drivers/infiniband/hw/hfi1/iowait.h - manifest_repos/valens - Git at Google

 #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
  * @lock: uses to record the list head lock
  * @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
  *
  * The lock field is used by waiters to record
  * the seqlock_t that guards the list head.
  * Waiters explicity know that, but the destroy
  * code that unwaits QPs does not.
  */

 struct iowait {
 	struct list_head list;
 	struct list_head tx_head;
 	int (*sleep)(
 		struct sdma_engine *sde,
 		struct iowait *wait,
 		struct sdma_txreq *tx,
 		uint seq,
 		bool pkts_sent
 		);
 	void (*wakeup)(struct iowait *wait, int reason);
 	void (*sdma_drained)(struct iowait *wait);
 	seqlock_t *lock;
 	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;
 	u8 starved_cnt;
 };

 #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,
 		uint seq,
 		bool pkts_sent),
 	void (*wakeup)(struct iowait *wait, int reason),
 	void (*sdma_drained)(struct iowait *wait))
 {
 	wait->count = 0;
 	wait->lock = NULL;
 	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;
 }

 /**
  * 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);
 }

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

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

 /**
  * 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);
 }

 /**
  * 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);
 }

 /**
  * 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);
 }

 /**
  * 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);
 }

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

 /**
  * 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);
 }

 /**
  * 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);
 }

 /**
  * 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;
 }

 /**
  * iowait_queue - Put the iowait on a wait queue
  * @pkts_sent: have some packets been sent before queuing?
  * @w: the iowait struct
  * @wait_head: the wait queue
  *
  * This function is called to insert an iowait struct into a
  * wait queue after a resource (eg, sdma decriptor or pio
  * buffer) is run out.
  */
 static inline void iowait_queue(bool pkts_sent, struct iowait *w,
 				struct list_head *wait_head)
 {
 	/*
 	 * To play fair, insert the iowait at the tail of the wait queue if it
 	 * has already sent some packets; Otherwise, put it at the head.
 	 */
 	if (pkts_sent) {
 		list_add_tail(&w->list, wait_head);
 		w->starved_cnt = 0;
 	} else {
 		list_add(&w->list, wait_head);
 		w->starved_cnt++;
 	}
 }

 /**
  * iowait_starve_clear - clear the wait queue's starve count
  * @pkts_sent: have some packets been sent?
  * @w: the iowait struct
  *
  * This function is called to clear the starve count. If no
  * packets have been sent, the starve count will not be cleared.
  */
 static inline void iowait_starve_clear(bool pkts_sent, struct iowait *w)
 {
 	if (pkts_sent)
 		w->starved_cnt = 0;
 }

 /**
  * iowait_starve_find_max - Find the maximum of the starve count
  * @w: the iowait struct
  * @max: a variable containing the max starve count
  * @idx: the index of the current iowait in an array
  * @max_idx: a variable containing the array index for the
  *         iowait entry that has the max starve count
  *
  * This function is called to compare the starve count of a
  * given iowait with the given max starve count. The max starve
  * count and the index will be updated if the iowait's start
  * count is larger.
  */
 static inline void iowait_starve_find_max(struct iowait *w, u8 *max,
 					  uint idx, uint *max_idx)
 {
 	if (w->starved_cnt > *max) {
 		*max = w->starved_cnt;
 		*max_idx = idx;
 	}
 }

 #endif
	#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
	* @lock: uses to record the list head lock
	* @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
	*
	* The lock field is used by waiters to record
	* the seqlock_t that guards the list head.
	* Waiters explicity know that, but the destroy
	* code that unwaits QPs does not.
	*/

	struct iowait {
	struct list_head list;
	struct list_head tx_head;
	int (*sleep)(
	struct sdma_engine *sde,
	struct iowait *wait,
	struct sdma_txreq *tx,
	uint seq,
	bool pkts_sent
	);
	void (wakeup)(struct iowait wait, int reason);
	void (sdma_drained)(struct iowait wait);
	seqlock_t *lock;
	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;
	u8 starved_cnt;
	};

	#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,
	uint seq,
	bool pkts_sent),
	void (wakeup)(struct iowait wait, int reason),
	void (sdma_drained)(struct iowait wait))
	{
	wait->count = 0;
	wait->lock = NULL;
	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;
	}

	/**
	* 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);
	}

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

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

	/**
	* 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);
	}

	/**
	* 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);
	}

	/**
	* 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);
	}

	/**
	* 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);
	}

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

	/**
	* 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);
	}

	/**
	* 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);
	}

	/**
	* 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;
	}

	/**
	* iowait_queue - Put the iowait on a wait queue
	* @pkts_sent: have some packets been sent before queuing?
	* @w: the iowait struct
	* @wait_head: the wait queue
	*
	* This function is called to insert an iowait struct into a
	* wait queue after a resource (eg, sdma decriptor or pio
	* buffer) is run out.
	*/
	static inline void iowait_queue(bool pkts_sent, struct iowait *w,
	struct list_head *wait_head)
	{
	/*
	* To play fair, insert the iowait at the tail of the wait queue if it
	* has already sent some packets; Otherwise, put it at the head.
	*/
	if (pkts_sent) {
	list_add_tail(&w->list, wait_head);
	w->starved_cnt = 0;
	} else {
	list_add(&w->list, wait_head);
	w->starved_cnt++;
	}
	}

	/**
	* iowait_starve_clear - clear the wait queue's starve count
	* @pkts_sent: have some packets been sent?
	* @w: the iowait struct
	*
	* This function is called to clear the starve count. If no
	* packets have been sent, the starve count will not be cleared.
	*/
	static inline void iowait_starve_clear(bool pkts_sent, struct iowait *w)
	{
	if (pkts_sent)
	w->starved_cnt = 0;
	}

	/**
	* iowait_starve_find_max - Find the maximum of the starve count
	* @w: the iowait struct
	* @max: a variable containing the max starve count
	* @idx: the index of the current iowait in an array
	* @max_idx: a variable containing the array index for the
	* iowait entry that has the max starve count
	*
	* This function is called to compare the starve count of a
	* given iowait with the given max starve count. The max starve
	* count and the index will be updated if the iowait's start
	* count is larger.
	*/
	static inline void iowait_starve_find_max(struct iowait w, u8 max,
	uint idx, uint *max_idx)
	{
	if (w->starved_cnt > *max) {
	*max = w->starved_cnt;
	*max_idx = idx;
	}
	}

	#endif