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
7 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
9 #include <linux/stddef.h>
10 #include <linux/spinlock.h>
11 #include <linux/slab.h>
12 #include <linux/rculist.h>
13 #include <net/caif/cfpkt.h>
14 #include <net/caif/cfmuxl.h>
15 #include <net/caif/cfsrvl.h>
16 #include <net/caif/cffrml.h>
18 #define container_obj(layr) container_of(layr, struct cfmuxl, layer)
20 #define CAIF_CTRL_CHANNEL 0
21 #define UP_CACHE_SIZE 8
22 #define DN_CACHE_SIZE 8
26 struct list_head srvl_list;
27 struct list_head frml_list;
28 struct cflayer *up_cache[UP_CACHE_SIZE];
29 struct cflayer *dn_cache[DN_CACHE_SIZE];
31 * Set when inserting or removing downwards layers.
33 spinlock_t transmit_lock;
36 * Set when inserting or removing upwards layers.
38 spinlock_t receive_lock;
42 static int cfmuxl_receive(struct cflayer *layr, struct cfpkt *pkt);
43 static int cfmuxl_transmit(struct cflayer *layr, struct cfpkt *pkt);
44 static void cfmuxl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
46 static struct cflayer *get_up(struct cfmuxl *muxl, u16 id);
48 struct cflayer *cfmuxl_create(void)
50 struct cfmuxl *this = kmalloc(sizeof(struct cfmuxl), GFP_ATOMIC);
53 memset(this, 0, sizeof(*this));
54 this->layer.receive = cfmuxl_receive;
55 this->layer.transmit = cfmuxl_transmit;
56 this->layer.ctrlcmd = cfmuxl_ctrlcmd;
57 INIT_LIST_HEAD(&this->srvl_list);
58 INIT_LIST_HEAD(&this->frml_list);
59 spin_lock_init(&this->transmit_lock);
60 spin_lock_init(&this->receive_lock);
61 snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "mux");
65 int cfmuxl_set_uplayer(struct cflayer *layr, struct cflayer *up, u8 linkid)
67 struct cfmuxl *muxl = container_obj(layr);
69 spin_lock_bh(&muxl->receive_lock);
70 list_add_rcu(&up->node, &muxl->srvl_list);
71 spin_unlock_bh(&muxl->receive_lock);
75 int cfmuxl_set_dnlayer(struct cflayer *layr, struct cflayer *dn, u8 phyid)
77 struct cfmuxl *muxl = (struct cfmuxl *) layr;
79 spin_lock_bh(&muxl->transmit_lock);
80 list_add_rcu(&dn->node, &muxl->frml_list);
81 spin_unlock_bh(&muxl->transmit_lock);
85 static struct cflayer *get_from_id(struct list_head *list, u16 id)
88 list_for_each_entry_rcu(lyr, list, node) {
96 struct cflayer *cfmuxl_remove_dnlayer(struct cflayer *layr, u8 phyid)
98 struct cfmuxl *muxl = container_obj(layr);
100 int idx = phyid % DN_CACHE_SIZE;
102 spin_lock_bh(&muxl->transmit_lock);
103 rcu_assign_pointer(muxl->dn_cache[idx], NULL);
104 dn = get_from_id(&muxl->frml_list, phyid);
108 list_del_rcu(&dn->node);
109 caif_assert(dn != NULL);
111 spin_unlock_bh(&muxl->transmit_lock);
115 static struct cflayer *get_up(struct cfmuxl *muxl, u16 id)
118 int idx = id % UP_CACHE_SIZE;
119 up = rcu_dereference(muxl->up_cache[idx]);
120 if (up == NULL || up->id != id) {
121 spin_lock_bh(&muxl->receive_lock);
122 up = get_from_id(&muxl->srvl_list, id);
123 rcu_assign_pointer(muxl->up_cache[idx], up);
124 spin_unlock_bh(&muxl->receive_lock);
129 static struct cflayer *get_dn(struct cfmuxl *muxl, struct dev_info *dev_info)
132 int idx = dev_info->id % DN_CACHE_SIZE;
133 dn = rcu_dereference(muxl->dn_cache[idx]);
134 if (dn == NULL || dn->id != dev_info->id) {
135 spin_lock_bh(&muxl->transmit_lock);
136 dn = get_from_id(&muxl->frml_list, dev_info->id);
137 rcu_assign_pointer(muxl->dn_cache[idx], dn);
138 spin_unlock_bh(&muxl->transmit_lock);
143 struct cflayer *cfmuxl_remove_uplayer(struct cflayer *layr, u8 id)
146 struct cfmuxl *muxl = container_obj(layr);
147 int idx = id % UP_CACHE_SIZE;
149 spin_lock_bh(&muxl->receive_lock);
150 up = get_from_id(&muxl->srvl_list, id);
154 rcu_assign_pointer(muxl->up_cache[idx], NULL);
155 list_del_rcu(&up->node);
157 spin_unlock_bh(&muxl->receive_lock);
161 static int cfmuxl_receive(struct cflayer *layr, struct cfpkt *pkt)
164 struct cfmuxl *muxl = container_obj(layr);
167 if (cfpkt_extr_head(pkt, &id, 1) < 0) {
168 pr_err("erroneous Caif Packet\n");
173 up = get_up(muxl, id);
176 pr_debug("Received data on unknown link ID = %d (0x%x)"
177 " up == NULL", id, id);
180 * Don't return ERROR, since modem misbehaves and sends out
181 * flow on before linksetup response.
185 return /* CFGLU_EPROT; */ 0;
188 /* We can't hold rcu_lock during receive, so take a ref count instead */
192 ret = up->receive(up, pkt);
198 static int cfmuxl_transmit(struct cflayer *layr, struct cfpkt *pkt)
200 struct cfmuxl *muxl = container_obj(layr);
204 struct caif_payload_info *info = cfpkt_info(pkt);
209 dn = get_dn(muxl, info->dev_info);
211 pr_debug("Send data on unknown phy ID = %d (0x%x)\n",
212 info->dev_info->id, info->dev_info->id);
219 linkid = info->channel_id;
220 cfpkt_add_head(pkt, &linkid, 1);
222 /* We can't hold rcu_lock during receive, so take a ref count instead */
227 err = dn->transmit(dn, pkt);
233 static void cfmuxl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
236 struct cfmuxl *muxl = container_obj(layr);
237 struct cflayer *layer;
240 list_for_each_entry_rcu(layer, &muxl->srvl_list, node) {
241 if (cfsrvl_phyid_match(layer, phyid) && layer->ctrlcmd)
242 /* NOTE: ctrlcmd is not allowed to block */
243 layer->ctrlcmd(layer, ctrl, phyid);