caif: Add ref-count to framing layer

Introduce Per-cpu reference for lower part of CAIF Stack.
Before freeing payload is disabled, synchronize_rcu() is called,
and then ref-count verified to be zero.

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

include/net/caif/cffrml.h

@@ -7,12 +7,15 @@
 #ifndef CFFRML_H_
 #define CFFRML_H_
 #include <net/caif/caif_layer.h>
+#include <linux/netdevice.h>
 
 struct cffrml;
-struct cflayer *cffrml_create(u16 phyid, bool DoFCS);
+struct cflayer *cffrml_create(u16 phyid, bool use_fcs);
+void cffrml_free(struct cflayer *layr);
 void cffrml_set_uplayer(struct cflayer *this, struct cflayer *up);
 void cffrml_set_dnlayer(struct cflayer *this, struct cflayer *dn);
 void cffrml_put(struct cflayer *layr);
 void cffrml_hold(struct cflayer *layr);
+int cffrml_refcnt_read(struct cflayer *layr);
 
 #endif /* CFFRML_H_ */