caif: Restructure how link caif link layer enroll

Enrolling CAIF link layers are refactored.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 132 insertions, 90 deletions

diff --git a/include/net/caif/caif_dev.h b/include/net/caif/caif_dev.h
index c011281d92c0..ef2dd9438bb1 100644
--- a/include/net/caif/caif_dev.h
+++ b/include/net/caif/caif_dev.h
@@ -9,6 +9,7 @@
 
 #include <net/caif/caif_layer.h>
 #include <net/caif/cfcnfg.h>
+#include <net/caif/caif_device.h>
 #include <linux/caif/caif_socket.h>
 #include <linux/if.h>
 #include <linux/net.h>
@@ -104,4 +105,24 @@ void caif_client_register_refcnt(struct cflayer *adapt_layer,
  */
 void caif_free_client(struct cflayer *adap_layer);
 
+/**
+ * struct caif_enroll_dev - Enroll a net-device as a CAIF Link layer
+ * @dev:                Network device to enroll.
+ * @caifdev:            Configuration information from CAIF Link Layer
+ * @link_support:       Link layer support layer
+ * @head_room:          Head room needed by link support layer
+ * @layer:              Lowest layer in CAIF stack
+ * @rcv_fun:            Receive function for CAIF stack.
+ *
+ * This function enroll a CAIF link layer into CAIF Stack and
+ * expects the interface to be able to handle CAIF payload.
+ * The link_support layer is used to add any Link Layer specific
+ * framing.
+ */
+void caif_enroll_dev(struct net_device *dev, struct caif_dev_common *caifdev,
+                        struct cflayer *link_support, int head_room,
+                        struct cflayer **layer, int (**rcv_func)(
+                                struct sk_buff *, struct net_device *,
+                                struct packet_type *, struct net_device *));
+
 #endif /* CAIF_DEV_H_ */
diff --git a/include/net/caif/cfcnfg.h b/include/net/caif/cfcnfg.h
index 3e93a4a4b677..a421723e986f 100644
--- a/include/net/caif/cfcnfg.h
+++ b/include/net/caif/cfcnfg.h
@@ -72,15 +72,16 @@ void cfcnfg_remove(struct cfcnfg *cfg);
  * @phy_layer:  Specify the physical layer. The transmit function
  *              MUST be set in the structure.
  * @pref:       The phy (link layer) preference.
+ * @link_support: Protocol implementation for link layer specific protocol.
  * @fcs:        Specify if checksum is used in CAIF Framing Layer.
- * @stx:        Specify if Start Of Frame eXtention is used.
+ * @head_room:  Head space needed by link specific protocol.
  */
-
 void
-cfcnfg_add_phy_layer(struct cfcnfg *cnfg, enum cfcnfg_phy_type phy_type,
+cfcnfg_add_phy_layer(struct cfcnfg *cnfg,
                      struct net_device *dev, struct cflayer *phy_layer,
                      enum cfcnfg_phy_preference pref,
-                     bool fcs, bool stx);
+                     struct cflayer *link_support,
+                     bool fcs, int head_room);
 
 /**
  * cfcnfg_del_phy_layer - Deletes an phy layer from the CAIF stack.
diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c
index f1fa1f6e658d..70034c017825 100644
--- a/net/caif/caif_dev.c
+++ b/net/caif/caif_dev.c
@@ -24,6 +24,7 @@
 #include <net/caif/caif_layer.h>
 #include <net/caif/cfpkt.h>
 #include <net/caif/cfcnfg.h>
+#include <net/caif/cfserl.h>
 
 MODULE_LICENSE("GPL");
 
@@ -53,7 +54,8 @@ struct cfcnfg *get_cfcnfg(struct net *net)
         struct caif_net *caifn;
         BUG_ON(!net);
         caifn = net_generic(net, caif_net_id);
-        BUG_ON(!caifn);
+        if (!caifn)
+                return NULL;
         return caifn->cfg;
 }
 EXPORT_SYMBOL(get_cfcnfg);
@@ -63,7 +65,8 @@ static struct caif_device_entry_list *caif_device_list(struct net *net)
         struct caif_net *caifn;
         BUG_ON(!net);
         caifn = net_generic(net, caif_net_id);
-        BUG_ON(!caifn);
+        if (!caifn)
+                return NULL;
         return &caifn->caifdevs;
 }
 
@@ -92,7 +95,8 @@ static struct caif_device_entry *caif_device_alloc(struct net_device *dev)
         struct caif_device_entry *caifd;
 
         caifdevs = caif_device_list(dev_net(dev));
-        BUG_ON(!caifdevs);
+        if (!caifdevs)
+                return NULL;
 
         caifd = kzalloc(sizeof(*caifd), GFP_KERNEL);
         if (!caifd)
@@ -112,7 +116,9 @@ static struct caif_device_entry *caif_get(struct net_device *dev)
         struct caif_device_entry_list *caifdevs =
             caif_device_list(dev_net(dev));
         struct caif_device_entry *caifd;
-        BUG_ON(!caifdevs);
+        if (!caifdevs)
+                return NULL;
+
         list_for_each_entry_rcu(caifd, &caifdevs->list, list) {
                 if (caifd->netdev == dev)
                         return caifd;
@@ -129,6 +135,8 @@ static int transmit(struct cflayer *layer, struct cfpkt *pkt)
 
         skb = cfpkt_tonative(pkt);
         skb->dev = caifd->netdev;
+        skb_reset_network_header(skb);
+        skb->protocol = htons(ETH_P_CAIF);
 
         err = dev_queue_xmit(skb);
         if (err > 0)
@@ -172,7 +180,10 @@ static int receive(struct sk_buff *skb, struct net_device *dev,
 
         /* Release reference to stack upwards */
         caifd_put(caifd);
-        return 0;
+
+        if (err != 0)
+                err = NET_RX_DROP;
+        return err;
 }
 
 static struct packet_type caif_packet_type __read_mostly = {
@@ -203,6 +214,55 @@ static void dev_flowctrl(struct net_device *dev, int on)
         caifd_put(caifd);
 }
 
+void caif_enroll_dev(struct net_device *dev, struct caif_dev_common *caifdev,
+                        struct cflayer *link_support, int head_room,
+                        struct cflayer **layer, int (**rcv_func)(
+                                struct sk_buff *, struct net_device *,
+                                struct packet_type *, struct net_device *))
+{
+        struct caif_device_entry *caifd;
+        enum cfcnfg_phy_preference pref;
+        struct cfcnfg *cfg = get_cfcnfg(dev_net(dev));
+        struct caif_device_entry_list *caifdevs;
+
+        caifdevs = caif_device_list(dev_net(dev));
+        if (!cfg || !caifdevs)
+                return;
+        caifd = caif_device_alloc(dev);
+        if (!caifd)
+                return;
+        *layer = &caifd->layer;
+
+        switch (caifdev->link_select) {
+        case CAIF_LINK_HIGH_BANDW:
+                pref = CFPHYPREF_HIGH_BW;
+                break;
+        case CAIF_LINK_LOW_LATENCY:
+                pref = CFPHYPREF_LOW_LAT;
+                break;
+        default:
+                pref = CFPHYPREF_HIGH_BW;
+                break;
+        }
+        mutex_lock(&caifdevs->lock);
+        list_add_rcu(&caifd->list, &caifdevs->list);
+
+        strncpy(caifd->layer.name, dev->name,
+                sizeof(caifd->layer.name) - 1);
+        caifd->layer.name[sizeof(caifd->layer.name) - 1] = 0;
+        caifd->layer.transmit = transmit;
+        cfcnfg_add_phy_layer(cfg,
+                                dev,
+                                &caifd->layer,
+                                pref,
+                                link_support,
+                                caifdev->use_fcs,
+                                head_room);
+        mutex_unlock(&caifdevs->lock);
+        if (rcv_func)
+                *rcv_func = receive;
+}
+
 /* notify Caif of device events */
 static int caif_device_notify(struct notifier_block *me, unsigned long what,
                               void *arg)
@@ -210,62 +270,40 @@ static int caif_device_notify(struct notifier_block *me, unsigned long what,
         struct net_device *dev = arg;
         struct caif_device_entry *caifd = NULL;
         struct caif_dev_common *caifdev;
-        enum cfcnfg_phy_preference pref;
-        enum cfcnfg_phy_type phy_type;
         struct cfcnfg *cfg;
+        struct cflayer *layer, *link_support;
+        int head_room = 0;
         struct caif_device_entry_list *caifdevs;
 
-        if (dev->type != ARPHRD_CAIF)
-                return 0;
-
         cfg = get_cfcnfg(dev_net(dev));
-        if (cfg == NULL)
+        caifdevs = caif_device_list(dev_net(dev));
+        if (!cfg || !caifdevs)
                 return 0;
 
-        caifdevs = caif_device_list(dev_net(dev));
+        caifd = caif_get(dev);
+        if (caifd == NULL && dev->type != ARPHRD_CAIF)
+                return 0;
 
         switch (what) {
         case NETDEV_REGISTER:
-                caifd = caif_device_alloc(dev);
-                if (!caifd)
-                        return 0;
+                if (caifd != NULL)
+                        break;
 
                 caifdev = netdev_priv(dev);
-                caifdev->flowctrl = dev_flowctrl;
 
-                caifd->layer.transmit = transmit;
-
-                if (caifdev->use_frag)
-                        phy_type = CFPHYTYPE_FRAG;
-                else
-                        phy_type = CFPHYTYPE_CAIF;
-
-                switch (caifdev->link_select) {
-                case CAIF_LINK_HIGH_BANDW:
-                        pref = CFPHYPREF_HIGH_BW;
-                        break;
-                case CAIF_LINK_LOW_LATENCY:
-                        pref = CFPHYPREF_LOW_LAT;
-                        break;
-                default:
-                        pref = CFPHYPREF_HIGH_BW;
-                        break;
+                link_support = NULL;
+                if (caifdev->use_frag) {
+                        head_room = 1;
+                        link_support = cfserl_create(dev->ifindex,
+                                        CFPHYTYPE_FRAG, caifdev->use_stx);
+                        if (!link_support) {
+                                pr_warn("Out of memory\n");
+                                break;
+                        }
                 }
-                strncpy(caifd->layer.name, dev->name,
-                        sizeof(caifd->layer.name) - 1);
-                caifd->layer.name[sizeof(caifd->layer.name) - 1] = 0;
-
-                mutex_lock(&caifdevs->lock);
-                list_add_rcu(&caifd->list, &caifdevs->list);
-
-                cfcnfg_add_phy_layer(cfg,
-                                     phy_type,
-                                     dev,
-                                     &caifd->layer,
-                                     pref,
-                                     caifdev->use_fcs,
-                                     caifdev->use_stx);
-                mutex_unlock(&caifdevs->lock);
+                caif_enroll_dev(dev, caifdev, link_support, head_room,
+                                &layer, NULL);
+                caifdev->flowctrl = dev_flowctrl;
                 break;
 
         case NETDEV_UP:
@@ -371,17 +409,14 @@ static void caif_exit_net(struct net *net)
         struct caif_device_entry *caifd, *tmp;
         struct caif_device_entry_list *caifdevs =
             caif_device_list(net);
-        struct cfcnfg *cfg;
+        struct cfcnfg *cfg =  get_cfcnfg(net);
+
+        if (!cfg || !caifdevs)
+                return;
 
         rtnl_lock();
         mutex_lock(&caifdevs->lock);
 
-        cfg = get_cfcnfg(net);
-        if (cfg == NULL) {
-                mutex_unlock(&caifdevs->lock);
-                return;
-        }
-
         list_for_each_entry_safe(caifd, tmp, &caifdevs->list, list) {
                 int i = 0;
                 list_del_rcu(&caifd->list);
diff --git a/net/caif/cfcnfg.c b/net/caif/cfcnfg.c
index 00523ecc4ced..598aafb4cb51 100644
--- a/net/caif/cfcnfg.c
+++ b/net/caif/cfcnfg.c
@@ -45,8 +45,8 @@ struct cfcnfg_phyinfo {
         /* Interface index */
         int ifindex;
 
-        /* Use Start of frame extension */
-        bool use_stx;
+        /* Protocol head room added for CAIF link layer */
+        int head_room;
 
         /* Use Start of frame checksum */
         bool use_fcs;
@@ -187,11 +187,11 @@ int caif_disconnect_client(struct net *net, struct cflayer *adap_layer)
         if (channel_id != 0) {
                 struct cflayer *servl;
                 servl = cfmuxl_remove_uplayer(cfg->mux, channel_id);
+                cfctrl_linkdown_req(cfg->ctrl, channel_id, adap_layer);
                 if (servl != NULL)
                         layer_set_up(servl, NULL);
         } else
                 pr_debug("nothing to disconnect\n");
-        cfctrl_linkdown_req(cfg->ctrl, channel_id, adap_layer);
 
         /* Do RCU sync before initiating cleanup */
         synchronize_rcu();
@@ -350,9 +350,7 @@ int caif_connect_client(struct net *net, struct caif_connect_request *conn_req,
 
         *ifindex = phy->ifindex;
         *proto_tail = 2;
-        *proto_head =
-
-        protohead[param.linktype] + (phy->use_stx ? 1 : 0);
+        *proto_head = protohead[param.linktype] + phy->head_room;
 
         rcu_read_unlock();
 
@@ -460,13 +458,13 @@ unlock:
 }
 
 void
-cfcnfg_add_phy_layer(struct cfcnfg *cnfg, enum cfcnfg_phy_type phy_type,
+cfcnfg_add_phy_layer(struct cfcnfg *cnfg,
                      struct net_device *dev, struct cflayer *phy_layer,
                      enum cfcnfg_phy_preference pref,
-                     bool fcs, bool stx)
+                     struct cflayer *link_support,
+                     bool fcs, int head_room)
 {
         struct cflayer *frml;
-        struct cflayer *phy_driver = NULL;
         struct cfcnfg_phyinfo *phyinfo = NULL;
         int i;
         u8 phyid;
@@ -482,26 +480,13 @@ cfcnfg_add_phy_layer(struct cfcnfg *cnfg, enum cfcnfg_phy_type phy_type,
                         goto got_phyid;
         }
         pr_warn("Too many CAIF Link Layers (max 6)\n");
-        goto out_err;
+        goto out;
 
 got_phyid:
         phyinfo = kzalloc(sizeof(struct cfcnfg_phyinfo), GFP_ATOMIC);
         if (!phyinfo)
                 goto out_err;
 
-        switch (phy_type) {
-        case CFPHYTYPE_FRAG:
-                phy_driver =
-                    cfserl_create(CFPHYTYPE_FRAG, phyid, stx);
-                if (!phy_driver)
-                        goto out_err;
-                break;
-        case CFPHYTYPE_CAIF:
-                phy_driver = NULL;
-                break;
-        default:
-                goto out_err;
-        }
         phy_layer->id = phyid;
         phyinfo->pref = pref;
         phyinfo->id = phyid;
@@ -509,7 +494,7 @@ got_phyid:
         phyinfo->dev_info.dev = dev;
         phyinfo->phy_layer = phy_layer;
         phyinfo->ifindex = dev->ifindex;
-        phyinfo->use_stx = stx;
+        phyinfo->head_room = head_room;
         phyinfo->use_fcs = fcs;
 
         frml = cffrml_create(phyid, fcs);
@@ -519,23 +504,23 @@ got_phyid:
         phyinfo->frm_layer = frml;
         layer_set_up(frml, cnfg->mux);
 
-        if (phy_driver != NULL) {
-                phy_driver->id = phyid;
-                layer_set_dn(frml, phy_driver);
-                layer_set_up(phy_driver, frml);
-                layer_set_dn(phy_driver, phy_layer);
-                layer_set_up(phy_layer, phy_driver);
+        if (link_support != NULL) {
+                link_support->id = phyid;
+                layer_set_dn(frml, link_support);
+                layer_set_up(link_support, frml);
+                layer_set_dn(link_support, phy_layer);
+                layer_set_up(phy_layer, link_support);
         } else {
                 layer_set_dn(frml, phy_layer);
                 layer_set_up(phy_layer, frml);
         }
 
         list_add_rcu(&phyinfo->node, &cnfg->phys);
+out:
         mutex_unlock(&cnfg->lock);
         return;
 
 out_err:
-        kfree(phy_driver);
         kfree(phyinfo);
         mutex_unlock(&cnfg->lock);
 }