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>

3 files changed, 40 insertions, 0 deletions

diff --git a/include/net/caif/caif_dev.h b/include/net/caif/caif_dev.h
index 3aa1ff642323..318ab9478a44 100644
--- a/include/net/caif/caif_dev.h
+++ b/include/net/caif/caif_dev.h
@@ -70,6 +70,17 @@ int caif_connect_client(struct caif_connect_request *config,
 int caif_disconnect_client(struct cflayer *client_layer);
 
 /**
+ * caif_release_client - Release adaptation layer reference to client.
+ *
+ * @client_layer: Client layer.
+ *
+ * Releases a client/adaptation layer use of the caif stack.
+ * This function must be used after caif_disconnect_client to
+ * decrease the reference count of the service layer.
+ */
+void caif_release_client(struct cflayer *client_layer);
+
+/**
  * connect_req_to_link_param - Translate configuration parameters
  *				from socket format to internal format.
  * @cnfg:	Pointer to configuration handler
diff --git a/include/net/caif/cfcnfg.h b/include/net/caif/cfcnfg.h
index f16b875acc48..9fc2fc20b884 100644
--- a/include/net/caif/cfcnfg.h
+++ b/include/net/caif/cfcnfg.h
@@ -97,6 +97,13 @@ int cfcnfg_disconn_adapt_layer(struct cfcnfg *cnfg,
 			struct cflayer *adap_layer);
 
 /**
+ * cfcnfg_release_adap_layer - Used by client to release the adaptation layer.
+ *
+ * @adap_layer: Adaptation layer.
+ */
+void cfcnfg_release_adap_layer(struct cflayer *adap_layer);
+
+/**
  * cfcnfg_add_adaptation_layer - Add an adaptation layer to the CAIF stack.
  *
  * The adaptation Layer is where the interface to application or higher-level
diff --git a/include/net/caif/cfsrvl.h b/include/net/caif/cfsrvl.h
index b2a12db20cd2..2dc9eb193ecf 100644
--- a/include/net/caif/cfsrvl.h
+++ b/include/net/caif/cfsrvl.h
@@ -9,14 +9,18 @@
 #include <linux/list.h>
 #include <linux/stddef.h>
 #include <linux/types.h>
+#include <linux/kref.h>
+
 struct cfsrvl {
 	struct cflayer layer;
 	bool open;
 	bool phy_flow_on;
 	bool modem_flow_on;
 	struct dev_info dev_info;
+	struct kref ref;
 };
 
+void cfsrvl_release(struct kref *kref);
 struct cflayer *cfvei_create(u8 linkid, struct dev_info *dev_info);
 struct cflayer *cfdgml_create(u8 linkid, struct dev_info *dev_info);
 struct cflayer *cfutill_create(u8 linkid, struct dev_info *dev_info);
@@ -31,4 +35,22 @@ void cfsrvl_init(struct cfsrvl *service,
 bool cfsrvl_ready(struct cfsrvl *service, int *err);
 u8 cfsrvl_getphyid(struct cflayer *layer);
 
+static inline void cfsrvl_get(struct cflayer *layr)
+{
+	struct cfsrvl *s;
+	if (layr == NULL)
+		return;
+	s = container_of(layr, struct cfsrvl, layer);
+	kref_get(&s->ref);
+}
+
+static inline void cfsrvl_put(struct cflayer *layr)
+{
+	struct cfsrvl *s;
+	if (layr == NULL)
+		return;
+	s = container_of(layr, struct cfsrvl, layer);
+	kref_put(&s->ref, cfsrvl_release);
+}
+
 #endif				/* CFSRVL_H_ */