[PATCH net-next 4/5] net: lan966x: Add basic XDP support

From: Horatiu Vultur
Date: Wed Oct 19 2022 - 10:08:40 EST


Introduce basic XDP support to lan966x driver. Currently the driver
supports only the actions XDP_PASS, XDP_DROP and XDP_ABORTED.
Currently the driver doesn't support xdp programs if any of the ports
have the MTU bigger than a page size.

Signed-off-by: Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx>
---
.../net/ethernet/microchip/lan966x/Makefile | 3 +-
.../ethernet/microchip/lan966x/lan966x_fdma.c | 14 ++-
.../ethernet/microchip/lan966x/lan966x_main.c | 5 +
.../ethernet/microchip/lan966x/lan966x_main.h | 14 +++
.../ethernet/microchip/lan966x/lan966x_xdp.c | 100 ++++++++++++++++++
5 files changed, 134 insertions(+), 2 deletions(-)
create mode 100644 drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c

diff --git a/drivers/net/ethernet/microchip/lan966x/Makefile b/drivers/net/ethernet/microchip/lan966x/Makefile
index 962f7c5f9e7dd..251a7d561d633 100644
--- a/drivers/net/ethernet/microchip/lan966x/Makefile
+++ b/drivers/net/ethernet/microchip/lan966x/Makefile
@@ -11,4 +11,5 @@ lan966x-switch-objs := lan966x_main.o lan966x_phylink.o lan966x_port.o \
lan966x_ptp.o lan966x_fdma.o lan966x_lag.o \
lan966x_tc.o lan966x_mqprio.o lan966x_taprio.o \
lan966x_tbf.o lan966x_cbs.o lan966x_ets.o \
- lan966x_tc_matchall.o lan966x_police.o lan966x_mirror.o
+ lan966x_tc_matchall.o lan966x_police.o lan966x_mirror.o \
+ lan966x_xdp.o
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
index 6b6baf6a3d1ee..4e8f7e47c5536 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
@@ -422,6 +422,7 @@ static bool lan966x_fdma_rx_more_frames(struct lan966x_rx *rx)
static int lan966x_fdma_rx_check_frame(struct lan966x_rx *rx, u64 *src_port)
{
struct lan966x *lan966x = rx->lan966x;
+ struct lan966x_port *port;
struct lan966x_db *db;
struct page *page;

@@ -439,7 +440,11 @@ static int lan966x_fdma_rx_check_frame(struct lan966x_rx *rx, u64 *src_port)
if (WARN_ON(*src_port >= lan966x->num_phys_ports))
return FDMA_RX_ERROR;

- return FDMA_RX_OK;
+ port = lan966x->ports[*src_port];
+ if (!lan966x_xdp_port_present(port))
+ return FDMA_RX_OK;
+
+ return lan966x_xdp_run(port, page, FDMA_DCB_STATUS_BLOCKL(db->status));
}

static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx,
@@ -518,6 +523,10 @@ static int lan966x_fdma_napi_poll(struct napi_struct *napi, int weight)
switch (err) {
case FDMA_RX_OK:
break;
+ case FDMA_RX_DROP:
+ lan966x_fdma_rx_free_page(rx);
+ lan966x_fdma_rx_advance_dcb(rx);
+ continue;
case FDMA_RX_ERROR:
lan966x_fdma_rx_free_page(rx);
lan966x_fdma_rx_advance_dcb(rx);
@@ -776,6 +785,9 @@ int lan966x_fdma_change_mtu(struct lan966x *lan966x)
lan966x->rx.page_order)
return 0;

+ if (lan966x_xdp_present(lan966x) && max_mtu >= PAGE_SIZE)
+ return -EINVAL;
+
/* Disable the CPU port */
lan_rmw(QSYS_SW_PORT_MODE_PORT_ENA_SET(0),
QSYS_SW_PORT_MODE_PORT_ENA,
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index 4fa8c07039d9f..2e48caaadd59c 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
@@ -487,6 +487,7 @@ static const struct net_device_ops lan966x_port_netdev_ops = {
.ndo_get_port_parent_id = lan966x_port_get_parent_id,
.ndo_eth_ioctl = lan966x_port_ioctl,
.ndo_setup_tc = lan966x_tc_setup,
+ .ndo_bpf = lan966x_xdp,
};

bool lan966x_netdevice_check(const struct net_device *dev)
@@ -713,6 +714,7 @@ static void lan966x_cleanup_ports(struct lan966x *lan966x)
if (port->dev)
unregister_netdev(port->dev);

+ lan966x_xdp_port_deinit(port);
if (lan966x->fdma && lan966x->fdma_ndev == port->dev)
lan966x_fdma_netdev_deinit(lan966x, port->dev);

@@ -1155,6 +1157,9 @@ static int lan966x_probe(struct platform_device *pdev)
lan966x->ports[p]->serdes = serdes;

lan966x_port_init(lan966x->ports[p]);
+ err = lan966x_xdp_port_init(lan966x->ports[p]);
+ if (err)
+ goto cleanup_ports;
}

lan966x_mdb_init(lan966x);
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
index 608e2cb81b095..e635e529df0d4 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
@@ -100,10 +100,12 @@ enum macaccess_entry_type {

/* FDMA rx error codes for checking if the frame is valid
* FDMA_RX_OK, frame is valid and can be used
+ * FDMA_RX_DROP, frame is dropped, but continue to get more frames
* FDMA_RX_ERROR, something went wrong, stop getting more frames
*/
enum lan966x_fdma_rx_error {
FDMA_RX_OK = 0,
+ FDMA_RX_DROP,
FDMA_RX_ERROR,
};

@@ -327,6 +329,9 @@ struct lan966x_port {
enum netdev_lag_hash hash_type;

struct lan966x_port_tc tc;
+
+ struct bpf_prog *xdp_prog;
+ struct xdp_rxq_info xdp_rxq;
};

extern const struct phylink_mac_ops lan966x_phylink_mac_ops;
@@ -536,6 +541,15 @@ void lan966x_mirror_port_stats(struct lan966x_port *port,
struct flow_stats *stats,
bool ingress);

+int lan966x_xdp_port_init(struct lan966x_port *port);
+void lan966x_xdp_port_deinit(struct lan966x_port *port);
+int lan966x_xdp(struct net_device *dev, struct netdev_bpf *xdp);
+int lan966x_xdp_run(struct lan966x_port *port,
+ struct page *page,
+ u32 data_len);
+bool lan966x_xdp_present(struct lan966x *lan966x);
+bool lan966x_xdp_port_present(struct lan966x_port *port);
+
static inline void __iomem *lan_addr(void __iomem *base[],
int id, int tinst, int tcnt,
int gbase, int ginst,
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
new file mode 100644
index 0000000000000..b65bf648c543b
--- /dev/null
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <linux/bpf.h>
+#include <linux/bpf_trace.h>
+#include <linux/filter.h>
+
+#include "lan966x_main.h"
+
+static int lan966x_xdp_setup(struct net_device *dev, struct netdev_bpf *xdp)
+{
+ struct lan966x_port *port = netdev_priv(dev);
+ struct lan966x *lan966x = port->lan966x;
+ struct bpf_prog *old_prog;
+
+ if (!lan966x->fdma) {
+ NL_SET_ERR_MSG_MOD(xdp->extack,
+ "Allow to set xdp only when using fdma");
+ return -EOPNOTSUPP;
+ }
+
+ if (lan966x_get_max_mtu(lan966x) >= PAGE_SIZE) {
+ NL_SET_ERR_MSG_MOD(xdp->extack,
+ "Jumbo frames not supported on XDP");
+ return -EOPNOTSUPP;
+ }
+
+ old_prog = xchg(&port->xdp_prog, xdp->prog);
+ if (old_prog)
+ bpf_prog_put(old_prog);
+
+ return 0;
+}
+
+int lan966x_xdp(struct net_device *dev, struct netdev_bpf *xdp)
+{
+ switch (xdp->command) {
+ case XDP_SETUP_PROG:
+ return lan966x_xdp_setup(dev, xdp);
+ default:
+ return -EINVAL;
+ }
+}
+
+int lan966x_xdp_run(struct lan966x_port *port, struct page *page, u32 data_len)
+{
+ struct bpf_prog *xdp_prog = port->xdp_prog;
+ struct xdp_buff xdp;
+ u32 act;
+
+ xdp_init_buff(&xdp, PAGE_SIZE, &port->xdp_rxq);
+ xdp_prepare_buff(&xdp, page_address(page), IFH_LEN_BYTES,
+ data_len - IFH_LEN_BYTES, false);
+ act = bpf_prog_run_xdp(xdp_prog, &xdp);
+ switch (act) {
+ case XDP_PASS:
+ return FDMA_RX_OK;
+ default:
+ bpf_warn_invalid_xdp_action(port->dev, xdp_prog, act);
+ fallthrough;
+ case XDP_ABORTED:
+ trace_xdp_exception(port->dev, xdp_prog, act);
+ fallthrough;
+ case XDP_DROP:
+ return FDMA_RX_DROP;
+ }
+}
+
+bool lan966x_xdp_port_present(struct lan966x_port *port)
+{
+ return !!port->xdp_prog;
+}
+
+bool lan966x_xdp_present(struct lan966x *lan966x)
+{
+ int p;
+
+ for (p = 0; p < lan966x->num_phys_ports; ++p) {
+ if (!lan966x->ports[p])
+ continue;
+
+ if (lan966x_xdp_port_present(lan966x->ports[p]))
+ return true;
+ }
+
+ return false;
+}
+
+int lan966x_xdp_port_init(struct lan966x_port *port)
+{
+ struct lan966x *lan966x = port->lan966x;
+
+ return xdp_rxq_info_reg(&port->xdp_rxq, port->dev, 0,
+ lan966x->napi.napi_id);
+}
+
+void lan966x_xdp_port_deinit(struct lan966x_port *port)
+{
+ if (xdp_rxq_info_is_reg(&port->xdp_rxq))
+ xdp_rxq_info_unreg(&port->xdp_rxq);
+}
--
2.38.0