caif: Add reference counting to service layer

Changes:
o Added functions cfsrvl_get and cfsrvl_put.
o Added support release_client to use by socket and net device.
o Increase reference counting for in-flight packets from cfmuxl

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

4 files changed, 26 insertions, 1 deletions

diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c
index be1f674a3b67..0145bae0274f 100644
--- a/net/caif/caif_dev.c
+++ b/net/caif/caif_dev.c
@@ -346,6 +346,12 @@ int caif_disconnect_client(struct cflayer *adap_layer)
 }
 EXPORT_SYMBOL(caif_disconnect_client);
 
+void caif_release_client(struct cflayer *adap_layer)
+{
+       cfcnfg_release_adap_layer(adap_layer);
+}
+EXPORT_SYMBOL(caif_release_client);
+
 /* Per-namespace Caif devices handling */
 static int caif_init_net(struct net *net)
 {
diff --git a/net/caif/cfcnfg.c b/net/caif/cfcnfg.c
index d52f2566916e..f94f3dfe85c1 100644
--- a/net/caif/cfcnfg.c
+++ b/net/caif/cfcnfg.c
@@ -247,6 +247,13 @@ end:
 }
 EXPORT_SYMBOL(cfcnfg_disconn_adapt_layer);
 
+void cfcnfg_release_adap_layer(struct cflayer *adap_layer)
+{
+        if (adap_layer->dn)
+                cfsrvl_put(adap_layer->dn);
+}
+EXPORT_SYMBOL(cfcnfg_release_adap_layer);
+
 static void cfcnfg_linkdestroy_rsp(struct cflayer *layer, u8 channel_id,
                                   struct cflayer *client_layer)
 {
diff --git a/net/caif/cfmuxl.c b/net/caif/cfmuxl.c
index 6fb9f9e96cf8..7372f27f1d32 100644
--- a/net/caif/cfmuxl.c
+++ b/net/caif/cfmuxl.c
@@ -62,6 +62,7 @@ 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;
@@ -172,8 +173,11 @@ struct cflayer *cfmuxl_remove_uplayer(struct cflayer *layr, u8 id)
         struct cfmuxl *muxl = container_obj(layr);
         spin_lock(&muxl->receive_lock);
         up = get_up(muxl, id);
+        if (up == NULL)
+                return NULL;
         memset(muxl->up_cache, 0, sizeof(muxl->up_cache));
         list_del(&up->node);
+        cfsrvl_put(up);
         spin_unlock(&muxl->receive_lock);
         return up;
 }
@@ -203,8 +207,9 @@ static int cfmuxl_receive(struct cflayer *layr, struct cfpkt *pkt)
                  */
                 return /* CFGLU_EPROT; */ 0;
         }
-
+        cfsrvl_get(up);
         ret = up->receive(up, pkt);
+        cfsrvl_put(up);
         return ret;
 }
 
diff --git a/net/caif/cfsrvl.c b/net/caif/cfsrvl.c
index d470c51c6431..aff31f34528f 100644
--- a/net/caif/cfsrvl.c
+++ b/net/caif/cfsrvl.c
@@ -158,6 +158,13 @@ void cfsrvl_init(struct cfsrvl *service,
         service->layer.ctrlcmd = cfservl_ctrlcmd;
         service->layer.modemcmd = cfservl_modemcmd;
         service->dev_info = *dev_info;
+        kref_init(&service->ref);
+}
+
+void cfsrvl_release(struct kref *kref)
+{
+        struct cfsrvl *service = container_of(kref, struct cfsrvl, ref);
+        kfree(service);
 }
 
 bool cfsrvl_ready(struct cfsrvl *service, int *err)