net: dsa: add dsa_is_unused_port helper

As the comment above the chunk states, the b53 driver attempts to
disable the unused ports. But using ds->enabled_port_mask is misleading,
because this mask reports in fact the user ports.

To avoid confusion and fix this, this patch introduces an explicit
dsa_is_unused_port helper which ensures the corresponding bit is not
masked in any of the switch port masks.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 38961ef91d3d..6b1bc1c8f7e2 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -254,6 +254,13 @@ struct dsa_switch {
 	struct dsa_port ports[];
 };
 
+static inline bool dsa_is_unused_port(struct dsa_switch *ds, int p)
+{
+	u32 m = ds->enabled_port_mask | ds->dsa_port_mask | ds->cpu_port_mask;
+
+	return !(m & BIT(p));
+}
+
 static inline bool dsa_is_cpu_port(struct dsa_switch *ds, int p)
 {
 	return !!(ds->cpu_port_mask & (1 << p));