[PATCH net-next v8 10/15] net: lan966x: add shutdown callback to stop the FDMA on reboot
flat view
COOLING11d
REVIEWED: 16 (16M)
From: Daniel Machon <daniel.machon@microchip.com>
Date: 2026-09-24 19:57:52
Also in:
bpf, lkml, netdev
Subsystem:
microchip lan966x ethernet driver, networking drivers, the rest · Maintainers:
Horatiu Vultur, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
2 review trailers.
As a PCIe endpoint, lan966x is not reset by a host reboot: its FDMA channels and interrupt sources stay armed, and the OIC ORs every source into the shared PCIe INTx, asserted before the driver has re-probed. A still-active channel also keeps write access to host memory the next kernel will reuse. Add a shutdown callback that: - frees the ana, xtr and FDMA irqs, masking and unmapping them at the OIC (disable_irq() would leave both set - the OIC has no irq_disable()) - masks the analyzer source, armed unconditionally by lan966x_init() and re-armed by the MAC table's age timer - stops and detaches the netdevs, draining in-flight xmit and clearing netif_device_present() so ndo_open/ndo_change_mtu cannot re-enter the FDMA against a disabled NAPI - disables both FDMA channels and masks their interrupts - unmaps the outbound ATU windows, leaving none armed (the windows are mapped by the PCIe FDMA backend added later in this series) NAPI is skipped when fdma_ndev is unset (a probed switch with no usable port never adds one), and XDP attach cannot re-enter the FDMA either: on PCIe, lan966x_xdp_setup() returns before the page pool reload, which is the only point where it touches the FDMA. Only the PCIe instantiation needs this - the SoC one resets with the chip - so the callback returns early on a platform device; the check is at runtime since .shutdown belongs to the driver, and a PCIe-enabled kernel binds both. FDMA_INTR_ENA persists across a warm reboot, so also restore the full enable in lan966x_fdma_rx_start(), run after both rings are allocated. The PCIe FDMA backend added later in this series starts RX through the same function, so both backends are re-armed from one site. Tested-by: Herve Codina <herve.codina@bootlin.com> Signed-off-by: Daniel Machon <daniel.machon@microchip.com> Reviewed-by: Simon Horman <horms@kernel.org> --- .../net/ethernet/microchip/lan966x/lan966x_fdma.c | 4 ++ .../net/ethernet/microchip/lan966x/lan966x_main.c | 56 ++++++++++++++++++++++ .../net/ethernet/microchip/lan966x/lan966x_regs.h | 15 ++++++ 3 files changed, 75 insertions(+)
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
index 5f46166cbfe4..2e8f786d6fee 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c@@ -146,6 +146,10 @@ void lan966x_fdma_rx_start(struct lan966x_rx *rx) struct fdma *fdma = &rx->fdma; u32 mask; + lan_wr(FDMA_INTR_ENA_INTR_PORT_ENA_SET(GENMASK(1, 0)) | + FDMA_INTR_ENA_INTR_CH_ENA_SET(GENMASK(7, 0)), + lan966x, FDMA_INTR_ENA); + lan_wr(FDMA_CH_CFG_CH_DCB_DB_CNT_SET(fdma->n_dbs) | FDMA_CH_CFG_CH_INTR_DB_EOF_ONLY_SET(1) | FDMA_CH_CFG_CH_INJ_PORT_SET(0) |
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index 259d81e75907..024ce9f9916c 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c@@ -1324,9 +1324,65 @@ static void lan966x_remove(struct platform_device *pdev) debugfs_remove_recursive(lan966x->debugfs_root); } +static void lan966x_shutdown(struct platform_device *pdev) +{ + struct lan966x *lan966x = platform_get_drvdata(pdev); + + /* As a PCIe endpoint the switch is not reset by the host reboot, so it + * has to be quiesced here: + * + * Free the irqs and mask the sources: no source can assert INTx. + * Disable NAPI: the teardown must not race a poll. + * Stop and detach the netdevs: drains xmit, closes ndo_open and MTU. + * Stop the FDMA channels: waits for the engine to go idle. + * Unmap the ATU windows: revokes the engine's access to host memory. + */ + if (!lan966x_is_pci(lan966x)) + return; + + if (lan966x->xtr_irq > 0) + devm_free_irq(lan966x->dev, lan966x->xtr_irq, lan966x); + if (lan966x->ana_irq > 0) + devm_free_irq(lan966x->dev, lan966x->ana_irq, lan966x); + if (lan966x->fdma_irq > 0) + devm_free_irq(lan966x->dev, lan966x->fdma_irq, lan966x); + + lan_wr(0, lan966x, ANA_ANAINTR); + + if (!lan966x->fdma) + return; + + rtnl_lock(); + + if (lan966x->fdma_ndev) + napi_disable(&lan966x->napi); + + for (int p = 0; p < lan966x->num_phys_ports; p++) { + if (!lan966x->ports[p] || !lan966x->ports[p]->dev) + continue; + + netif_tx_disable(lan966x->ports[p]->dev); + netif_device_detach(lan966x->ports[p]->dev); + } + + lan966x_fdma_rx_disable(&lan966x->rx); + lan966x_fdma_tx_disable(&lan966x->tx); + + lan_wr(0, lan966x, FDMA_INTR_ENA); + lan_wr(0, lan966x, FDMA_INTR_DB_ENA); + +#if IS_ENABLED(CONFIG_MCHP_LAN966X_PCI) + fdma_pci_atu_region_unmap(lan966x->rx.fdma.atu_region); + fdma_pci_atu_region_unmap(lan966x->tx.fdma.atu_region); +#endif + + rtnl_unlock(); +} + static struct platform_driver lan966x_driver = { .probe = lan966x_probe, .remove = lan966x_remove, + .shutdown = lan966x_shutdown, .driver = { .name = "lan966x-switch", .of_match_table = lan966x_match,
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_regs.h b/drivers/net/ethernet/microchip/lan966x/lan966x_regs.h
index 4b553927d2e0..aba0d36ae6b5 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_regs.h
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_regs.h@@ -1039,6 +1039,21 @@ enum lan966x_target { /* FDMA:FDMA:FDMA_INTR_ERR */ #define FDMA_INTR_ERR __REG(TARGET_FDMA, 0, 1, 8, 0, 1, 428, 400, 0, 1, 4) +/* FDMA:FDMA:FDMA_INTR_ENA */ +#define FDMA_INTR_ENA __REG(TARGET_FDMA, 0, 1, 8, 0, 1, 428, 404, 0, 1, 4) + +#define FDMA_INTR_ENA_INTR_PORT_ENA GENMASK(9, 8) +#define FDMA_INTR_ENA_INTR_PORT_ENA_SET(x)\ + FIELD_PREP(FDMA_INTR_ENA_INTR_PORT_ENA, x) +#define FDMA_INTR_ENA_INTR_PORT_ENA_GET(x)\ + FIELD_GET(FDMA_INTR_ENA_INTR_PORT_ENA, x) + +#define FDMA_INTR_ENA_INTR_CH_ENA GENMASK(7, 0) +#define FDMA_INTR_ENA_INTR_CH_ENA_SET(x)\ + FIELD_PREP(FDMA_INTR_ENA_INTR_CH_ENA, x) +#define FDMA_INTR_ENA_INTR_CH_ENA_GET(x)\ + FIELD_GET(FDMA_INTR_ENA_INTR_CH_ENA, x) + /* FDMA:FDMA:FDMA_ERRORS */ #define FDMA_ERRORS __REG(TARGET_FDMA, 0, 1, 8, 0, 1, 428, 412, 0, 1, 4)
--
2.34.1