net/funeth: add the data path

Add the driver's data path. Tx handles skbs, XDP, and kTLS, Rx has skbs
and XDP. Also included are Rx and Tx queue creation/tear-down and
tracing.
Signed-off-by: NDimitris Michailidis <dmichail@fungible.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/fungible/funeth/funeth_trace.h

+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM funeth
+
+#if !defined(_TRACE_FUNETH_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_FUNETH_H
+
+#include <linux/tracepoint.h>
+
+#include "funeth_txrx.h"
+
+TRACE_EVENT(funeth_tx,
+
+	TP_PROTO(const struct funeth_txq *txq,
+		 u32 len,
+		 u32 sqe_idx,
+		 u32 ngle),
+
+	TP_ARGS(txq, len, sqe_idx, ngle),
+
+	TP_STRUCT__entry(
+		__field(u32, qidx)
+		__field(u32, len)
+		__field(u32, sqe_idx)
+		__field(u32, ngle)
+		__string(devname, txq->netdev->name)
+	),
+
+	TP_fast_assign(
+		__entry->qidx = txq->qidx;
+		__entry->len = len;
+		__entry->sqe_idx = sqe_idx;
+		__entry->ngle = ngle;
+		__assign_str(devname, txq->netdev->name);
+	),
+
+	TP_printk("%s: Txq %u, SQE idx %u, len %u, num GLEs %u",
+		  __get_str(devname), __entry->qidx, __entry->sqe_idx,
+		  __entry->len, __entry->ngle)
+);
+
+TRACE_EVENT(funeth_tx_free,
+
+	TP_PROTO(const struct funeth_txq *txq,
+		 u32 sqe_idx,
+		 u32 num_sqes,
+		 u32 hw_head),
+
+	TP_ARGS(txq, sqe_idx, num_sqes, hw_head),
+
+	TP_STRUCT__entry(
+		__field(u32, qidx)
+		__field(u32, sqe_idx)
+		__field(u32, num_sqes)
+		__field(u32, hw_head)
+		__string(devname, txq->netdev->name)
+	),
+
+	TP_fast_assign(
+		__entry->qidx = txq->qidx;
+		__entry->sqe_idx = sqe_idx;
+		__entry->num_sqes = num_sqes;
+		__entry->hw_head = hw_head;
+		__assign_str(devname, txq->netdev->name);
+	),
+
+	TP_printk("%s: Txq %u, SQE idx %u, SQEs %u, HW head %u",
+		  __get_str(devname), __entry->qidx, __entry->sqe_idx,
+		  __entry->num_sqes, __entry->hw_head)
+);
+
+TRACE_EVENT(funeth_rx,
+
+	TP_PROTO(const struct funeth_rxq *rxq,
+		 u32 num_rqes,
+		 u32 pkt_len,
+		 u32 hash,
+		 u32 cls_vec),
+
+	TP_ARGS(rxq, num_rqes, pkt_len, hash, cls_vec),
+
+	TP_STRUCT__entry(
+		__field(u32, qidx)
+		__field(u32, cq_head)
+		__field(u32, num_rqes)
+		__field(u32, len)
+		__field(u32, hash)
+		__field(u32, cls_vec)
+		__string(devname, rxq->netdev->name)
+	),
+
+	TP_fast_assign(
+		__entry->qidx = rxq->qidx;
+		__entry->cq_head = rxq->cq_head;
+		__entry->num_rqes = num_rqes;
+		__entry->len = pkt_len;
+		__entry->hash = hash;
+		__entry->cls_vec = cls_vec;
+		__assign_str(devname, rxq->netdev->name);
+	),
+
+	TP_printk("%s: Rxq %u, CQ head %u, RQEs %u, len %u, hash %u, CV %#x",
+		  __get_str(devname), __entry->qidx, __entry->cq_head,
+		  __entry->num_rqes, __entry->len, __entry->hash,
+		  __entry->cls_vec)
+);
+
+#endif /* _TRACE_FUNETH_H */
+
+/* Below must be outside protection. */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE funeth_trace
+
+#include <trace/define_trace.h>

drivers/net/ethernet/fungible/funeth/funeth_txrx.h

+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) */
+
+#ifndef _FUNETH_TXRX_H
+#define _FUNETH_TXRX_H
+
+#include <linux/netdevice.h>
+#include <linux/u64_stats_sync.h>
+
+/* Tx descriptor size */
+#define FUNETH_SQE_SIZE 64U
+
+/* Size of device headers per Tx packet */
+#define FUNETH_FUNOS_HDR_SZ (sizeof(struct fun_eth_tx_req))
+
+/* Number of gather list entries per Tx descriptor */
+#define FUNETH_GLE_PER_DESC (FUNETH_SQE_SIZE / sizeof(struct fun_dataop_gl))
+
+/* Max gather list size in bytes for an sk_buff. */
+#define FUNETH_MAX_GL_SZ ((MAX_SKB_FRAGS + 1) * sizeof(struct fun_dataop_gl))
+
+#if IS_ENABLED(CONFIG_TLS_DEVICE)
+# define FUNETH_TLS_SZ sizeof(struct fun_eth_tls)
+#else
+# define FUNETH_TLS_SZ 0
+#endif
+
+/* Max number of Tx descriptors for an sk_buff using a gather list. */
+#define FUNETH_MAX_GL_DESC \
+	DIV_ROUND_UP((FUNETH_FUNOS_HDR_SZ + FUNETH_MAX_GL_SZ + FUNETH_TLS_SZ), \
+		     FUNETH_SQE_SIZE)
+
+/* Max number of Tx descriptors for any packet. */
+#define FUNETH_MAX_PKT_DESC FUNETH_MAX_GL_DESC
+
+/* Rx CQ descriptor size. */
+#define FUNETH_CQE_SIZE 64U
+
+/* Offset of cqe_info within a CQE. */
+#define FUNETH_CQE_INFO_OFFSET (FUNETH_CQE_SIZE - sizeof(struct fun_cqe_info))
+
+/* Construct the IRQ portion of a CQ doorbell. The resulting value arms the
+ * interrupt with the supplied time delay and packet count moderation settings.
+ */
+#define FUN_IRQ_CQ_DB(usec, pkts) \
+	(FUN_DB_IRQ_ARM_F | ((usec) << FUN_DB_INTCOAL_USEC_S) | \
+	 ((pkts) << FUN_DB_INTCOAL_ENTRIES_S))
+
+/* As above for SQ doorbells. */
+#define FUN_IRQ_SQ_DB(usec, pkts) \
+	(FUN_DB_IRQ_ARM_F | \
+	 ((usec) << FUN_DB_INTCOAL_USEC_S) | \
+	 ((pkts) << FUN_DB_INTCOAL_ENTRIES_S))
+
+/* Per packet tailroom. Present only for 1-frag packets. */
+#define FUN_RX_TAILROOM SKB_DATA_ALIGN(sizeof(struct skb_shared_info))
+
+/* Per packet headroom for XDP. Preferred over XDP_PACKET_HEADROOM to
+ * accommodate two packets per buffer for 4K pages and 1500B MTUs.
+ */
+#define FUN_XDP_HEADROOM 192
+
+/* Initialization state of a queue. */
+enum {
+	FUN_QSTATE_DESTROYED, /* what queue? */
+	FUN_QSTATE_INIT_SW,   /* exists in SW, not on the device */
+	FUN_QSTATE_INIT_FULL, /* exists both in SW and on device */
+};
+
+/* Initialization state of an interrupt. */
+enum {
+	FUN_IRQ_INIT,      /* initialized and in the XArray but inactive */
+	FUN_IRQ_REQUESTED, /* request_irq() done */
+	FUN_IRQ_ENABLED,   /* processing enabled */
+	FUN_IRQ_DISABLED,  /* processing disabled */
+};
+
+struct bpf_prog;
+
+struct funeth_txq_stats {  /* per Tx queue SW counters */
+	u64 tx_pkts;       /* # of Tx packets */
+	u64 tx_bytes;      /* total bytes of Tx packets */
+	u64 tx_cso;        /* # of packets with checksum offload */
+	u64 tx_tso;        /* # of non-encapsulated TSO super-packets */
+	u64 tx_encap_tso;  /* # of encapsulated TSO super-packets */
+	u64 tx_more;       /* # of DBs elided due to xmit_more */
+	u64 tx_nstops;     /* # of times the queue has stopped */
+	u64 tx_nrestarts;  /* # of times the queue has restarted */
+	u64 tx_map_err;    /* # of packets dropped due to DMA mapping errors */
+	u64 tx_xdp_full;   /* # of XDP packets that could not be enqueued */
+	u64 tx_tls_pkts;   /* # of Tx TLS packets offloaded to HW */
+	u64 tx_tls_bytes;  /* Tx bytes of HW-handled TLS payload */
+	u64 tx_tls_fallback; /* attempted Tx TLS offloads punted to SW */
+	u64 tx_tls_drops;  /* attempted Tx TLS offloads dropped */
+};
+
+struct funeth_tx_info {      /* per Tx descriptor state */
+	union {
+		struct sk_buff *skb; /* associated packet */
+		void *vaddr;         /* start address for XDP */
+	};
+};
+
+struct funeth_txq {
+	/* RO cacheline of frequently accessed data */
+	u32 mask;               /* queue depth - 1 */
+	u32 hw_qid;             /* device ID of the queue */
+	void *desc;             /* base address of descriptor ring */
+	struct funeth_tx_info *info;
+	struct device *dma_dev; /* device for DMA mappings */
+	volatile __be64 *hw_wb; /* HW write-back location */
+	u32 __iomem *db;        /* SQ doorbell register address */
+	struct netdev_queue *ndq;
+	dma_addr_t dma_addr;    /* DMA address of descriptor ring */
+	/* producer R/W cacheline */
+	u16 qidx;               /* queue index within net_device */
+	u16 ethid;
+	u32 prod_cnt;           /* producer counter */
+	struct funeth_txq_stats stats;
+	/* shared R/W cacheline, primarily accessed by consumer */
+	u32 irq_db_val;         /* value written to IRQ doorbell */
+	u32 cons_cnt;           /* consumer (cleanup) counter */
+	struct net_device *netdev;
+	struct fun_irq *irq;
+	int numa_node;
+	u8 init_state;          /* queue initialization state */
+	struct u64_stats_sync syncp;
+};
+
+struct funeth_rxq_stats {  /* per Rx queue SW counters */
+	u64 rx_pkts;       /* # of received packets, including SW drops */
+	u64 rx_bytes;      /* total size of received packets */
+	u64 rx_cso;        /* # of packets with checksum offload */
+	u64 rx_bufs;       /* total # of Rx buffers provided to device */
+	u64 gro_pkts;      /* # of GRO superpackets */
+	u64 gro_merged;    /* # of pkts merged into existing GRO superpackets */
+	u64 rx_page_alloc; /* # of page allocations for Rx buffers */
+	u64 rx_budget;     /* NAPI iterations that exhausted their budget */
+	u64 rx_mem_drops;  /* # of packets dropped due to memory shortage */
+	u64 rx_map_err;    /* # of page DMA mapping errors */
+	u64 xdp_drops;     /* XDP_DROPped packets */
+	u64 xdp_tx;        /* successful XDP transmits */
+	u64 xdp_redir;     /* successful XDP redirects */
+	u64 xdp_err;       /* packets dropped due to XDP errors */
+};
+
+struct funeth_rxbuf {          /* per Rx buffer state */
+	struct page *page;     /* associated page */
+	dma_addr_t dma_addr;   /* DMA address of page start */
+	int pg_refs;           /* page refs held by driver */
+	int node;              /* page node, or -1 if it is PF_MEMALLOC */
+};
+
+struct funeth_rx_cache {       /* cache of DMA-mapped previously used buffers */
+	struct funeth_rxbuf *bufs; /* base of Rx buffer state ring */
+	unsigned int prod_cnt;     /* producer counter */
+	unsigned int cons_cnt;     /* consumer counter */
+	unsigned int mask;         /* depth - 1 */
+};
+
+/* An Rx queue consists of a CQ and an SQ used to provide Rx buffers. */
+struct funeth_rxq {
+	struct net_device *netdev;
+	struct napi_struct *napi;
+	struct device *dma_dev;    /* device for DMA mappings */
+	void *cqes;                /* base of CQ descriptor ring */
+	const void *next_cqe_info; /* fun_cqe_info of next CQE */
+	u32 __iomem *cq_db;        /* CQ doorbell register address */
+	unsigned int cq_head;      /* CQ head index */
+	unsigned int cq_mask;      /* CQ depth - 1 */
+	u16 phase;                 /* CQ phase tag */
+	u16 qidx;                  /* queue index within net_device */
+	unsigned int irq_db_val;   /* IRQ info for CQ doorbell */
+	struct fun_eprq_rqbuf *rqes; /* base of RQ descriptor ring */
+	struct funeth_rxbuf *bufs; /* base of Rx buffer state ring */
+	struct funeth_rxbuf *cur_buf; /* currently active buffer */
+	u32 __iomem *rq_db;        /* RQ doorbell register address */
+	unsigned int rq_cons;      /* RQ consumer counter */
+	unsigned int rq_mask;      /* RQ depth - 1 */
+	unsigned int buf_offset;   /* offset of next pkt in head buffer */
+	u8 xdp_flush;              /* XDP flush types needed at NAPI end */
+	u8 init_state;             /* queue initialization state */
+	u16 headroom;              /* per packet headroom */
+	unsigned int rq_cons_db;   /* value of rq_cons at last RQ db */
+	unsigned int rq_db_thres;  /* # of new buffers needed to write RQ db */
+	struct funeth_rxbuf spare_buf; /* spare for next buffer replacement */
+	struct funeth_rx_cache cache; /* used buffer cache */
+	struct bpf_prog *xdp_prog; /* optional XDP BPF program */
+	struct funeth_rxq_stats stats;
+	dma_addr_t cq_dma_addr;    /* DMA address of CQE ring */
+	dma_addr_t rq_dma_addr;    /* DMA address of RQE ring */
+	u16 irq_cnt;
+	u32 hw_cqid;               /* device ID of the queue's CQ */
+	u32 hw_sqid;               /* device ID of the queue's SQ */
+	int numa_node;
+	struct u64_stats_sync syncp;
+	struct xdp_rxq_info xdp_rxq;
+};
+
+#define FUN_QSTAT_INC(q, counter) \
+	do { \
+		u64_stats_update_begin(&(q)->syncp); \
+		(q)->stats.counter++; \
+		u64_stats_update_end(&(q)->syncp); \
+	} while (0)
+
+#define FUN_QSTAT_READ(q, seq, stats_copy) \
+	do { \
+		seq = u64_stats_fetch_begin(&(q)->syncp); \
+		stats_copy = (q)->stats; \
+	} while (u64_stats_fetch_retry(&(q)->syncp, (seq)))
+
+#define FUN_INT_NAME_LEN (IFNAMSIZ + 16)
+
+struct fun_irq {
+	struct napi_struct napi;
+	struct funeth_txq *txq;
+	struct funeth_rxq *rxq;
+	u8 state;
+	u16 irq_idx;              /* index of MSI-X interrupt */
+	int irq;                  /* Linux IRQ vector */
+	cpumask_t affinity_mask;  /* IRQ affinity */
+	struct irq_affinity_notify aff_notify;
+	char name[FUN_INT_NAME_LEN];
+} ____cacheline_internodealigned_in_smp;
+
+/* Return the start address of the idx-th Tx descriptor. */
+static inline void *fun_tx_desc_addr(const struct funeth_txq *q,
+				     unsigned int idx)
+{
+	return q->desc + idx * FUNETH_SQE_SIZE;
+}
+
+static inline void fun_txq_wr_db(const struct funeth_txq *q)
+{
+	unsigned int tail = q->prod_cnt & q->mask;
+
+	writel(tail, q->db);
+}
+
+static inline int fun_irq_node(const struct fun_irq *p)
+{
+	return local_memory_node(cpu_to_node(cpumask_first(&p->affinity_mask)));
+}
+
+int fun_rxq_napi_poll(struct napi_struct *napi, int budget);
+int fun_txq_napi_poll(struct napi_struct *napi, int budget);
+netdev_tx_t fun_start_xmit(struct sk_buff *skb, struct net_device *netdev);
+bool fun_xdp_tx(struct funeth_txq *q, void *data, unsigned int len);
+int fun_xdp_xmit_frames(struct net_device *dev, int n,
+			struct xdp_frame **frames, u32 flags);
+
+int funeth_txq_create(struct net_device *dev, unsigned int qidx,
+		      unsigned int ndesc, struct fun_irq *irq, int state,
+		      struct funeth_txq **qp);
+int fun_txq_create_dev(struct funeth_txq *q, struct fun_irq *irq);
+struct funeth_txq *funeth_txq_free(struct funeth_txq *q, int state);
+int funeth_rxq_create(struct net_device *dev, unsigned int qidx,
+		      unsigned int ncqe, unsigned int nrqe, struct fun_irq *irq,
+		      int state, struct funeth_rxq **qp);
+int fun_rxq_create_dev(struct funeth_rxq *q, struct fun_irq *irq);
+struct funeth_rxq *funeth_rxq_free(struct funeth_rxq *q, int state);
+int fun_rxq_set_bpf(struct funeth_rxq *q, struct bpf_prog *prog);
+
+#endif /* _FUNETH_TXRX_H */