xref: /openbmc/linux/net/caif/cfctrl.c (revision 9b93eb47) 
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
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 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 
199 int 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 
304 int 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 
331 int 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 
350 static 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;
546 error:
547 	cfpkt_destroy(pkt);
548 	return ret;
549 }
550 
551 static 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
586 static 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;
605 found:
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