[RFC net-next 2/2] net: dsa: mt7530: trap packets from standalone ports to the CPU
From: DENG Qingfang
Date: Wed Jul 28 2021 - 13:53:57 EST
Consider the following bridge configuration, where bond0 is not
offloaded:
+-- br0 --+
/ / | \
/ / | \
/ | | bond0
/ | | / \
swp0 swp1 swp2 swp3 swp4
. . .
. . .
A B C
Ideally, when the switch receives a packet from swp3 or swp4, it should
forward the packet to the CPU, according to the port matrix and unknown
unicast flood settings.
But packet loss will happen if the destination address is at one of the
offloaded ports (swp0~2). For example, when client C sends a packet to
A, the FDB lookup will indicate that it should be forwarded to swp0, but
the port matrix of swp3 and swp4 is configured to only allow the CPU to
be its destination, so it is dropped.
MT7530's FDB has 8 filter IDs, but they are only available for shared
VLAN learning, and all VLAN-unaware ports use 0 as the default filter
ID.
Fortunately, MT7530 supports ACL, and the ACL action happens before the
FDB lookup. So we install an ACL rule which traps all packets to the
CPU, and enable it for standalone ports. This way, the packet loss can
be avoided.
Signed-off-by: DENG Qingfang <dqfext@xxxxxxxxx>
---
drivers/net/dsa/mt7530.c | 28 ++++++++++++++++++++
drivers/net/dsa/mt7530.h | 56 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 84 insertions(+)
diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 69f21b71614c..6b5c85446e6f 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -1228,6 +1228,8 @@ mt7530_port_bridge_join(struct dsa_switch *ds, int port,
mt7530_rmw(priv, MT7530_PCR_P(port),
PCR_MATRIX_MASK, PCR_MATRIX(port_bitmap));
priv->ports[port].pm |= PCR_MATRIX(port_bitmap);
+ /* Don't trap frames to the CPU port */
+ mt7530_clear(priv, MT7530_PCR_P(port), PORT_ACL_EN);
mutex_unlock(&priv->reg_mutex);
@@ -1328,6 +1330,8 @@ mt7530_port_bridge_leave(struct dsa_switch *ds, int port,
mt7530_rmw(priv, MT7530_PCR_P(port), PCR_MATRIX_MASK,
PCR_MATRIX(BIT(MT7530_CPU_PORT)));
priv->ports[port].pm = PCR_MATRIX(BIT(MT7530_CPU_PORT));
+ /* Trap all frames to the CPU port */
+ mt7530_set(priv, MT7530_PCR_P(port), PORT_ACL_EN);
mutex_unlock(&priv->reg_mutex);
}
@@ -2037,6 +2041,24 @@ mt7530_setup_mdio(struct mt7530_priv *priv)
return ret;
}
+static void
+mt7530_setup_acl(struct mt7530_priv *priv)
+{
+ u32 action;
+
+ /* Set ACL pattern mask to 0 to match unconditionally */
+ mt7530_write(priv, MT7530_VAWD1, 0);
+ mt7530_write(priv, MT7530_VAWD2, 0);
+ mt7530_vlan_cmd(priv, MT7530_VTCR_WR_ACL_MASK, 0);
+
+ /* Set ACL action to forward frames to the CPU port */
+ action = ACL_PORT_EN | ACL_PORT(BIT(MT7530_CPU_PORT)) |
+ ACL_EG_TAG(MT7530_VLAN_EG_CONSISTENT);
+ mt7530_write(priv, MT7530_VAWD1, action);
+ mt7530_write(priv, MT7530_VAWD2, 0);
+ mt7530_vlan_cmd(priv, MT7530_VTCR_WR_ACL_ACTION, 0);
+}
+
static int
mt7530_setup(struct dsa_switch *ds)
{
@@ -2133,6 +2155,8 @@ mt7530_setup(struct dsa_switch *ds)
/* Disable learning by default on all user ports */
mt7530_set(priv, MT7530_PSC_P(i), SA_DIS);
+ /* Trap all frames to the CPU port */
+ mt7530_set(priv, MT7530_PCR_P(i), PORT_ACL_EN);
}
/* Enable consistent egress tag */
mt7530_rmw(priv, MT7530_PVC_P(i), PVC_EG_TAG_MASK,
@@ -2300,6 +2324,8 @@ mt7531_setup(struct dsa_switch *ds)
/* Disable learning by default on all user ports */
mt7530_set(priv, MT7530_PSC_P(i), SA_DIS);
+ /* Trap all frames to the CPU port */
+ mt7530_set(priv, MT7530_PCR_P(i), PORT_ACL_EN);
}
/* Enable consistent egress tag */
@@ -3005,6 +3031,8 @@ mt753x_setup(struct dsa_switch *ds)
if (ret)
return ret;
+ mt7530_setup_acl(priv);
+
ret = mt7530_setup_irq(priv);
if (ret)
return ret;
diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
index b19b389ff10a..10cb278d7c36 100644
--- a/drivers/net/dsa/mt7530.h
+++ b/drivers/net/dsa/mt7530.h
@@ -137,6 +137,15 @@ enum mt7530_vlan_cmd {
*/
MT7530_VTCR_RD_VID = 0,
MT7530_VTCR_WR_VID = 1,
+ /* Read/Write the specified ACL rule pattern */
+ MT7530_VTCR_RD_ACL_PATTERN = 4,
+ MT7530_VTCR_WR_ACL_PATTERN = 5,
+ /* Read/Write the specified ACL rule mask */
+ MT7530_VTCR_RD_ACL_MASK = 8,
+ MT7530_VTCR_WR_ACL_MASK = 9,
+ /* Read/Write the specified ACL rule action */
+ MT7530_VTCR_RD_ACL_ACTION = 10,
+ MT7530_VTCR_WR_ACL_ACTION = 11,
};
/* Register for setup vlan and acl write data */
@@ -153,6 +162,35 @@ enum mt7530_vlan_cmd {
#define PORT_MEM_SHFT 16
#define PORT_MEM_MASK 0xff
+/* ACL rule pattern */
+#define BIT_CMP(x) (((x) & 0xffff) << 16)
+#define CMP_PAT(x) ((x) & 0xffff)
+
+/* ACL rule action */
+#define ACL_MANG BIT(29)
+#define ACL_INT_EN BIT(28)
+#define ACL_CNT_EN BIT(27)
+#define ACL_CNT_IDX(x) (((x) & 0x7) << 24)
+#define VLAN_PORT_EN BIT(23)
+#define DA_SWAP BIT(22)
+#define SA_SWAP BIT(21)
+#define PPP_RM BIT(20)
+#define LKY_VLAN BIT(19)
+#define ACL_EG_TAG(x) (((x) & 0x7) << 16)
+#define ACL_PORT(x) (((x) & 0xff) << 8)
+#define ACL_PORT_EN BIT(7)
+#define PRI_USER(x) (((x) & 0x7) << 4)
+#define ACL_MIR_EN BIT(3)
+#define ACL_PORT_FW(x) ((x) & 0x7)
+
+enum mt7530_to_cpu_port_fw {
+ PORT_FW_DEFAULT,
+ PORT_FW_EXCLUDE_CPU = 4,
+ PORT_FW_INCLUDE_CPU,
+ PORT_FW_CPU_ONLY,
+ PORT_FW_DROP,
+};
+
#define MT7530_VAWD2 0x98
/* Egress Tag Control */
#define ETAG_CTRL_P(p, x) (((x) & 0x3) << ((p) << 1))
@@ -164,6 +202,23 @@ enum mt7530_vlan_egress_attr {
MT7530_VLAN_EGRESS_STACK = 3,
};
+/* ACL rule pattern */
+#define ACL_TABLE_EN BIT(19)
+#define OFST_TP(x) (((x) & 0x7) << 16)
+#define ACL_SP(x) (((x) & 0xff) << 8)
+#define WORD_OFST(x) (((x) & 0x7f) << 1)
+#define CMP_SEL BIT(0)
+
+enum mt7530_acl_offset_type {
+ MT7530_ACL_MAC_HEADER,
+ MT7530_ACL_L2_PAYLOAD,
+ MT7530_ACL_IP_HEADER,
+ MT7530_ACL_IP_DATAGRAM,
+ MT7530_ACL_TCP_UDP_HEADER,
+ MT7530_ACL_TCP_UDP_DATAGRAM,
+ MT7530_ACL_IPV6_HEADER,
+};
+
/* Register for address age control */
#define MT7530_AAC 0xa0
/* Disable ageing */
@@ -192,6 +247,7 @@ enum mt7530_stp_state {
/* Register for port control */
#define MT7530_PCR_P(x) (0x2004 + ((x) * 0x100))
+#define PORT_ACL_EN BIT(10)
#define PORT_TX_MIR BIT(9)
#define PORT_RX_MIR BIT(8)
#define PORT_VLAN(x) ((x) & 0x3)
--
2.25.1