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 #ifdef CAIF_NO_LOOP
handle_loop(struct cfctrl * ctrl,int cmd,struct cfpkt * pkt)21 static int handle_loop(struct cfctrl *ctrl,
22 			      int cmd, struct cfpkt *pkt){
23 	return -1;
24 }
25 #else
26 static int handle_loop(struct cfctrl *ctrl,
27 		int cmd, struct cfpkt *pkt);
28 #endif
29 static int cfctrl_recv(struct cflayer *layr, struct cfpkt *pkt);
30 static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
31 			   int phyid);
32 
33 
cfctrl_create(void)34 struct cflayer *cfctrl_create(void)
35 {
36 	struct dev_info dev_info;
37 	struct cfctrl *this =
38 		kzalloc(sizeof(struct cfctrl), GFP_ATOMIC);
39 	if (!this)
40 		return NULL;
41 	caif_assert(offsetof(struct cfctrl, serv.layer) == 0);
42 	memset(&dev_info, 0, sizeof(dev_info));
43 	dev_info.id = 0xff;
44 	cfsrvl_init(&this->serv, 0, &dev_info, false);
45 	atomic_set(&this->req_seq_no, 1);
46 	atomic_set(&this->rsp_seq_no, 1);
47 	this->serv.layer.receive = cfctrl_recv;
48 	sprintf(this->serv.layer.name, "ctrl");
49 	this->serv.layer.ctrlcmd = cfctrl_ctrlcmd;
50 #ifndef CAIF_NO_LOOP
51 	spin_lock_init(&this->loop_linkid_lock);
52 	this->loop_linkid = 1;
53 #endif
54 	spin_lock_init(&this->info_list_lock);
55 	INIT_LIST_HEAD(&this->list);
56 	return &this->serv.layer;
57 }
58 
cfctrl_remove(struct cflayer * layer)59 void cfctrl_remove(struct cflayer *layer)
60 {
61 	struct cfctrl_request_info *p, *tmp;
62 	struct cfctrl *ctrl = container_obj(layer);
63 
64 	spin_lock_bh(&ctrl->info_list_lock);
65 	list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
66 		list_del(&p->list);
67 		kfree(p);
68 	}
69 	spin_unlock_bh(&ctrl->info_list_lock);
70 	kfree(layer);
71 }
72 
param_eq(const struct cfctrl_link_param * p1,const struct cfctrl_link_param * p2)73 static bool param_eq(const struct cfctrl_link_param *p1,
74 			const struct cfctrl_link_param *p2)
75 {
76 	bool eq =
77 	    p1->linktype == p2->linktype &&
78 	    p1->priority == p2->priority &&
79 	    p1->phyid == p2->phyid &&
80 	    p1->endpoint == p2->endpoint && p1->chtype == p2->chtype;
81 
82 	if (!eq)
83 		return false;
84 
85 	switch (p1->linktype) {
86 	case CFCTRL_SRV_VEI:
87 		return true;
88 	case CFCTRL_SRV_DATAGRAM:
89 		return p1->u.datagram.connid == p2->u.datagram.connid;
90 	case CFCTRL_SRV_RFM:
91 		return
92 		    p1->u.rfm.connid == p2->u.rfm.connid &&
93 		    strcmp(p1->u.rfm.volume, p2->u.rfm.volume) == 0;
94 	case CFCTRL_SRV_UTIL:
95 		return
96 		    p1->u.utility.fifosize_kb == p2->u.utility.fifosize_kb
97 		    && p1->u.utility.fifosize_bufs ==
98 		    p2->u.utility.fifosize_bufs
99 		    && strcmp(p1->u.utility.name, p2->u.utility.name) == 0
100 		    && p1->u.utility.paramlen == p2->u.utility.paramlen
101 		    && memcmp(p1->u.utility.params, p2->u.utility.params,
102 			      p1->u.utility.paramlen) == 0;
103 
104 	case CFCTRL_SRV_VIDEO:
105 		return p1->u.video.connid == p2->u.video.connid;
106 	case CFCTRL_SRV_DBG:
107 		return true;
108 	case CFCTRL_SRV_DECM:
109 		return false;
110 	default:
111 		return false;
112 	}
113 	return false;
114 }
115 
cfctrl_req_eq(const struct cfctrl_request_info * r1,const struct cfctrl_request_info * r2)116 static bool cfctrl_req_eq(const struct cfctrl_request_info *r1,
117 			  const struct cfctrl_request_info *r2)
118 {
119 	if (r1->cmd != r2->cmd)
120 		return false;
121 	if (r1->cmd == CFCTRL_CMD_LINK_SETUP)
122 		return param_eq(&r1->param, &r2->param);
123 	else
124 		return r1->channel_id == r2->channel_id;
125 }
126 
127 /* Insert request at the end */
cfctrl_insert_req(struct cfctrl * ctrl,struct cfctrl_request_info * req)128 static void cfctrl_insert_req(struct cfctrl *ctrl,
129 			      struct cfctrl_request_info *req)
130 {
131 	spin_lock_bh(&ctrl->info_list_lock);
132 	atomic_inc(&ctrl->req_seq_no);
133 	req->sequence_no = atomic_read(&ctrl->req_seq_no);
134 	list_add_tail(&req->list, &ctrl->list);
135 	spin_unlock_bh(&ctrl->info_list_lock);
136 }
137 
138 /* Compare and remove request */
cfctrl_remove_req(struct cfctrl * ctrl,struct cfctrl_request_info * req)139 static struct cfctrl_request_info *cfctrl_remove_req(struct cfctrl *ctrl,
140 						struct cfctrl_request_info *req)
141 {
142 	struct cfctrl_request_info *p, *tmp, *first;
143 
144 	first = list_first_entry(&ctrl->list, struct cfctrl_request_info, list);
145 
146 	list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
147 		if (cfctrl_req_eq(req, p)) {
148 			if (p != first)
149 				pr_warn("Requests are not received in order\n");
150 
151 			atomic_set(&ctrl->rsp_seq_no,
152 					 p->sequence_no);
153 			list_del(&p->list);
154 			goto out;
155 		}
156 	}
157 	p = NULL;
158 out:
159 	return p;
160 }
161 
cfctrl_get_respfuncs(struct cflayer * layer)162 struct cfctrl_rsp *cfctrl_get_respfuncs(struct cflayer *layer)
163 {
164 	struct cfctrl *this = container_obj(layer);
165 	return &this->res;
166 }
167 
init_info(struct caif_payload_info * info,struct cfctrl * cfctrl)168 static void init_info(struct caif_payload_info *info, struct cfctrl *cfctrl)
169 {
170 	info->hdr_len = 0;
171 	info->channel_id = cfctrl->serv.layer.id;
172 	info->dev_info = &cfctrl->serv.dev_info;
173 }
174 
cfctrl_enum_req(struct cflayer * layer,u8 physlinkid)175 void cfctrl_enum_req(struct cflayer *layer, u8 physlinkid)
176 {
177 	struct cfctrl *cfctrl = container_obj(layer);
178 	struct cfpkt *pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
179 	struct cflayer *dn = cfctrl->serv.layer.dn;
180 	if (!pkt)
181 		return;
182 	if (!dn) {
183 		pr_debug("not able to send enum request\n");
184 		return;
185 	}
186 	caif_assert(offsetof(struct cfctrl, serv.layer) == 0);
187 	init_info(cfpkt_info(pkt), cfctrl);
188 	cfpkt_info(pkt)->dev_info->id = physlinkid;
189 	cfctrl->serv.dev_info.id = physlinkid;
190 	cfpkt_addbdy(pkt, CFCTRL_CMD_ENUM);
191 	cfpkt_addbdy(pkt, physlinkid);
192 	dn->transmit(dn, pkt);
193 }
194 
cfctrl_linkup_request(struct cflayer * layer,struct cfctrl_link_param * param,struct cflayer * user_layer)195 int cfctrl_linkup_request(struct cflayer *layer,
196 			   struct cfctrl_link_param *param,
197 			   struct cflayer *user_layer)
198 {
199 	struct cfctrl *cfctrl = container_obj(layer);
200 	u32 tmp32;
201 	u16 tmp16;
202 	u8 tmp8;
203 	struct cfctrl_request_info *req;
204 	int ret;
205 	char utility_name[16];
206 	struct cfpkt *pkt;
207 	struct cflayer *dn = cfctrl->serv.layer.dn;
208 
209 	if (!dn) {
210 		pr_debug("not able to send linkup request\n");
211 		return -ENODEV;
212 	}
213 
214 	if (cfctrl_cancel_req(layer, user_layer) > 0) {
215 		/* Slight Paranoia, check if already connecting */
216 		pr_err("Duplicate connect request for same client\n");
217 		WARN_ON(1);
218 		return -EALREADY;
219 	}
220 
221 	pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
222 	if (!pkt)
223 		return -ENOMEM;
224 	cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_SETUP);
225 	cfpkt_addbdy(pkt, (param->chtype << 4) | param->linktype);
226 	cfpkt_addbdy(pkt, (param->priority << 3) | param->phyid);
227 	cfpkt_addbdy(pkt, param->endpoint & 0x03);
228 
229 	switch (param->linktype) {
230 	case CFCTRL_SRV_VEI:
231 		break;
232 	case CFCTRL_SRV_VIDEO:
233 		cfpkt_addbdy(pkt, (u8) param->u.video.connid);
234 		break;
235 	case CFCTRL_SRV_DBG:
236 		break;
237 	case CFCTRL_SRV_DATAGRAM:
238 		tmp32 = cpu_to_le32(param->u.datagram.connid);
239 		cfpkt_add_body(pkt, &tmp32, 4);
240 		break;
241 	case CFCTRL_SRV_RFM:
242 		/* Construct a frame, convert DatagramConnectionID to network
243 		 * format long and copy it out...
244 		 */
245 		tmp32 = cpu_to_le32(param->u.rfm.connid);
246 		cfpkt_add_body(pkt, &tmp32, 4);
247 		/* Add volume name, including zero termination... */
248 		cfpkt_add_body(pkt, param->u.rfm.volume,
249 			       strlen(param->u.rfm.volume) + 1);
250 		break;
251 	case CFCTRL_SRV_UTIL:
252 		tmp16 = cpu_to_le16(param->u.utility.fifosize_kb);
253 		cfpkt_add_body(pkt, &tmp16, 2);
254 		tmp16 = cpu_to_le16(param->u.utility.fifosize_bufs);
255 		cfpkt_add_body(pkt, &tmp16, 2);
256 		memset(utility_name, 0, sizeof(utility_name));
257 		strncpy(utility_name, param->u.utility.name,
258 			UTILITY_NAME_LENGTH - 1);
259 		cfpkt_add_body(pkt, utility_name, UTILITY_NAME_LENGTH);
260 		tmp8 = param->u.utility.paramlen;
261 		cfpkt_add_body(pkt, &tmp8, 1);
262 		cfpkt_add_body(pkt, param->u.utility.params,
263 			       param->u.utility.paramlen);
264 		break;
265 	default:
266 		pr_warn("Request setup of bad link type = %d\n",
267 			param->linktype);
268 		return -EINVAL;
269 	}
270 	req = kzalloc(sizeof(*req), GFP_KERNEL);
271 	if (!req)
272 		return -ENOMEM;
273 	req->client_layer = user_layer;
274 	req->cmd = CFCTRL_CMD_LINK_SETUP;
275 	req->param = *param;
276 	cfctrl_insert_req(cfctrl, req);
277 	init_info(cfpkt_info(pkt), cfctrl);
278 	/*
279 	 * NOTE:Always send linkup and linkdown request on the same
280 	 *	device as the payload. Otherwise old queued up payload
281 	 *	might arrive with the newly allocated channel ID.
282 	 */
283 	cfpkt_info(pkt)->dev_info->id = param->phyid;
284 	ret =
285 	    dn->transmit(dn, pkt);
286 	if (ret < 0) {
287 		int count;
288 
289 		count = cfctrl_cancel_req(&cfctrl->serv.layer,
290 						user_layer);
291 		if (count != 1) {
292 			pr_err("Could not remove request (%d)", count);
293 			return -ENODEV;
294 		}
295 	}
296 	return 0;
297 }
298 
cfctrl_linkdown_req(struct cflayer * layer,u8 channelid,struct cflayer * client)299 int cfctrl_linkdown_req(struct cflayer *layer, u8 channelid,
300 				struct cflayer *client)
301 {
302 	int ret;
303 	struct cfctrl *cfctrl = container_obj(layer);
304 	struct cfpkt *pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
305 	struct cflayer *dn = cfctrl->serv.layer.dn;
306 
307 	if (!pkt)
308 		return -ENOMEM;
309 
310 	if (!dn) {
311 		pr_debug("not able to send link-down request\n");
312 		return -ENODEV;
313 	}
314 
315 	cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_DESTROY);
316 	cfpkt_addbdy(pkt, channelid);
317 	init_info(cfpkt_info(pkt), cfctrl);
318 	ret =
319 	    dn->transmit(dn, pkt);
320 #ifndef CAIF_NO_LOOP
321 	cfctrl->loop_linkused[channelid] = 0;
322 #endif
323 	return ret;
324 }
325 
cfctrl_cancel_req(struct cflayer * layr,struct cflayer * adap_layer)326 int cfctrl_cancel_req(struct cflayer *layr, struct cflayer *adap_layer)
327 {
328 	struct cfctrl_request_info *p, *tmp;
329 	struct cfctrl *ctrl = container_obj(layr);
330 	int found = 0;
331 	spin_lock_bh(&ctrl->info_list_lock);
332 
333 	list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
334 		if (p->client_layer == adap_layer) {
335 			list_del(&p->list);
336 			kfree(p);
337 			found++;
338 		}
339 	}
340 
341 	spin_unlock_bh(&ctrl->info_list_lock);
342 	return found;
343 }
344 
cfctrl_recv(struct cflayer * layer,struct cfpkt * pkt)345 static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
346 {
347 	u8 cmdrsp;
348 	u8 cmd;
349 	int ret = -1;
350 	u16 tmp16;
351 	u8 len;
352 	u8 param[255];
353 	u8 linkid;
354 	struct cfctrl *cfctrl = container_obj(layer);
355 	struct cfctrl_request_info rsp, *req;
356 
357 
358 	cfpkt_extr_head(pkt, &cmdrsp, 1);
359 	cmd = cmdrsp & CFCTRL_CMD_MASK;
360 	if (cmd != CFCTRL_CMD_LINK_ERR
361 	    && CFCTRL_RSP_BIT != (CFCTRL_RSP_BIT & cmdrsp)
362 		&& CFCTRL_ERR_BIT != (CFCTRL_ERR_BIT & cmdrsp)) {
363 		if (handle_loop(cfctrl, cmd, pkt) != 0)
364 			cmdrsp |= CFCTRL_ERR_BIT;
365 	}
366 
367 	switch (cmd) {
368 	case CFCTRL_CMD_LINK_SETUP:
369 		{
370 			enum cfctrl_srv serv;
371 			enum cfctrl_srv servtype;
372 			u8 endpoint;
373 			u8 physlinkid;
374 			u8 prio;
375 			u8 tmp;
376 			u32 tmp32;
377 			u8 *cp;
378 			int i;
379 			struct cfctrl_link_param linkparam;
380 			memset(&linkparam, 0, sizeof(linkparam));
381 
382 			cfpkt_extr_head(pkt, &tmp, 1);
383 
384 			serv = tmp & CFCTRL_SRV_MASK;
385 			linkparam.linktype = serv;
386 
387 			servtype = tmp >> 4;
388 			linkparam.chtype = servtype;
389 
390 			cfpkt_extr_head(pkt, &tmp, 1);
391 			physlinkid = tmp & 0x07;
392 			prio = tmp >> 3;
393 
394 			linkparam.priority = prio;
395 			linkparam.phyid = physlinkid;
396 			cfpkt_extr_head(pkt, &endpoint, 1);
397 			linkparam.endpoint = endpoint & 0x03;
398 
399 			switch (serv) {
400 			case CFCTRL_SRV_VEI:
401 			case CFCTRL_SRV_DBG:
402 				if (CFCTRL_ERR_BIT & cmdrsp)
403 					break;
404 				/* Link ID */
405 				cfpkt_extr_head(pkt, &linkid, 1);
406 				break;
407 			case CFCTRL_SRV_VIDEO:
408 				cfpkt_extr_head(pkt, &tmp, 1);
409 				linkparam.u.video.connid = tmp;
410 				if (CFCTRL_ERR_BIT & cmdrsp)
411 					break;
412 				/* Link ID */
413 				cfpkt_extr_head(pkt, &linkid, 1);
414 				break;
415 
416 			case CFCTRL_SRV_DATAGRAM:
417 				cfpkt_extr_head(pkt, &tmp32, 4);
418 				linkparam.u.datagram.connid =
419 				    le32_to_cpu(tmp32);
420 				if (CFCTRL_ERR_BIT & cmdrsp)
421 					break;
422 				/* Link ID */
423 				cfpkt_extr_head(pkt, &linkid, 1);
424 				break;
425 			case CFCTRL_SRV_RFM:
426 				/* Construct a frame, convert
427 				 * DatagramConnectionID
428 				 * to network format long and copy it out...
429 				 */
430 				cfpkt_extr_head(pkt, &tmp32, 4);
431 				linkparam.u.rfm.connid =
432 				  le32_to_cpu(tmp32);
433 				cp = (u8 *) linkparam.u.rfm.volume;
434 				for (cfpkt_extr_head(pkt, &tmp, 1);
435 				     cfpkt_more(pkt) && tmp != '\0';
436 				     cfpkt_extr_head(pkt, &tmp, 1))
437 					*cp++ = tmp;
438 				*cp = '\0';
439 
440 				if (CFCTRL_ERR_BIT & cmdrsp)
441 					break;
442 				/* Link ID */
443 				cfpkt_extr_head(pkt, &linkid, 1);
444 
445 				break;
446 			case CFCTRL_SRV_UTIL:
447 				/* Construct a frame, convert
448 				 * DatagramConnectionID
449 				 * to network format long and copy it out...
450 				 */
451 				/* Fifosize KB */
452 				cfpkt_extr_head(pkt, &tmp16, 2);
453 				linkparam.u.utility.fifosize_kb =
454 				    le16_to_cpu(tmp16);
455 				/* Fifosize bufs */
456 				cfpkt_extr_head(pkt, &tmp16, 2);
457 				linkparam.u.utility.fifosize_bufs =
458 				    le16_to_cpu(tmp16);
459 				/* name */
460 				cp = (u8 *) linkparam.u.utility.name;
461 				caif_assert(sizeof(linkparam.u.utility.name)
462 					     >= UTILITY_NAME_LENGTH);
463 				for (i = 0;
464 				     i < UTILITY_NAME_LENGTH
465 				     && cfpkt_more(pkt); i++) {
466 					cfpkt_extr_head(pkt, &tmp, 1);
467 					*cp++ = tmp;
468 				}
469 				/* Length */
470 				cfpkt_extr_head(pkt, &len, 1);
471 				linkparam.u.utility.paramlen = len;
472 				/* Param Data */
473 				cp = linkparam.u.utility.params;
474 				while (cfpkt_more(pkt) && len--) {
475 					cfpkt_extr_head(pkt, &tmp, 1);
476 					*cp++ = tmp;
477 				}
478 				if (CFCTRL_ERR_BIT & cmdrsp)
479 					break;
480 				/* Link ID */
481 				cfpkt_extr_head(pkt, &linkid, 1);
482 				/* Length */
483 				cfpkt_extr_head(pkt, &len, 1);
484 				/* Param Data */
485 				cfpkt_extr_head(pkt, &param, len);
486 				break;
487 			default:
488 				pr_warn("Request setup, invalid type (%d)\n",
489 					serv);
490 				goto error;
491 			}
492 
493 			rsp.cmd = cmd;
494 			rsp.param = linkparam;
495 			spin_lock_bh(&cfctrl->info_list_lock);
496 			req = cfctrl_remove_req(cfctrl, &rsp);
497 
498 			if (CFCTRL_ERR_BIT == (CFCTRL_ERR_BIT & cmdrsp) ||
499 				cfpkt_erroneous(pkt)) {
500 				pr_err("Invalid O/E bit or parse error "
501 						"on CAIF control channel\n");
502 				cfctrl->res.reject_rsp(cfctrl->serv.layer.up,
503 						       0,
504 						       req ? req->client_layer
505 						       : NULL);
506 			} else {
507 				cfctrl->res.linksetup_rsp(cfctrl->serv.
508 							  layer.up, linkid,
509 							  serv, physlinkid,
510 							  req ? req->
511 							  client_layer : NULL);
512 			}
513 
514 			if (req != NULL)
515 				kfree(req);
516 
517 			spin_unlock_bh(&cfctrl->info_list_lock);
518 		}
519 		break;
520 	case CFCTRL_CMD_LINK_DESTROY:
521 		cfpkt_extr_head(pkt, &linkid, 1);
522 		cfctrl->res.linkdestroy_rsp(cfctrl->serv.layer.up, linkid);
523 		break;
524 	case CFCTRL_CMD_LINK_ERR:
525 		pr_err("Frame Error Indication received\n");
526 		cfctrl->res.linkerror_ind();
527 		break;
528 	case CFCTRL_CMD_ENUM:
529 		cfctrl->res.enum_rsp();
530 		break;
531 	case CFCTRL_CMD_SLEEP:
532 		cfctrl->res.sleep_rsp();
533 		break;
534 	case CFCTRL_CMD_WAKE:
535 		cfctrl->res.wake_rsp();
536 		break;
537 	case CFCTRL_CMD_LINK_RECONF:
538 		cfctrl->res.restart_rsp();
539 		break;
540 	case CFCTRL_CMD_RADIO_SET:
541 		cfctrl->res.radioset_rsp();
542 		break;
543 	default:
544 		pr_err("Unrecognized Control Frame\n");
545 		goto error;
546 		break;
547 	}
548 	ret = 0;
549 error:
550 	cfpkt_destroy(pkt);
551 	return ret;
552 }
553 
cfctrl_ctrlcmd(struct cflayer * layr,enum caif_ctrlcmd ctrl,int phyid)554 static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
555 			int phyid)
556 {
557 	struct cfctrl *this = container_obj(layr);
558 	switch (ctrl) {
559 	case _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND:
560 	case CAIF_CTRLCMD_FLOW_OFF_IND:
561 		spin_lock_bh(&this->info_list_lock);
562 		if (!list_empty(&this->list))
563 			pr_debug("Received flow off in control layer\n");
564 		spin_unlock_bh(&this->info_list_lock);
565 		break;
566 	case _CAIF_CTRLCMD_PHYIF_DOWN_IND: {
567 		struct cfctrl_request_info *p, *tmp;
568 
569 		/* Find all connect request and report failure */
570 		spin_lock_bh(&this->info_list_lock);
571 		list_for_each_entry_safe(p, tmp, &this->list, list) {
572 			if (p->param.phyid == phyid) {
573 				list_del(&p->list);
574 				p->client_layer->ctrlcmd(p->client_layer,
575 						CAIF_CTRLCMD_INIT_FAIL_RSP,
576 						phyid);
577 				kfree(p);
578 			}
579 		}
580 		spin_unlock_bh(&this->info_list_lock);
581 		break;
582 	}
583 	default:
584 		break;
585 	}
586 }
587 
588 #ifndef CAIF_NO_LOOP
handle_loop(struct cfctrl * ctrl,int cmd,struct cfpkt * pkt)589 static int handle_loop(struct cfctrl *ctrl, int cmd, struct cfpkt *pkt)
590 {
591 	static int last_linkid;
592 	static int dec;
593 	u8 linkid, linktype, tmp;
594 	switch (cmd) {
595 	case CFCTRL_CMD_LINK_SETUP:
596 		spin_lock_bh(&ctrl->loop_linkid_lock);
597 		if (!dec) {
598 			for (linkid = last_linkid + 1; linkid < 254; linkid++)
599 				if (!ctrl->loop_linkused[linkid])
600 					goto found;
601 		}
602 		dec = 1;
603 		for (linkid = last_linkid - 1; linkid > 1; linkid--)
604 			if (!ctrl->loop_linkused[linkid])
605 				goto found;
606 		spin_unlock_bh(&ctrl->loop_linkid_lock);
607 		return -1;
608 found:
609 		if (linkid < 10)
610 			dec = 0;
611 
612 		if (!ctrl->loop_linkused[linkid])
613 			ctrl->loop_linkused[linkid] = 1;
614 
615 		last_linkid = linkid;
616 
617 		cfpkt_add_trail(pkt, &linkid, 1);
618 		spin_unlock_bh(&ctrl->loop_linkid_lock);
619 		cfpkt_peek_head(pkt, &linktype, 1);
620 		if (linktype ==  CFCTRL_SRV_UTIL) {
621 			tmp = 0x01;
622 			cfpkt_add_trail(pkt, &tmp, 1);
623 			cfpkt_add_trail(pkt, &tmp, 1);
624 		}
625 		break;
626 
627 	case CFCTRL_CMD_LINK_DESTROY:
628 		spin_lock_bh(&ctrl->loop_linkid_lock);
629 		cfpkt_peek_head(pkt, &linkid, 1);
630 		ctrl->loop_linkused[linkid] = 0;
631 		spin_unlock_bh(&ctrl->loop_linkid_lock);
632 		break;
633 	default:
634 		break;
635 	}
636 	return 0;
637 }
638 #endif
639