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/cfpkt.h>
13 #include <net/caif/cfmuxl.h>
14 #include <net/caif/cfsrvl.h>
15 #include <net/caif/cffrml.h>
16
17 #define container_obj(layr) container_of(layr, struct cfmuxl, layer)
18
19 #define CAIF_CTRL_CHANNEL 0
20 #define UP_CACHE_SIZE 8
21 #define DN_CACHE_SIZE 8
22
23 struct cfmuxl {
24 struct cflayer layer;
25 struct list_head srvl_list;
26 struct list_head frml_list;
27 struct cflayer *up_cache[UP_CACHE_SIZE];
28 struct cflayer *dn_cache[DN_CACHE_SIZE];
29 /*
30 * Set when inserting or removing downwards layers.
31 */
32 spinlock_t transmit_lock;
33
34 /*
35 * Set when inserting or removing upwards layers.
36 */
37 spinlock_t receive_lock;
38
39 };
40
41 static int cfmuxl_receive(struct cflayer *layr, struct cfpkt *pkt);
42 static int cfmuxl_transmit(struct cflayer *layr, struct cfpkt *pkt);
43 static void cfmuxl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
44 int phyid);
45 static struct cflayer *get_up(struct cfmuxl *muxl, u16 id);
46
cfmuxl_create(void)47 struct cflayer *cfmuxl_create(void)
48 {
49 struct cfmuxl *this = kmalloc(sizeof(struct cfmuxl), GFP_ATOMIC);
50 if (!this)
51 return NULL;
52 memset(this, 0, sizeof(*this));
53 this->layer.receive = cfmuxl_receive;
54 this->layer.transmit = cfmuxl_transmit;
55 this->layer.ctrlcmd = cfmuxl_ctrlcmd;
56 INIT_LIST_HEAD(&this->srvl_list);
57 INIT_LIST_HEAD(&this->frml_list);
58 spin_lock_init(&this->transmit_lock);
59 spin_lock_init(&this->receive_lock);
60 snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "mux");
61 return &this->layer;
62 }
63
cfmuxl_set_uplayer(struct cflayer * layr,struct cflayer * up,u8 linkid)64 int cfmuxl_set_uplayer(struct cflayer *layr, struct cflayer *up, u8 linkid)
65 {
66 struct cfmuxl *muxl = container_obj(layr);
67 spin_lock(&muxl->receive_lock);
68 cfsrvl_get(up);
69 list_add(&up->node, &muxl->srvl_list);
70 spin_unlock(&muxl->receive_lock);
71 return 0;
72 }
73
cfmuxl_is_phy_inuse(struct cflayer * layr,u8 phyid)74 bool cfmuxl_is_phy_inuse(struct cflayer *layr, u8 phyid)
75 {
76 struct list_head *node;
77 struct cflayer *layer;
78 struct cfmuxl *muxl = container_obj(layr);
79 bool match = false;
80 spin_lock(&muxl->receive_lock);
81
82 list_for_each(node, &muxl->srvl_list) {
83 layer = list_entry(node, struct cflayer, node);
84 if (cfsrvl_phyid_match(layer, phyid)) {
85 match = true;
86 break;
87 }
88
89 }
90 spin_unlock(&muxl->receive_lock);
91 return match;
92 }
93
cfmuxl_get_phyid(struct cflayer * layr,u8 channel_id)94 u8 cfmuxl_get_phyid(struct cflayer *layr, u8 channel_id)
95 {
96 struct cflayer *up;
97 int phyid;
98 struct cfmuxl *muxl = container_obj(layr);
99 spin_lock(&muxl->receive_lock);
100 up = get_up(muxl, channel_id);
101 if (up != NULL)
102 phyid = cfsrvl_getphyid(up);
103 else
104 phyid = 0;
105 spin_unlock(&muxl->receive_lock);
106 return phyid;
107 }
108
cfmuxl_set_dnlayer(struct cflayer * layr,struct cflayer * dn,u8 phyid)109 int cfmuxl_set_dnlayer(struct cflayer *layr, struct cflayer *dn, u8 phyid)
110 {
111 struct cfmuxl *muxl = (struct cfmuxl *) layr;
112 spin_lock(&muxl->transmit_lock);
113 list_add(&dn->node, &muxl->frml_list);
114 spin_unlock(&muxl->transmit_lock);
115 return 0;
116 }
117
get_from_id(struct list_head * list,u16 id)118 static struct cflayer *get_from_id(struct list_head *list, u16 id)
119 {
120 struct list_head *node;
121 struct cflayer *layer;
122 list_for_each(node, list) {
123 layer = list_entry(node, struct cflayer, node);
124 if (layer->id == id)
125 return layer;
126 }
127 return NULL;
128 }
129
cfmuxl_remove_dnlayer(struct cflayer * layr,u8 phyid)130 struct cflayer *cfmuxl_remove_dnlayer(struct cflayer *layr, u8 phyid)
131 {
132 struct cfmuxl *muxl = container_obj(layr);
133 struct cflayer *dn;
134 spin_lock(&muxl->transmit_lock);
135 memset(muxl->dn_cache, 0, sizeof(muxl->dn_cache));
136 dn = get_from_id(&muxl->frml_list, phyid);
137 if (dn == NULL) {
138 spin_unlock(&muxl->transmit_lock);
139 return NULL;
140 }
141 list_del(&dn->node);
142 caif_assert(dn != NULL);
143 spin_unlock(&muxl->transmit_lock);
144 return dn;
145 }
146
147 /* Invariant: lock is taken */
get_up(struct cfmuxl * muxl,u16 id)148 static struct cflayer *get_up(struct cfmuxl *muxl, u16 id)
149 {
150 struct cflayer *up;
151 int idx = id % UP_CACHE_SIZE;
152 up = muxl->up_cache[idx];
153 if (up == NULL || up->id != id) {
154 up = get_from_id(&muxl->srvl_list, id);
155 muxl->up_cache[idx] = up;
156 }
157 return up;
158 }
159
160 /* Invariant: lock is taken */
get_dn(struct cfmuxl * muxl,struct dev_info * dev_info)161 static struct cflayer *get_dn(struct cfmuxl *muxl, struct dev_info *dev_info)
162 {
163 struct cflayer *dn;
164 int idx = dev_info->id % DN_CACHE_SIZE;
165 dn = muxl->dn_cache[idx];
166 if (dn == NULL || dn->id != dev_info->id) {
167 dn = get_from_id(&muxl->frml_list, dev_info->id);
168 muxl->dn_cache[idx] = dn;
169 }
170 return dn;
171 }
172
cfmuxl_remove_uplayer(struct cflayer * layr,u8 id)173 struct cflayer *cfmuxl_remove_uplayer(struct cflayer *layr, u8 id)
174 {
175 struct cflayer *up;
176 struct cfmuxl *muxl = container_obj(layr);
177 spin_lock(&muxl->receive_lock);
178 up = get_up(muxl, id);
179 if (up == NULL)
180 goto out;
181 memset(muxl->up_cache, 0, sizeof(muxl->up_cache));
182 list_del(&up->node);
183 cfsrvl_put(up);
184 out:
185 spin_unlock(&muxl->receive_lock);
186 return up;
187 }
188
cfmuxl_receive(struct cflayer * layr,struct cfpkt * pkt)189 static int cfmuxl_receive(struct cflayer *layr, struct cfpkt *pkt)
190 {
191 int ret;
192 struct cfmuxl *muxl = container_obj(layr);
193 u8 id;
194 struct cflayer *up;
195 if (cfpkt_extr_head(pkt, &id, 1) < 0) {
196 pr_err("erroneous Caif Packet\n");
197 cfpkt_destroy(pkt);
198 return -EPROTO;
199 }
200
201 spin_lock(&muxl->receive_lock);
202 up = get_up(muxl, id);
203 spin_unlock(&muxl->receive_lock);
204 if (up == NULL) {
205 pr_info("Received data on unknown link ID = %d (0x%x) up == NULL",
206 id, id);
207 cfpkt_destroy(pkt);
208 /*
209 * Don't return ERROR, since modem misbehaves and sends out
210 * flow on before linksetup response.
211 */
212 return /* CFGLU_EPROT; */ 0;
213 }
214 cfsrvl_get(up);
215 ret = up->receive(up, pkt);
216 cfsrvl_put(up);
217 return ret;
218 }
219
cfmuxl_transmit(struct cflayer * layr,struct cfpkt * pkt)220 static int cfmuxl_transmit(struct cflayer *layr, struct cfpkt *pkt)
221 {
222 int ret;
223 struct cfmuxl *muxl = container_obj(layr);
224 u8 linkid;
225 struct cflayer *dn;
226 struct caif_payload_info *info = cfpkt_info(pkt);
227 dn = get_dn(muxl, cfpkt_info(pkt)->dev_info);
228 if (dn == NULL) {
229 pr_warn("Send data on unknown phy ID = %d (0x%x)\n",
230 info->dev_info->id, info->dev_info->id);
231 return -ENOTCONN;
232 }
233 info->hdr_len += 1;
234 linkid = info->channel_id;
235 cfpkt_add_head(pkt, &linkid, 1);
236 ret = dn->transmit(dn, pkt);
237 /* Remove MUX protocol header upon error. */
238 if (ret < 0)
239 cfpkt_extr_head(pkt, &linkid, 1);
240 return ret;
241 }
242
cfmuxl_ctrlcmd(struct cflayer * layr,enum caif_ctrlcmd ctrl,int phyid)243 static void cfmuxl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
244 int phyid)
245 {
246 struct cfmuxl *muxl = container_obj(layr);
247 struct list_head *node, *next;
248 struct cflayer *layer;
249 list_for_each_safe(node, next, &muxl->srvl_list) {
250 layer = list_entry(node, struct cflayer, node);
251 if (cfsrvl_phyid_match(layer, phyid))
252 layer->ctrlcmd(layer, ctrl, phyid);
253 }
254 }
255