cregit-Linux how code gets into the kernel

Release 4.7 drivers/infiniband/hw/hfi1/iowait.h

#ifndef _HFI1_IOWAIT_H

#define _HFI1_IOWAIT_H
/*
 * Copyright(c) 2015, 2016 Intel Corporation.
 *
 * 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
 *
 * 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
 *
 * 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>

#include "sdma_txreq.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 wakeup
 * @sdma_drained: sdma count drained
 * @iowork: workqueue overhead
 * @wait_dma: wait for sdma_busy == 0
 * @wait_pio: wait for pio_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);
	
void (*sdma_drained)(struct iowait *wait);
	
struct work_struct iowork;
	
wait_queue_head_t wait_dma;
	
wait_queue_head_t wait_pio;
	
atomic_t sdma_busy;
	
atomic_t pio_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
 * @resume: 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), void (*sdma_drained)(struct iowait *wait)) { 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); 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; }

Contributors

PersonTokensPropCommitsCommitProp
mike marciniszynmike marciniszyn171100.00%3100.00%
Total171100.00%3100.00%

/** * iowait_schedule() - initialize wait structure * @wait: wait struct to schedule * @wq: workqueue for schedule * @cpu: cpu */
static inline void iowait_schedule( struct iowait *wait, struct workqueue_struct *wq, int cpu) { queue_work_on(cpu, wq, &wait->iowork); }

Contributors

PersonTokensPropCommitsCommitProp
mike marciniszynmike marciniszyn32100.00%2100.00%
Total32100.00%2100.00%

/** * 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)); }

Contributors

PersonTokensPropCommitsCommitProp
mike marciniszynmike marciniszyn28100.00%1100.00%
Total28100.00%1100.00%

/** * iowait_sdma_pending() - return sdma pending count * * @wait: iowait structure * */
static inline int iowait_sdma_pending(struct iowait *wait) { return atomic_read(&wait->sdma_busy); }

Contributors

PersonTokensPropCommitsCommitProp
mike marciniszynmike marciniszyn21100.00%1100.00%
Total21100.00%1100.00%

/** * iowait_sdma_inc - note sdma io pending * @wait: iowait structure */
static inline void iowait_sdma_inc(struct iowait *wait) { atomic_inc(&wait->sdma_busy); }

Contributors

PersonTokensPropCommitsCommitProp
mike marciniszynmike marciniszyn20100.00%1100.00%
Total20100.00%1100.00%

/** * iowait_sdma_add - add count to pending * @wait: iowait structure */
static inline void iowait_sdma_add(struct iowait *wait, int count) { atomic_add(count, &wait->sdma_busy); }

Contributors

PersonTokensPropCommitsCommitProp
mike marciniszynmike marciniszyn25100.00%1100.00%
Total25100.00%1100.00%

/** * iowait_sdma_dec - note sdma complete * @wait: iowait structure */
static inline int iowait_sdma_dec(struct iowait *wait) { return atomic_dec_and_test(&wait->sdma_busy); }

Contributors

PersonTokensPropCommitsCommitProp
mike marciniszynmike marciniszyn21100.00%1100.00%
Total21100.00%1100.00%

/** * iowait_pio_drain() - wait for pios to drain * * @wait: iowait structure * * This will delay until the iowait pios have * completed. */
static inline void iowait_pio_drain(struct iowait *wait) { wait_event_timeout(wait->wait_pio, !atomic_read(&wait->pio_busy), HZ); }

Contributors

PersonTokensPropCommitsCommitProp
mike marciniszynmike marciniszyn30100.00%1100.00%
Total30100.00%1100.00%

/** * iowait_pio_pending() - return pio pending count * * @wait: iowait structure * */
static inline int iowait_pio_pending(struct iowait *wait) { return atomic_read(&wait->pio_busy); }

Contributors

PersonTokensPropCommitsCommitProp
mike marciniszynmike marciniszyn21100.00%1100.00%
Total21100.00%1100.00%

/** * iowait_pio_inc - note pio pending * @wait: iowait structure */
static inline void iowait_pio_inc(struct iowait *wait) { atomic_inc(&wait->pio_busy); }

Contributors

PersonTokensPropCommitsCommitProp
mike marciniszynmike marciniszyn20100.00%1100.00%
Total20100.00%1100.00%

/** * iowait_sdma_dec - note pio complete * @wait: iowait structure */
static inline int iowait_pio_dec(struct iowait *wait) { return atomic_dec_and_test(&wait->pio_busy); }

Contributors

PersonTokensPropCommitsCommitProp
mike marciniszynmike marciniszyn21100.00%1100.00%
Total21100.00%1100.00%

/** * 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); wake_up(&wait->wait_pio); if (wait->sdma_drained) wait->sdma_drained(wait); }

Contributors

PersonTokensPropCommitsCommitProp
mike marciniszynmike marciniszyn41100.00%3100.00%
Total41100.00%3100.00%

/** * iowait_get_txhead() - get packet off of iowait list * * @wait wait struture */
static inline struct sdma_txreq *iowait_get_txhead(struct iowait *wait) { struct sdma_txreq *tx = NULL; if (!list_empty(&wait->tx_head)) { tx = list_first_entry( &wait->tx_head, struct sdma_txreq, list); list_del_init(&tx->list); } return tx; }

Contributors

PersonTokensPropCommitsCommitProp
mike marciniszynmike marciniszyn60100.00%1100.00%
Total60100.00%1100.00%

#endif

Overall Contributors

PersonTokensPropCommitsCommitProp
mike marciniszynmike marciniszyn65999.85%583.33%
jubin johnjubin john10.15%116.67%
Total660100.00%6100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
{% endraw %}