[PATCH v2 21/49] IB/hfi1: add progress delay/restart hooks

Mike Marciniszyn
2015-06-15T13:27:51Z

drivers/infiniband/hw/hfi1/iowait.h | 186 +++++++++++++++++++++++++++++++++++
1 file changed, 186 insertions(+)
create mode 100644 drivers/infiniband/hw/hfi1/iowait.h

diff --git a/drivers/infiniband/hw/hfi1/iowait.h b/drivers/infiniband/hw/hfi1/iowait.h
new file mode 100644
index 0000000..fa361b4
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/iowait.h
@@ -0,0 +1,186 @@
+#ifndef _HFI1_IOWAIT_H
+#define _HFI1_IOWAIT_H
+/*
+ *
+ * This file is provided under a dual BSD/GPLv2 license. When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * - Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <linux/list.h>
+#include <linux/workqueue.h>
+#include <linux/sched.h>
+
+/*
+ * typedef (*restart_t)() - restart callback
+ * @work: pointer to work structure
+ */
+typedef void (*restart_t)(struct work_struct *work);
+
+struct sdma_txreq;
+struct sdma_engine;
+/**
+ * struct iowait - linkage for delayed progress/waiting
+ * @list: used to add/insert into QP/PQ wait lists
+ * @tx_head: overflow list of sdma_txreq's
+ * @sleep: no space callback
+ * @wakeup: space callback
+ * @iowork: workqueue overhead
+ * @wait_dma: wait for sdma_busy == 0
+ * @sdma_busy: # of packets in flight
+ * @count: total number of descriptors in tx_head'ed list
+ * @tx_limit: limit for overflow queuing
+ * @tx_count: number of tx entry's in tx_head'ed list
+ *
+ * This is to be embedded in user's state structure
+ * (QP or PQ).
+ *
+ * The sleep and wakeup members are a
+ * bit misnamed. They do not strictly
+ * speaking sleep or wake up, but they
+ * are callbacks for the ULP to implement
+ * what ever queuing/dequeuing of
+ * the embedded iowait and its containing struct
+ * when a resource shortage like SDMA ring space is seen.
+ *
+ * Both potentially have locks help
+ * so sleeping is not allowed.
+ *
+ * The wait_dma member along with the iow
+ */
+
+struct iowait {
+ struct list_head list;
+ struct list_head tx_head;
+ int (*sleep)(
+ struct sdma_engine *sde,
+ struct iowait *wait,
+ struct sdma_txreq *tx,
+ unsigned seq);
+ void (*wakeup)(struct iowait *wait, int reason);
+ struct work_struct iowork;
+ wait_queue_head_t wait_dma;
+ atomic_t sdma_busy;
+ u32 count;
+ u32 tx_limit;
+ u32 tx_count;
+};
+
+#define SDMA_AVAIL_REASON 0
+
+/**
+ * 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
+ * @wakeup: wakeup function for no space
+ *
+ * This function initializes the iowait
+ * structure embedded in the QP or PQ.
+ *
+ */
+
+static inline void iowait_init(
+ struct iowait *wait,
+ u32 tx_limit,
+ void (*func)(struct work_struct *work),
+ int (*sleep)(
+ struct sdma_engine *sde,
+ struct iowait *wait,
+ struct sdma_txreq *tx,
+ unsigned seq),
+ void (*wakeup)(struct iowait *wait, int reason))
+{
+ wait->count = 0;
+ INIT_LIST_HEAD(&wait->list);
+ INIT_LIST_HEAD(&wait->tx_head);
+ INIT_WORK(&wait->iowork, func);
+ init_waitqueue_head(&wait->wait_dma);
+ atomic_set(&wait->sdma_busy, 0);
+ wait->tx_limit = tx_limit;
+ wait->sleep = sleep;
+ wait->wakeup = wakeup;
+}
+
+/**
+ * iowait_schedule() - initialize wait structure
+ * @wait: wait struct to schedule
+ * @wq: workqueue for schedule
+ */
+static inline void iowait_schedule(
+ struct iowait *wait,
+ struct workqueue_struct *wq)
+{
+ queue_work(wq, &wait->iowork);
+}
+
+/**
+ * iowait_sdma_drain() - wait for DMAs to drain
+ *
+ * @wait: iowait structure
+ *
+ * This will delay until the iowait sdmas have
+ * completed.
+ */
+static inline void iowait_sdma_drain(struct iowait *wait)
+{
+ wait_event(wait->wait_dma, !atomic_read(&wait->sdma_busy));
+}
+
+/**
+ * iowait_drain_wakeup() - trigger iowait_drain() waiter
+ *
+ * @wait: iowait structure
+ *
+ * This will trigger any waiters.
+ */
+static inline void iowait_drain_wakeup(struct iowait *wait)
+{
+ wake_up(&wait->wait_dma);
+}
+
+#endif