xref: /linux/net/caif/cfcnfg.c (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
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/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 	/* Protocol head room added for CAIF link layer */
49 	int head_room;
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 		return NULL;
83 	this->mux = cfmuxl_create();
84 	if (!this->mux)
85 		goto out_of_mem;
86 	this->ctrl = cfctrl_create();
87 	if (!this->ctrl)
88 		goto out_of_mem;
89 	/* Initiate response functions */
90 	resp = cfctrl_get_respfuncs(this->ctrl);
91 	resp->enum_rsp = cfctrl_enum_resp;
92 	resp->linkerror_ind = cfctrl_resp_func;
93 	resp->linkdestroy_rsp = cfcnfg_linkdestroy_rsp;
94 	resp->sleep_rsp = cfctrl_resp_func;
95 	resp->wake_rsp = cfctrl_resp_func;
96 	resp->restart_rsp = cfctrl_resp_func;
97 	resp->radioset_rsp = cfctrl_resp_func;
98 	resp->linksetup_rsp = cfcnfg_linkup_rsp;
99 	resp->reject_rsp = cfcnfg_reject_rsp;
100 	INIT_LIST_HEAD(&this->phys);
101 
102 	cfmuxl_set_uplayer(this->mux, this->ctrl, 0);
103 	layer_set_dn(this->ctrl, this->mux);
104 	layer_set_up(this->ctrl, this);
105 	mutex_init(&this->lock);
106 
107 	return this;
108 out_of_mem:
109 	synchronize_rcu();
110 
111 	kfree(this->mux);
112 	kfree(this->ctrl);
113 	kfree(this);
114 	return NULL;
115 }
116 
117 void cfcnfg_remove(struct cfcnfg *cfg)
118 {
119 	might_sleep();
120 	if (cfg) {
121 		synchronize_rcu();
122 
123 		kfree(cfg->mux);
124 		cfctrl_remove(cfg->ctrl);
125 		kfree(cfg);
126 	}
127 }
128 
129 static void cfctrl_resp_func(void)
130 {
131 }
132 
133 static struct cfcnfg_phyinfo *cfcnfg_get_phyinfo_rcu(struct cfcnfg *cnfg,
134 						     u8 phyid)
135 {
136 	struct cfcnfg_phyinfo *phy;
137 
138 	list_for_each_entry_rcu(phy, &cnfg->phys, node)
139 		if (phy->id == phyid)
140 			return phy;
141 	return NULL;
142 }
143 
144 static void cfctrl_enum_resp(void)
145 {
146 }
147 
148 static struct dev_info *cfcnfg_get_phyid(struct cfcnfg *cnfg,
149 				  enum cfcnfg_phy_preference phy_pref)
150 {
151 	/* Try to match with specified preference */
152 	struct cfcnfg_phyinfo *phy;
153 
154 	list_for_each_entry_rcu(phy, &cnfg->phys, node) {
155 		if (phy->up && phy->pref == phy_pref &&
156 				phy->frm_layer != NULL)
157 
158 			return &phy->dev_info;
159 	}
160 
161 	/* Otherwise just return something */
162 	list_for_each_entry_rcu(phy, &cnfg->phys, node)
163 		if (phy->up)
164 			return &phy->dev_info;
165 
166 	return NULL;
167 }
168 
169 static int cfcnfg_get_id_from_ifi(struct cfcnfg *cnfg, int ifi)
170 {
171 	struct cfcnfg_phyinfo *phy;
172 
173 	list_for_each_entry_rcu(phy, &cnfg->phys, node)
174 		if (phy->ifindex == ifi && phy->up)
175 			return phy->id;
176 	return -ENODEV;
177 }
178 
179 int caif_disconnect_client(struct net *net, struct cflayer *adap_layer)
180 {
181 	u8 channel_id;
182 	struct cfcnfg *cfg = get_cfcnfg(net);
183 
184 	caif_assert(adap_layer != NULL);
185 	cfctrl_cancel_req(cfg->ctrl, adap_layer);
186 	channel_id = adap_layer->id;
187 	if (channel_id != 0) {
188 		struct cflayer *servl;
189 		servl = cfmuxl_remove_uplayer(cfg->mux, channel_id);
190 		cfctrl_linkdown_req(cfg->ctrl, channel_id, adap_layer);
191 		if (servl != NULL)
192 			layer_set_up(servl, NULL);
193 	} else
194 		pr_debug("nothing to disconnect\n");
195 
196 	/* Do RCU sync before initiating cleanup */
197 	synchronize_rcu();
198 	if (adap_layer->ctrlcmd != NULL)
199 		adap_layer->ctrlcmd(adap_layer, CAIF_CTRLCMD_DEINIT_RSP, 0);
200 	return 0;
201 
202 }
203 EXPORT_SYMBOL(caif_disconnect_client);
204 
205 static void cfcnfg_linkdestroy_rsp(struct cflayer *layer, u8 channel_id)
206 {
207 }
208 
209 static const int protohead[CFCTRL_SRV_MASK] = {
210 	[CFCTRL_SRV_VEI] = 4,
211 	[CFCTRL_SRV_DATAGRAM] = 7,
212 	[CFCTRL_SRV_UTIL] = 4,
213 	[CFCTRL_SRV_RFM] = 3,
214 	[CFCTRL_SRV_DBG] = 3,
215 };
216 
217 
218 static int caif_connect_req_to_link_param(struct cfcnfg *cnfg,
219 					  struct caif_connect_request *s,
220 					  struct cfctrl_link_param *l)
221 {
222 	struct dev_info *dev_info;
223 	enum cfcnfg_phy_preference pref;
224 	int res;
225 
226 	memset(l, 0, sizeof(*l));
227 	/* In caif protocol low value is high priority */
228 	l->priority = CAIF_PRIO_MAX - s->priority + 1;
229 
230 	if (s->ifindex != 0) {
231 		res = cfcnfg_get_id_from_ifi(cnfg, s->ifindex);
232 		if (res < 0)
233 			return res;
234 		l->phyid = res;
235 	} else {
236 		switch (s->link_selector) {
237 		case CAIF_LINK_HIGH_BANDW:
238 			pref = CFPHYPREF_HIGH_BW;
239 			break;
240 		case CAIF_LINK_LOW_LATENCY:
241 			pref = CFPHYPREF_LOW_LAT;
242 			break;
243 		default:
244 			return -EINVAL;
245 		}
246 		dev_info = cfcnfg_get_phyid(cnfg, pref);
247 		if (dev_info == NULL)
248 			return -ENODEV;
249 		l->phyid = dev_info->id;
250 	}
251 	switch (s->protocol) {
252 	case CAIFPROTO_AT:
253 		l->linktype = CFCTRL_SRV_VEI;
254 		l->endpoint = (s->sockaddr.u.at.type >> 2) & 0x3;
255 		l->chtype = s->sockaddr.u.at.type & 0x3;
256 		break;
257 	case CAIFPROTO_DATAGRAM:
258 		l->linktype = CFCTRL_SRV_DATAGRAM;
259 		l->chtype = 0x00;
260 		l->u.datagram.connid = s->sockaddr.u.dgm.connection_id;
261 		break;
262 	case CAIFPROTO_DATAGRAM_LOOP:
263 		l->linktype = CFCTRL_SRV_DATAGRAM;
264 		l->chtype = 0x03;
265 		l->endpoint = 0x00;
266 		l->u.datagram.connid = s->sockaddr.u.dgm.connection_id;
267 		break;
268 	case CAIFPROTO_RFM:
269 		l->linktype = CFCTRL_SRV_RFM;
270 		l->u.datagram.connid = s->sockaddr.u.rfm.connection_id;
271 		strncpy(l->u.rfm.volume, s->sockaddr.u.rfm.volume,
272 			sizeof(l->u.rfm.volume)-1);
273 		l->u.rfm.volume[sizeof(l->u.rfm.volume)-1] = 0;
274 		break;
275 	case CAIFPROTO_UTIL:
276 		l->linktype = CFCTRL_SRV_UTIL;
277 		l->endpoint = 0x00;
278 		l->chtype = 0x00;
279 		strncpy(l->u.utility.name, s->sockaddr.u.util.service,
280 			sizeof(l->u.utility.name)-1);
281 		l->u.utility.name[sizeof(l->u.utility.name)-1] = 0;
282 		caif_assert(sizeof(l->u.utility.name) > 10);
283 		l->u.utility.paramlen = s->param.size;
284 		if (l->u.utility.paramlen > sizeof(l->u.utility.params))
285 			l->u.utility.paramlen = sizeof(l->u.utility.params);
286 
287 		memcpy(l->u.utility.params, s->param.data,
288 		       l->u.utility.paramlen);
289 
290 		break;
291 	case CAIFPROTO_DEBUG:
292 		l->linktype = CFCTRL_SRV_DBG;
293 		l->endpoint = s->sockaddr.u.dbg.service;
294 		l->chtype = s->sockaddr.u.dbg.type;
295 		break;
296 	default:
297 		return -EINVAL;
298 	}
299 	return 0;
300 }
301 
302 int caif_connect_client(struct net *net, struct caif_connect_request *conn_req,
303 			struct cflayer *adap_layer, int *ifindex,
304 			int *proto_head, int *proto_tail)
305 {
306 	struct cflayer *frml;
307 	struct cfcnfg_phyinfo *phy;
308 	int err;
309 	struct cfctrl_link_param param;
310 	struct cfcnfg *cfg = get_cfcnfg(net);
311 
312 	rcu_read_lock();
313 	err = caif_connect_req_to_link_param(cfg, conn_req, &param);
314 	if (err)
315 		goto unlock;
316 
317 	phy = cfcnfg_get_phyinfo_rcu(cfg, param.phyid);
318 	if (!phy) {
319 		err = -ENODEV;
320 		goto unlock;
321 	}
322 	err = -EINVAL;
323 
324 	if (adap_layer == NULL) {
325 		pr_err("adap_layer is zero\n");
326 		goto unlock;
327 	}
328 	if (adap_layer->receive == NULL) {
329 		pr_err("adap_layer->receive is NULL\n");
330 		goto unlock;
331 	}
332 	if (adap_layer->ctrlcmd == NULL) {
333 		pr_err("adap_layer->ctrlcmd == NULL\n");
334 		goto unlock;
335 	}
336 
337 	err = -ENODEV;
338 	frml = phy->frm_layer;
339 	if (frml == NULL) {
340 		pr_err("Specified PHY type does not exist!\n");
341 		goto unlock;
342 	}
343 	caif_assert(param.phyid == phy->id);
344 	caif_assert(phy->frm_layer->id ==
345 		     param.phyid);
346 	caif_assert(phy->phy_layer->id ==
347 		     param.phyid);
348 
349 	*ifindex = phy->ifindex;
350 	*proto_tail = 2;
351 	*proto_head = protohead[param.linktype] + phy->head_room;
352 
353 	rcu_read_unlock();
354 
355 	/* FIXME: ENUMERATE INITIALLY WHEN ACTIVATING PHYSICAL INTERFACE */
356 	cfctrl_enum_req(cfg->ctrl, param.phyid);
357 	return cfctrl_linkup_request(cfg->ctrl, &param, adap_layer);
358 
359 unlock:
360 	rcu_read_unlock();
361 	return err;
362 }
363 EXPORT_SYMBOL(caif_connect_client);
364 
365 static void cfcnfg_reject_rsp(struct cflayer *layer, u8 channel_id,
366 			      struct cflayer *adapt_layer)
367 {
368 	if (adapt_layer != NULL && adapt_layer->ctrlcmd != NULL)
369 		adapt_layer->ctrlcmd(adapt_layer,
370 				     CAIF_CTRLCMD_INIT_FAIL_RSP, 0);
371 }
372 
373 static void
374 cfcnfg_linkup_rsp(struct cflayer *layer, u8 channel_id, enum cfctrl_srv serv,
375 		  u8 phyid, struct cflayer *adapt_layer)
376 {
377 	struct cfcnfg *cnfg = container_obj(layer);
378 	struct cflayer *servicel = NULL;
379 	struct cfcnfg_phyinfo *phyinfo;
380 	struct net_device *netdev;
381 
382 	if (channel_id == 0) {
383 		pr_warn("received channel_id zero\n");
384 		if (adapt_layer != NULL && adapt_layer->ctrlcmd != NULL)
385 			adapt_layer->ctrlcmd(adapt_layer,
386 						CAIF_CTRLCMD_INIT_FAIL_RSP, 0);
387 		return;
388 	}
389 
390 	rcu_read_lock();
391 
392 	if (adapt_layer == NULL) {
393 		pr_debug("link setup response but no client exist, send linkdown back\n");
394 		cfctrl_linkdown_req(cnfg->ctrl, channel_id, NULL);
395 		goto unlock;
396 	}
397 
398 	caif_assert(cnfg != NULL);
399 	caif_assert(phyid != 0);
400 
401 	phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phyid);
402 	if (phyinfo == NULL) {
403 		pr_err("ERROR: Link Layer Device disappeared while connecting\n");
404 		goto unlock;
405 	}
406 
407 	caif_assert(phyinfo != NULL);
408 	caif_assert(phyinfo->id == phyid);
409 	caif_assert(phyinfo->phy_layer != NULL);
410 	caif_assert(phyinfo->phy_layer->id == phyid);
411 
412 	adapt_layer->id = channel_id;
413 
414 	switch (serv) {
415 	case CFCTRL_SRV_VEI:
416 		servicel = cfvei_create(channel_id, &phyinfo->dev_info);
417 		break;
418 	case CFCTRL_SRV_DATAGRAM:
419 		servicel = cfdgml_create(channel_id,
420 					&phyinfo->dev_info);
421 		break;
422 	case CFCTRL_SRV_RFM:
423 		netdev = phyinfo->dev_info.dev;
424 		servicel = cfrfml_create(channel_id, &phyinfo->dev_info,
425 						netdev->mtu);
426 		break;
427 	case CFCTRL_SRV_UTIL:
428 		servicel = cfutill_create(channel_id, &phyinfo->dev_info);
429 		break;
430 	case CFCTRL_SRV_VIDEO:
431 		servicel = cfvidl_create(channel_id, &phyinfo->dev_info);
432 		break;
433 	case CFCTRL_SRV_DBG:
434 		servicel = cfdbgl_create(channel_id, &phyinfo->dev_info);
435 		break;
436 	default:
437 		pr_err("Protocol error. Link setup response - unknown channel type\n");
438 		goto unlock;
439 	}
440 	if (!servicel)
441 		goto unlock;
442 	layer_set_dn(servicel, cnfg->mux);
443 	cfmuxl_set_uplayer(cnfg->mux, servicel, channel_id);
444 	layer_set_up(servicel, adapt_layer);
445 	layer_set_dn(adapt_layer, servicel);
446 
447 	rcu_read_unlock();
448 
449 	servicel->ctrlcmd(servicel, CAIF_CTRLCMD_INIT_RSP, 0);
450 	return;
451 unlock:
452 	rcu_read_unlock();
453 }
454 
455 void
456 cfcnfg_add_phy_layer(struct cfcnfg *cnfg,
457 		     struct net_device *dev, struct cflayer *phy_layer,
458 		     enum cfcnfg_phy_preference pref,
459 		     struct cflayer *link_support,
460 		     bool fcs, int head_room)
461 {
462 	struct cflayer *frml;
463 	struct cfcnfg_phyinfo *phyinfo = NULL;
464 	int i;
465 	u8 phyid;
466 
467 	mutex_lock(&cnfg->lock);
468 
469 	/* CAIF protocol allow maximum 6 link-layers */
470 	for (i = 0; i < 7; i++) {
471 		phyid = (dev->ifindex + i) & 0x7;
472 		if (phyid == 0)
473 			continue;
474 		if (cfcnfg_get_phyinfo_rcu(cnfg, phyid) == NULL)
475 			goto got_phyid;
476 	}
477 	pr_warn("Too many CAIF Link Layers (max 6)\n");
478 	goto out;
479 
480 got_phyid:
481 	phyinfo = kzalloc(sizeof(struct cfcnfg_phyinfo), GFP_ATOMIC);
482 	if (!phyinfo)
483 		goto out_err;
484 
485 	phy_layer->id = phyid;
486 	phyinfo->pref = pref;
487 	phyinfo->id = phyid;
488 	phyinfo->dev_info.id = phyid;
489 	phyinfo->dev_info.dev = dev;
490 	phyinfo->phy_layer = phy_layer;
491 	phyinfo->ifindex = dev->ifindex;
492 	phyinfo->head_room = head_room;
493 	phyinfo->use_fcs = fcs;
494 
495 	frml = cffrml_create(phyid, fcs);
496 
497 	if (!frml)
498 		goto out_err;
499 	phyinfo->frm_layer = frml;
500 	layer_set_up(frml, cnfg->mux);
501 
502 	if (link_support != NULL) {
503 		link_support->id = phyid;
504 		layer_set_dn(frml, link_support);
505 		layer_set_up(link_support, frml);
506 		layer_set_dn(link_support, phy_layer);
507 		layer_set_up(phy_layer, link_support);
508 	} else {
509 		layer_set_dn(frml, phy_layer);
510 		layer_set_up(phy_layer, frml);
511 	}
512 
513 	list_add_rcu(&phyinfo->node, &cnfg->phys);
514 out:
515 	mutex_unlock(&cnfg->lock);
516 	return;
517 
518 out_err:
519 	kfree(phyinfo);
520 	mutex_unlock(&cnfg->lock);
521 }
522 EXPORT_SYMBOL(cfcnfg_add_phy_layer);
523 
524 int cfcnfg_set_phy_state(struct cfcnfg *cnfg, struct cflayer *phy_layer,
525 			 bool up)
526 {
527 	struct cfcnfg_phyinfo *phyinfo;
528 
529 	rcu_read_lock();
530 	phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phy_layer->id);
531 	if (phyinfo == NULL) {
532 		rcu_read_unlock();
533 		return -ENODEV;
534 	}
535 
536 	if (phyinfo->up == up) {
537 		rcu_read_unlock();
538 		return 0;
539 	}
540 	phyinfo->up = up;
541 
542 	if (up) {
543 		cffrml_hold(phyinfo->frm_layer);
544 		cfmuxl_set_dnlayer(cnfg->mux, phyinfo->frm_layer,
545 					phy_layer->id);
546 	} else {
547 		cfmuxl_remove_dnlayer(cnfg->mux, phy_layer->id);
548 		cffrml_put(phyinfo->frm_layer);
549 	}
550 
551 	rcu_read_unlock();
552 	return 0;
553 }
554 EXPORT_SYMBOL(cfcnfg_set_phy_state);
555 
556 int cfcnfg_del_phy_layer(struct cfcnfg *cnfg, struct cflayer *phy_layer)
557 {
558 	struct cflayer *frml, *frml_dn;
559 	u16 phyid;
560 	struct cfcnfg_phyinfo *phyinfo;
561 
562 	might_sleep();
563 
564 	mutex_lock(&cnfg->lock);
565 
566 	phyid = phy_layer->id;
567 	phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phyid);
568 
569 	if (phyinfo == NULL) {
570 		mutex_unlock(&cnfg->lock);
571 		return 0;
572 	}
573 	caif_assert(phyid == phyinfo->id);
574 	caif_assert(phy_layer == phyinfo->phy_layer);
575 	caif_assert(phy_layer->id == phyid);
576 	caif_assert(phyinfo->frm_layer->id == phyid);
577 
578 	list_del_rcu(&phyinfo->node);
579 	synchronize_rcu();
580 
581 	/* Fail if reference count is not zero */
582 	if (cffrml_refcnt_read(phyinfo->frm_layer) != 0) {
583 		pr_info("Wait for device inuse\n");
584 		list_add_rcu(&phyinfo->node, &cnfg->phys);
585 		mutex_unlock(&cnfg->lock);
586 		return -EAGAIN;
587 	}
588 
589 	frml = phyinfo->frm_layer;
590 	frml_dn = frml->dn;
591 	cffrml_set_uplayer(frml, NULL);
592 	cffrml_set_dnlayer(frml, NULL);
593 	if (phy_layer != frml_dn) {
594 		layer_set_up(frml_dn, NULL);
595 		layer_set_dn(frml_dn, NULL);
596 	}
597 	layer_set_up(phy_layer, NULL);
598 
599 	if (phyinfo->phy_layer != frml_dn)
600 		kfree(frml_dn);
601 
602 	cffrml_free(frml);
603 	kfree(phyinfo);
604 	mutex_unlock(&cnfg->lock);
605 
606 	return 0;
607 }
608 EXPORT_SYMBOL(cfcnfg_del_phy_layer);
609