[PATCH net v3 0/3] net: dsa: rzn1-a5psw: fix STP states handling

[PATCH net v3 0/3] net: dsa: rzn1-a5psw: fix STP states handling

[alexis.lothore]

From: Alexis Lothoré <alexis.lothore@bootlin.com>

This small series fixes STP support and while adding a new function to
enable/disable learning, use that to disable learning on standalone ports
at switch setup as reported by Vladimir Oltean.

This series was initially submitted on net-next by Clement Leger, but some
career evolutions has made him hand me over those topics.
Also, this new revision is submitted on net instead of net-next for V1
based on Vladimir Oltean's suggestion

Changes since v2:
- fix commit split by moving A5PSW_MGMT_CFG_ENABLE in relevant commit
- fix reverse christmas tree ordering in a5psw_port_stp_state_set

Changes since v1:
- fix typos in commit messages and doc
- re-split STP states handling commit
- add Fixes: tag and new Signed-off-by
- submit series as fix on net instead of net-next
- split learning and blocking setting functions
- remove unused define A5PSW_PORT_ENA_TX_SHIFT
- add boolean for tx/rx enabled for clarity

Alexis Lothoré (1):
  net: dsa: rzn1-a5psw: fix STP states handling

Clément Léger (2):
  net: dsa: rzn1-a5psw: enable management frames for CPU port
  net: dsa: rzn1-a5psw: disable learning for standalone ports

 drivers/net/dsa/rzn1_a5psw.c | 83 ++++++++++++++++++++++++++++--------
 drivers/net/dsa/rzn1_a5psw.h |  3 +-
 2 files changed, 67 insertions(+), 19 deletions(-)

-- 
2.40.1

[PATCH net v3 1/3] net: dsa: rzn1-a5psw: enable management frames for CPU port

[alexis.lothore]

From: Clément Léger <clement.leger@bootlin.com>

Currently, management frame were discarded before reaching the CPU port due
to a misconfiguration of the MGMT_CONFIG register. Enable them by setting
the correct value in this register in order to correctly receive management
frame and handle STP.

Fixes: 888cdb892b61 ("net: dsa: rzn1-a5psw: add Renesas RZ/N1 advanced 5 port switch driver")
Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
---
Changes since v2:
- move A5PSW_MGMT_CFG_ENABLE definition in this commit
---
 drivers/net/dsa/rzn1_a5psw.c | 2 +-
 drivers/net/dsa/rzn1_a5psw.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/dsa/rzn1_a5psw.c b/drivers/net/dsa/rzn1_a5psw.c
index 919027cf2012..8a419e2ffe2a 100644
--- a/drivers/net/dsa/rzn1_a5psw.c
+++ b/drivers/net/dsa/rzn1_a5psw.c
@@ -673,7 +673,7 @@ static int a5psw_setup(struct dsa_switch *ds)
 	}
 
 	/* Configure management port */
-	reg = A5PSW_CPU_PORT | A5PSW_MGMT_CFG_DISCARD;
+	reg = A5PSW_CPU_PORT | A5PSW_MGMT_CFG_ENABLE;
 	a5psw_reg_writel(a5psw, A5PSW_MGMT_CFG, reg);
 
 	/* Set pattern 0 to forward all frame to mgmt port */
diff --git a/drivers/net/dsa/rzn1_a5psw.h b/drivers/net/dsa/rzn1_a5psw.h
index c67abd49c013..b4fbf453ff74 100644
--- a/drivers/net/dsa/rzn1_a5psw.h
+++ b/drivers/net/dsa/rzn1_a5psw.h
@@ -36,7 +36,7 @@
 #define A5PSW_INPUT_LEARN_BLOCK(p)	BIT(p)
 
 #define A5PSW_MGMT_CFG			0x20
-#define A5PSW_MGMT_CFG_DISCARD		BIT(7)
+#define A5PSW_MGMT_CFG_ENABLE		BIT(6)
 
 #define A5PSW_MODE_CFG			0x24
 #define A5PSW_MODE_STATS_RESET		BIT(31)
-- 
2.40.1

[PATCH net v3 2/3] net: dsa: rzn1-a5psw: fix STP states handling

[alexis.lothore]

From: Alexis Lothoré <alexis.lothore@bootlin.com>

stp_set_state() should actually allow receiving BPDU while in LEARNING
mode which is not the case. Additionally, the BLOCKEN bit does not
actually forbid sending forwarded frames from that port. To fix this, add
a5psw_port_tx_enable() function which allows to disable TX. However, while
its name suggest that TX is totally disabled, it is not and can still
allow to send BPDUs even if disabled. This can be done by using forced
forwarding with the switch tagging mechanism but keeping "filtering"
disabled (which is already the case in the rzn1-a5sw tag driver). With
these fixes, STP support is now functional.

Fixes: 888cdb892b61 ("net: dsa: rzn1-a5psw: add Renesas RZ/N1 advanced 5 port switch driver")
Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
---
Changes since v2:
- move A5PSW_MGMT_CFG_ENABLE definition to previous commit
- fix reverse christmas tree ordering in a5psw_port_stp_state_set
---
 drivers/net/dsa/rzn1_a5psw.c | 57 ++++++++++++++++++++++++++++++------
 drivers/net/dsa/rzn1_a5psw.h |  1 +
 2 files changed, 49 insertions(+), 9 deletions(-)

diff --git a/drivers/net/dsa/rzn1_a5psw.c b/drivers/net/dsa/rzn1_a5psw.c
index 8a419e2ffe2a..e2549cb31d00 100644
--- a/drivers/net/dsa/rzn1_a5psw.c
+++ b/drivers/net/dsa/rzn1_a5psw.c
@@ -120,6 +120,22 @@ static void a5psw_port_mgmtfwd_set(struct a5psw *a5psw, int port, bool enable)
 	a5psw_port_pattern_set(a5psw, port, A5PSW_PATTERN_MGMTFWD, enable);
 }
 
+static void a5psw_port_tx_enable(struct a5psw *a5psw, int port, bool enable)
+{
+	u32 mask = A5PSW_PORT_ENA_TX(port);
+	u32 reg = enable ? mask : 0;
+
+	/* Even though the port TX is disabled through TXENA bit in the
+	 * PORT_ENA register, it can still send BPDUs. This depends on the tag
+	 * configuration added when sending packets from the CPU port to the
+	 * switch port. Indeed, when using forced forwarding without filtering,
+	 * even disabled ports will be able to send packets that are tagged.
+	 * This allows to implement STP support when ports are in a state where
+	 * forwarding traffic should be stopped but BPDUs should still be sent.
+	 */
+	a5psw_reg_rmw(a5psw, A5PSW_PORT_ENA, mask, reg);
+}
+
 static void a5psw_port_enable_set(struct a5psw *a5psw, int port, bool enable)
 {
 	u32 port_ena = 0;
@@ -292,6 +308,22 @@ static int a5psw_set_ageing_time(struct dsa_switch *ds, unsigned int msecs)
 	return 0;
 }
 
+static void a5psw_port_learning_set(struct a5psw *a5psw, int port, bool learn)
+{
+	u32 mask = A5PSW_INPUT_LEARN_DIS(port);
+	u32 reg = !learn ? mask : 0;
+
+	a5psw_reg_rmw(a5psw, A5PSW_INPUT_LEARN, mask, reg);
+}
+
+static void a5psw_port_rx_block_set(struct a5psw *a5psw, int port, bool block)
+{
+	u32 mask = A5PSW_INPUT_LEARN_BLOCK(port);
+	u32 reg = block ? mask : 0;
+
+	a5psw_reg_rmw(a5psw, A5PSW_INPUT_LEARN, mask, reg);
+}
+
 static void a5psw_flooding_set_resolution(struct a5psw *a5psw, int port,
 					  bool set)
 {
@@ -344,28 +376,35 @@ static void a5psw_port_bridge_leave(struct dsa_switch *ds, int port,
 
 static void a5psw_port_stp_state_set(struct dsa_switch *ds, int port, u8 state)
 {
-	u32 mask = A5PSW_INPUT_LEARN_DIS(port) | A5PSW_INPUT_LEARN_BLOCK(port);
+	bool learning_enabled, rx_enabled, tx_enabled;
 	struct a5psw *a5psw = ds->priv;
-	u32 reg = 0;
 
 	switch (state) {
 	case BR_STATE_DISABLED:
 	case BR_STATE_BLOCKING:
-		reg |= A5PSW_INPUT_LEARN_DIS(port);
-		reg |= A5PSW_INPUT_LEARN_BLOCK(port);
-		break;
 	case BR_STATE_LISTENING:
-		reg |= A5PSW_INPUT_LEARN_DIS(port);
+		rx_enabled = false;
+		tx_enabled = false;
+		learning_enabled = false;
 		break;
 	case BR_STATE_LEARNING:
-		reg |= A5PSW_INPUT_LEARN_BLOCK(port);
+		rx_enabled = false;
+		tx_enabled = false;
+		learning_enabled = true;
 		break;
 	case BR_STATE_FORWARDING:
-	default:
+		rx_enabled = true;
+		tx_enabled = true;
+		learning_enabled = true;
 		break;
+	default:
+		dev_err(ds->dev, "invalid STP state: %d\n", state);
+		return;
 	}
 
-	a5psw_reg_rmw(a5psw, A5PSW_INPUT_LEARN, mask, reg);
+	a5psw_port_learning_set(a5psw, port, learning_enabled);
+	a5psw_port_rx_block_set(a5psw, port, !rx_enabled);
+	a5psw_port_tx_enable(a5psw, port, tx_enabled);
 }
 
 static void a5psw_port_fast_age(struct dsa_switch *ds, int port)
diff --git a/drivers/net/dsa/rzn1_a5psw.h b/drivers/net/dsa/rzn1_a5psw.h
index b4fbf453ff74..b869192eef3f 100644
--- a/drivers/net/dsa/rzn1_a5psw.h
+++ b/drivers/net/dsa/rzn1_a5psw.h
@@ -19,6 +19,7 @@
 #define A5PSW_PORT_OFFSET(port)		(0x400 * (port))
 
 #define A5PSW_PORT_ENA			0x8
+#define A5PSW_PORT_ENA_TX(port)		BIT(port)
 #define A5PSW_PORT_ENA_RX_SHIFT		16
 #define A5PSW_PORT_ENA_TX_RX(port)	(BIT((port) + A5PSW_PORT_ENA_RX_SHIFT) | \
 					 BIT(port))
-- 
2.40.1

[PATCH net v3 3/3] net: dsa: rzn1-a5psw: disable learning for standalone ports

[alexis.lothore]

From: Clément Léger <clement.leger@bootlin.com>

When ports are in standalone mode, they should have learning disabled to
avoid adding new entries in the MAC lookup table which might be used by
other bridge ports to forward packets. While adding that, also make sure
learning is enabled for CPU port.

Fixes: 888cdb892b61 ("net: dsa: rzn1-a5psw: add Renesas RZ/N1 advanced 5 port switch driver")
Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
---
 drivers/net/dsa/rzn1_a5psw.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/drivers/net/dsa/rzn1_a5psw.c b/drivers/net/dsa/rzn1_a5psw.c
index e2549cb31d00..c37d2e537230 100644
--- a/drivers/net/dsa/rzn1_a5psw.c
+++ b/drivers/net/dsa/rzn1_a5psw.c
@@ -340,6 +340,14 @@ static void a5psw_flooding_set_resolution(struct a5psw *a5psw, int port,
 		a5psw_reg_writel(a5psw, offsets[i], a5psw->bridged_ports);
 }
 
+static void a5psw_port_set_standalone(struct a5psw *a5psw, int port,
+				      bool standalone)
+{
+	a5psw_port_learning_set(a5psw, port, !standalone);
+	a5psw_flooding_set_resolution(a5psw, port, !standalone);
+	a5psw_port_mgmtfwd_set(a5psw, port, standalone);
+}
+
 static int a5psw_port_bridge_join(struct dsa_switch *ds, int port,
 				  struct dsa_bridge bridge,
 				  bool *tx_fwd_offload,
@@ -355,8 +363,7 @@ static int a5psw_port_bridge_join(struct dsa_switch *ds, int port,
 	}
 
 	a5psw->br_dev = bridge.dev;
-	a5psw_flooding_set_resolution(a5psw, port, true);
-	a5psw_port_mgmtfwd_set(a5psw, port, false);
+	a5psw_port_set_standalone(a5psw, port, false);
 
 	return 0;
 }
@@ -366,8 +373,7 @@ static void a5psw_port_bridge_leave(struct dsa_switch *ds, int port,
 {
 	struct a5psw *a5psw = ds->priv;
 
-	a5psw_flooding_set_resolution(a5psw, port, false);
-	a5psw_port_mgmtfwd_set(a5psw, port, true);
+	a5psw_port_set_standalone(a5psw, port, true);
 
 	/* No more ports bridged */
 	if (a5psw->bridged_ports == BIT(A5PSW_CPU_PORT))
@@ -761,13 +767,15 @@ static int a5psw_setup(struct dsa_switch *ds)
 		if (dsa_port_is_unused(dp))
 			continue;
 
-		/* Enable egress flooding for CPU port */
-		if (dsa_port_is_cpu(dp))
+		/* Enable egress flooding and learning for CPU port */
+		if (dsa_port_is_cpu(dp)) {
 			a5psw_flooding_set_resolution(a5psw, port, true);
+			a5psw_port_learning_set(a5psw, port, true);
+		}
 
-		/* Enable management forward only for user ports */
+		/* Enable standalone mode for user ports */
 		if (dsa_port_is_user(dp))
-			a5psw_port_mgmtfwd_set(a5psw, port, true);
+			a5psw_port_set_standalone(a5psw, port, true);
 	}
 
 	return 0;
-- 
2.40.1

Re: [PATCH net v3 1/3] net: dsa: rzn1-a5psw: enable management frames for CPU port

[Piotr Raczynski]

On Fri, May 12, 2023 at 09:27:10AM +0200, alexis.lothore@bootlin.com wrote:
> From: Clément Léger <clement.leger@bootlin.com>
> 
> Currently, management frame were discarded before reaching the CPU port due
> to a misconfiguration of the MGMT_CONFIG register. Enable them by setting
> the correct value in this register in order to correctly receive management
> frame and handle STP.
> 
> Fixes: 888cdb892b61 ("net: dsa: rzn1-a5psw: add Renesas RZ/N1 advanced 5 port switch driver")
> Signed-off-by: Clément Léger <clement.leger@bootlin.com>
> Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
> ---
> Changes since v2:
> - move A5PSW_MGMT_CFG_ENABLE definition in this commit
> ---
Looks OK, thanks.
Reviewed-by: Piotr Raczynski <piotr.raczynski@intel.com>

Re: [PATCH net v3 3/3] net: dsa: rzn1-a5psw: disable learning for standalone ports

[Piotr Raczynski]

On Fri, May 12, 2023 at 09:27:12AM +0200, alexis.lothore@bootlin.com wrote:
> From: Clément Léger <clement.leger@bootlin.com>
> 
> When ports are in standalone mode, they should have learning disabled to
> avoid adding new entries in the MAC lookup table which might be used by
> other bridge ports to forward packets. While adding that, also make sure
> learning is enabled for CPU port.
> 
> Fixes: 888cdb892b61 ("net: dsa: rzn1-a5psw: add Renesas RZ/N1 advanced 5 port switch driver")
> Signed-off-by: Clément Léger <clement.leger@bootlin.com>
> Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
Reviewed-by: Piotr Raczynski <piotr.raczynski@intel.com>

Re: [PATCH net v3 0/3] net: dsa: rzn1-a5psw: fix STP states handling

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (main)
by David S. Miller <davem@davemloft.net>:

On Fri, 12 May 2023 09:27:09 +0200 you wrote:
> From: Alexis Lothoré <alexis.lothore@bootlin.com>
> 
> This small series fixes STP support and while adding a new function to
> enable/disable learning, use that to disable learning on standalone ports
> at switch setup as reported by Vladimir Oltean.
> 
> This series was initially submitted on net-next by Clement Leger, but some
> career evolutions has made him hand me over those topics.
> Also, this new revision is submitted on net instead of net-next for V1
> based on Vladimir Oltean's suggestion
> 
> [...]

Here is the summary with links:
  - [net,v3,1/3] net: dsa: rzn1-a5psw: enable management frames for CPU port
    https://git.kernel.org/netdev/net/c/9e4b45f20c5a
  - [net,v3,2/3] net: dsa: rzn1-a5psw: fix STP states handling
    https://git.kernel.org/netdev/net/c/ebe9bc509527
  - [net,v3,3/3] net: dsa: rzn1-a5psw: disable learning for standalone ports
    https://git.kernel.org/netdev/net/c/ec52b69c046a

You are awesome, thank you!
-- 
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