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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 | #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
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