diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 75464df191ef..ef10f5a70e5a 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -561,6 +561,35 @@ unsigned long phylink_get_capabilities(phy_interface_t interface,
 }
 EXPORT_SYMBOL_GPL(phylink_get_capabilities);
 
+/**
+ * phylink_validate_mask_caps() - Restrict link modes based on caps
+ * @supported: ethtool bitmask for supported link modes.
+ * @state: an (optional) pointer to a &struct phylink_link_state.
+ * @mac_capabilities: bitmask of MAC capabilities
+ *
+ * Calculate the supported link modes based on @mac_capabilities, and restrict
+ * @supported and @state based on that. Use this function if your capabiliies
+ * aren't constant, such as if they vary depending on the interface.
+ */
+void phylink_validate_mask_caps(unsigned long *supported,
+				struct phylink_link_state *state,
+				unsigned long mac_capabilities)
+{
+	__ETHTOOL_DECLARE_LINK_MODE_MASK(mask) = { 0, };
+	unsigned long caps;
+
+	phylink_set_port_modes(mask);
+	phylink_set(mask, Autoneg);
+	caps = phylink_get_capabilities(state->interface, mac_capabilities,
+					state->rate_matching);
+	phylink_caps_to_linkmodes(mask, caps);
+
+	linkmode_and(supported, supported, mask);
+	if (state)
+		linkmode_and(state->advertising, state->advertising, mask);
+}
+EXPORT_SYMBOL_GPL(phylink_validate_mask_caps);
+
 /**
  * phylink_generic_validate() - generic validate() callback implementation
  * @config: a pointer to a &struct phylink_config.
@@ -569,24 +598,12 @@ EXPORT_SYMBOL_GPL(phylink_get_capabilities);
  *
  * Generic implementation of the validate() callback that MAC drivers can
  * use when they pass the range of supported interfaces and MAC capabilities.
- * This makes use of phylink_get_linkmodes().
  */
 void phylink_generic_validate(struct phylink_config *config,
 			      unsigned long *supported,
 			      struct phylink_link_state *state)
 {
-	__ETHTOOL_DECLARE_LINK_MODE_MASK(mask) = { 0, };
-	unsigned long caps;
-
-	phylink_set_port_modes(mask);
-	phylink_set(mask, Autoneg);
-	caps = phylink_get_capabilities(state->interface,
-					config->mac_capabilities,
-					state->rate_matching);
-	phylink_caps_to_linkmodes(mask, caps);
-
-	linkmode_and(supported, supported, mask);
-	linkmode_and(state->advertising, state->advertising, mask);
+	phylink_validate_mask_caps(supported, state, config->mac_capabilities);
 }
 EXPORT_SYMBOL_GPL(phylink_generic_validate);
 
diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index 664dd409feb9..c29c3f174972 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -556,6 +556,9 @@ void phylink_caps_to_linkmodes(unsigned long *linkmodes, unsigned long caps);
 unsigned long phylink_get_capabilities(phy_interface_t interface,
 				       unsigned long mac_capabilities,
 				       int rate_matching);
+void phylink_validate_mask_caps(unsigned long *supported,
+				struct phylink_link_state *state,
+				unsigned long caps);
 void phylink_generic_validate(struct phylink_config *config,
 			      unsigned long *supported,
 			      struct phylink_link_state *state);