake_rsp = cfctrl_resp_func;
  98         resp->restart_rsp = cfctrl_resp_func;
  99         resp->radioset_rsp = cfctrl_resp_func;
 100         resp->linksetup_rsp = cfcnfg_linkup_rsp;
 101         resp->reject_rsp = cfcnfg_reject_rsp;
 102         INIT_LIST_HEAD(&this->phys);
 103
 104         cfmuxl_set_uplayer(this->mux, this->ctrl, 0);
 105         layer_set_dn(this->ctrl, this->mux);
 106         layer_set_up(this->ctrl, this);
 107         mutex_init(&this->lock);
 108
 109         return this;
 110 out_of_mem:
 111         pr_warn("Out of memory\n");
 112
 113         synchronize_rcu();
 114
 115         kfree(this->mux);
 116         kfree(this->ctrl);
 117         kfree(this);
 118         return NULL;
 119 }
 120
 121 void cfcnfg_remove(struct cfcnfg *cfg)
 122 {
 123         might_sleep();
 124         if (cfg) {
 125                 synchronize_rcu();
 126
 127                 kfree(cfg->mux);
 128                 cfctrl_remove(cfg->ctrl);
 129                 kfree(cfg);
 130         }
 131 }
 132
 133 static void cfctrl_resp_func(void)
 134 {
 135 }
 136
 137 static struct cfcnfg_phyinfo *cfcnfg_get_phyinfo_rcu(struct cfcnfg *cnfg,
 138                                                         u8 phyid)
 139 {
 140         struct cfcnfg_phyinfo *phy;
 141
 142         list_for_each_entry_rcu(phy, &cnfg->phys, node)
 143                 if (phy->id == phyid)
 144                         return phy;
 145         return NULL;
 146 }
 147
 148 static void cfctrl_enum_resp(void)
 149 {
 150 }
 151
 152 static struct dev_info *cfcnfg_get_phyid(struct cfcnfg *cnfg,
 153                                   enum cfcnfg_phy_preference phy_pref)
 154 {
 155         /* Try to match with specified preference */
 156         struct cfcnfg_phyinfo *phy;
 157
 158         list_for_each_entry_rcu(phy, &cnfg->phys, node) {
 159                 if (phy->up && phy->pref == phy_pref &&
 160                                 phy->frm_layer != NULL)
 161
 162                         return &phy->dev_info;
 163         }
 164
 165         /* Otherwise just return something */
 166         list_for_each_entry_rcu(phy, &cnfg->phys, node)
 167                 if (phy->up)
 168                         return &phy->dev_info;
 169
 170         return NULL;
 171 }
 172
 173 static int cfcnfg_get_id_from_ifi(struct cfcnfg *cnfg, int ifi)
 174 {
 175         struct cfcnfg_phyinfo *phy;
 176
 177         list_for_each_entry_rcu(phy, &cnfg->phys, node)
 178                 if (phy->ifindex == ifi && phy->up)
 179                         return phy->id;
 180         return -ENODEV;
 181 }
 182
 183 int caif_disconnect_client(struct net *net, struct cflayer *adap_layer)
 184 {
 185         u8 channel_id;
 186         struct cfcnfg *cfg = get_cfcnfg(net);
 187
 188         caif_assert(adap_layer != NULL);
 189         cfctrl_cancel_req(cfg->ctrl, adap_layer);
 190         channel_id = adap_layer->id;
 191         if (channel_id != 0) {
 192                 struct cflayer *servl;
 193                 servl = cfmuxl_remove_uplayer(cfg->mux, channel_id);
 194                 if (servl != NULL)
 195                         layer_set_up(servl, NULL);
 196         } else
 197                 pr_debug("nothing to disconnect\n");
 198         cfctrl_linkdown_req(cfg->ctrl, channel_id, adap_layer);
 199
 200         /* Do RCU sync before initiating cleanup */
 201         synchronize_rcu();
 202         if (adap_layer->ctrlcmd != NULL)
 203                 adap_layer->ctrlcmd(adap_layer, CAIF_CTRLCMD_DEINIT_RSP, 0);
 204         return 0;
 205
 206 }
 207 EXPORT_SYMBOL(caif_disconnect_client);
 208
 209 static void cfcnfg_linkdestroy_rsp(struct cflayer *layer, u8 channel_id)
 210 {
 211 }
 212
 213 static const int protohead[CFCTRL_SRV_MASK] = {
 214         [CFCTRL_SRV_VEI] = 4,
 215         [CFCTRL_SRV_DATAGRAM] = 7,
 216         [CFCTRL_SRV_UTIL] = 4,
 217         [CFCTRL_SRV_RFM] = 3,
 218         [CFCTRL_SRV_DBG] = 3,
 219 };
 220
 221
 222 static int caif_connect_req_to_link_param(struct cfcnfg *cnfg,
 223                                    struct caif_connect_request *s,
 224                                    struct cfctrl_link_param *l)
 225 {
 226         struct dev_info *dev_info;
 227         enum cfcnfg_phy_preference pref;
 228         int res;
 229
 230         memset(l, 0, sizeof(*l));
 231         /* In caif protocol low value is high priority */
 232         l->priority = CAIF_PRIO_MAX - s->priority + 1;
 233
 234         if (s->ifindex != 0) {
 235                 res = cfcnfg_get_id_from_ifi(cnfg, s->ifindex);
 236                 if (res < 0)
 237                         return res;
 238                 l->phyid = res;
 239         } else {
 240                 switch (s->link_selector) {
 241                 case CAIF_LINK_HIGH_BANDW:
 242                         pref = CFPHYPREF_HIGH_BW;
 243                         break;
 244                 case CAIF_LINK_LOW_LATENCY:
 245                         pref = CFPHYPREF_LOW_LAT;
 246                         break;
 247                 default:
 248                         return -EINVAL;
 249                 }
 250                 dev_info = cfcnfg_get_phyid(cnfg, pref);
 251                 if (dev_info == NULL)
 252                         return -ENODEV;
 253                 l->phyid = dev_info->id;
 254         }
 255         switch (s->protocol) {
 256         case CAIFPROTO_AT:
 257                 l->linktype = CFCTRL_SRV_VEI;
 258                 l->endpoint = (s->sockaddr.u.at.type >> 2) & 0x3;
 259                 l->chtype = s->sockaddr.u.at.type & 0x3;
 260                 break;
 261         case CAIFPROTO_DATAGRAM:
 262                 l->linktype = CFCTRL_SRV_DATAGRAM;
 263                 l->chtype = 0x00;
 264                 l->u.datagram.connid = s->sockaddr.u.dgm.connection_id;
 265                 break;
 266         case CAIFPROTO_DATAGRAM_LOOP:
 267                 l->linktype = CFCTRL_SRV_DATAGRAM;
 268                 l->chtype = 0x03;
 269                 l->endpoint = 0x00;
 270                 l->u.datagram.connid = s->sockaddr.u.dgm.connection_id;
 271                 break;
 272         case CAIFPROTO_RFM:
 273                 l->linktype = CFCTRL_SRV_RFM;
 274                 l->u.datagram.connid = s->sockaddr.u.rfm.connection_id;
 275                 strncpy(l->u.rfm.volume, s->sockaddr.u.rfm.volume,
 276                         sizeof(l->u.rfm.volume)-1);
 277                 l->u.rfm.volume[sizeof(l->u.rfm.volume)-1] = 0;
 278                 break;
 279         case CAIFPROTO_UTIL:
 280                 l->linktype = CFCTRL_SRV_UTIL;
 281                 l->endpoint = 0x00;
 282                 l->chtype = 0x00;
 283                 strncpy(l->u.utility.name, s->sockaddr.u.util.service,
 284                         sizeof(l->u.utility.name)-1);
 285                 l->u.utility.name[sizeof(l->u.utility.name)-1] = 0;
 286                 caif_assert(sizeof(l->u.utility.name) > 10);
 287                 l->u.utility.paramlen = s->param.size;
 288                 if (l->u.utility.paramlen > sizeof(l->u.utility.params))
 289                         l->u.utility.paramlen = sizeof(l->u.utility.params);
 290
 291                 memcpy(l->u.utility.params, s->param.data,
 292                        l->u.utility.paramlen);
 293
 294                 break;
 295         case CAIFPROTO_DEBUG:
 296                 l->linktype = CFCTRL_SRV_DBG;
 297                 l->endpoint = s->sockaddr.u.dbg.service;
 298                 l->chtype = s->sockaddr.u.dbg.type;
 299                 break;
 300         default:
 301                 return -EINVAL;
 302         }
 303         return 0;
 304 }
 305
 306 int caif_connect_client(struct net *net, struct caif_connect_request *conn_req,
 307                         struct cflayer *adap_layer, int *ifindex,
 308                                 int *proto_head,
 309                                 int *proto_tail)
 310 {
 311         struct cflayer *frml;
 312         struct cfcnfg_phyinfo *phy;
 313         int err;
 314         struct cfctrl_link_param param;
 315         struct cfcnfg *cfg = get_cfcnfg(net);
 316
 317         rcu_read_lock();
 318         err = caif_connect_req_to_link_param(cfg, conn_req, &param);
 319         if (err)
 320                 goto unlock;
 321
 322         phy = cfcnfg_get_phyinfo_rcu(cfg, param.phyid);
 323         if (!phy) {
 324                 err = -ENODEV;
 325                 goto unlock;
 326         }
 327         err = -EINVAL;
 328
 329         if (adap_layer == NULL) {
 330                 pr_err("adap_layer is zero\n");
 331                 goto unlock;
 332         }
 333         if (adap_layer->receive == NULL) {
 334                 pr_err("adap_layer->receive is NULL\n");
 335                 goto unlock;
 336         }
 337         if (adap_layer->ctrlcmd == NULL) {
 338                 pr_err("adap_layer->ctrlcmd == NULL\n");
 339                 goto unlock;
 340         }
 341
 342         err = -ENODEV;
 343         frml = phy->frm_layer;
 344         if (frml == NULL) {
 345                 pr_err("Specified PHY type does not exist!\n");
 346                 goto unlock;
 347         }
 348         caif_assert(param.phyid == phy->id);
 349         caif_assert(phy->frm_layer->id ==
 350                      param.phyid);
 351         caif_assert(phy->phy_layer->id ==
 352                      param.phyid);
 353
 354         *ifindex = phy->ifindex;
 355         *proto_tail = 2;
 356         *proto_head =
 357
 358         protohead[param.linktype] + (phy->use_stx ? 1 : 0);
 359
 360         rcu_read_unlock();
 361
 362         /* FIXME: ENUMERATE INITIALLY WHEN ACTIVATING PHYSICAL INTERFACE */
 363         cfctrl_enum_req(cfg->ctrl, param.phyid);
 364         return cfctrl_linkup_request(cfg->ctrl, &param, adap_layer);
 365
 366 unlock:
 367         rcu_read_unlock();
 368         return err;
 369 }
 370 EXPORT_SYMBOL(caif_connect_client);
 371
 372 static void cfcnfg_reject_rsp(struct cflayer *layer, u8 channel_id,
 373                              struct cflayer *adapt_layer)
 374 {
 375         if (adapt_layer != NULL && adapt_layer->ctrlcmd != NULL)
 376                 adapt_layer->ctrlcmd(adapt_layer,
 377                                      CAIF_CTRLCMD_INIT_FAIL_RSP, 0);
 378 }
 379
 380 static void
 381 cfcnfg_linkup_rsp(struct cflayer *layer, u8 channel_id, enum cfctrl_srv serv,
 382                   u8 phyid, struct cflayer *adapt_layer)
 383 {
 384         struct cfcnfg *cnfg = container_obj(layer);
 385         struct cflayer *servicel = NULL;
 386         struct cfcnfg_phyinfo *phyinfo;
 387         struct net_device *netdev;
 388
 389         if (channel_id == 0) {
 390                 pr_warn("received channel_id zero\n");
 391                 if (adapt_layer != NULL && adapt_layer->ctrlcmd != NULL)
 392                         adapt_layer->ctrlcmd(adapt_layer,
 393                                                 CAIF_CTRLCMD_INIT_FAIL_RSP, 0);
 394                 return;
 395         }
 396
 397         rcu_read_lock();
 398
 399         if (adapt_layer == NULL) {
 400                 pr_debug("link setup response but no client exist,"
 401                                 "send linkdown back\n");
 402                 cfctrl_linkdown_req(cnfg->ctrl, channel_id, NULL);
 403                 goto unlock;
 404         }
 405
 406         caif_assert(cnfg != NULL);
 407         caif_assert(phyid != 0);
 408
 409         phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phyid);
 410         if (phyinfo == NULL) {
 411                 pr_err("ERROR: Link Layer Device dissapeared"
 412                                 "while connecting\n");
 413                 goto unlock;
 414         }
 415
 416         caif_assert(phyinfo != NULL);
 417         caif_assert(phyinfo->id == phyid);
 418         caif_assert(phyinfo->phy_layer != NULL);
 419         caif_assert(phyinfo->phy_layer->id == phyid);
 420
 421         adapt_layer->id = channel_id;
 422
 423         switch (serv) {
 424         case CFCTRL_SRV_VEI:
 425                 servicel = cfvei_create(channel_id, &phyinfo->dev_info);
 426                 break;
 427         case CFCTRL_SRV_DATAGRAM:
 428                 servicel = cfdgml_create(channel_id,
 429                                         &phyinfo->dev_info);
 430                 break;
 431         case CFCTRL_SRV_RFM:
 432                 netdev = phyinfo->dev_info.dev;
 433                 servicel = cfrfml_create(channel_id, &phyinfo->dev_info,
 434                                                 netdev->mtu);
 435                 break;
 436         case CFCTRL_SRV_UTIL:
 437                 servicel = cfutill_create(channel_id, &phyinfo->dev_info);
 438                 break;
 439         case CFCTRL_SRV_VIDEO:
 440                 servicel = cfvidl_create(channel_id, &phyinfo->dev_info);
 441                 break;
 442         case CFCTRL_SRV_DBG:
 443                 servicel = cfdbgl_create(channel_id, &phyinfo->dev_info);
 444                 break;
 445         default:
 446                 pr_err("Protocol error. Link setup response "
 447                                 "- unknown channel type\n");
 448                 goto unlock;
 449         }
 450         if (!servicel) {
 451                 pr_warn("Out of memory\n");
 452                 goto unlock;
 453         }
 454         layer_set_dn(servicel, cnfg->mux);
 455         cfmuxl_set_uplayer(cnfg->mux, servicel, channel_id);
 456         layer_set_up(servicel, adapt_layer);
 457         layer_set_dn(adapt_layer, servicel);
 458
 459         rcu_read_unlock();
 460
 461         servicel->ctrlcmd(servicel, CAIF_CTRLCMD_INIT_RSP, 0);
 462         return;
 463 unlock:
 464         rcu_read_unlock();
 465 }
 466
 467 void
 468 cfcnfg_add_phy_layer(struct cfcnfg *cnfg, enum cfcnfg_phy_type phy_type,
 469                      struct net_device *dev, struct cflayer *phy_layer,
 470                      enum cfcnfg_phy_preference pref,
 471                      bool fcs, bool stx)
 472 {
 473         struct cflayer *frml;
 474         struct cflayer *phy_driver = NULL;
 475         struct cfcnfg_phyinfo *phyinfo;
 476         int i;
 477         u8 phyid;
 478
 479         mutex_lock(&cnfg->lock);
 480
 481         /* CAIF protocol allow maximum 6 link-layers */
 482         for (i = 0; i < 7; i++) {
 483                 phyid = (dev->ifindex + i) & 0x7;
 484                 if (phyid == 0)
 485                         continue;
 486                 if (cfcnfg_get_phyinfo_rcu(cnfg, phyid) == NULL)
 487                         goto got_phyid;
 488         }
 489         pr_warn("Too many CAIF Link Layers (max 6)\n");
 490         goto out;
 491
 492 got_phyid:
 493         phyinfo = kzalloc(sizeof(struct cfcnfg_phyinfo), GFP_ATOMIC);
 494
 495         switch (phy_type) {
 496         case CFPHYTYPE_FRAG:
 497                 phy_driver =
 498                     cfserl_create(CFPHYTYPE_FRAG, phyid, stx);
 499                 if (!phy_driver) {
 500                         pr_warn("Out of memory\n");
 501                         goto out;
 502                 }
 503                 break;
 504         case CFPHYTYPE_CAIF:
 505                 phy_driver = NULL;
 506                 break;
 507         default:
 508                 goto out;
 509         }
 510         phy_layer->id = phyid;
 511         phyinfo->pref = pref;
 512         phyinfo->id = phyid;
 513         phyinfo->dev_info.id = phyid;
 514         phyinfo->dev_info.dev = dev;
 515         phyinfo->phy_layer = phy_layer;
 516         phyinfo->ifindex = dev->ifindex;
 517         phyinfo->use_stx = stx;
 518         phyinfo->use_fcs = fcs;
 519
 520         frml = cffrml_create(phyid, fcs);
 521
 522         if (!frml) {
 523                 pr_warn("Out of memory\n");
 524                 kfree(phyinfo);
 525                 goto out;
 526         }
 527         phyinfo->frm_layer = frml;
 528         layer_set_up(frml, cnfg->mux);
 529
 530         if (phy_driver != NULL) {
 531                 phy_driver->id = phyid;
 532                 layer_set_dn(frml, phy_driver);
 533                 layer_set_up(phy_driver, frml);
 534                 layer_set_dn(phy_driver, phy_layer);
 535                 layer_set_up(phy_layer, phy_driver);
 536         } else {
 537                 layer_set_dn(frml, phy_layer);
 538                 layer_set_up(phy_layer, frml);
 539         }
 540
 541         list_add_rcu(&phyinfo->node, &cnfg->phys);
 542 out:
 543         mutex_unlock(&cnfg->lock);
 544 }
 545 EXPORT_SYMBOL(cfcnfg_add_phy_layer);
 546
 547 int cfcnfg_set_phy_state(struct cfcnfg *cnfg, struct cflayer *phy_layer,
 548                 bool up)
 549 {
 550         struct cfcnfg_phyinfo *phyinfo;
 551
 552         rcu_read_lock();
 553         phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phy_layer->id);
 554         if (phyinfo == NULL) {
 555                 rcu_read_unlock();
 556                 return -ENODEV;
 557         }
 558
 559         if (phyinfo->up == up) {
 560                 rcu_read_unlock();
 561                 return 0;
 562         }
 563         phyinfo->up = up;
 564
 565         if (up) {
 566                 cffrml_hold(phyinfo->frm_layer);
 567                 cfmuxl_set_dnlayer(cnfg->mux, phyinfo->frm_layer,
 568                                         phy_layer->id);
 569         } else {
 570                 cfmuxl_remove_dnlayer(cnfg->mux, phy_layer->id);
 571                 cffrml_put(phyinfo->frm_layer);
 572         }
 573
 574         rcu_read_unlock();
 575         return 0;
 576 }
 577 EXPORT_SYMBOL(cfcnfg_set_phy_state);
 578
 579 int cfcnfg_del_phy_layer(struct cfcnfg *cnfg, struct cflayer *phy_layer)
 580 {
 581         struct cflayer *frml, *frml_dn;
 582         u16 phyid;
 583         struct cfcnfg_phyinfo *phyinfo;
 584
 585         might_sleep();
 586
 587         mutex_lock(&cnfg->lock);
 588
 589         phyid = phy_layer->id;
 590         phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phyid);
 591
 592         if (phyinfo == NULL) {
 593                 mutex_unlock(&cnfg->lock);
 594                 return 0;
 595         }
 596         caif_assert(phyid == phyinfo->id);
 597         caif_assert(phy_layer == phyinfo->phy_layer);
 598         caif_assert(phy_layer->id == phyid);
 599         caif_assert(phyinfo->frm_layer->id == phyid);
 600
 601         list_del_rcu(&phyinfo->node);
 602         synchronize_rcu();
 603
 604         /* Fail if reference count is not zero */
 605         if (cffrml_refcnt_read(phyinfo->frm_layer) != 0) {
 606                 pr_info("Wait for device inuse\n");
 607                 list_add_rcu(&phyinfo->node, &cnfg->phys);
 608                 mutex_unlock(&cnfg->lock);
 609                 return -EAGAIN;
 610         }
 611
 612         frml = phyinfo->frm_layer;
 613         frml_dn = frml->dn;
 614         cffrml_set_uplayer(frml, NULL);
 615         cffrml_set_dnlayer(frml, NULL);
 616         if (phy_layer != frml_dn) {
 617                 layer_set_up(frml_dn, NULL);
 618                 layer_set_dn(frml_dn, NULL);
 619         }
 620         layer_set_up(phy_layer, NULL);
 621
 622         if (phyinfo->phy_layer != frml_dn)
 623                 kfree(frml_dn);
 624
 625         cffrml_free(frml);
 626         kfree(phyinfo);
 627         mutex_unlock(&cnfg->lock);
 628
 629         return 0;
 630 }
 631 EXPORT_SYMBOL(cfcnfg_del_phy_layer);