From 2d61298fdd7b57a81b2ef9ad99c5752f9bed6d14 Mon Sep 17 00:00:00 2001 From: Lukasz Majewski Date: Fri, 22 Sep 2023 15:31:08 +0200 Subject: net: dsa: microchip: Enable HSR offloading for KSZ9477 This patch adds functions for providing in KSZ9477 switch HSR (High-availability Seamless Redundancy) hardware offloading. According to AN3474 application note following features are provided: - TX packet duplication from host to switch (NETIF_F_HW_HSR_DUP) - RX packet duplication discarding - Prevention of packet loop For last two ones - there is a probability that some packets will not be filtered in HW (in some special cases - described in AN3474). Hence, the HSR core code shall be used to discard those not caught frames. Moreover, some switch registers adjustments are required - like setting MAC address of HSR network interface. Additionally, the KSZ9477 switch has been configured to forward frames between HSR ports (e.g. 1,2) members to provide support for NETIF_F_HW_HSR_FWD flag. Join and leave functions are written in a way, that are executed with single port - i.e. configuration is NOT done only when second HSR port is configured. Co-developed-by: Vladimir Oltean Signed-off-by: Vladimir Oltean Signed-off-by: Lukasz Majewski Reviewed-by: Vladimir Oltean Signed-off-by: Paolo Abeni --- drivers/net/dsa/microchip/ksz9477.c | 77 +++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) (limited to 'drivers/net/dsa/microchip/ksz9477.c') diff --git a/drivers/net/dsa/microchip/ksz9477.c b/drivers/net/dsa/microchip/ksz9477.c index 9e63ed820c92..cde8ef33d029 100644 --- a/drivers/net/dsa/microchip/ksz9477.c +++ b/drivers/net/dsa/microchip/ksz9477.c @@ -1143,6 +1143,83 @@ int ksz9477_tc_cbs_set_cinc(struct ksz_device *dev, int port, u32 val) return ksz_pwrite16(dev, port, REG_PORT_MTI_CREDIT_INCREMENT, val); } +/* The KSZ9477 provides following HW features to accelerate + * HSR frames handling: + * + * 1. TX PACKET DUPLICATION FROM HOST TO SWITCH + * 2. RX PACKET DUPLICATION DISCARDING + * 3. PREVENTING PACKET LOOP IN THE RING BY SELF-ADDRESS FILTERING + * + * Only one from point 1. has the NETIF_F* flag available. + * + * Ones from point 2 and 3 are "best effort" - i.e. those will + * work correctly most of the time, but it may happen that some + * frames will not be caught - to be more specific; there is a race + * condition in hardware such that, when duplicate packets are received + * on member ports very close in time to each other, the hardware fails + * to detect that they are duplicates. + * + * Hence, the SW needs to handle those special cases. However, the speed + * up gain is considerable when above features are used. + * + * Moreover, the NETIF_F_HW_HSR_FWD feature is also enabled, as HSR frames + * can be forwarded in the switch fabric between HSR ports. + */ +#define KSZ9477_SUPPORTED_HSR_FEATURES (NETIF_F_HW_HSR_DUP | NETIF_F_HW_HSR_FWD) + +void ksz9477_hsr_join(struct dsa_switch *ds, int port, struct net_device *hsr) +{ + struct ksz_device *dev = ds->priv; + struct net_device *slave; + struct dsa_port *hsr_dp; + u8 data, hsr_ports = 0; + + /* Program which port(s) shall support HSR */ + ksz_rmw32(dev, REG_HSR_PORT_MAP__4, BIT(port), BIT(port)); + + /* Forward frames between HSR ports (i.e. bridge together HSR ports) */ + if (dev->hsr_ports) { + dsa_hsr_foreach_port(hsr_dp, ds, hsr) + hsr_ports |= BIT(hsr_dp->index); + + hsr_ports |= BIT(dsa_upstream_port(ds, port)); + dsa_hsr_foreach_port(hsr_dp, ds, hsr) + ksz9477_cfg_port_member(dev, hsr_dp->index, hsr_ports); + } + + if (!dev->hsr_ports) { + /* Enable discarding of received HSR frames */ + ksz_read8(dev, REG_HSR_ALU_CTRL_0__1, &data); + data |= HSR_DUPLICATE_DISCARD; + data &= ~HSR_NODE_UNICAST; + ksz_write8(dev, REG_HSR_ALU_CTRL_0__1, data); + } + + /* Enable per port self-address filtering. + * The global self-address filtering has already been enabled in the + * ksz9477_reset_switch() function. + */ + ksz_port_cfg(dev, port, REG_PORT_LUE_CTRL, PORT_SRC_ADDR_FILTER, true); + + /* Setup HW supported features for lan HSR ports */ + slave = dsa_to_port(ds, port)->slave; + slave->features |= KSZ9477_SUPPORTED_HSR_FEATURES; +} + +void ksz9477_hsr_leave(struct dsa_switch *ds, int port, struct net_device *hsr) +{ + struct ksz_device *dev = ds->priv; + + /* Clear port HSR support */ + ksz_rmw32(dev, REG_HSR_PORT_MAP__4, BIT(port), 0); + + /* Disable forwarding frames between HSR ports */ + ksz9477_cfg_port_member(dev, port, BIT(dsa_upstream_port(ds, port))); + + /* Disable per port self-address filtering */ + ksz_port_cfg(dev, port, REG_PORT_LUE_CTRL, PORT_SRC_ADDR_FILTER, false); +} + int ksz9477_switch_init(struct ksz_device *dev) { u8 data8; -- cgit