xref: /linux/net/caif/cfctrl.c (revision 26b0d14106954ae46d2f4f7eec3481828a210f7d)
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 <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
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 		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 
60 void 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 
74 static 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 
117 static 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 */
129 static 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 */
140 static 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;
159 out:
160 	return p;
161 }
162 
163 struct cfctrl_rsp *cfctrl_get_respfuncs(struct cflayer *layer)
164 {
165 	struct cfctrl *this = container_obj(layer);
166 	return &this->res;
167 }
168 
169 static 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 
176 void cfctrl_enum_req(struct cflayer *layer, u8 physlinkid)
177 {
178 	struct cfctrl *cfctrl = container_obj(layer);
179 	struct cfpkt *pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
180 	struct cflayer *dn = cfctrl->serv.layer.dn;
181 	if (!pkt)
182 		return;
183 	if (!dn) {
184 		pr_debug("not able to send enum request\n");
185 		return;
186 	}
187 	caif_assert(offsetof(struct cfctrl, serv.layer) == 0);
188 	init_info(cfpkt_info(pkt), cfctrl);
189 	cfpkt_info(pkt)->dev_info->id = physlinkid;
190 	cfctrl->serv.dev_info.id = physlinkid;
191 	cfpkt_addbdy(pkt, CFCTRL_CMD_ENUM);
192 	cfpkt_addbdy(pkt, physlinkid);
193 	cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
194 	dn->transmit(dn, pkt);
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;
209 	struct cflayer *dn = cfctrl->serv.layer.dn;
210 
211 	if (!dn) {
212 		pr_debug("not able to send linkup request\n");
213 		return -ENODEV;
214 	}
215 
216 	if (cfctrl_cancel_req(layer, user_layer) > 0) {
217 		/* Slight Paranoia, check if already connecting */
218 		pr_err("Duplicate connect request for same client\n");
219 		WARN_ON(1);
220 		return -EALREADY;
221 	}
222 
223 	pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
224 	if (!pkt)
225 		return -ENOMEM;
226 	cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_SETUP);
227 	cfpkt_addbdy(pkt, (param->chtype << 4) | param->linktype);
228 	cfpkt_addbdy(pkt, (param->priority << 3) | param->phyid);
229 	cfpkt_addbdy(pkt, param->endpoint & 0x03);
230 
231 	switch (param->linktype) {
232 	case CFCTRL_SRV_VEI:
233 		break;
234 	case CFCTRL_SRV_VIDEO:
235 		cfpkt_addbdy(pkt, (u8) param->u.video.connid);
236 		break;
237 	case CFCTRL_SRV_DBG:
238 		break;
239 	case CFCTRL_SRV_DATAGRAM:
240 		tmp32 = cpu_to_le32(param->u.datagram.connid);
241 		cfpkt_add_body(pkt, &tmp32, 4);
242 		break;
243 	case CFCTRL_SRV_RFM:
244 		/* Construct a frame, convert DatagramConnectionID to network
245 		 * format long and copy it out...
246 		 */
247 		tmp32 = cpu_to_le32(param->u.rfm.connid);
248 		cfpkt_add_body(pkt, &tmp32, 4);
249 		/* Add volume name, including zero termination... */
250 		cfpkt_add_body(pkt, param->u.rfm.volume,
251 			       strlen(param->u.rfm.volume) + 1);
252 		break;
253 	case CFCTRL_SRV_UTIL:
254 		tmp16 = cpu_to_le16(param->u.utility.fifosize_kb);
255 		cfpkt_add_body(pkt, &tmp16, 2);
256 		tmp16 = cpu_to_le16(param->u.utility.fifosize_bufs);
257 		cfpkt_add_body(pkt, &tmp16, 2);
258 		memset(utility_name, 0, sizeof(utility_name));
259 		strncpy(utility_name, param->u.utility.name,
260 			UTILITY_NAME_LENGTH - 1);
261 		cfpkt_add_body(pkt, utility_name, UTILITY_NAME_LENGTH);
262 		tmp8 = param->u.utility.paramlen;
263 		cfpkt_add_body(pkt, &tmp8, 1);
264 		cfpkt_add_body(pkt, param->u.utility.params,
265 			       param->u.utility.paramlen);
266 		break;
267 	default:
268 		pr_warn("Request setup of bad link type = %d\n",
269 			param->linktype);
270 		return -EINVAL;
271 	}
272 	req = kzalloc(sizeof(*req), GFP_KERNEL);
273 	if (!req)
274 		return -ENOMEM;
275 	req->client_layer = user_layer;
276 	req->cmd = CFCTRL_CMD_LINK_SETUP;
277 	req->param = *param;
278 	cfctrl_insert_req(cfctrl, req);
279 	init_info(cfpkt_info(pkt), cfctrl);
280 	/*
281 	 * NOTE:Always send linkup and linkdown request on the same
282 	 *	device as the payload. Otherwise old queued up payload
283 	 *	might arrive with the newly allocated channel ID.
284 	 */
285 	cfpkt_info(pkt)->dev_info->id = param->phyid;
286 	cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
287 	ret =
288 	    dn->transmit(dn, pkt);
289 	if (ret < 0) {
290 		int count;
291 
292 		count = cfctrl_cancel_req(&cfctrl->serv.layer,
293 						user_layer);
294 		if (count != 1)
295 			pr_err("Could not remove request (%d)", count);
296 			return -ENODEV;
297 	}
298 	return 0;
299 }
300 
301 int cfctrl_linkdown_req(struct cflayer *layer, u8 channelid,
302 				struct cflayer *client)
303 {
304 	int ret;
305 	struct cfctrl *cfctrl = container_obj(layer);
306 	struct cfpkt *pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
307 	struct cflayer *dn = cfctrl->serv.layer.dn;
308 
309 	if (!pkt)
310 		return -ENOMEM;
311 
312 	if (!dn) {
313 		pr_debug("not able to send link-down request\n");
314 		return -ENODEV;
315 	}
316 
317 	cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_DESTROY);
318 	cfpkt_addbdy(pkt, channelid);
319 	init_info(cfpkt_info(pkt), cfctrl);
320 	cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
321 	ret =
322 	    dn->transmit(dn, pkt);
323 #ifndef CAIF_NO_LOOP
324 	cfctrl->loop_linkused[channelid] = 0;
325 #endif
326 	return ret;
327 }
328 
329 int cfctrl_cancel_req(struct cflayer *layr, struct cflayer *adap_layer)
330 {
331 	struct cfctrl_request_info *p, *tmp;
332 	struct cfctrl *ctrl = container_obj(layr);
333 	int found = 0;
334 	spin_lock_bh(&ctrl->info_list_lock);
335 
336 	list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
337 		if (p->client_layer == adap_layer) {
338 			list_del(&p->list);
339 			kfree(p);
340 			found++;
341 		}
342 	}
343 
344 	spin_unlock_bh(&ctrl->info_list_lock);
345 	return found;
346 }
347 
348 static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
349 {
350 	u8 cmdrsp;
351 	u8 cmd;
352 	int ret = -1;
353 	u16 tmp16;
354 	u8 len;
355 	u8 param[255];
356 	u8 linkid;
357 	struct cfctrl *cfctrl = container_obj(layer);
358 	struct cfctrl_request_info rsp, *req;
359 
360 
361 	cfpkt_extr_head(pkt, &cmdrsp, 1);
362 	cmd = cmdrsp & CFCTRL_CMD_MASK;
363 	if (cmd != CFCTRL_CMD_LINK_ERR
364 	    && CFCTRL_RSP_BIT != (CFCTRL_RSP_BIT & cmdrsp)
365 		&& CFCTRL_ERR_BIT != (CFCTRL_ERR_BIT & cmdrsp)) {
366 		if (handle_loop(cfctrl, cmd, pkt) != 0)
367 			cmdrsp |= CFCTRL_ERR_BIT;
368 	}
369 
370 	switch (cmd) {
371 	case CFCTRL_CMD_LINK_SETUP:
372 		{
373 			enum cfctrl_srv serv;
374 			enum cfctrl_srv servtype;
375 			u8 endpoint;
376 			u8 physlinkid;
377 			u8 prio;
378 			u8 tmp;
379 			u32 tmp32;
380 			u8 *cp;
381 			int i;
382 			struct cfctrl_link_param linkparam;
383 			memset(&linkparam, 0, sizeof(linkparam));
384 
385 			cfpkt_extr_head(pkt, &tmp, 1);
386 
387 			serv = tmp & CFCTRL_SRV_MASK;
388 			linkparam.linktype = serv;
389 
390 			servtype = tmp >> 4;
391 			linkparam.chtype = servtype;
392 
393 			cfpkt_extr_head(pkt, &tmp, 1);
394 			physlinkid = tmp & 0x07;
395 			prio = tmp >> 3;
396 
397 			linkparam.priority = prio;
398 			linkparam.phyid = physlinkid;
399 			cfpkt_extr_head(pkt, &endpoint, 1);
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 				cfpkt_extr_head(pkt, &linkid, 1);
409 				break;
410 			case CFCTRL_SRV_VIDEO:
411 				cfpkt_extr_head(pkt, &tmp, 1);
412 				linkparam.u.video.connid = tmp;
413 				if (CFCTRL_ERR_BIT & cmdrsp)
414 					break;
415 				/* Link ID */
416 				cfpkt_extr_head(pkt, &linkid, 1);
417 				break;
418 
419 			case CFCTRL_SRV_DATAGRAM:
420 				cfpkt_extr_head(pkt, &tmp32, 4);
421 				linkparam.u.datagram.connid =
422 				    le32_to_cpu(tmp32);
423 				if (CFCTRL_ERR_BIT & cmdrsp)
424 					break;
425 				/* Link ID */
426 				cfpkt_extr_head(pkt, &linkid, 1);
427 				break;
428 			case CFCTRL_SRV_RFM:
429 				/* Construct a frame, convert
430 				 * DatagramConnectionID
431 				 * to network format long and copy it out...
432 				 */
433 				cfpkt_extr_head(pkt, &tmp32, 4);
434 				linkparam.u.rfm.connid =
435 				  le32_to_cpu(tmp32);
436 				cp = (u8 *) linkparam.u.rfm.volume;
437 				for (cfpkt_extr_head(pkt, &tmp, 1);
438 				     cfpkt_more(pkt) && tmp != '\0';
439 				     cfpkt_extr_head(pkt, &tmp, 1))
440 					*cp++ = tmp;
441 				*cp = '\0';
442 
443 				if (CFCTRL_ERR_BIT & cmdrsp)
444 					break;
445 				/* Link ID */
446 				cfpkt_extr_head(pkt, &linkid, 1);
447 
448 				break;
449 			case CFCTRL_SRV_UTIL:
450 				/* Construct a frame, convert
451 				 * DatagramConnectionID
452 				 * to network format long and copy it out...
453 				 */
454 				/* Fifosize KB */
455 				cfpkt_extr_head(pkt, &tmp16, 2);
456 				linkparam.u.utility.fifosize_kb =
457 				    le16_to_cpu(tmp16);
458 				/* Fifosize bufs */
459 				cfpkt_extr_head(pkt, &tmp16, 2);
460 				linkparam.u.utility.fifosize_bufs =
461 				    le16_to_cpu(tmp16);
462 				/* name */
463 				cp = (u8 *) linkparam.u.utility.name;
464 				caif_assert(sizeof(linkparam.u.utility.name)
465 					     >= UTILITY_NAME_LENGTH);
466 				for (i = 0;
467 				     i < UTILITY_NAME_LENGTH
468 				     && cfpkt_more(pkt); i++) {
469 					cfpkt_extr_head(pkt, &tmp, 1);
470 					*cp++ = tmp;
471 				}
472 				/* Length */
473 				cfpkt_extr_head(pkt, &len, 1);
474 				linkparam.u.utility.paramlen = len;
475 				/* Param Data */
476 				cp = linkparam.u.utility.params;
477 				while (cfpkt_more(pkt) && len--) {
478 					cfpkt_extr_head(pkt, &tmp, 1);
479 					*cp++ = tmp;
480 				}
481 				if (CFCTRL_ERR_BIT & cmdrsp)
482 					break;
483 				/* Link ID */
484 				cfpkt_extr_head(pkt, &linkid, 1);
485 				/* Length */
486 				cfpkt_extr_head(pkt, &len, 1);
487 				/* Param Data */
488 				cfpkt_extr_head(pkt, &param, len);
489 				break;
490 			default:
491 				pr_warn("Request setup, invalid type (%d)\n",
492 					serv);
493 				goto error;
494 			}
495 
496 			rsp.cmd = cmd;
497 			rsp.param = linkparam;
498 			spin_lock_bh(&cfctrl->info_list_lock);
499 			req = cfctrl_remove_req(cfctrl, &rsp);
500 
501 			if (CFCTRL_ERR_BIT == (CFCTRL_ERR_BIT & cmdrsp) ||
502 				cfpkt_erroneous(pkt)) {
503 				pr_err("Invalid O/E bit or parse error "
504 						"on CAIF control channel\n");
505 				cfctrl->res.reject_rsp(cfctrl->serv.layer.up,
506 						       0,
507 						       req ? req->client_layer
508 						       : NULL);
509 			} else {
510 				cfctrl->res.linksetup_rsp(cfctrl->serv.
511 							  layer.up, linkid,
512 							  serv, physlinkid,
513 							  req ? req->
514 							  client_layer : NULL);
515 			}
516 
517 			if (req != NULL)
518 				kfree(req);
519 
520 			spin_unlock_bh(&cfctrl->info_list_lock);
521 		}
522 		break;
523 	case CFCTRL_CMD_LINK_DESTROY:
524 		cfpkt_extr_head(pkt, &linkid, 1);
525 		cfctrl->res.linkdestroy_rsp(cfctrl->serv.layer.up, linkid);
526 		break;
527 	case CFCTRL_CMD_LINK_ERR:
528 		pr_err("Frame Error Indication received\n");
529 		cfctrl->res.linkerror_ind();
530 		break;
531 	case CFCTRL_CMD_ENUM:
532 		cfctrl->res.enum_rsp();
533 		break;
534 	case CFCTRL_CMD_SLEEP:
535 		cfctrl->res.sleep_rsp();
536 		break;
537 	case CFCTRL_CMD_WAKE:
538 		cfctrl->res.wake_rsp();
539 		break;
540 	case CFCTRL_CMD_LINK_RECONF:
541 		cfctrl->res.restart_rsp();
542 		break;
543 	case CFCTRL_CMD_RADIO_SET:
544 		cfctrl->res.radioset_rsp();
545 		break;
546 	default:
547 		pr_err("Unrecognized Control Frame\n");
548 		goto error;
549 		break;
550 	}
551 	ret = 0;
552 error:
553 	cfpkt_destroy(pkt);
554 	return ret;
555 }
556 
557 static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
558 			int phyid)
559 {
560 	struct cfctrl *this = container_obj(layr);
561 	switch (ctrl) {
562 	case _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND:
563 	case CAIF_CTRLCMD_FLOW_OFF_IND:
564 		spin_lock_bh(&this->info_list_lock);
565 		if (!list_empty(&this->list))
566 			pr_debug("Received flow off in control layer\n");
567 		spin_unlock_bh(&this->info_list_lock);
568 		break;
569 	case _CAIF_CTRLCMD_PHYIF_DOWN_IND: {
570 		struct cfctrl_request_info *p, *tmp;
571 
572 		/* Find all connect request and report failure */
573 		spin_lock_bh(&this->info_list_lock);
574 		list_for_each_entry_safe(p, tmp, &this->list, list) {
575 			if (p->param.phyid == phyid) {
576 				list_del(&p->list);
577 				p->client_layer->ctrlcmd(p->client_layer,
578 						CAIF_CTRLCMD_INIT_FAIL_RSP,
579 						phyid);
580 				kfree(p);
581 			}
582 		}
583 		spin_unlock_bh(&this->info_list_lock);
584 		break;
585 	}
586 	default:
587 		break;
588 	}
589 }
590 
591 #ifndef CAIF_NO_LOOP
592 static int handle_loop(struct cfctrl *ctrl, int cmd, struct cfpkt *pkt)
593 {
594 	static int last_linkid;
595 	static int dec;
596 	u8 linkid, linktype, tmp;
597 	switch (cmd) {
598 	case CFCTRL_CMD_LINK_SETUP:
599 		spin_lock_bh(&ctrl->loop_linkid_lock);
600 		if (!dec) {
601 			for (linkid = last_linkid + 1; linkid < 254; linkid++)
602 				if (!ctrl->loop_linkused[linkid])
603 					goto found;
604 		}
605 		dec = 1;
606 		for (linkid = last_linkid - 1; linkid > 1; linkid--)
607 			if (!ctrl->loop_linkused[linkid])
608 				goto found;
609 		spin_unlock_bh(&ctrl->loop_linkid_lock);
610 		return -1;
611 found:
612 		if (linkid < 10)
613 			dec = 0;
614 
615 		if (!ctrl->loop_linkused[linkid])
616 			ctrl->loop_linkused[linkid] = 1;
617 
618 		last_linkid = linkid;
619 
620 		cfpkt_add_trail(pkt, &linkid, 1);
621 		spin_unlock_bh(&ctrl->loop_linkid_lock);
622 		cfpkt_peek_head(pkt, &linktype, 1);
623 		if (linktype ==  CFCTRL_SRV_UTIL) {
624 			tmp = 0x01;
625 			cfpkt_add_trail(pkt, &tmp, 1);
626 			cfpkt_add_trail(pkt, &tmp, 1);
627 		}
628 		break;
629 
630 	case CFCTRL_CMD_LINK_DESTROY:
631 		spin_lock_bh(&ctrl->loop_linkid_lock);
632 		cfpkt_peek_head(pkt, &linkid, 1);
633 		ctrl->loop_linkused[linkid] = 0;
634 		spin_unlock_bh(&ctrl->loop_linkid_lock);
635 		break;
636 	default:
637 		break;
638 	}
639 	return 0;
640 }
641 #endif
642