Messages in this thread Patch in this message | | | From | Lukasz Majewski <> | Subject | [[RFC PATCH v4 net-next] 2/2] net: dsa: hsr: Enable in KSZ9477 switch HW HSR offloading | Date | Wed, 6 Sep 2023 17:28:01 +0200 |
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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.
Signed-off-by: Lukasz Majewski <lukma@denx.de> --- Changes for v2: - Use struct ksz_device to store hsr ports information (not struct dsa)
Changes for v3: - Enable in-switch forwarding of frames between HSR ports (i.e. enable bridging of those two ports)
- The NETIF_F_HW_HSR_FWD flag has been marked as supported by the HSR network device
- Remove ETH MAC address validity check as it is done earlier in the net driver
- Add comment regarding adding support for NETIF_F_HW_HSR_FWD flag
Changes for v4: - Merge patches for ksz_common.c and ksz9477.c
- Remove code to set global self-address filtering as this bit has already been set at ksz9477_reset_switch() function. Update also comment.
- Use already available ksz9477_cfg_port_member() instead of ksz_prmw32()
- Add description about chip limitations
- Allow having only one offloaded hsr interface (e.g. hsr0). Other ones (like hsr1) will have only SW HSR support
- Add check if MAC address of HSR device is equal to one from DSA master - Rewrite the code to support per port join (i.e. not making init only when second HSR port is join) - Add check to allow only one HSR port HW offloading - Add hsr_ports to ksz_device struct to allow clean removal of network interfaces composing hsr device --- drivers/net/dsa/microchip/ksz9477.c | 81 ++++++++++++++++++++++++++ drivers/net/dsa/microchip/ksz9477.h | 2 + drivers/net/dsa/microchip/ksz_common.c | 76 ++++++++++++++++++++++++ drivers/net/dsa/microchip/ksz_common.h | 3 + 4 files changed, 162 insertions(+)
diff --git a/drivers/net/dsa/microchip/ksz9477.c b/drivers/net/dsa/microchip/ksz9477.c index 83b7f2d5c1ea..f36bc427c468 100644 --- a/drivers/net/dsa/microchip/ksz9477.c +++ b/drivers/net/dsa/microchip/ksz9477.c @@ -1141,6 +1141,87 @@ 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; + u8 i, data; + + /* 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) */ + ksz9477_cfg_port_member(dev, port, + BIT(dsa_upstream_port(ds, port)) | BIT(port)); + + 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); + + /* Self MAC address filtering for HSR frames to avoid + * traverse of the HSR ring more than once. + * + * The HSR port (i.e. hsr0) MAC address is used. + */ + for (i = 0; i < ETH_ALEN; i++) + ksz_write8(dev, REG_SW_MAC_ADDR_0 + i, + hsr->dev_addr[i]); + } + + /* 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; + + pr_debug("%s: HSR join port: %d\n", __func__, port); +} + +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; diff --git a/drivers/net/dsa/microchip/ksz9477.h b/drivers/net/dsa/microchip/ksz9477.h index a6f425866a29..8625bf474764 100644 --- a/drivers/net/dsa/microchip/ksz9477.h +++ b/drivers/net/dsa/microchip/ksz9477.h @@ -56,5 +56,7 @@ int ksz9477_reset_switch(struct ksz_device *dev); int ksz9477_switch_init(struct ksz_device *dev); void ksz9477_switch_exit(struct ksz_device *dev); void ksz9477_port_queue_split(struct ksz_device *dev, int port); +void ksz9477_hsr_join(struct dsa_switch *ds, int port, struct net_device *hsr); +void ksz9477_hsr_leave(struct dsa_switch *ds, int port, struct net_device *hsr); #endif diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c index 42db7679c360..b81c3ac422f9 100644 --- a/drivers/net/dsa/microchip/ksz_common.c +++ b/drivers/net/dsa/microchip/ksz_common.c @@ -16,6 +16,7 @@ #include <linux/etherdevice.h> #include <linux/if_bridge.h> #include <linux/if_vlan.h> +#include <linux/if_hsr.h> #include <linux/irq.h> #include <linux/irqdomain.h> #include <linux/of.h> @@ -3419,6 +3420,79 @@ static int ksz_setup_tc(struct dsa_switch *ds, int port, } } +static int ksz_hsr_join(struct dsa_switch *ds, int port, struct net_device *hsr) +{ + struct net_device *dm = dsa_port_to_master(dsa_to_port(ds, port)); + struct ksz_device *dev = ds->priv; + enum hsr_version ver; + int ret; + + ret = hsr_get_version(hsr, &ver); + if (ret) + return ret; + + /* Check if HSR net_device's MAC address equals to DSA master. + * + * Only in that way one can assure correct operation between + * different switch features - like WoL, PAUSE and HSR, which + * are using in-switch programmed MAC address. + */ + if (!ether_addr_equal(dm->dev_addr, hsr->dev_addr)) { + dev_err(dev->dev, + "DSA master and HSR dev MAC must equal for offloading"); + return -EOPNOTSUPP; + } + + switch (dev->chip_id) { + case KSZ9477_CHIP_ID: + /* KSZ9477 can support HW offloading of only 1 HSR device */ + if (dev->hsr_dev && hsr != dev->hsr_dev) { + dev_err(dev->dev, "Offload supported for a single HSR"); + return -EOPNOTSUPP; + } + + /* KSZ9477 only supports HSR v0 and v1 */ + if (!(ver == HSR_V0 || ver == HSR_V1)) { + dev_err(dev->dev, "Only HSR v0 and v1 supported"); + return -EOPNOTSUPP; + } + + ksz9477_hsr_join(ds, port, hsr); + dev->hsr_dev = hsr; + dev->hsr_ports |= BIT(port); + + break; + default: + return -EOPNOTSUPP; + } + + return 0; +} + +static int ksz_hsr_leave(struct dsa_switch *ds, int port, + struct net_device *hsr) +{ + struct ksz_device *dev = ds->priv; + int ret = 0; + + switch (dev->chip_id) { + case KSZ9477_CHIP_ID: + if (hsr != dev->hsr_dev) + return -EOPNOTSUPP; + + ksz9477_hsr_leave(ds, port, hsr); + dev->hsr_ports &= ~BIT(port); + if (!dev->hsr_ports) + dev->hsr_dev = NULL; + + break; + default: + return -EOPNOTSUPP; + } + + return ret; +} + static const struct dsa_switch_ops ksz_switch_ops = { .get_tag_protocol = ksz_get_tag_protocol, .connect_tag_protocol = ksz_connect_tag_protocol, @@ -3438,6 +3512,8 @@ static const struct dsa_switch_ops ksz_switch_ops = { .get_sset_count = ksz_sset_count, .port_bridge_join = ksz_port_bridge_join, .port_bridge_leave = ksz_port_bridge_leave, + .port_hsr_join = ksz_hsr_join, + .port_hsr_leave = ksz_hsr_leave, .port_stp_state_set = ksz_port_stp_state_set, .port_pre_bridge_flags = ksz_port_pre_bridge_flags, .port_bridge_flags = ksz_port_bridge_flags, diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h index a4de58847dea..e36d459de5a1 100644 --- a/drivers/net/dsa/microchip/ksz_common.h +++ b/drivers/net/dsa/microchip/ksz_common.h @@ -169,6 +169,9 @@ struct ksz_device { struct mutex lock_irq; /* IRQ Access */ struct ksz_irq girq; struct ksz_ptp_data ptp_data; + + struct net_device *hsr_dev; /* HSR */ + u8 hsr_ports; }; /* List of supported models */ -- 2.20.1
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