aboutsummaryrefslogtreecommitdiffstats
path: root/net/caif/cfmuxl.c
blob: 46f34b2e04784d8fd379384851c3d5b19377ddee (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
/*
 * Copyright (C) ST-Ericsson AB 2010
 * Author:	Sjur Brendeland/sjur.brandeland@stericsson.com
 * License terms: GNU General Public License (GPL) version 2
 */

#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__

#include <linux/stddef.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <net/caif/cfpkt.h>
#include <net/caif/cfmuxl.h>
#include <net/caif/cfsrvl.h>
#include <net/caif/cffrml.h>

#define container_obj(layr) container_of(layr, struct cfmuxl, layer)

#define CAIF_CTRL_CHANNEL 0
#define UP_CACHE_SIZE 8
#define DN_CACHE_SIZE 8

struct cfmuxl {
	struct cflayer layer;
	struct list_head srvl_list;
	struct list_head frml_list;
	struct cflayer *up_cache[UP_CACHE_SIZE];
	struct cflayer *dn_cache[DN_CACHE_SIZE];
	/*
	 * Set when inserting or removing downwards layers.
	 */
	spinlock_t transmit_lock;

	/*
	 * Set when inserting or removing upwards layers.
	 */
	spinlock_t receive_lock;

};

static int cfmuxl_receive(struct cflayer *layr, struct cfpkt *pkt);
static int cfmuxl_transmit(struct cflayer *layr, struct cfpkt *pkt);
static void cfmuxl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
				int phyid);
static struct cflayer *get_up(struct cfmuxl *muxl, u16 id);

struct cflayer *cfmuxl_create(void)
{
	struct cfmuxl *this = kmalloc(sizeof(struct cfmuxl), GFP_ATOMIC);
	if (!this)
		return NULL;
	memset(this, 0, sizeof(*this));
	this->layer.receive = cfmuxl_receive;
	this->layer.transmit = cfmuxl_transmit;
	this->layer.ctrlcmd = cfmuxl_ctrlcmd;
	INIT_LIST_HEAD(&this->srvl_list);
	INIT_LIST_HEAD(&this->frml_list);
	spin_lock_init(&this->transmit_lock);
	spin_lock_init(&this->receive_lock);
	snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "mux");
	return &this->layer;
}

int cfmuxl_set_uplayer(struct cflayer *layr, struct cflayer *up, u8 linkid)
{
	struct cfmuxl *muxl = container_obj(layr);
	spin_lock(&muxl->receive_lock);
	cfsrvl_get(up);
	list_add(&up->node, &muxl->srvl_list);
	spin_unlock(&muxl->receive_lock);
	return 0;
}

bool cfmuxl_is_phy_inuse(struct cflayer *layr, u8 phyid)
{
	struct list_head *node;
	struct cflayer *layer;
	struct cfmuxl *muxl = container_obj(layr);
	bool match = false;
	spin_lock(&muxl->receive_lock);

	list_for_each(node, &muxl->srvl_list) {
		layer = list_entry(node, struct cflayer, node);
		if (cfsrvl_phyid_match(layer, phyid)) {
			match = true;
			break;
		}

	}
	spin_unlock(&muxl->receive_lock);
	return match;
}

u8 cfmuxl_get_phyid(struct cflayer *layr, u8 channel_id)
{
	struct cflayer *up;
	int phyid;
	struct cfmuxl *muxl = container_obj(layr);
	spin_lock(&muxl->receive_lock);
	up = get_up(muxl, channel_id);
	if (up != NULL)
		phyid = cfsrvl_getphyid(up);
	else
		phyid = 0;
	spin_unlock(&muxl->receive_lock);
	return phyid;
}

int cfmuxl_set_dnlayer(struct cflayer *layr, struct cflayer *dn, u8 phyid)
{
	struct cfmuxl *muxl = (struct cfmuxl *) layr;
	spin_lock(&muxl->transmit_lock);
	list_add(&dn->node, &muxl->frml_list);
	spin_unlock(&muxl->transmit_lock);
	return 0;
}

static struct cflayer *get_from_id(struct list_head *list, u16 id)
{
	struct list_head *node;
	struct cflayer *layer;
	list_for_each(node, list) {
		layer = list_entry(node, struct cflayer, node);
		if (layer->id == id)
			return layer;
	}
	return NULL;
}

struct cflayer *cfmuxl_remove_dnlayer(struct cflayer *layr, u8 phyid)
{
	struct cfmuxl *muxl = container_obj(layr);
	struct cflayer *dn;
	spin_lock(&muxl->transmit_lock);
	memset(muxl->dn_cache, 0, sizeof(muxl->dn_cache));
	dn = get_from_id(&muxl->frml_list, phyid);
	if (dn == NULL) {
		spin_unlock(&muxl->transmit_lock);
		return NULL;
	}
	list_del(&dn->node);
	caif_assert(dn != NULL);
	spin_unlock(&muxl->transmit_lock);
	return dn;
}

/* Invariant: lock is taken */
static struct cflayer *get_up(struct cfmuxl *muxl, u16 id)
{
	struct cflayer *up;
	int idx = id % UP_CACHE_SIZE;
	up = muxl->up_cache[idx];
	if (up == NULL || up->id != id) {
		up = get_from_id(&muxl->srvl_list, id);
		muxl->up_cache[idx] = up;
	}
	return up;
}

/* Invariant: lock is taken */
static struct cflayer *get_dn(struct cfmuxl *muxl, struct dev_info *dev_info)
{
	struct cflayer *dn;
	int idx = dev_info->id % DN_CACHE_SIZE;
	dn = muxl->dn_cache[idx];
	if (dn == NULL || dn->id != dev_info->id) {
		dn = get_from_id(&muxl->frml_list, dev_info->id);
		muxl->dn_cache[idx] = dn;
	}
	return dn;
}

struct cflayer *cfmuxl_remove_uplayer(struct cflayer *layr, u8 id)
{
	struct cflayer *up;
	struct cfmuxl *muxl = container_obj(layr);
	spin_lock(&muxl->receive_lock);
	up = get_up(muxl, id);
	if (up == NULL)
		goto out;
	memset(muxl->up_cache, 0, sizeof(muxl->up_cache));
	list_del(&up->node);
	cfsrvl_put(up);
out:
	spin_unlock(&muxl->receive_lock);
	return up;
}

static int cfmuxl_receive(struct cflayer *layr, struct cfpkt *pkt)
{
	int ret;
	struct cfmuxl *muxl = container_obj(layr);
	u8 id;
	struct cflayer *up;
	if (cfpkt_extr_head(pkt, &id, 1) < 0) {
		pr_err("erroneous Caif Packet\n");
		cfpkt_destroy(pkt);
		return -EPROTO;
	}

	spin_lock(&muxl->receive_lock);
	up = get_up(muxl, id);
	spin_unlock(&muxl->receive_lock);
	if (up == NULL) {
		pr_info("Received data on unknown link ID = %d (0x%x) up == NULL",
			id, id);
		cfpkt_destroy(pkt);
		/*
		 * Don't return ERROR, since modem misbehaves and sends out
		 * flow on before linksetup response.
		 */
		return /* CFGLU_EPROT; */ 0;
	}
	cfsrvl_get(up);
	ret = up->receive(up, pkt);
	cfsrvl_put(up);
	return ret;
}

static int cfmuxl_transmit(struct cflayer *layr, struct cfpkt *pkt)
{
	int ret;
	struct cfmuxl *muxl = container_obj(layr);
	u8 linkid;
	struct cflayer *dn;
	struct caif_payload_info *info = cfpkt_info(pkt);
	dn = get_dn(muxl, cfpkt_info(pkt)->dev_info);
	if (dn == NULL) {
		pr_warn("Send data on unknown phy ID = %d (0x%x)\n",
			info->dev_info->id, info->dev_info->id);
		return -ENOTCONN;
	}
	info->hdr_len += 1;
	linkid = info->channel_id;
	cfpkt_add_head(pkt, &linkid, 1);
	ret = dn->transmit(dn, pkt);
	/* Remove MUX protocol header upon error. */
	if (ret < 0)
		cfpkt_extr_head(pkt, &linkid, 1);
	return ret;
}

static void cfmuxl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
				int phyid)
{
	struct cfmuxl *muxl = container_obj(layr);
	struct list_head *node;
	struct cflayer *layer;
	list_for_each(node, &muxl->srvl_list) {
		layer = list_entry(node, struct cflayer, node);
		if (cfsrvl_phyid_match(layer, phyid))
			layer->ctrlcmd(layer, ctrl, phyid);
	}
}

Privacy Policy