net/caif/cfmuxl.c

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