From: Mohsin Bashir Date: Mon, 2 Mar 2026 23:01:47 +0000 (-0800) Subject: eth: fbnic: Add protection against pause storm X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9b7c8728f53a5652a5184651c7b78ed1587542a4;p=thirdparty%2Fkernel%2Flinux.git eth: fbnic: Add protection against pause storm Add protection against TX pause storms. A pause storm occurs when a device fails to send received packets up to the stack. When a pause storm is detected (pause state persists beyond the configured timeout), the device stops sending the pause frames and begins dropping packets instead of back-pressuring. The timeout is configurable via ethtool tunable (pfc-prevention-tout) with a maximum value of 10485ms, and the default value of 500ms. Once the device transitions to the storm-detected state, the service task periodically attempts recovery, returning the device to normal operation to handle any subsequent pause storm episodes. Signed-off-by: Jakub Kicinski Signed-off-by: Mohsin Bashir Link: https://patch.msgid.link/20260302230149.1580195-4-mohsin.bashr@gmail.com Signed-off-by: Paolo Abeni --- diff --git a/drivers/net/ethernet/meta/fbnic/fbnic.h b/drivers/net/ethernet/meta/fbnic/fbnic.h index 779a083b92159..a760a27b15161 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic.h +++ b/drivers/net/ethernet/meta/fbnic/fbnic.h @@ -98,6 +98,9 @@ struct fbnic_dev { /* MDIO bus for PHYs */ struct mii_bus *mdio_bus; + + /* In units of ms since API supports values in ms */ + u16 ps_timeout; }; /* Reserve entry 0 in the MSI-X "others" array until we have filled all diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_csr.h b/drivers/net/ethernet/meta/fbnic/fbnic_csr.h index b717db879cd31..e68c56237b613 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_csr.h +++ b/drivers/net/ethernet/meta/fbnic/fbnic_csr.h @@ -230,6 +230,7 @@ enum { #define FBNIC_INTR_MSIX_CTRL_VECTOR_MASK CSR_GENMASK(7, 0) #define FBNIC_INTR_MSIX_CTRL_ENABLE CSR_BIT(31) enum { + FBNIC_INTR_MSIX_CTRL_RXB_IDX = 7, FBNIC_INTR_MSIX_CTRL_PCS_IDX = 34, }; @@ -560,6 +561,11 @@ enum { #define FBNIC_RXB_DROP_THLD_CNT 8 #define FBNIC_RXB_DROP_THLD_ON CSR_GENMASK(12, 0) #define FBNIC_RXB_DROP_THLD_OFF CSR_GENMASK(25, 13) +#define FBNIC_RXB_PAUSE_STORM(n) (0x08019 + (n)) /* 0x20064 + 4*n */ +#define FBNIC_RXB_PAUSE_STORM_CNT 4 +#define FBNIC_RXB_PAUSE_STORM_FORCE_NORMAL CSR_BIT(20) +#define FBNIC_RXB_PAUSE_STORM_THLD_TIME CSR_GENMASK(19, 0) +#define FBNIC_RXB_PAUSE_STORM_UNIT_WR 0x0801d /* 0x20074 */ #define FBNIC_RXB_ECN_THLD(n) (0x0801e + (n)) /* 0x20078 + 4*n */ #define FBNIC_RXB_ECN_THLD_CNT 8 #define FBNIC_RXB_ECN_THLD_ON CSR_GENMASK(12, 0) @@ -596,6 +602,9 @@ enum { #define FBNIC_RXB_INTF_CREDIT_MASK2 CSR_GENMASK(11, 8) #define FBNIC_RXB_INTF_CREDIT_MASK3 CSR_GENMASK(15, 12) +#define FBNIC_RXB_ERR_INTR_STS 0x08050 /* 0x20140 */ +#define FBNIC_RXB_ERR_INTR_STS_PS CSR_GENMASK(15, 12) +#define FBNIC_RXB_ERR_INTR_MASK 0x08052 /* 0x20148 */ #define FBNIC_RXB_PAUSE_EVENT_CNT(n) (0x08053 + (n)) /* 0x2014c + 4*n */ #define FBNIC_RXB_DROP_FRMS_STS(n) (0x08057 + (n)) /* 0x2015c + 4*n */ #define FBNIC_RXB_DROP_BYTES_STS_L(n) \ @@ -636,6 +645,7 @@ enum { #define FBNIC_RXB_PBUF_FIFO_LEVEL(n) (0x0811d + (n)) /* 0x20474 + 4*n */ +#define FBNIC_RXB_PAUSE_STORM_UNIT_RD 0x08125 /* 0x20494 */ #define FBNIC_RXB_INTEGRITY_ERR(n) (0x0812f + (n)) /* 0x204bc + 4*n */ #define FBNIC_RXB_MAC_ERR(n) (0x08133 + (n)) /* 0x204cc + 4*n */ #define FBNIC_RXB_PARSER_ERR(n) (0x08137 + (n)) /* 0x204dc + 4*n */ diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c index 401c2196b9ff3..ade9e667640f4 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c +++ b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c @@ -1641,6 +1641,47 @@ static void fbnic_get_ts_stats(struct net_device *netdev, } } +static int fbnic_get_tunable(struct net_device *netdev, + const struct ethtool_tunable *tun, + void *data) +{ + struct fbnic_net *fbn = netdev_priv(netdev); + int err = 0; + + switch (tun->id) { + case ETHTOOL_PFC_PREVENTION_TOUT: + *(u16 *)data = fbn->fbd->ps_timeout; + break; + default: + err = -EOPNOTSUPP; + break; + } + + return err; +} + +static int fbnic_set_tunable(struct net_device *netdev, + const struct ethtool_tunable *tun, + const void *data) +{ + struct fbnic_net *fbn = netdev_priv(netdev); + int err; + + switch (tun->id) { + case ETHTOOL_PFC_PREVENTION_TOUT: { + u16 ps_timeout = *(u16 *)data; + + err = fbnic_mac_ps_protect_to_config(fbn->fbd, ps_timeout); + break; + } + default: + err = -EOPNOTSUPP; + break; + } + + return err; +} + static int fbnic_get_module_eeprom_by_page(struct net_device *netdev, const struct ethtool_module_eeprom *page_data, @@ -1915,6 +1956,8 @@ static const struct ethtool_ops fbnic_ethtool_ops = { .set_channels = fbnic_set_channels, .get_ts_info = fbnic_get_ts_info, .get_ts_stats = fbnic_get_ts_stats, + .get_tunable = fbnic_get_tunable, + .set_tunable = fbnic_set_tunable, .get_link_ksettings = fbnic_phylink_ethtool_ksettings_get, .get_fec_stats = fbnic_get_fec_stats, .get_fecparam = fbnic_phylink_get_fecparam, diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_irq.c b/drivers/net/ethernet/meta/fbnic/fbnic_irq.c index 02e8b0b257fed..1e6a8fd6f702a 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_irq.c +++ b/drivers/net/ethernet/meta/fbnic/fbnic_irq.c @@ -170,6 +170,8 @@ int fbnic_mac_request_irq(struct fbnic_dev *fbd) fbnic_wr32(fbd, FBNIC_INTR_MSIX_CTRL(FBNIC_INTR_MSIX_CTRL_PCS_IDX), FBNIC_PCS_MSIX_ENTRY | FBNIC_INTR_MSIX_CTRL_ENABLE); + fbnic_wr32(fbd, FBNIC_INTR_MSIX_CTRL(FBNIC_INTR_MSIX_CTRL_RXB_IDX), 0); + fbd->mac_msix_vector = vector; return 0; diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_mac.c b/drivers/net/ethernet/meta/fbnic/fbnic_mac.c index 9d0e4b2cc9ac4..805107ba3b101 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_mac.c +++ b/drivers/net/ethernet/meta/fbnic/fbnic_mac.c @@ -143,6 +143,7 @@ static void fbnic_mac_init_qm(struct fbnic_dev *fbd) #define FBNIC_DROP_EN_MASK 0x7d #define FBNIC_PAUSE_EN_MASK 0x14 #define FBNIC_ECN_EN_MASK 0x10 +#define FBNIC_PS_EN_MASK 0x01 struct fbnic_fifo_config { unsigned int addr; @@ -420,6 +421,14 @@ static void __fbnic_mac_stat_rd64(struct fbnic_dev *fbd, bool reset, u32 reg, #define fbnic_mac_stat_rd64(fbd, reset, __stat, __CSR) \ __fbnic_mac_stat_rd64(fbd, reset, FBNIC_##__CSR##_L, &(__stat)) +bool fbnic_mac_check_tx_pause(struct fbnic_dev *fbd) +{ + u32 command_config; + + command_config = rd32(fbd, FBNIC_MAC_COMMAND_CONFIG); + return !(command_config & FBNIC_MAC_COMMAND_CONFIG_TX_PAUSE_DIS); +} + static void fbnic_mac_tx_pause_config(struct fbnic_dev *fbd, bool tx_pause) { u32 rxb_pause_ctrl; @@ -434,6 +443,49 @@ static void fbnic_mac_tx_pause_config(struct fbnic_dev *fbd, bool tx_pause) wr32(fbd, FBNIC_RXB_PAUSE_DROP_CTRL, rxb_pause_ctrl); } +static void +fbnic_mac_ps_protect_to_reset(struct fbnic_dev *fbd, u16 timeout_ms) +{ + wr32(fbd, FBNIC_RXB_PAUSE_STORM_UNIT_WR, FBNIC_RXB_PS_CLK_DIV); + + wr32(fbd, FBNIC_RXB_PAUSE_STORM(FBNIC_RXB_INTF_NET), + FIELD_PREP(FBNIC_RXB_PAUSE_STORM_THLD_TIME, + FBNIC_MAC_RXB_PS_TO(timeout_ms)) | + FBNIC_RXB_PAUSE_STORM_FORCE_NORMAL); + wrfl(fbd); + wr32(fbd, FBNIC_RXB_PAUSE_STORM(FBNIC_RXB_INTF_NET), + FIELD_PREP(FBNIC_RXB_PAUSE_STORM_THLD_TIME, + FBNIC_MAC_RXB_PS_TO(timeout_ms))); +} + +static void +fbnic_mac_ps_protect_config(struct fbnic_dev *fbd, bool ps_protect) +{ + u16 timeout; + u32 reg; + + ps_protect = ps_protect && fbd->ps_timeout; + timeout = ps_protect ? fbd->ps_timeout : FBNIC_MAC_PS_TO_DEFAULT_MS; + + fbnic_mac_ps_protect_to_reset(fbd, timeout); + + reg = rd32(fbd, FBNIC_RXB_PAUSE_DROP_CTRL); + reg &= ~FBNIC_RXB_PAUSE_DROP_CTRL_PS_ENABLE; + reg |= FIELD_PREP(FBNIC_RXB_PAUSE_DROP_CTRL_PS_ENABLE, ps_protect); + wr32(fbd, FBNIC_RXB_PAUSE_DROP_CTRL, reg); + + /* Clear any pending interrupt status first */ + wr32(fbd, FBNIC_RXB_ERR_INTR_STS, + FIELD_PREP(FBNIC_RXB_ERR_INTR_STS_PS, FBNIC_PS_EN_MASK)); + + /* Unmask the Network to Host PS interrupt if tx_pause is on */ + reg = rd32(fbd, FBNIC_RXB_ERR_INTR_MASK); + reg |= FBNIC_RXB_ERR_INTR_STS_PS; + if (ps_protect) + reg &= ~FBNIC_RXB_ERR_INTR_STS_PS; + wr32(fbd, FBNIC_RXB_ERR_INTR_MASK, reg); +} + static int fbnic_mac_get_link_event(struct fbnic_dev *fbd) { u32 intr_mask = rd32(fbd, FBNIC_SIG_PCS_INTR_STS); @@ -658,6 +710,7 @@ static void fbnic_mac_link_up_asic(struct fbnic_dev *fbd, u32 cmd_cfg, mac_ctrl; fbnic_mac_tx_pause_config(fbd, tx_pause); + fbnic_mac_ps_protect_config(fbd, tx_pause); cmd_cfg = __fbnic_mac_cmd_config_asic(fbd, tx_pause, rx_pause); mac_ctrl = rd32(fbd, FBNIC_SIG_MAC_IN0); @@ -918,3 +971,46 @@ int fbnic_mac_init(struct fbnic_dev *fbd) return 0; } + +int fbnic_mac_ps_protect_to_config(struct fbnic_dev *fbd, u16 timeout_ms) +{ + u16 old_timeout_ms = fbd->ps_timeout; + + if (timeout_ms == old_timeout_ms) + return 0; + + if (timeout_ms == PFC_STORM_PREVENTION_AUTO) + timeout_ms = FBNIC_MAC_PS_TO_DEFAULT_MS; + + if (timeout_ms > FBNIC_MAC_PS_TO_MAX_MS) + return -EINVAL; + + fbd->ps_timeout = timeout_ms; + + if (!fbnic_mac_check_tx_pause(fbd)) + return 0; + + if (timeout_ms == 0) + fbnic_mac_ps_protect_config(fbd, false); + else if (old_timeout_ms == 0) + fbnic_mac_ps_protect_config(fbd, true); + else + fbnic_mac_ps_protect_to_reset(fbd, fbd->ps_timeout); + + return 0; +} + +void fbnic_mac_ps_protect_handler(struct fbnic_dev *fbd) +{ + u32 rxb_err_sts = rd32(fbd, FBNIC_RXB_ERR_INTR_STS); + + /* Check if pause storm interrupt for network was triggered */ + if (rxb_err_sts & FIELD_PREP(FBNIC_RXB_ERR_INTR_STS_PS, + FBNIC_PS_EN_MASK)) { + /* Write 1 to clear the interrupt status first */ + wr32(fbd, FBNIC_RXB_ERR_INTR_STS, + FIELD_PREP(FBNIC_RXB_ERR_INTR_STS_PS, FBNIC_PS_EN_MASK)); + + fbnic_mac_ps_protect_to_reset(fbd, fbd->ps_timeout); + } +} diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_mac.h b/drivers/net/ethernet/meta/fbnic/fbnic_mac.h index f08fe8b7c497a..10f30e0e8f691 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_mac.h +++ b/drivers/net/ethernet/meta/fbnic/fbnic_mac.h @@ -8,6 +8,30 @@ struct fbnic_dev; +/* The RXB clock runs at 600 MHZ in the ASIC and the PAUSE_STORM_UNIT_WR + * is 10us granularity, so set the clock to 6000 (0x1770) + */ +#define FBNIC_RXB_PS_CLK_DIV 0x1770 + +/* Convert milliseconds to pause storm timeout units (10us granularity) */ +#define FBNIC_MAC_RXB_PS_TO(ms) ((ms) * 100) + +/* Convert pause storm timeout units (10us granularity) to milliseconds */ +#define FBNIC_MAC_RXB_PS_TO_MS(ps) ((ps) / 100) + +/* Set the default timer to 500ms, which should be longer than any + * reasonable period of continuous pausing. The service task, which runs + * once per second, periodically resets the pause storm trigger. + * + * As a result, on a functioning system, if pause continues, we enforce + * a duty cycle determined by the configured pause storm timeout (50% + * default). A crashed system will not have the service task and therefore + * pause will remain disabled until reboot recovery. + */ +#define FBNIC_MAC_PS_TO_DEFAULT_MS 500 +#define FBNIC_MAC_PS_TO_MAX_MS \ + FBNIC_MAC_RXB_PS_TO_MS(FIELD_MAX(FBNIC_RXB_PAUSE_STORM_THLD_TIME)) + #define FBNIC_MAX_JUMBO_FRAME_SIZE 9742 /* States loosely based on section 136.8.11.7.5 of IEEE 802.3-2022 Ethernet @@ -119,4 +143,7 @@ struct fbnic_mac { int fbnic_mac_init(struct fbnic_dev *fbd); void fbnic_mac_get_fw_settings(struct fbnic_dev *fbd, u8 *aui, u8 *fec); +int fbnic_mac_ps_protect_to_config(struct fbnic_dev *fbd, u16 timeout); +void fbnic_mac_ps_protect_handler(struct fbnic_dev *fbd); +bool fbnic_mac_check_tx_pause(struct fbnic_dev *fbd); #endif /* _FBNIC_MAC_H_ */ diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_pci.c b/drivers/net/ethernet/meta/fbnic/fbnic_pci.c index 3fa9d1910daa1..e3aebbe3656d5 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_pci.c +++ b/drivers/net/ethernet/meta/fbnic/fbnic_pci.c @@ -220,6 +220,9 @@ static void fbnic_service_task(struct work_struct *work) fbnic_get_hw_stats32(fbd); + if (fbd->ps_timeout && fbnic_mac_check_tx_pause(fbd)) + fbnic_mac_ps_protect_handler(fbd); + fbnic_fw_check_heartbeat(fbd); fbnic_health_check(fbd); @@ -296,6 +299,8 @@ static int fbnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent) /* Populate driver with hardware-specific info and handlers */ fbd->max_num_queues = info->max_num_queues; + fbd->ps_timeout = FBNIC_MAC_PS_TO_DEFAULT_MS; + pci_set_master(pdev); pci_save_state(pdev);