xref: /openbmc/linux/net/caif/cfcnfg.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/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 		strlcpy(l->u.rfm.volume, s->sockaddr.u.rfm.volume,
272 			sizeof(l->u.rfm.volume));
273 		break;
274 	case CAIFPROTO_UTIL:
275 		l->linktype = CFCTRL_SRV_UTIL;
276 		l->endpoint = 0x00;
277 		l->chtype = 0x00;
278 		strlcpy(l->u.utility.name, s->sockaddr.u.util.service,
279 			sizeof(l->u.utility.name));
280 		caif_assert(sizeof(l->u.utility.name) > 10);
281 		l->u.utility.paramlen = s->param.size;
282 		if (l->u.utility.paramlen > sizeof(l->u.utility.params))
283 			l->u.utility.paramlen = sizeof(l->u.utility.params);
284 
285 		memcpy(l->u.utility.params, s->param.data,
286 		       l->u.utility.paramlen);
287 
288 		break;
289 	case CAIFPROTO_DEBUG:
290 		l->linktype = CFCTRL_SRV_DBG;
291 		l->endpoint = s->sockaddr.u.dbg.service;
292 		l->chtype = s->sockaddr.u.dbg.type;
293 		break;
294 	default:
295 		return -EINVAL;
296 	}
297 	return 0;
298 }
299 
300 int caif_connect_client(struct net *net, struct caif_connect_request *conn_req,
301 			struct cflayer *adap_layer, int *ifindex,
302 			int *proto_head, int *proto_tail)
303 {
304 	struct cflayer *frml;
305 	struct cfcnfg_phyinfo *phy;
306 	int err;
307 	struct cfctrl_link_param param;
308 	struct cfcnfg *cfg = get_cfcnfg(net);
309 
310 	rcu_read_lock();
311 	err = caif_connect_req_to_link_param(cfg, conn_req, &param);
312 	if (err)
313 		goto unlock;
314 
315 	phy = cfcnfg_get_phyinfo_rcu(cfg, param.phyid);
316 	if (!phy) {
317 		err = -ENODEV;
318 		goto unlock;
319 	}
320 	err = -EINVAL;
321 
322 	if (adap_layer == NULL) {
323 		pr_err("adap_layer is zero\n");
324 		goto unlock;
325 	}
326 	if (adap_layer->receive == NULL) {
327 		pr_err("adap_layer->receive is NULL\n");
328 		goto unlock;
329 	}
330 	if (adap_layer->ctrlcmd == NULL) {
331 		pr_err("adap_layer->ctrlcmd == NULL\n");
332 		goto unlock;
333 	}
334 
335 	err = -ENODEV;
336 	frml = phy->frm_layer;
337 	if (frml == NULL) {
338 		pr_err("Specified PHY type does not exist!\n");
339 		goto unlock;
340 	}
341 	caif_assert(param.phyid == phy->id);
342 	caif_assert(phy->frm_layer->id ==
343 		     param.phyid);
344 	caif_assert(phy->phy_layer->id ==
345 		     param.phyid);
346 
347 	*ifindex = phy->ifindex;
348 	*proto_tail = 2;
349 	*proto_head = protohead[param.linktype] + phy->head_room;
350 
351 	rcu_read_unlock();
352 
353 	/* FIXME: ENUMERATE INITIALLY WHEN ACTIVATING PHYSICAL INTERFACE */
354 	cfctrl_enum_req(cfg->ctrl, param.phyid);
355 	return cfctrl_linkup_request(cfg->ctrl, &param, adap_layer);
356 
357 unlock:
358 	rcu_read_unlock();
359 	return err;
360 }
361 EXPORT_SYMBOL(caif_connect_client);
362 
363 static void cfcnfg_reject_rsp(struct cflayer *layer, u8 channel_id,
364 			      struct cflayer *adapt_layer)
365 {
366 	if (adapt_layer != NULL && adapt_layer->ctrlcmd != NULL)
367 		adapt_layer->ctrlcmd(adapt_layer,
368 				     CAIF_CTRLCMD_INIT_FAIL_RSP, 0);
369 }
370 
371 static void
372 cfcnfg_linkup_rsp(struct cflayer *layer, u8 channel_id, enum cfctrl_srv serv,
373 		  u8 phyid, struct cflayer *adapt_layer)
374 {
375 	struct cfcnfg *cnfg = container_obj(layer);
376 	struct cflayer *servicel = NULL;
377 	struct cfcnfg_phyinfo *phyinfo;
378 	struct net_device *netdev;
379 
380 	if (channel_id == 0) {
381 		pr_warn("received channel_id zero\n");
382 		if (adapt_layer != NULL && adapt_layer->ctrlcmd != NULL)
383 			adapt_layer->ctrlcmd(adapt_layer,
384 						CAIF_CTRLCMD_INIT_FAIL_RSP, 0);
385 		return;
386 	}
387 
388 	rcu_read_lock();
389 
390 	if (adapt_layer == NULL) {
391 		pr_debug("link setup response but no client exist, send linkdown back\n");
392 		cfctrl_linkdown_req(cnfg->ctrl, channel_id, NULL);
393 		goto unlock;
394 	}
395 
396 	caif_assert(cnfg != NULL);
397 	caif_assert(phyid != 0);
398 
399 	phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phyid);
400 	if (phyinfo == NULL) {
401 		pr_err("ERROR: Link Layer Device disappeared while connecting\n");
402 		goto unlock;
403 	}
404 
405 	caif_assert(phyinfo != NULL);
406 	caif_assert(phyinfo->id == phyid);
407 	caif_assert(phyinfo->phy_layer != NULL);
408 	caif_assert(phyinfo->phy_layer->id == phyid);
409 
410 	adapt_layer->id = channel_id;
411 
412 	switch (serv) {
413 	case CFCTRL_SRV_VEI:
414 		servicel = cfvei_create(channel_id, &phyinfo->dev_info);
415 		break;
416 	case CFCTRL_SRV_DATAGRAM:
417 		servicel = cfdgml_create(channel_id,
418 					&phyinfo->dev_info);
419 		break;
420 	case CFCTRL_SRV_RFM:
421 		netdev = phyinfo->dev_info.dev;
422 		servicel = cfrfml_create(channel_id, &phyinfo->dev_info,
423 						netdev->mtu);
424 		break;
425 	case CFCTRL_SRV_UTIL:
426 		servicel = cfutill_create(channel_id, &phyinfo->dev_info);
427 		break;
428 	case CFCTRL_SRV_VIDEO:
429 		servicel = cfvidl_create(channel_id, &phyinfo->dev_info);
430 		break;
431 	case CFCTRL_SRV_DBG:
432 		servicel = cfdbgl_create(channel_id, &phyinfo->dev_info);
433 		break;
434 	default:
435 		pr_err("Protocol error. Link setup response - unknown channel type\n");
436 		goto unlock;
437 	}
438 	if (!servicel)
439 		goto unlock;
440 	layer_set_dn(servicel, cnfg->mux);
441 	cfmuxl_set_uplayer(cnfg->mux, servicel, channel_id);
442 	layer_set_up(servicel, adapt_layer);
443 	layer_set_dn(adapt_layer, servicel);
444 
445 	rcu_read_unlock();
446 
447 	servicel->ctrlcmd(servicel, CAIF_CTRLCMD_INIT_RSP, 0);
448 	return;
449 unlock:
450 	rcu_read_unlock();
451 }
452 
453 void
454 cfcnfg_add_phy_layer(struct cfcnfg *cnfg,
455 		     struct net_device *dev, struct cflayer *phy_layer,
456 		     enum cfcnfg_phy_preference pref,
457 		     struct cflayer *link_support,
458 		     bool fcs, int head_room)
459 {
460 	struct cflayer *frml;
461 	struct cfcnfg_phyinfo *phyinfo = NULL;
462 	int i;
463 	u8 phyid;
464 
465 	mutex_lock(&cnfg->lock);
466 
467 	/* CAIF protocol allow maximum 6 link-layers */
468 	for (i = 0; i < 7; i++) {
469 		phyid = (dev->ifindex + i) & 0x7;
470 		if (phyid == 0)
471 			continue;
472 		if (cfcnfg_get_phyinfo_rcu(cnfg, phyid) == NULL)
473 			goto got_phyid;
474 	}
475 	pr_warn("Too many CAIF Link Layers (max 6)\n");
476 	goto out;
477 
478 got_phyid:
479 	phyinfo = kzalloc(sizeof(struct cfcnfg_phyinfo), GFP_ATOMIC);
480 	if (!phyinfo)
481 		goto out_err;
482 
483 	phy_layer->id = phyid;
484 	phyinfo->pref = pref;
485 	phyinfo->id = phyid;
486 	phyinfo->dev_info.id = phyid;
487 	phyinfo->dev_info.dev = dev;
488 	phyinfo->phy_layer = phy_layer;
489 	phyinfo->ifindex = dev->ifindex;
490 	phyinfo->head_room = head_room;
491 	phyinfo->use_fcs = fcs;
492 
493 	frml = cffrml_create(phyid, fcs);
494 
495 	if (!frml)
496 		goto out_err;
497 	phyinfo->frm_layer = frml;
498 	layer_set_up(frml, cnfg->mux);
499 
500 	if (link_support != NULL) {
501 		link_support->id = phyid;
502 		layer_set_dn(frml, link_support);
503 		layer_set_up(link_support, frml);
504 		layer_set_dn(link_support, phy_layer);
505 		layer_set_up(phy_layer, link_support);
506 	} else {
507 		layer_set_dn(frml, phy_layer);
508 		layer_set_up(phy_layer, frml);
509 	}
510 
511 	list_add_rcu(&phyinfo->node, &cnfg->phys);
512 out:
513 	mutex_unlock(&cnfg->lock);
514 	return;
515 
516 out_err:
517 	kfree(phyinfo);
518 	mutex_unlock(&cnfg->lock);
519 }
520 EXPORT_SYMBOL(cfcnfg_add_phy_layer);
521 
522 int cfcnfg_set_phy_state(struct cfcnfg *cnfg, struct cflayer *phy_layer,
523 			 bool up)
524 {
525 	struct cfcnfg_phyinfo *phyinfo;
526 
527 	rcu_read_lock();
528 	phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phy_layer->id);
529 	if (phyinfo == NULL) {
530 		rcu_read_unlock();
531 		return -ENODEV;
532 	}
533 
534 	if (phyinfo->up == up) {
535 		rcu_read_unlock();
536 		return 0;
537 	}
538 	phyinfo->up = up;
539 
540 	if (up) {
541 		cffrml_hold(phyinfo->frm_layer);
542 		cfmuxl_set_dnlayer(cnfg->mux, phyinfo->frm_layer,
543 					phy_layer->id);
544 	} else {
545 		cfmuxl_remove_dnlayer(cnfg->mux, phy_layer->id);
546 		cffrml_put(phyinfo->frm_layer);
547 	}
548 
549 	rcu_read_unlock();
550 	return 0;
551 }
552 EXPORT_SYMBOL(cfcnfg_set_phy_state);
553 
554 int cfcnfg_del_phy_layer(struct cfcnfg *cnfg, struct cflayer *phy_layer)
555 {
556 	struct cflayer *frml, *frml_dn;
557 	u16 phyid;
558 	struct cfcnfg_phyinfo *phyinfo;
559 
560 	might_sleep();
561 
562 	mutex_lock(&cnfg->lock);
563 
564 	phyid = phy_layer->id;
565 	phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phyid);
566 
567 	if (phyinfo == NULL) {
568 		mutex_unlock(&cnfg->lock);
569 		return 0;
570 	}
571 	caif_assert(phyid == phyinfo->id);
572 	caif_assert(phy_layer == phyinfo->phy_layer);
573 	caif_assert(phy_layer->id == phyid);
574 	caif_assert(phyinfo->frm_layer->id == phyid);
575 
576 	list_del_rcu(&phyinfo->node);
577 	synchronize_rcu();
578 
579 	/* Fail if reference count is not zero */
580 	if (cffrml_refcnt_read(phyinfo->frm_layer) != 0) {
581 		pr_info("Wait for device inuse\n");
582 		list_add_rcu(&phyinfo->node, &cnfg->phys);
583 		mutex_unlock(&cnfg->lock);
584 		return -EAGAIN;
585 	}
586 
587 	frml = phyinfo->frm_layer;
588 	frml_dn = frml->dn;
589 	cffrml_set_uplayer(frml, NULL);
590 	cffrml_set_dnlayer(frml, NULL);
591 	if (phy_layer != frml_dn) {
592 		layer_set_up(frml_dn, NULL);
593 		layer_set_dn(frml_dn, NULL);
594 	}
595 	layer_set_up(phy_layer, NULL);
596 
597 	if (phyinfo->phy_layer != frml_dn)
598 		kfree(frml_dn);
599 
600 	cffrml_free(frml);
601 	kfree(phyinfo);
602 	mutex_unlock(&cnfg->lock);
603 
604 	return 0;
605 }
606 EXPORT_SYMBOL(cfcnfg_del_phy_layer);
607