xref: /linux/net/caif/cfctrl.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) ST-Ericsson AB 2010
4  * Author:	Sjur Brendeland
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 	struct cflayer *dn = cfctrl->serv.layer.dn;
205 	char utility_name[UTILITY_NAME_LENGTH];
206 	struct cfctrl_request_info *req;
207 	struct cfpkt *pkt;
208 	u32 tmp32;
209 	u16 tmp16;
210 	u8 tmp8;
211 	int ret;
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 		strscpy_pad(utility_name, param->u.utility.name);
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 		cfpkt_destroy(pkt);
271 		return -EINVAL;
272 	}
273 	req = kzalloc(sizeof(*req), GFP_KERNEL);
274 	if (!req) {
275 		cfpkt_destroy(pkt);
276 		return -ENOMEM;
277 	}
278 
279 	req->client_layer = user_layer;
280 	req->cmd = CFCTRL_CMD_LINK_SETUP;
281 	req->param = *param;
282 	cfctrl_insert_req(cfctrl, req);
283 	init_info(cfpkt_info(pkt), cfctrl);
284 	/*
285 	 * NOTE:Always send linkup and linkdown request on the same
286 	 *	device as the payload. Otherwise old queued up payload
287 	 *	might arrive with the newly allocated channel ID.
288 	 */
289 	cfpkt_info(pkt)->dev_info->id = param->phyid;
290 	cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
291 	ret =
292 	    dn->transmit(dn, pkt);
293 	if (ret < 0) {
294 		int count;
295 
296 		count = cfctrl_cancel_req(&cfctrl->serv.layer,
297 						user_layer);
298 		if (count != 1) {
299 			pr_err("Could not remove request (%d)", count);
300 			return -ENODEV;
301 		}
302 	}
303 	return 0;
304 }
305 
306 int cfctrl_linkdown_req(struct cflayer *layer, u8 channelid,
307 			struct cflayer *client)
308 {
309 	int ret;
310 	struct cfpkt *pkt;
311 	struct cfctrl *cfctrl = container_obj(layer);
312 	struct cflayer *dn = cfctrl->serv.layer.dn;
313 
314 	if (!dn) {
315 		pr_debug("not able to send link-down request\n");
316 		return -ENODEV;
317 	}
318 	pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
319 	if (!pkt)
320 		return -ENOMEM;
321 	cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_DESTROY);
322 	cfpkt_addbdy(pkt, channelid);
323 	init_info(cfpkt_info(pkt), cfctrl);
324 	cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
325 	ret =
326 	    dn->transmit(dn, pkt);
327 #ifndef CAIF_NO_LOOP
328 	cfctrl->loop_linkused[channelid] = 0;
329 #endif
330 	return ret;
331 }
332 
333 int cfctrl_cancel_req(struct cflayer *layr, struct cflayer *adap_layer)
334 {
335 	struct cfctrl_request_info *p, *tmp;
336 	struct cfctrl *ctrl = container_obj(layr);
337 	int found = 0;
338 	spin_lock_bh(&ctrl->info_list_lock);
339 
340 	list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
341 		if (p->client_layer == adap_layer) {
342 			list_del(&p->list);
343 			kfree(p);
344 			found++;
345 		}
346 	}
347 
348 	spin_unlock_bh(&ctrl->info_list_lock);
349 	return found;
350 }
351 
352 static int cfctrl_link_setup(struct cfctrl *cfctrl, struct cfpkt *pkt, u8 cmdrsp)
353 {
354 	u8 len;
355 	u8 linkid = 0;
356 	enum cfctrl_srv serv;
357 	enum cfctrl_srv servtype;
358 	u8 endpoint;
359 	u8 physlinkid;
360 	u8 prio;
361 	u8 tmp;
362 	u8 *cp;
363 	int i;
364 	struct cfctrl_link_param linkparam;
365 	struct cfctrl_request_info rsp, *req;
366 
367 	memset(&linkparam, 0, sizeof(linkparam));
368 
369 	tmp = cfpkt_extr_head_u8(pkt);
370 
371 	serv = tmp & CFCTRL_SRV_MASK;
372 	linkparam.linktype = serv;
373 
374 	servtype = tmp >> 4;
375 	linkparam.chtype = servtype;
376 
377 	tmp = cfpkt_extr_head_u8(pkt);
378 	physlinkid = tmp & 0x07;
379 	prio = tmp >> 3;
380 
381 	linkparam.priority = prio;
382 	linkparam.phyid = physlinkid;
383 	endpoint = cfpkt_extr_head_u8(pkt);
384 	linkparam.endpoint = endpoint & 0x03;
385 
386 	switch (serv) {
387 	case CFCTRL_SRV_VEI:
388 	case CFCTRL_SRV_DBG:
389 		if (CFCTRL_ERR_BIT & cmdrsp)
390 			break;
391 		/* Link ID */
392 		linkid = cfpkt_extr_head_u8(pkt);
393 		break;
394 	case CFCTRL_SRV_VIDEO:
395 		tmp = cfpkt_extr_head_u8(pkt);
396 		linkparam.u.video.connid = tmp;
397 		if (CFCTRL_ERR_BIT & cmdrsp)
398 			break;
399 		/* Link ID */
400 		linkid = cfpkt_extr_head_u8(pkt);
401 		break;
402 
403 	case CFCTRL_SRV_DATAGRAM:
404 		linkparam.u.datagram.connid = cfpkt_extr_head_u32(pkt);
405 		if (CFCTRL_ERR_BIT & cmdrsp)
406 			break;
407 		/* Link ID */
408 		linkid = cfpkt_extr_head_u8(pkt);
409 		break;
410 	case CFCTRL_SRV_RFM:
411 		/* Construct a frame, convert
412 		 * DatagramConnectionID
413 		 * to network format long and copy it out...
414 		 */
415 		linkparam.u.rfm.connid = cfpkt_extr_head_u32(pkt);
416 		cp = (u8 *) linkparam.u.rfm.volume;
417 		for (tmp = cfpkt_extr_head_u8(pkt);
418 		     cfpkt_more(pkt) && tmp != '\0';
419 		     tmp = cfpkt_extr_head_u8(pkt))
420 			*cp++ = tmp;
421 		*cp = '\0';
422 
423 		if (CFCTRL_ERR_BIT & cmdrsp)
424 			break;
425 		/* Link ID */
426 		linkid = cfpkt_extr_head_u8(pkt);
427 
428 		break;
429 	case CFCTRL_SRV_UTIL:
430 		/* Construct a frame, convert
431 		 * DatagramConnectionID
432 		 * to network format long and copy it out...
433 		 */
434 		/* Fifosize KB */
435 		linkparam.u.utility.fifosize_kb = cfpkt_extr_head_u16(pkt);
436 		/* Fifosize bufs */
437 		linkparam.u.utility.fifosize_bufs = cfpkt_extr_head_u16(pkt);
438 		/* name */
439 		cp = (u8 *) linkparam.u.utility.name;
440 		caif_assert(sizeof(linkparam.u.utility.name)
441 			     >= UTILITY_NAME_LENGTH);
442 		for (i = 0; i < UTILITY_NAME_LENGTH && cfpkt_more(pkt); i++) {
443 			tmp = cfpkt_extr_head_u8(pkt);
444 			*cp++ = tmp;
445 		}
446 		/* Length */
447 		len = cfpkt_extr_head_u8(pkt);
448 		linkparam.u.utility.paramlen = len;
449 		/* Param Data */
450 		cp = linkparam.u.utility.params;
451 		while (cfpkt_more(pkt) && len--) {
452 			tmp = cfpkt_extr_head_u8(pkt);
453 			*cp++ = tmp;
454 		}
455 		if (CFCTRL_ERR_BIT & cmdrsp)
456 			break;
457 		/* Link ID */
458 		linkid = cfpkt_extr_head_u8(pkt);
459 		/* Length */
460 		len = cfpkt_extr_head_u8(pkt);
461 		/* Param Data */
462 		cfpkt_extr_head(pkt, NULL, len);
463 		break;
464 	default:
465 		pr_warn("Request setup, invalid type (%d)\n", serv);
466 		return -1;
467 	}
468 
469 	rsp.cmd = CFCTRL_CMD_LINK_SETUP;
470 	rsp.param = linkparam;
471 	spin_lock_bh(&cfctrl->info_list_lock);
472 	req = cfctrl_remove_req(cfctrl, &rsp);
473 
474 	if (CFCTRL_ERR_BIT == (CFCTRL_ERR_BIT & cmdrsp) ||
475 		cfpkt_erroneous(pkt)) {
476 		pr_err("Invalid O/E bit or parse error "
477 				"on CAIF control channel\n");
478 		cfctrl->res.reject_rsp(cfctrl->serv.layer.up, 0,
479 				       req ? req->client_layer : NULL);
480 	} else {
481 		cfctrl->res.linksetup_rsp(cfctrl->serv.layer.up, linkid,
482 					  serv, physlinkid,
483 					  req ?  req->client_layer : NULL);
484 	}
485 
486 	kfree(req);
487 
488 	spin_unlock_bh(&cfctrl->info_list_lock);
489 
490 	return 0;
491 }
492 
493 static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
494 {
495 	u8 cmdrsp;
496 	u8 cmd;
497 	int ret = 0;
498 	u8 linkid = 0;
499 	struct cfctrl *cfctrl = container_obj(layer);
500 
501 	cmdrsp = cfpkt_extr_head_u8(pkt);
502 	cmd = cmdrsp & CFCTRL_CMD_MASK;
503 	if (cmd != CFCTRL_CMD_LINK_ERR
504 	    && CFCTRL_RSP_BIT != (CFCTRL_RSP_BIT & cmdrsp)
505 		&& CFCTRL_ERR_BIT != (CFCTRL_ERR_BIT & cmdrsp)) {
506 		if (handle_loop(cfctrl, cmd, pkt) != 0)
507 			cmdrsp |= CFCTRL_ERR_BIT;
508 	}
509 
510 	switch (cmd) {
511 	case CFCTRL_CMD_LINK_SETUP:
512 		ret = cfctrl_link_setup(cfctrl, pkt, cmdrsp);
513 		break;
514 	case CFCTRL_CMD_LINK_DESTROY:
515 		linkid = cfpkt_extr_head_u8(pkt);
516 		cfctrl->res.linkdestroy_rsp(cfctrl->serv.layer.up, linkid);
517 		break;
518 	case CFCTRL_CMD_LINK_ERR:
519 		pr_err("Frame Error Indication received\n");
520 		cfctrl->res.linkerror_ind();
521 		break;
522 	case CFCTRL_CMD_ENUM:
523 		cfctrl->res.enum_rsp();
524 		break;
525 	case CFCTRL_CMD_SLEEP:
526 		cfctrl->res.sleep_rsp();
527 		break;
528 	case CFCTRL_CMD_WAKE:
529 		cfctrl->res.wake_rsp();
530 		break;
531 	case CFCTRL_CMD_LINK_RECONF:
532 		cfctrl->res.restart_rsp();
533 		break;
534 	case CFCTRL_CMD_RADIO_SET:
535 		cfctrl->res.radioset_rsp();
536 		break;
537 	default:
538 		pr_err("Unrecognized Control Frame\n");
539 		ret = -1;
540 		goto error;
541 	}
542 error:
543 	cfpkt_destroy(pkt);
544 	return ret;
545 }
546 
547 static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
548 			   int phyid)
549 {
550 	struct cfctrl *this = container_obj(layr);
551 	switch (ctrl) {
552 	case _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND:
553 	case CAIF_CTRLCMD_FLOW_OFF_IND:
554 		spin_lock_bh(&this->info_list_lock);
555 		if (!list_empty(&this->list))
556 			pr_debug("Received flow off in control layer\n");
557 		spin_unlock_bh(&this->info_list_lock);
558 		break;
559 	case _CAIF_CTRLCMD_PHYIF_DOWN_IND: {
560 		struct cfctrl_request_info *p, *tmp;
561 
562 		/* Find all connect request and report failure */
563 		spin_lock_bh(&this->info_list_lock);
564 		list_for_each_entry_safe(p, tmp, &this->list, list) {
565 			if (p->param.phyid == phyid) {
566 				list_del(&p->list);
567 				p->client_layer->ctrlcmd(p->client_layer,
568 						CAIF_CTRLCMD_INIT_FAIL_RSP,
569 						phyid);
570 				kfree(p);
571 			}
572 		}
573 		spin_unlock_bh(&this->info_list_lock);
574 		break;
575 	}
576 	default:
577 		break;
578 	}
579 }
580 
581 #ifndef CAIF_NO_LOOP
582 static int handle_loop(struct cfctrl *ctrl, int cmd, struct cfpkt *pkt)
583 {
584 	static int last_linkid;
585 	static int dec;
586 	u8 linkid, linktype, tmp;
587 	switch (cmd) {
588 	case CFCTRL_CMD_LINK_SETUP:
589 		spin_lock_bh(&ctrl->loop_linkid_lock);
590 		if (!dec) {
591 			for (linkid = last_linkid + 1; linkid < 254; linkid++)
592 				if (!ctrl->loop_linkused[linkid])
593 					goto found;
594 		}
595 		dec = 1;
596 		for (linkid = last_linkid - 1; linkid > 1; linkid--)
597 			if (!ctrl->loop_linkused[linkid])
598 				goto found;
599 		spin_unlock_bh(&ctrl->loop_linkid_lock);
600 		return -1;
601 found:
602 		if (linkid < 10)
603 			dec = 0;
604 
605 		if (!ctrl->loop_linkused[linkid])
606 			ctrl->loop_linkused[linkid] = 1;
607 
608 		last_linkid = linkid;
609 
610 		cfpkt_add_trail(pkt, &linkid, 1);
611 		spin_unlock_bh(&ctrl->loop_linkid_lock);
612 		cfpkt_peek_head(pkt, &linktype, 1);
613 		if (linktype ==  CFCTRL_SRV_UTIL) {
614 			tmp = 0x01;
615 			cfpkt_add_trail(pkt, &tmp, 1);
616 			cfpkt_add_trail(pkt, &tmp, 1);
617 		}
618 		break;
619 
620 	case CFCTRL_CMD_LINK_DESTROY:
621 		spin_lock_bh(&ctrl->loop_linkid_lock);
622 		cfpkt_peek_head(pkt, &linkid, 1);
623 		ctrl->loop_linkused[linkid] = 0;
624 		spin_unlock_bh(&ctrl->loop_linkid_lock);
625 		break;
626 	default:
627 		break;
628 	}
629 	return 0;
630 }
631 #endif
632