IB/hfi1: Prepare resource waits for dual leg

Current implementation allows each qp to have only one send engine.  As
such, each qp has only one list to queue prebuilt packets when send engine
resources are not available. To improve performance, it is desired to
support multiple send engines for each qp.

This patch creates the framework to support two send engines
(two legs) for each qp for the TID RDMA protocol, which can be easily
extended to support more send engines. It achieves the goal by creating a
leg specific struct, iowait_work in the iowait struct, to hold the
work_struct and the tx_list as well as a pointer to the parent iowait
struct.

The hfi1_pkt_state now has an additional field to record the current legs
work structure and that is now passed to all egress waiters to determine
the leg that needs to wait via a new iowait helper.  The APIs are adjusted
to use the new leg specific struct as required.

Many new and modified helpers are added to support this change.

Reviewed-by: Mitko Haralanov <mitko.haralanov@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

1 files changed, 91 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/hfi1/iowait.c b/drivers/infiniband/hw/hfi1/iowait.c
new file mode 100644
index 000000000000..59dc955f1880
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/iowait.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/*
+ * Copyright(c) 2018 Intel Corporation.
+ *
+ */
+#include "iowait.h"
+
+void iowait_set_flag(struct iowait *wait, u32 flag)
+{
+	set_bit(flag, &wait->flags);
+}
+
+bool iowait_flag_set(struct iowait *wait, u32 flag)
+{
+	return test_bit(flag, &wait->flags);
+}
+
+inline void iowait_clear_flag(struct iowait *wait, u32 flag)
+{
+	clear_bit(flag, &wait->flags);
+}
+
+/**
+ * iowait_init() - initialize wait structure
+ * @wait: wait struct to initialize
+ * @tx_limit: limit for overflow queuing
+ * @func: restart function for workqueue
+ * @sleep: sleep function for no space
+ * @resume: wakeup function for no space
+ *
+ * This function initializes the iowait
+ * structure embedded in the QP or PQ.
+ *
+ */
+void iowait_init(struct iowait *wait, u32 tx_limit,
+		 void (*func)(struct work_struct *work),
+		 void (*tidfunc)(struct work_struct *work),
+		 int (*sleep)(struct sdma_engine *sde,
+			      struct iowait_work *wait,
+			      struct sdma_txreq *tx,
+			      uint seq,
+			      bool pkts_sent),
+		 void (*wakeup)(struct iowait *wait, int reason),
+		 void (*sdma_drained)(struct iowait *wait))
+{
+	int i;
+
+	wait->count = 0;
+	INIT_LIST_HEAD(&wait->list);
+	init_waitqueue_head(&wait->wait_dma);
+	init_waitqueue_head(&wait->wait_pio);
+	atomic_set(&wait->sdma_busy, 0);
+	atomic_set(&wait->pio_busy, 0);
+	wait->tx_limit = tx_limit;
+	wait->sleep = sleep;
+	wait->wakeup = wakeup;
+	wait->sdma_drained = sdma_drained;
+	wait->flags = 0;
+	for (i = 0; i < IOWAIT_SES; i++) {
+		wait->wait[i].iow = wait;
+		INIT_LIST_HEAD(&wait->wait[i].tx_head);
+		if (i == IOWAIT_IB_SE)
+			INIT_WORK(&wait->wait[i].iowork, func);
+		else
+			INIT_WORK(&wait->wait[i].iowork, tidfunc);
+	}
+}
+
+/**
+ * iowait_cancel_work - cancel all work in iowait
+ * @w: the iowait struct
+ */
+void iowait_cancel_work(struct iowait *w)
+{
+	cancel_work_sync(&iowait_get_ib_work(w)->iowork);
+	cancel_work_sync(&iowait_get_tid_work(w)->iowork);
+}
+
+/**
+ * iowait_set_work_flag - set work flag based on leg
+ * @w - the iowait work struct
+ */
+int iowait_set_work_flag(struct iowait_work *w)
+{
+	if (w == &w->iow->wait[IOWAIT_IB_SE]) {
+		iowait_set_flag(w->iow, IOWAIT_PENDING_IB);
+		return IOWAIT_IB_SE;
+	}
+	iowait_set_flag(w->iow, IOWAIT_PENDING_TID);
+	return IOWAIT_TID_SE;
+}