net: pcs: xpcs: export xpcs_validate

Calling a function pointer with a single implementation through
struct mdio_xpcs_ops is clunky, and the stmmac_do_callback system forces
this to return int, even though it always returns zero.

Simply remove the "validate" function pointer from struct mdio_xpcs_ops
and replace it with an exported xpcs_validate symbol which is called
directly by stmmac.

priv->hw->xpcs is of the type "const struct mdio_xpcs_ops *" and is used
as a placeholder/synonym for priv->plat->mdio_bus_data->has_xpcs. It is
done that way because the mdio_bus_data pointer might or might not be
populated in all stmmac instantiations.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/hwif.h

@@ -614,8 +614,6 @@ struct stmmac_mmc_ops {
 	stmmac_do_void_callback(__priv, mmc, read, __args)
 
 /* XPCS callbacks */
-#define stmmac_xpcs_validate(__priv, __args...) \
-	stmmac_do_callback(__priv, xpcs, validate, __args)
 #define stmmac_xpcs_config(__priv, __args...) \
 	stmmac_do_callback(__priv, xpcs, config, __args)
 #define stmmac_xpcs_get_state(__priv, __args...) \

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -996,7 +996,8 @@ static void stmmac_validate(struct phylink_config *config,
 	linkmode_andnot(state->advertising, state->advertising, mask);
 
 	/* If PCS is supported, check which modes it supports. */
-	stmmac_xpcs_validate(priv, &priv->hw->xpcs_args, supported, state);
+	if (priv->hw->xpcs)
+		xpcs_validate(&priv->hw->xpcs_args, supported, state);
 }
 
 static void stmmac_mac_pcs_get_state(struct phylink_config *config,

drivers/net/pcs/pcs-xpcs.c

@@ -685,9 +685,8 @@ static void xpcs_resolve_pma(struct mdio_xpcs_args *xpcs,
 	}
 }
 
-static int xpcs_validate(struct mdio_xpcs_args *xpcs,
-			 unsigned long *supported,
-			 struct phylink_link_state *state)
+void xpcs_validate(struct mdio_xpcs_args *xpcs, unsigned long *supported,
+		   struct phylink_link_state *state)
 {
 	__ETHTOOL_DECLARE_LINK_MODE_MASK(xpcs_supported);
 	const struct xpcs_compat *compat;
@@ -698,7 +697,7 @@ static int xpcs_validate(struct mdio_xpcs_args *xpcs,
 	 * advertising masks and exit.
 	 */
 	if (state->interface == PHY_INTERFACE_MODE_NA)
-		return 0;
+		return;
 
 	bitmap_zero(xpcs_supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
 
@@ -713,9 +712,8 @@ static int xpcs_validate(struct mdio_xpcs_args *xpcs,
 
 	linkmode_and(supported, supported, xpcs_supported);
 	linkmode_and(state->advertising, state->advertising, xpcs_supported);
-
-	return 0;
 }
+EXPORT_SYMBOL_GPL(xpcs_validate);
 
 static int xpcs_config_eee(struct mdio_xpcs_args *xpcs, int mult_fact_100ns,
 			   int enable)
@@ -1031,7 +1029,6 @@ static int xpcs_probe(struct mdio_xpcs_args *xpcs, phy_interface_t interface)
 }
 
 static struct mdio_xpcs_ops xpcs_ops = {
-	.validate = xpcs_validate,
 	.config = xpcs_config,
 	.get_state = xpcs_get_state,
 	.link_up = xpcs_link_up,

include/linux/pcs/pcs-xpcs.h

@@ -23,9 +23,6 @@ struct mdio_xpcs_args {
 };
 
 struct mdio_xpcs_ops {
-	int (*validate)(struct mdio_xpcs_args *xpcs,
-			unsigned long *supported,
-			struct phylink_link_state *state);
 	int (*config)(struct mdio_xpcs_args *xpcs,
 		      const struct phylink_link_state *state);
 	int (*get_state)(struct mdio_xpcs_args *xpcs,
@@ -39,5 +36,7 @@ struct mdio_xpcs_ops {
 
 int xpcs_get_an_mode(struct mdio_xpcs_args *xpcs, phy_interface_t interface);
 struct mdio_xpcs_ops *mdio_xpcs_get_ops(void);
+void xpcs_validate(struct mdio_xpcs_args *xpcs, unsigned long *supported,
+		   struct phylink_link_state *state);
 
 #endif /* __LINUX_PCS_XPCS_H */