Merge branch 'stmmac-xdp'

Ong Boon Leong says:

====================
stmmac: Add XDP support

This is the v4 patch series for adding XDP native support to stmmac.

Changes in v4:
5/6: Move TX clean timer setup to the end of NAPI RX process and
     group it under stmmac_finalize_xdp_rx().
     Also, fixed stmmac_xdp_xmit_back() returns STMMAC_XDP_CONSUMED
     if XDP buffer conversion to XDP frame fails.

6/6: Move xdp_do_flush(0 into stmmac_finalize_xdp_rx() and combine
     the XDP verdict of XDP TX and XDP REDIRECT together.

I retested the patch series on the 'xdp2' and 'xdp_redirect' related to
changes above and found the result to be satisfactory.

History of previous patch series:
v3: https://patchwork.kernel.org/project/netdevbpf/cover/20210331154135.8507-1-boon.leong.ong@intel.com/
v2: https://patchwork.kernel.org/project/netdevbpf/list/?series=457757
v1: https://patchwork.kernel.org/project/netdevbpf/list/?series=457139

It will be great if community can help to test or review the v4 series
and provide me any input if any.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/Makefile

@@ -6,6 +6,7 @@ stmmac-objs:= stmmac_main.o stmmac_ethtool.o stmmac_mdio.o ring_mode.o	\
 	      mmc_core.o stmmac_hwtstamp.o stmmac_ptp.o dwmac4_descs.o	\
 	      dwmac4_dma.o dwmac4_lib.o dwmac4_core.o dwmac5.o hwif.o \
 	      stmmac_tc.o dwxgmac2_core.o dwxgmac2_dma.o dwxgmac2_descs.o \
+	      stmmac_xdp.o \
 	      $(stmmac-y)
 
 stmmac-$(CONFIG_STMMAC_SELFTESTS) += stmmac_selftests.o

drivers/net/ethernet/stmicro/stmmac/stmmac.h

@@ -36,12 +36,19 @@ struct stmmac_resources {
 	int tx_irq[MTL_MAX_TX_QUEUES];
 };
 
+enum stmmac_txbuf_type {
+	STMMAC_TXBUF_T_SKB,
+	STMMAC_TXBUF_T_XDP_TX,
+	STMMAC_TXBUF_T_XDP_NDO,
+};
+
 struct stmmac_tx_info {
 	dma_addr_t buf;
 	bool map_as_page;
 	unsigned len;
 	bool last_segment;
 	bool is_jumbo;
+	enum stmmac_txbuf_type buf_type;
 };
 
 #define STMMAC_TBS_AVAIL	BIT(0)
@@ -57,7 +64,10 @@ struct stmmac_tx_queue {
 	struct dma_extended_desc *dma_etx ____cacheline_aligned_in_smp;
 	struct dma_edesc *dma_entx;
 	struct dma_desc *dma_tx;
-	struct sk_buff **tx_skbuff;
+	union {
+		struct sk_buff **tx_skbuff;
+		struct xdp_frame **xdpf;
+	};
 	struct stmmac_tx_info *tx_skbuff_dma;
 	unsigned int cur_tx;
 	unsigned int dirty_tx;
@@ -68,14 +78,16 @@ struct stmmac_tx_queue {
 
 struct stmmac_rx_buffer {
 	struct page *page;
-	struct page *sec_page;
 	dma_addr_t addr;
+	__u32 page_offset;
+	struct page *sec_page;
 	dma_addr_t sec_addr;
 };
 
 struct stmmac_rx_queue {
 	u32 rx_count_frames;
 	u32 queue_index;
+	struct xdp_rxq_info xdp_rxq;
 	struct page_pool *page_pool;
 	struct stmmac_rx_buffer *buf_pool;
 	struct stmmac_priv *priv_data;
@@ -160,6 +172,7 @@ struct stmmac_priv {
 	bool tx_path_in_lpi_mode;
 	bool tso;
 	int sph;
+	int sph_cap;
 	u32 sarc_type;
 
 	unsigned int dma_buf_sz;
@@ -268,6 +281,9 @@ struct stmmac_priv {
 
 	/* Receive Side Scaling */
 	struct stmmac_rss rss;
+
+	/* XDP BPF Program */
+	struct bpf_prog *xdp_prog;
 };
 
 enum stmmac_state {
@@ -284,6 +300,8 @@ void stmmac_set_ethtool_ops(struct net_device *netdev);
 
 void stmmac_ptp_register(struct stmmac_priv *priv);
 void stmmac_ptp_unregister(struct stmmac_priv *priv);
+int stmmac_open(struct net_device *dev);
+int stmmac_release(struct net_device *dev);
 int stmmac_resume(struct device *dev);
 int stmmac_suspend(struct device *dev);
 int stmmac_dvr_remove(struct device *dev);
@@ -297,6 +315,19 @@ int stmmac_reinit_ringparam(struct net_device *dev, u32 rx_size, u32 tx_size);
 int stmmac_bus_clks_config(struct stmmac_priv *priv, bool enabled);
 void stmmac_fpe_handshake(struct stmmac_priv *priv, bool enable);
 
+static inline bool stmmac_xdp_is_enabled(struct stmmac_priv *priv)
+{
+	return !!priv->xdp_prog;
+}
+
+static inline unsigned int stmmac_rx_offset(struct stmmac_priv *priv)
+{
+	if (stmmac_xdp_is_enabled(priv))
+		return XDP_PACKET_HEADROOM;
+
+	return 0;
+}
+
 #if IS_ENABLED(CONFIG_STMMAC_SELFTESTS)
 void stmmac_selftest_run(struct net_device *dev,
 			 struct ethtool_test *etest, u64 *buf);

drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.c

+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021, Intel Corporation. */
+
+#include "stmmac.h"
+#include "stmmac_xdp.h"
+
+int stmmac_xdp_set_prog(struct stmmac_priv *priv, struct bpf_prog *prog,
+			struct netlink_ext_ack *extack)
+{
+	struct net_device *dev = priv->dev;
+	struct bpf_prog *old_prog;
+	bool need_update;
+	bool if_running;
+
+	if_running = netif_running(dev);
+
+	if (prog && dev->mtu > ETH_DATA_LEN) {
+		/* For now, the driver doesn't support XDP functionality with
+		 * jumbo frames so we return error.
+		 */
+		NL_SET_ERR_MSG_MOD(extack, "Jumbo frames not supported");
+		return -EOPNOTSUPP;
+	}
+
+	need_update = !!priv->xdp_prog != !!prog;
+	if (if_running && need_update)
+		stmmac_release(dev);
+
+	old_prog = xchg(&priv->xdp_prog, prog);
+	if (old_prog)
+		bpf_prog_put(old_prog);
+
+	/* Disable RX SPH for XDP operation */
+	priv->sph = priv->sph_cap && !stmmac_xdp_is_enabled(priv);
+
+	if (if_running && need_update)
+		stmmac_open(dev);
+
+	return 0;
+}

drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2021, Intel Corporation. */
+
+#ifndef _STMMAC_XDP_H_
+#define _STMMAC_XDP_H_
+
+#define STMMAC_MAX_RX_BUF_SIZE(num)	(((num) * PAGE_SIZE) - XDP_PACKET_HEADROOM)
+
+int stmmac_xdp_set_prog(struct stmmac_priv *priv, struct bpf_prog *prog,
+			struct netlink_ext_ack *extack);
+
+#endif /* _STMMAC_XDP_H_ */