IB/hfi1: Add functions to transmit datagram ipoib packets

This patch implements the mechanism to accelerate the transmit side of
a multiple transmit queue RDMA netdev by submitting the packets to
the SDMA engine directly instead of sending through the verbs layer.

This patch also changes the UD/SEND_ONLY op to output the entropy value
in byte 0 of deth[1]. UD/SEND_ONLY_WITH_IMMEDIATE uses the previous
behavior with no entropy value being output.

The code in the ipoib rdma netdev which submits tx requests upon
successful submission will call trace_sdma_output_ibhdr to output
the ibhdr to the trace buffer.

Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Mike Marciniszyn <[email protected]>
Reviewed-by: Dennis Dalessandro <[email protected]>
Signed-off-by: Gary Leshner <[email protected]>
Signed-off-by: Kaike Wan <[email protected]>
Signed-off-by: Dennis Dalessandro <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>

Author: gsleshne

drivers/infiniband/hw/hfi1/Makefile

@@ -22,6 +22,7 @@ hfi1-y := \
 	init.o \
 	intr.o \
 	iowait.o \
+	ipoib_tx.o \
 	mad.o \
 	mmu_rb.o \
 	msix.o \

drivers/infiniband/hw/hfi1/ipoib.h

@@ -0,0 +1,145 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+/*
+ * Copyright(c) 2020 Intel Corporation.
+ *
+ */
+
+/*
+ * This file contains HFI1 support for IPOIB functionality
+ */
+
+#ifndef HFI1_IPOIB_H
+#define HFI1_IPOIB_H
+
+#include <linux/types.h>
+#include <linux/stddef.h>
+#include <linux/atomic.h>
+#include <linux/netdevice.h>
+#include <linux/slab.h>
+#include <linux/skbuff.h>
+#include <linux/list.h>
+#include <linux/if_infiniband.h>
+
+#include "hfi.h"
+#include "iowait.h"
+
+#include <rdma/ib_verbs.h>
+
+#define HFI1_IPOIB_ENTROPY_SHIFT   24
+
+#define HFI1_IPOIB_TXREQ_NAME_LEN   32
+
+#define HFI1_IPOIB_ENCAP_LEN 4
+
+struct hfi1_ipoib_dev_priv;
+
+union hfi1_ipoib_flow {
+	u16 as_int;
+	struct {
+		u8 tx_queue;
+		u8 sc5;
+	} __attribute__((__packed__));
+};
+
+/**
+ * struct hfi1_ipoib_circ_buf - List of items to be processed
+ * @items: ring of items
+ * @head: ring head
+ * @tail: ring tail
+ * @max_items: max items + 1 that the ring can contain
+ * @producer_lock: producer sync lock
+ * @consumer_lock: consumer sync lock
+ */
+struct hfi1_ipoib_circ_buf {
+	void **items;
+	unsigned long head;
+	unsigned long tail;
+	unsigned long max_items;
+	spinlock_t producer_lock; /* head sync lock */
+	spinlock_t consumer_lock; /* tail sync lock */
+};
+
+/**
+ * struct hfi1_ipoib_txq - IPOIB per Tx queue information
+ * @priv: private pointer
+ * @sde: sdma engine
+ * @tx_list: tx request list
+ * @sent_txreqs: count of txreqs posted to sdma
+ * @flow: tracks when list needs to be flushed for a flow change
+ * @q_idx: ipoib Tx queue index
+ * @pkts_sent: indicator packets have been sent from this queue
+ * @wait: iowait structure
+ * @complete_txreqs: count of txreqs completed by sdma
+ * @napi: pointer to tx napi interface
+ * @tx_ring: ring of ipoib txreqs to be reaped by napi callback
+ */
+struct hfi1_ipoib_txq {
+	struct hfi1_ipoib_dev_priv *priv;
+	struct sdma_engine *sde;
+	struct list_head tx_list;
+	u64 sent_txreqs;
+	union hfi1_ipoib_flow flow;
+	u8 q_idx;
+	bool pkts_sent;
+	struct iowait wait;
+
+	atomic64_t ____cacheline_aligned_in_smp complete_txreqs;
+	struct napi_struct *napi;
+	struct hfi1_ipoib_circ_buf tx_ring;
+};
+
+struct hfi1_ipoib_dev_priv {
+	struct hfi1_devdata *dd;
+	struct net_device   *netdev;
+	struct ib_device    *device;
+	struct hfi1_ipoib_txq *txqs;
+	struct kmem_cache *txreq_cache;
+	struct napi_struct *tx_napis;
+	u16 pkey;
+	u16 pkey_index;
+	u32 qkey;
+	u8 port_num;
+
+	const struct net_device_ops *netdev_ops;
+	struct rvt_qp *qp;
+	struct pcpu_sw_netstats __percpu *netstats;
+};
+
+/* hfi1 ipoib rdma netdev's private data structure */
+struct hfi1_ipoib_rdma_netdev {
+	struct rdma_netdev rn;  /* keep this first */
+	/* followed by device private data */
+	struct hfi1_ipoib_dev_priv dev_priv;
+};
+
+static inline struct hfi1_ipoib_dev_priv *
+hfi1_ipoib_priv(const struct net_device *dev)
+{
+	return &((struct hfi1_ipoib_rdma_netdev *)netdev_priv(dev))->dev_priv;
+}
+
+static inline void
+hfi1_ipoib_update_tx_netstats(struct hfi1_ipoib_dev_priv *priv,
+			      u64 packets,
+			      u64 bytes)
+{
+	struct pcpu_sw_netstats *netstats = this_cpu_ptr(priv->netstats);
+
+	u64_stats_update_begin(&netstats->syncp);
+	netstats->tx_packets += packets;
+	netstats->tx_bytes += bytes;
+	u64_stats_update_end(&netstats->syncp);
+}
+
+int hfi1_ipoib_send_dma(struct net_device *dev,
+			struct sk_buff *skb,
+			struct ib_ah *address,
+			u32 dqpn);
+
+int hfi1_ipoib_txreq_init(struct hfi1_ipoib_dev_priv *priv);
+void hfi1_ipoib_txreq_deinit(struct hfi1_ipoib_dev_priv *priv);
+
+void hfi1_ipoib_napi_tx_enable(struct net_device *dev);
+void hfi1_ipoib_napi_tx_disable(struct net_device *dev);
+
+#endif /* _IPOIB_H */