[PATCH net 0/7] ksz8795 VLAN fixes

[PATCH net 0/7] ksz8795 VLAN fixes

[Ben Hutchings]

This series fixes a number of bugs in the ksz8795 driver that affect
VLAN filtering, tag insertion, and tag removal.

I've tested these on the KSZ8795CLXD evaluation board, and checked the
register usage against the datasheets for the other supported chips.

Ben.

Ben Hutchings (7):
  net: dsa: microchip: Fix ksz_read64()
  net: dsa: microchip: ksz8795: Fix PVID tag insertion
  net: dsa: microchip: ksz8795: Reject unsupported VLAN configuration
  net: dsa: microchip: ksz8795: Fix VLAN untagged flag change on
    deletion
  net: dsa: microchip: ksz8795: Use software untagging on CPU port
  net: dsa: microchip: ksz8795: Fix VLAN filtering
  net: dsa: microchip: ksz8795: Don't use phy_port_cnt in VLAN table
    lookup

 drivers/net/dsa/microchip/ksz8795.c     | 82 ++++++++++++++++++++-----
 drivers/net/dsa/microchip/ksz8795_reg.h |  4 ++
 drivers/net/dsa/microchip/ksz_common.h  |  9 +--
 3 files changed, 74 insertions(+), 21 deletions(-)

-- 
2.20.1

[PATCH net 1/7] net: dsa: microchip: Fix ksz_read64()

[Ben Hutchings]

ksz_read64() currently does some dubious byte-swapping on the two
halves of a 64-bit register, and then only returns the high bits.
Replace this with a straightforward expression.

Fixes: e66f840c08a2 ("net: dsa: ksz: Add Microchip KSZ8795 DSA driver")
Signed-off-by: Ben Hutchings <ben.hutchings@mind.be>
---
 drivers/net/dsa/microchip/ksz_common.h | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index 2e6bfd333f50..6afbb41ad39e 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -205,12 +205,8 @@ static inline int ksz_read64(struct ksz_device *dev, u32 reg, u64 *val)
 	int ret;
 
 	ret = regmap_bulk_read(dev->regmap[2], reg, value, 2);
-	if (!ret) {
-		/* Ick! ToDo: Add 64bit R/W to regmap on 32bit systems */
-		value[0] = swab32(value[0]);
-		value[1] = swab32(value[1]);
-		*val = swab64((u64)*value);
-	}
+	if (!ret)
+		*val = (u64)value[0] << 32 | value[1];
 
 	return ret;
 }
-- 
2.20.1

[PATCH net 2/7] net: dsa: microchip: ksz8795: Fix PVID tag insertion

[Ben Hutchings]

ksz8795 has never actually enabled PVID tag insertion, and it also
programmed the PVID incorrectly.  To fix this:

* Allow tag insertion to be controlled per ingress port.  On most
  chips, set bit 2 in Global Control 19.  On KSZ88x3 this control
  flag doesn't exist.

* When adding a PVID:
  - Set the appropriate register bits to enable tag insertion on
    egress at every other port if this was the packet's ingress port.
  - Mask *out* the VID from the default tag, before or-ing in the new
    PVID.

* When removing a PVID:
  - Clear the same control bits to disable tag insertion.
  - Don't update the default tag.  This wasn't doing anything useful.

Fixes: e66f840c08a2 ("net: dsa: ksz: Add Microchip KSZ8795 DSA driver")
Signed-off-by: Ben Hutchings <ben.hutchings@mind.be>
---
 drivers/net/dsa/microchip/ksz8795.c     | 26 ++++++++++++++++++-------
 drivers/net/dsa/microchip/ksz8795_reg.h |  4 ++++
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index b0e2b844478a..95842f7b2f1b 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -1124,6 +1124,16 @@ static int ksz8_port_vlan_filtering(struct dsa_switch *ds, int port, bool flag,
 	return 0;
 }
 
+static void ksz8_port_enable_pvid(struct ksz_device *dev, int port, bool state)
+{
+	if (ksz_is_ksz88x3(dev)) {
+		ksz_cfg(dev, REG_SW_INSERT_SRC_PVID,
+			0x03 << (4 - 2 * port), state);
+	} else {
+		ksz_pwrite8(dev, port, REG_PORT_CTRL_12, state ? 0x0f : 0x00);
+	}
+}
+
 static int ksz8_port_vlan_add(struct dsa_switch *ds, int port,
 			      const struct switchdev_obj_port_vlan *vlan,
 			      struct netlink_ext_ack *extack)
@@ -1160,9 +1170,11 @@ static int ksz8_port_vlan_add(struct dsa_switch *ds, int port,
 		u16 vid;
 
 		ksz_pread16(dev, port, REG_PORT_CTRL_VID, &vid);
-		vid &= 0xfff;
+		vid &= ~VLAN_VID_MASK;
 		vid |= new_pvid;
 		ksz_pwrite16(dev, port, REG_PORT_CTRL_VID, vid);
+
+		ksz8_port_enable_pvid(dev, port, true);
 	}
 
 	return 0;
@@ -1173,7 +1185,7 @@ static int ksz8_port_vlan_del(struct dsa_switch *ds, int port,
 {
 	bool untagged = vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED;
 	struct ksz_device *dev = ds->priv;
-	u16 data, pvid, new_pvid = 0;
+	u16 data, pvid;
 	u8 fid, member, valid;
 
 	if (ksz_is_ksz88x3(dev))
@@ -1195,14 +1207,11 @@ static int ksz8_port_vlan_del(struct dsa_switch *ds, int port,
 		valid = 0;
 	}
 
-	if (pvid == vlan->vid)
-		new_pvid = 1;
-
 	ksz8_to_vlan(dev, fid, member, valid, &data);
 	ksz8_w_vlan_table(dev, vlan->vid, data);
 
-	if (new_pvid != pvid)
-		ksz_pwrite16(dev, port, REG_PORT_CTRL_VID, pvid);
+	if (pvid == vlan->vid)
+		ksz8_port_enable_pvid(dev, port, false);
 
 	return 0;
 }
@@ -1438,6 +1447,9 @@ static int ksz8_setup(struct dsa_switch *ds)
 
 	ksz_cfg(dev, S_MIRROR_CTRL, SW_MIRROR_RX_TX, false);
 
+	if (!ksz_is_ksz88x3(dev))
+		ksz_cfg(dev, REG_SW_CTRL_19, SW_INS_TAG_ENABLE, true);
+
 	/* set broadcast storm protection 10% rate */
 	regmap_update_bits(dev->regmap[1], S_REPLACE_VID_CTRL,
 			   BROADCAST_STORM_RATE,
diff --git a/drivers/net/dsa/microchip/ksz8795_reg.h b/drivers/net/dsa/microchip/ksz8795_reg.h
index a32355624f31..6b40bc25f7ff 100644
--- a/drivers/net/dsa/microchip/ksz8795_reg.h
+++ b/drivers/net/dsa/microchip/ksz8795_reg.h
@@ -631,6 +631,10 @@
 #define REG_PORT_4_OUT_RATE_3		0xEE
 #define REG_PORT_5_OUT_RATE_3		0xFE
 
+/* 88x3 specific */
+
+#define REG_SW_INSERT_SRC_PVID		0xC2
+
 /* PME */
 
 #define SW_PME_OUTPUT_ENABLE		BIT(1)
-- 
2.20.1

[PATCH net 3/7] net: dsa: microchip: ksz8795: Reject unsupported VLAN configuration

[Ben Hutchings]

The switches supported by ksz8795 only have a per-port flag for Tag
Removal.  This means it is not possible to support both tagged and
untagged VLANs on the same port.  Reject attempts to add a VLAN that
requires the flag to be changed, unless there are no VLANs currently
configured.

VID 0 is excluded from this check since it is untagged regardless of
the state of the flag.

On the CPU port we could support tagged and untagged VLANs at the same
time.  This will be enabled by a later patch.

Fixes: e66f840c08a2 ("net: dsa: ksz: Add Microchip KSZ8795 DSA driver")
Signed-off-by: Ben Hutchings <ben.hutchings@mind.be>
---
 drivers/net/dsa/microchip/ksz8795.c    | 27 +++++++++++++++++++++++++-
 drivers/net/dsa/microchip/ksz_common.h |  1 +
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index 95842f7b2f1b..045786f4e29e 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -1140,13 +1140,38 @@ static int ksz8_port_vlan_add(struct dsa_switch *ds, int port,
 {
 	bool untagged = vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED;
 	struct ksz_device *dev = ds->priv;
+	struct ksz_port *p = &dev->ports[port];
 	u16 data, new_pvid = 0;
 	u8 fid, member, valid;
 
 	if (ksz_is_ksz88x3(dev))
 		return -ENOTSUPP;
 
-	ksz_port_cfg(dev, port, P_TAG_CTRL, PORT_REMOVE_TAG, untagged);
+	/* If a VLAN is added with untagged flag different from the
+	 * port's Remove Tag flag, we need to change the latter.
+	 * Ignore VID 0, which is always untagged.
+	 */
+	if (untagged != p->remove_tag && vlan->vid != 0) {
+		unsigned int vid;
+
+		/* Reject attempts to add a VLAN that requires the
+		 * Remove Tag flag to be changed, unless there are no
+		 * other VLANs currently configured.
+		 */
+		for (vid = 1; vid < dev->num_vlans; ++vid) {
+			/* Skip the VID we are going to add or reconfigure */
+			if (vid == vlan->vid)
+				continue;
+
+			ksz8_from_vlan(dev, dev->vlan_cache[vid].table[0],
+				       &fid, &member, &valid);
+			if (valid && (member & BIT(port)))
+				return -EINVAL;
+		}
+
+		ksz_port_cfg(dev, port, P_TAG_CTRL, PORT_REMOVE_TAG, untagged);
+		p->remove_tag = untagged;
+	}
 
 	ksz8_r_vlan_table(dev, vlan->vid, &data);
 	ksz8_from_vlan(dev, data, &fid, &member, &valid);
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index 6afbb41ad39e..1597c63988b4 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -27,6 +27,7 @@ struct ksz_port_mib {
 struct ksz_port {
 	u16 member;
 	u16 vid_member;
+	bool remove_tag;		/* Remove Tag flag set, for ksz8795 only */
 	int stp_state;
 	struct phy_device phydev;
 
-- 
2.20.1

[PATCH net 4/7] net: dsa: microchip: ksz8795: Fix VLAN untagged flag change on deletion

[Ben Hutchings]

When a VLAN is deleted from a port, the flags in struct
switchdev_obj_port_vlan are always 0.  ksz8_port_vlan_del() copies the
BRIDGE_VLAN_INFO_UNTAGGED flag to the port's Tag Removal flag, and
therefore always clears it.

In case there are multiple VLANs configured as untagged on this port -
which seems useless, but is allowed - deleting one of them changes the
remaining VLANs to be tagged.

It's only ever necessary to change this flag when a VLAN is added to
the port, so leave it unchanged in ksz8_port_vlan_del().

Fixes: e66f840c08a2 ("net: dsa: ksz: Add Microchip KSZ8795 DSA driver")
Signed-off-by: Ben Hutchings <ben.hutchings@mind.be>
---
 drivers/net/dsa/microchip/ksz8795.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index 045786f4e29e..7a3d0d137ed1 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -1208,7 +1208,6 @@ static int ksz8_port_vlan_add(struct dsa_switch *ds, int port,
 static int ksz8_port_vlan_del(struct dsa_switch *ds, int port,
 			      const struct switchdev_obj_port_vlan *vlan)
 {
-	bool untagged = vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED;
 	struct ksz_device *dev = ds->priv;
 	u16 data, pvid;
 	u8 fid, member, valid;
@@ -1219,8 +1218,6 @@ static int ksz8_port_vlan_del(struct dsa_switch *ds, int port,
 	ksz_pread16(dev, port, REG_PORT_CTRL_VID, &pvid);
 	pvid = pvid & 0xFFF;
 
-	ksz_port_cfg(dev, port, P_TAG_CTRL, PORT_REMOVE_TAG, untagged);
-
 	ksz8_r_vlan_table(dev, vlan->vid, &data);
 	ksz8_from_vlan(dev, data, &fid, &member, &valid);
 
-- 
2.20.1

[PATCH net 5/7] net: dsa: microchip: ksz8795: Use software untagging on CPU port

[Ben Hutchings]

On the CPU port, we can support both tagged and untagged VLANs at the
same time by doing any necessary untagging in software rather than
hardware.  To enable that, keep the CPU port's Remove Tag flag cleared
and set the dsa_switch::untag_bridge_pvid flag.

Fixes: e66f840c08a2 ("net: dsa: ksz: Add Microchip KSZ8795 DSA driver")
Signed-off-by: Ben Hutchings <ben.hutchings@mind.be>
---
 drivers/net/dsa/microchip/ksz8795.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index 7a3d0d137ed1..ddfe9cd6b7bd 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -1150,8 +1150,10 @@ static int ksz8_port_vlan_add(struct dsa_switch *ds, int port,
 	/* If a VLAN is added with untagged flag different from the
 	 * port's Remove Tag flag, we need to change the latter.
 	 * Ignore VID 0, which is always untagged.
+	 * Ignore CPU port, which will always be tagged.
 	 */
-	if (untagged != p->remove_tag && vlan->vid != 0) {
+	if (untagged != p->remove_tag && vlan->vid != 0 &&
+	    port != dev->cpu_port) {
 		unsigned int vid;
 
 		/* Reject attempts to add a VLAN that requires the
@@ -1767,6 +1769,11 @@ static int ksz8_switch_init(struct ksz_device *dev)
 	/* set the real number of ports */
 	dev->ds->num_ports = dev->port_cnt;
 
+	/* We rely on software untagging on the CPU port, so that we
+	 * can support both tagged and untagged VLANs
+	 */
+	dev->ds->untag_bridge_pvid = true;
+
 	return 0;
 }
 
-- 
2.20.1

[PATCH net 6/7] net: dsa: microchip: ksz8795: Fix VLAN filtering

[Ben Hutchings]

Currently ksz8_port_vlan_filtering() sets or clears the VLAN Enable
hardware flag.  That controls discarding of packets with a VID that
has not been enabled for any port on the switch.

Since it is a global flag, set the dsa_switch::vlan_filtering_is_global
flag so that the DSA core understands this can't be controlled per
port.

When VLAN filtering is enabled, the switch should also discard packets
with a VID that's not enabled on the ingress port.  Set or clear each
external port's VLAN Ingress Filter flag in ksz8_port_vlan_filtering()
to make that happen.

Fixes: e66f840c08a2 ("net: dsa: ksz: Add Microchip KSZ8795 DSA driver")
Signed-off-by: Ben Hutchings <ben.hutchings@mind.be>
---
 drivers/net/dsa/microchip/ksz8795.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index ddfe9cd6b7bd..891eaeb62ad0 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -1119,8 +1119,14 @@ static int ksz8_port_vlan_filtering(struct dsa_switch *ds, int port, bool flag,
 	if (ksz_is_ksz88x3(dev))
 		return -ENOTSUPP;
 
+	/* Discard packets with VID not enabled on the switch */
 	ksz_cfg(dev, S_MIRROR_CTRL, SW_VLAN_ENABLE, flag);
 
+	/* Discard packets with VID not enabled on the ingress port */
+	for (port = 0; port < dev->phy_port_cnt; ++port)
+		ksz_port_cfg(dev, port, REG_PORT_CTRL_2, PORT_INGRESS_FILTER,
+			     flag);
+
 	return 0;
 }
 
@@ -1774,6 +1780,11 @@ static int ksz8_switch_init(struct ksz_device *dev)
 	 */
 	dev->ds->untag_bridge_pvid = true;
 
+	/* VLAN filtering is partly controlled by the global VLAN
+	 * Enable flag
+	 */
+	dev->ds->vlan_filtering_is_global = true;
+
 	return 0;
 }
 
-- 
2.20.1

[PATCH net 7/7] net: dsa: microchip: ksz8795: Don't use phy_port_cnt in VLAN table lookup

[Ben Hutchings]

The magic number 4 in VLAN table lookup was the number of entries we
can read and write at once.  Using phy_port_cnt here doesn't make
sense and presumably broke VLAN filtering for 3-port switches.  Change
it back to 4.

Fixes: 4ce2a984abd8 ("net: dsa: microchip: ksz8795: use phy_port_cnt ...")
Signed-off-by: Ben Hutchings <ben.hutchings@mind.be>
---
 drivers/net/dsa/microchip/ksz8795.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index 891eaeb62ad0..4a6a3838418f 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -687,8 +687,8 @@ static void ksz8_r_vlan_entries(struct ksz_device *dev, u16 addr)
 	shifts = ksz8->shifts;
 
 	ksz8_r_table(dev, TABLE_VLAN, addr, &data);
-	addr *= dev->phy_port_cnt;
-	for (i = 0; i < dev->phy_port_cnt; i++) {
+	addr *= 4;
+	for (i = 0; i < 4; i++) {
 		dev->vlan_cache[addr + i].table[0] = (u16)data;
 		data >>= shifts[VLAN_TABLE];
 	}
@@ -702,7 +702,7 @@ static void ksz8_r_vlan_table(struct ksz_device *dev, u16 vid, u16 *vlan)
 	u64 buf;
 
 	data = (u16 *)&buf;
-	addr = vid / dev->phy_port_cnt;
+	addr = vid / 4;
 	index = vid & 3;
 	ksz8_r_table(dev, TABLE_VLAN, addr, &buf);
 	*vlan = data[index];
@@ -716,7 +716,7 @@ static void ksz8_w_vlan_table(struct ksz_device *dev, u16 vid, u16 vlan)
 	u64 buf;
 
 	data = (u16 *)&buf;
-	addr = vid / dev->phy_port_cnt;
+	addr = vid / 4;
 	index = vid & 3;
 	ksz8_r_table(dev, TABLE_VLAN, addr, &buf);
 	data[index] = vlan;
-- 
2.20.1

Re: [PATCH net 0/7] ksz8795 VLAN fixes

[Jakub Kicinski]

On Tue, 10 Aug 2021 00:57:54 +0200 Ben Hutchings wrote:
> This series fixes a number of bugs in the ksz8795 driver that affect
> VLAN filtering, tag insertion, and tag removal.
> 
> I've tested these on the KSZ8795CLXD evaluation board, and checked the
> register usage against the datasheets for the other supported chips.

Let's remember to CC authors of patches under Fixes, adding them now.

Re: [PATCH net 0/7] ksz8795 VLAN fixes

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (refs/heads/master):

On Tue, 10 Aug 2021 00:57:54 +0200 you wrote:
> This series fixes a number of bugs in the ksz8795 driver that affect
> VLAN filtering, tag insertion, and tag removal.
> 
> I've tested these on the KSZ8795CLXD evaluation board, and checked the
> register usage against the datasheets for the other supported chips.
> 
> Ben.
> 
> [...]

Here is the summary with links:
  - [net,1/7] net: dsa: microchip: Fix ksz_read64()
    https://git.kernel.org/netdev/net/c/c34f674c8875
  - [net,2/7] net: dsa: microchip: ksz8795: Fix PVID tag insertion
    https://git.kernel.org/netdev/net/c/ef3b02a1d79b
  - [net,3/7] net: dsa: microchip: ksz8795: Reject unsupported VLAN configuration
    https://git.kernel.org/netdev/net/c/8f4f58f88fe0
  - [net,4/7] net: dsa: microchip: ksz8795: Fix VLAN untagged flag change on deletion
    https://git.kernel.org/netdev/net/c/af01754f9e3c
  - [net,5/7] net: dsa: microchip: ksz8795: Use software untagging on CPU port
    https://git.kernel.org/netdev/net/c/9130c2d30c17
  - [net,6/7] net: dsa: microchip: ksz8795: Fix VLAN filtering
    https://git.kernel.org/netdev/net/c/164844135a3f
  - [net,7/7] net: dsa: microchip: ksz8795: Don't use phy_port_cnt in VLAN table lookup
    https://git.kernel.org/netdev/net/c/411d466d94a6

You are awesome, thank you!
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