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 */
29struct 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
55struct cfcnfg {
56	struct cflayer layer;
57	struct cflayer *ctrl;
58	struct cflayer *mux;
59	struct list_head phys;
60	struct mutex lock;
61};
62
63static void cfcnfg_linkup_rsp(struct cflayer *layer, u8 channel_id,
64			      enum cfctrl_srv serv, u8 phyid,
65			      struct cflayer *adapt_layer);
66static void cfcnfg_linkdestroy_rsp(struct cflayer *layer, u8 channel_id);
67static void cfcnfg_reject_rsp(struct cflayer *layer, u8 channel_id,
68			      struct cflayer *adapt_layer);
69static void cfctrl_resp_func(void);
70static void cfctrl_enum_resp(void);
71
72struct 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;
108out_of_mem:
109	synchronize_rcu();
110
111	kfree(this->mux);
112	kfree(this->ctrl);
113	kfree(this);
114	return NULL;
115}
116
117void 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
129static void cfctrl_resp_func(void)
130{
131}
132
133static 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
144static void cfctrl_enum_resp(void)
145{
146}
147
148static 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
169static 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
179int 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}
203EXPORT_SYMBOL(caif_disconnect_client);
204
205static void cfcnfg_linkdestroy_rsp(struct cflayer *layer, u8 channel_id)
206{
207}
208
209static 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
218static 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
302int 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
359unlock:
360	rcu_read_unlock();
361	return err;
362}
363EXPORT_SYMBOL(caif_connect_client);
364
365static 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
373static void
374cfcnfg_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,"
394				"send linkdown back\n");
395		cfctrl_linkdown_req(cnfg->ctrl, channel_id, NULL);
396		goto unlock;
397	}
398
399	caif_assert(cnfg != NULL);
400	caif_assert(phyid != 0);
401
402	phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phyid);
403	if (phyinfo == NULL) {
404		pr_err("ERROR: Link Layer Device disappeared"
405				"while connecting\n");
406		goto unlock;
407	}
408
409	caif_assert(phyinfo != NULL);
410	caif_assert(phyinfo->id == phyid);
411	caif_assert(phyinfo->phy_layer != NULL);
412	caif_assert(phyinfo->phy_layer->id == phyid);
413
414	adapt_layer->id = channel_id;
415
416	switch (serv) {
417	case CFCTRL_SRV_VEI:
418		servicel = cfvei_create(channel_id, &phyinfo->dev_info);
419		break;
420	case CFCTRL_SRV_DATAGRAM:
421		servicel = cfdgml_create(channel_id,
422					&phyinfo->dev_info);
423		break;
424	case CFCTRL_SRV_RFM:
425		netdev = phyinfo->dev_info.dev;
426		servicel = cfrfml_create(channel_id, &phyinfo->dev_info,
427						netdev->mtu);
428		break;
429	case CFCTRL_SRV_UTIL:
430		servicel = cfutill_create(channel_id, &phyinfo->dev_info);
431		break;
432	case CFCTRL_SRV_VIDEO:
433		servicel = cfvidl_create(channel_id, &phyinfo->dev_info);
434		break;
435	case CFCTRL_SRV_DBG:
436		servicel = cfdbgl_create(channel_id, &phyinfo->dev_info);
437		break;
438	default:
439		pr_err("Protocol error. Link setup response "
440				"- unknown channel type\n");
441		goto unlock;
442	}
443	if (!servicel)
444		goto unlock;
445	layer_set_dn(servicel, cnfg->mux);
446	cfmuxl_set_uplayer(cnfg->mux, servicel, channel_id);
447	layer_set_up(servicel, adapt_layer);
448	layer_set_dn(adapt_layer, servicel);
449
450	rcu_read_unlock();
451
452	servicel->ctrlcmd(servicel, CAIF_CTRLCMD_INIT_RSP, 0);
453	return;
454unlock:
455	rcu_read_unlock();
456}
457
458void
459cfcnfg_add_phy_layer(struct cfcnfg *cnfg,
460		     struct net_device *dev, struct cflayer *phy_layer,
461		     enum cfcnfg_phy_preference pref,
462		     struct cflayer *link_support,
463		     bool fcs, int head_room)
464{
465	struct cflayer *frml;
466	struct cfcnfg_phyinfo *phyinfo = NULL;
467	int i;
468	u8 phyid;
469
470	mutex_lock(&cnfg->lock);
471
472	/* CAIF protocol allow maximum 6 link-layers */
473	for (i = 0; i < 7; i++) {
474		phyid = (dev->ifindex + i) & 0x7;
475		if (phyid == 0)
476			continue;
477		if (cfcnfg_get_phyinfo_rcu(cnfg, phyid) == NULL)
478			goto got_phyid;
479	}
480	pr_warn("Too many CAIF Link Layers (max 6)\n");
481	goto out;
482
483got_phyid:
484	phyinfo = kzalloc(sizeof(struct cfcnfg_phyinfo), GFP_ATOMIC);
485	if (!phyinfo)
486		goto out_err;
487
488	phy_layer->id = phyid;
489	phyinfo->pref = pref;
490	phyinfo->id = phyid;
491	phyinfo->dev_info.id = phyid;
492	phyinfo->dev_info.dev = dev;
493	phyinfo->phy_layer = phy_layer;
494	phyinfo->ifindex = dev->ifindex;
495	phyinfo->head_room = head_room;
496	phyinfo->use_fcs = fcs;
497
498	frml = cffrml_create(phyid, fcs);
499
500	if (!frml)
501		goto out_err;
502	phyinfo->frm_layer = frml;
503	layer_set_up(frml, cnfg->mux);
504
505	if (link_support != NULL) {
506		link_support->id = phyid;
507		layer_set_dn(frml, link_support);
508		layer_set_up(link_support, frml);
509		layer_set_dn(link_support, phy_layer);
510		layer_set_up(phy_layer, link_support);
511	} else {
512		layer_set_dn(frml, phy_layer);
513		layer_set_up(phy_layer, frml);
514	}
515
516	list_add_rcu(&phyinfo->node, &cnfg->phys);
517out:
518	mutex_unlock(&cnfg->lock);
519	return;
520
521out_err:
522	kfree(phyinfo);
523	mutex_unlock(&cnfg->lock);
524}
525EXPORT_SYMBOL(cfcnfg_add_phy_layer);
526
527int cfcnfg_set_phy_state(struct cfcnfg *cnfg, struct cflayer *phy_layer,
528			 bool up)
529{
530	struct cfcnfg_phyinfo *phyinfo;
531
532	rcu_read_lock();
533	phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phy_layer->id);
534	if (phyinfo == NULL) {
535		rcu_read_unlock();
536		return -ENODEV;
537	}
538
539	if (phyinfo->up == up) {
540		rcu_read_unlock();
541		return 0;
542	}
543	phyinfo->up = up;
544
545	if (up) {
546		cffrml_hold(phyinfo->frm_layer);
547		cfmuxl_set_dnlayer(cnfg->mux, phyinfo->frm_layer,
548					phy_layer->id);
549	} else {
550		cfmuxl_remove_dnlayer(cnfg->mux, phy_layer->id);
551		cffrml_put(phyinfo->frm_layer);
552	}
553
554	rcu_read_unlock();
555	return 0;
556}
557EXPORT_SYMBOL(cfcnfg_set_phy_state);
558
559int cfcnfg_del_phy_layer(struct cfcnfg *cnfg, struct cflayer *phy_layer)
560{
561	struct cflayer *frml, *frml_dn;
562	u16 phyid;
563	struct cfcnfg_phyinfo *phyinfo;
564
565	might_sleep();
566
567	mutex_lock(&cnfg->lock);
568
569	phyid = phy_layer->id;
570	phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phyid);
571
572	if (phyinfo == NULL) {
573		mutex_unlock(&cnfg->lock);
574		return 0;
575	}
576	caif_assert(phyid == phyinfo->id);
577	caif_assert(phy_layer == phyinfo->phy_layer);
578	caif_assert(phy_layer->id == phyid);
579	caif_assert(phyinfo->frm_layer->id == phyid);
580
581	list_del_rcu(&phyinfo->node);
582	synchronize_rcu();
583
584	/* Fail if reference count is not zero */
585	if (cffrml_refcnt_read(phyinfo->frm_layer) != 0) {
586		pr_info("Wait for device inuse\n");
587		list_add_rcu(&phyinfo->node, &cnfg->phys);
588		mutex_unlock(&cnfg->lock);
589		return -EAGAIN;
590	}
591
592	frml = phyinfo->frm_layer;
593	frml_dn = frml->dn;
594	cffrml_set_uplayer(frml, NULL);
595	cffrml_set_dnlayer(frml, NULL);
596	if (phy_layer != frml_dn) {
597		layer_set_up(frml_dn, NULL);
598		layer_set_dn(frml_dn, NULL);
599	}
600	layer_set_up(phy_layer, NULL);
601
602	if (phyinfo->phy_layer != frml_dn)
603		kfree(frml_dn);
604
605	cffrml_free(frml);
606	kfree(phyinfo);
607	mutex_unlock(&cnfg->lock);
608
609	return 0;
610}
611EXPORT_SYMBOL(cfcnfg_del_phy_layer);
612