net: dsa: microchip: ksz8: add MTU configuration support

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>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/dsa/microchip/ksz8.h b/drivers/net/dsa/microchip/ksz8.h
index 8582b4b67d989f2fc2dc671adef90caa046c3dd4..ea05abfbd51d648624489782f054b429025c2b75 100644 (file)
--- 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 bd3b133e7085b8aea692c288f79ccaf39bdd44dd..d01bfd6091305fbfe1fabde784274a3cc98b0809 100644 (file)
--- 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 77487d61182420dfc7811fd4ed0442c761d6fd68..7a57c6088f8097eaa34f3f3c083486b5cd1d33da 100644 (file)
--- 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 49a5a236d95889ac2129e5d4ceefa3a4478be50e..f39b041765fb21768f1019b9909c3313c9ee1cfa 100644 (file)
--- 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 5f404a444ce115d922d0bc552eab15997af7a423..cb27f5a180c77e4e29422197895185f8cb87375d 100644 (file)
--- 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 */