Merge branch 'mt7530-dsa-subdriver-fix-vlan-egress-and-handling-of-all-link-local-frames'

 says:

====================
MT7530 DSA subdriver fix VLAN egress and handling of all link-local frames

This patch series fixes the VLAN tag egress procedure for link-local
frames, and fixes handling of all link-local frames.

Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
====================

Link: https://lore.kernel.org/r/20240314-b4-for-net-mt7530-fix-link-local-vlan-v2-0-7dbcf6429ba0@arinc9.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

2 files changed, 65 insertions, 9 deletions

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 6986f538a4d01..767f66c37f6b5 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -950,20 +950,56 @@ static void mt7530_setup_port5(struct dsa_switch *ds, phy_interface_t interface)
 	mutex_unlock(&priv->reg_mutex);
 }
 
+/* On page 205, section "8.6.3 Frame filtering" of the active standard, IEEE Std
+ * 802.1Q™-2022, it is stated that frames with 01:80:C2:00:00:00-0F as MAC DA
+ * must only be propagated to C-VLAN and MAC Bridge components. That means
+ * VLAN-aware and VLAN-unaware bridges. On the switch designs with CPU ports,
+ * these frames are supposed to be processed by the CPU (software). So we make
+ * the switch only forward them to the CPU port. And if received from a CPU
+ * port, forward to a single port. The software is responsible of making the
+ * switch conform to the latter by setting a single port as destination port on
+ * the special tag.
+ *
+ * This switch intellectual property cannot conform to this part of the standard
+ * fully. Whilst the REV_UN frame tag covers the remaining :04-0D and :0F MAC
+ * DAs, it also includes :22-FF which the scope of propagation is not supposed
+ * to be restricted for these MAC DAs.
+ */
 static void
 mt753x_trap_frames(struct mt7530_priv *priv)
 {
-	/* Trap BPDUs to the CPU port(s) */
-	mt7530_rmw(priv, MT753X_BPC, MT753X_BPDU_PORT_FW_MASK,
+	/* Trap 802.1X PAE frames and BPDUs to the CPU port(s) and egress them
+	 * VLAN-untagged.
+	 */
+	mt7530_rmw(priv, MT753X_BPC, MT753X_PAE_EG_TAG_MASK |
+		   MT753X_PAE_PORT_FW_MASK | MT753X_BPDU_EG_TAG_MASK |
+		   MT753X_BPDU_PORT_FW_MASK,
+		   MT753X_PAE_EG_TAG(MT7530_VLAN_EG_UNTAGGED) |
+		   MT753X_PAE_PORT_FW(MT753X_BPDU_CPU_ONLY) |
+		   MT753X_BPDU_EG_TAG(MT7530_VLAN_EG_UNTAGGED) |
 		   MT753X_BPDU_CPU_ONLY);
 
-	/* Trap 802.1X PAE frames to the CPU port(s) */
-	mt7530_rmw(priv, MT753X_BPC, MT753X_PAE_PORT_FW_MASK,
-		   MT753X_PAE_PORT_FW(MT753X_BPDU_CPU_ONLY));
+	/* Trap frames with :01 and :02 MAC DAs to the CPU port(s) and egress
+	 * them VLAN-untagged.
+	 */
+	mt7530_rmw(priv, MT753X_RGAC1, MT753X_R02_EG_TAG_MASK |
+		   MT753X_R02_PORT_FW_MASK | MT753X_R01_EG_TAG_MASK |
+		   MT753X_R01_PORT_FW_MASK,
+		   MT753X_R02_EG_TAG(MT7530_VLAN_EG_UNTAGGED) |
+		   MT753X_R02_PORT_FW(MT753X_BPDU_CPU_ONLY) |
+		   MT753X_R01_EG_TAG(MT7530_VLAN_EG_UNTAGGED) |
+		   MT753X_BPDU_CPU_ONLY);
 
-	/* Trap LLDP frames with :0E MAC DA to the CPU port(s) */
-	mt7530_rmw(priv, MT753X_RGAC2, MT753X_R0E_PORT_FW_MASK,
-		   MT753X_R0E_PORT_FW(MT753X_BPDU_CPU_ONLY));
+	/* Trap frames with :03 and :0E MAC DAs to the CPU port(s) and egress
+	 * them VLAN-untagged.
+	 */
+	mt7530_rmw(priv, MT753X_RGAC2, MT753X_R0E_EG_TAG_MASK |
+		   MT753X_R0E_PORT_FW_MASK | MT753X_R03_EG_TAG_MASK |
+		   MT753X_R03_PORT_FW_MASK,
+		   MT753X_R0E_EG_TAG(MT7530_VLAN_EG_UNTAGGED) |
+		   MT753X_R0E_PORT_FW(MT753X_BPDU_CPU_ONLY) |
+		   MT753X_R03_EG_TAG(MT7530_VLAN_EG_UNTAGGED) |
+		   MT753X_BPDU_CPU_ONLY);
 }
 
 static void
diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
index a71166e0a7fcf..d17b318e6ee48 100644
--- a/drivers/net/dsa/mt7530.h
+++ b/drivers/net/dsa/mt7530.h
@@ -65,14 +65,33 @@ enum mt753x_id {
 
 /* Registers for BPDU and PAE frame control*/
 #define MT753X_BPC			0x24
-#define  MT753X_BPDU_PORT_FW_MASK	GENMASK(2, 0)
+#define  MT753X_PAE_EG_TAG_MASK		GENMASK(24, 22)
+#define  MT753X_PAE_EG_TAG(x)		FIELD_PREP(MT753X_PAE_EG_TAG_MASK, x)
 #define  MT753X_PAE_PORT_FW_MASK	GENMASK(18, 16)
 #define  MT753X_PAE_PORT_FW(x)		FIELD_PREP(MT753X_PAE_PORT_FW_MASK, x)
+#define  MT753X_BPDU_EG_TAG_MASK	GENMASK(8, 6)
+#define  MT753X_BPDU_EG_TAG(x)		FIELD_PREP(MT753X_BPDU_EG_TAG_MASK, x)
+#define  MT753X_BPDU_PORT_FW_MASK	GENMASK(2, 0)
+
+/* Register for :01 and :02 MAC DA frame control */
+#define MT753X_RGAC1			0x28
+#define  MT753X_R02_EG_TAG_MASK		GENMASK(24, 22)
+#define  MT753X_R02_EG_TAG(x)		FIELD_PREP(MT753X_R02_EG_TAG_MASK, x)
+#define  MT753X_R02_PORT_FW_MASK	GENMASK(18, 16)
+#define  MT753X_R02_PORT_FW(x)		FIELD_PREP(MT753X_R02_PORT_FW_MASK, x)
+#define  MT753X_R01_EG_TAG_MASK		GENMASK(8, 6)
+#define  MT753X_R01_EG_TAG(x)		FIELD_PREP(MT753X_R01_EG_TAG_MASK, x)
+#define  MT753X_R01_PORT_FW_MASK	GENMASK(2, 0)
 
 /* Register for :03 and :0E MAC DA frame control */
 #define MT753X_RGAC2			0x2c
+#define  MT753X_R0E_EG_TAG_MASK		GENMASK(24, 22)
+#define  MT753X_R0E_EG_TAG(x)		FIELD_PREP(MT753X_R0E_EG_TAG_MASK, x)
 #define  MT753X_R0E_PORT_FW_MASK	GENMASK(18, 16)
 #define  MT753X_R0E_PORT_FW(x)		FIELD_PREP(MT753X_R0E_PORT_FW_MASK, x)
+#define  MT753X_R03_EG_TAG_MASK		GENMASK(8, 6)
+#define  MT753X_R03_EG_TAG(x)		FIELD_PREP(MT753X_R03_EG_TAG_MASK, x)
+#define  MT753X_R03_PORT_FW_MASK	GENMASK(2, 0)
 
 enum mt753x_bpdu_port_fw {
 	MT753X_BPDU_FOLLOW_MFC,
@@ -253,6 +272,7 @@ enum mt7530_port_mode {
 enum mt7530_vlan_port_eg_tag {
 	MT7530_VLAN_EG_DISABLED = 0,
 	MT7530_VLAN_EG_CONSISTENT = 1,
+	MT7530_VLAN_EG_UNTAGGED = 4,
 };
 
 enum mt7530_vlan_port_attr {