diff mbox series

[net-next,v7,4/6] net: dsa: microchip: ksz8: add MTU configuration support

Message ID 20221205052232.2834166-5-o.rempel@pengutronix.de (mailing list archive)
State Accepted
Commit 29d1e85f45e03c9fd1b8985f983f33c021e130c8
Delegated to: Netdev Maintainers
Headers show
Series net: dsa: microchip: add MTU support for KSZ8 series | expand

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netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 1 maintainers not CCed: linux@armlinux.org.uk
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 109 lines checked
netdev/kdoc success Errors and warnings before: 1 this patch: 1
netdev/source_inline success Was 0 now: 0

Commit Message

Oleksij Rempel Dec. 5, 2022, 5:22 a.m. UTC 
Make MTU configurable on KSZ87xx and KSZ88xx series of switches.

Before this patch, pre-configured behavior was different on different
switch series, due to opposite meaning of the same bit:
- KSZ87xx: Reg 4, Bit 1 - if 1, max frame size is 1532; if 0 - 1514
- KSZ88xx: Reg 4, Bit 1 - if 1, max frame size is 1514; if 0 - 1532

Since the code was telling "... SW_LEGAL_PACKET_DISABLE, true)", I
assume, the idea was to set max frame size to 1532.

With this patch, by setting MTU size 1500, both switch series will be
configured to the 1532 frame limit.

This patch was tested on KSZ8873.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/dsa/microchip/ksz8.h        |  1 +
 drivers/net/dsa/microchip/ksz8795.c     | 53 ++++++++++++++++++++++++-
 drivers/net/dsa/microchip/ksz8795_reg.h |  3 ++
 drivers/net/dsa/microchip/ksz_common.c  |  7 ++++
 drivers/net/dsa/microchip/ksz_common.h  |  4 ++
 5 files changed, 66 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/dsa/microchip/ksz8.h b/drivers/net/dsa/microchip/ksz8.h
index 8582b4b67d98..ea05abfbd51d 100644
--- a/drivers/net/dsa/microchip/ksz8.h
+++ b/drivers/net/dsa/microchip/ksz8.h
@@ -57,5 +57,6 @@  int ksz8_reset_switch(struct ksz_device *dev);
 int ksz8_switch_detect(struct ksz_device *dev);
 int ksz8_switch_init(struct ksz_device *dev);
 void ksz8_switch_exit(struct ksz_device *dev);
+int ksz8_change_mtu(struct ksz_device *dev, int port, int mtu);
 
 #endif
diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index bd3b133e7085..d01bfd609130 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -76,6 +76,57 @@  int ksz8_reset_switch(struct ksz_device *dev)
 	return 0;
 }
 
+static int ksz8863_change_mtu(struct ksz_device *dev, int frame_size)
+{
+	u8 ctrl2 = 0;
+
+	if (frame_size <= KSZ8_LEGAL_PACKET_SIZE)
+		ctrl2 |= KSZ8863_LEGAL_PACKET_ENABLE;
+	else if (frame_size > KSZ8863_NORMAL_PACKET_SIZE)
+		ctrl2 |= KSZ8863_HUGE_PACKET_ENABLE;
+
+	return ksz_rmw8(dev, REG_SW_CTRL_2, KSZ8863_LEGAL_PACKET_ENABLE |
+			KSZ8863_HUGE_PACKET_ENABLE, ctrl2);
+}
+
+static int ksz8795_change_mtu(struct ksz_device *dev, int frame_size)
+{
+	u8 ctrl1 = 0, ctrl2 = 0;
+	int ret;
+
+	if (frame_size > KSZ8_LEGAL_PACKET_SIZE)
+		ctrl2 |= SW_LEGAL_PACKET_DISABLE;
+	else if (frame_size > KSZ8863_NORMAL_PACKET_SIZE)
+		ctrl1 |= SW_HUGE_PACKET;
+
+	ret = ksz_rmw8(dev, REG_SW_CTRL_1, SW_HUGE_PACKET, ctrl1);
+	if (ret)
+		return ret;
+
+	return ksz_rmw8(dev, REG_SW_CTRL_2, SW_LEGAL_PACKET_DISABLE, ctrl2);
+}
+
+int ksz8_change_mtu(struct ksz_device *dev, int port, int mtu)
+{
+	u16 frame_size;
+
+	if (!dsa_is_cpu_port(dev->ds, port))
+		return 0;
+
+	frame_size = mtu + VLAN_ETH_HLEN + ETH_FCS_LEN;
+
+	switch (dev->chip_id) {
+	case KSZ8795_CHIP_ID:
+	case KSZ8794_CHIP_ID:
+	case KSZ8765_CHIP_ID:
+		return ksz8795_change_mtu(dev, frame_size);
+	case KSZ8830_CHIP_ID:
+		return ksz8863_change_mtu(dev, frame_size);
+	}
+
+	return -EOPNOTSUPP;
+}
+
 static void ksz8795_set_prio_queue(struct ksz_device *dev, int port, int queue)
 {
 	u8 hi, lo;
@@ -1233,8 +1284,6 @@  void ksz8_config_cpu_port(struct dsa_switch *ds)
 	masks = dev->info->masks;
 	regs = dev->info->regs;
 
-	/* Switch marks the maximum frame with extra byte as oversize. */
-	ksz_cfg(dev, REG_SW_CTRL_2, SW_LEGAL_PACKET_DISABLE, true);
 	ksz_cfg(dev, regs[S_TAIL_TAG_CTRL], masks[SW_TAIL_TAG_ENABLE], true);
 
 	p = &dev->ports[dev->cpu_port];
diff --git a/drivers/net/dsa/microchip/ksz8795_reg.h b/drivers/net/dsa/microchip/ksz8795_reg.h
index 77487d611824..7a57c6088f80 100644
--- a/drivers/net/dsa/microchip/ksz8795_reg.h
+++ b/drivers/net/dsa/microchip/ksz8795_reg.h
@@ -48,6 +48,9 @@ 
 #define NO_EXC_COLLISION_DROP		BIT(3)
 #define SW_LEGAL_PACKET_DISABLE		BIT(1)
 
+#define KSZ8863_HUGE_PACKET_ENABLE	BIT(2)
+#define KSZ8863_LEGAL_PACKET_ENABLE	BIT(1)
+
 #define REG_SW_CTRL_3			0x05
  #define WEIGHTED_FAIR_QUEUE_ENABLE	BIT(3)
 
diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index 49a5a236d958..f39b041765fb 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -172,6 +172,7 @@  static const struct ksz_dev_ops ksz8_dev_ops = {
 	.reset = ksz8_reset_switch,
 	.init = ksz8_switch_init,
 	.exit = ksz8_switch_exit,
+	.change_mtu = ksz8_change_mtu,
 };
 
 static void ksz9477_phylink_mac_link_up(struct ksz_device *dev, int port,
@@ -2500,6 +2501,12 @@  static int ksz_max_mtu(struct dsa_switch *ds, int port)
 	struct ksz_device *dev = ds->priv;
 
 	switch (dev->chip_id) {
+	case KSZ8795_CHIP_ID:
+	case KSZ8794_CHIP_ID:
+	case KSZ8765_CHIP_ID:
+		return KSZ8795_HUGE_PACKET_SIZE - VLAN_ETH_HLEN - ETH_FCS_LEN;
+	case KSZ8830_CHIP_ID:
+		return KSZ8863_HUGE_PACKET_SIZE - VLAN_ETH_HLEN - ETH_FCS_LEN;
 	case KSZ8563_CHIP_ID:
 	case KSZ9477_CHIP_ID:
 	case KSZ9563_CHIP_ID:
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index 5f404a444ce1..cb27f5a180c7 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -591,6 +591,10 @@  static inline int is_lan937x(struct ksz_device *dev)
 
 #define PORT_SRC_PHY_INT		1
 
+#define KSZ8795_HUGE_PACKET_SIZE	2000
+#define KSZ8863_HUGE_PACKET_SIZE	1916
+#define KSZ8863_NORMAL_PACKET_SIZE	1536
+#define KSZ8_LEGAL_PACKET_SIZE		1518
 #define KSZ9477_MAX_FRAME_SIZE		9000
 
 /* Regmap tables generation */