[mirror_ubuntu-zesty-kernel.git] / drivers / staging / rdma / 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;
}

/**
 * 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;
}

#endif
Commit	Line	Data
77241056 MM	1	#ifndef _HFI1_IOWAIT_H
	2	#define _HFI1_IOWAIT_H
	3	/*
05d6ac1d	4	* Copyright(c) 2015, 2016 Intel Corporation.
77241056 MM	5	*
	6	* This file is provided under a dual BSD/GPLv2 license. When using or
	7	* redistributing this file, you may do so under either license.
	8	*
	9	* GPL LICENSE SUMMARY
	10	*
77241056 MM	11	* This program is free software; you can redistribute it and/or modify
	12	* it under the terms of version 2 of the GNU General Public License as
	13	* published by the Free Software Foundation.
	14	*
	15	* This program is distributed in the hope that it will be useful, but
	16	* WITHOUT ANY WARRANTY; without even the implied warranty of
	17	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	18	* General Public License for more details.
	19	*
	20	* BSD LICENSE
	21	*
77241056 MM	22	* Redistribution and use in source and binary forms, with or without
	23	* modification, are permitted provided that the following conditions
	24	* are met:
	25	*
	26	* - Redistributions of source code must retain the above copyright
	27	* notice, this list of conditions and the following disclaimer.
	28	* - Redistributions in binary form must reproduce the above copyright
	29	* notice, this list of conditions and the following disclaimer in
	30	* the documentation and/or other materials provided with the
	31	* distribution.
	32	* - Neither the name of Intel Corporation nor the names of its
	33	* contributors may be used to endorse or promote products derived
	34	* from this software without specific prior written permission.
	35	*
	36	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	37	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	38	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	39	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	40	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	41	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	42	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	43	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	44	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	45	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	46	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	47	*
	48	*/
	49
	50	#include <linux/list.h>
	51	#include <linux/workqueue.h>
	52	#include <linux/sched.h>
	53
711e104d	54	#include "sdma_txreq.h"
14553ca1	55
77241056 MM	56	/*
	57	* typedef (*restart_t)() - restart callback
	58	* @work: pointer to work structure
	59	*/
	60	typedef void (restart_t)(struct work_struct work);
	61
	62	struct sdma_txreq;
	63	struct sdma_engine;
	64	/**
	65	* struct iowait - linkage for delayed progress/waiting
	66	* @list: used to add/insert into QP/PQ wait lists
	67	* @tx_head: overflow list of sdma_txreq's
	68	* @sleep: no space callback
a545f530 MM	69	* @wakeup: space callback wakeup
a545f530 MM	70	* @sdma_drained: sdma count drained
77241056 MM	71	* @iowork: workqueue overhead
77241056 MM	72	* @wait_dma: wait for sdma_busy == 0
14553ca1	73	* @wait_pio: wait for pio_busy == 0
77241056 MM	74	* @sdma_busy: # of packets in flight
	75	* @count: total number of descriptors in tx_head'ed list
	76	* @tx_limit: limit for overflow queuing
	77	* @tx_count: number of tx entry's in tx_head'ed list
	78	*
	79	* This is to be embedded in user's state structure
	80	* (QP or PQ).
	81	*
	82	* The sleep and wakeup members are a
	83	* bit misnamed. They do not strictly
	84	* speaking sleep or wake up, but they
	85	* are callbacks for the ULP to implement
	86	* what ever queuing/dequeuing of
	87	* the embedded iowait and its containing struct
	88	* when a resource shortage like SDMA ring space is seen.
	89	*
	90	* Both potentially have locks help
	91	* so sleeping is not allowed.
	92	*
	93	* The wait_dma member along with the iow
	94	*/
	95
	96	struct iowait {
	97	struct list_head list;
	98	struct list_head tx_head;
	99	int (*sleep)(
	100	struct sdma_engine *sde,
	101	struct iowait *wait,
	102	struct sdma_txreq *tx,
	103	unsigned seq);
	104	void (wakeup)(struct iowait wait, int reason);
a545f530	105	void (sdma_drained)(struct iowait wait);
77241056 MM	106	struct work_struct iowork;
77241056 MM	107	wait_queue_head_t wait_dma;
14553ca1	108	wait_queue_head_t wait_pio;
77241056	109	atomic_t sdma_busy;
14553ca1	110	atomic_t pio_busy;
77241056 MM	111	u32 count;
	112	u32 tx_limit;
	113	u32 tx_count;
	114	};
	115
	116	#define SDMA_AVAIL_REASON 0
	117
	118	/**
	119	* iowait_init() - initialize wait structure
	120	* @wait: wait struct to initialize
	121	* @tx_limit: limit for overflow queuing
	122	* @func: restart function for workqueue
	123	* @sleep: sleep function for no space
a545f530	124	* @resume: wakeup function for no space
77241056 MM	125	*
	126	* This function initializes the iowait
	127	* structure embedded in the QP or PQ.
	128	*
	129	*/
	130
	131	static inline void iowait_init(
	132	struct iowait *wait,
	133	u32 tx_limit,
	134	void (func)(struct work_struct work),
	135	int (*sleep)(
	136	struct sdma_engine *sde,
	137	struct iowait *wait,
	138	struct sdma_txreq *tx,
	139	unsigned seq),
a545f530 MM	140	void (wakeup)(struct iowait wait, int reason),
a545f530 MM	141	void (sdma_drained)(struct iowait wait))
77241056 MM	142	{
	143	wait->count = 0;
	144	INIT_LIST_HEAD(&wait->list);
	145	INIT_LIST_HEAD(&wait->tx_head);
	146	INIT_WORK(&wait->iowork, func);
	147	init_waitqueue_head(&wait->wait_dma);
14553ca1	148	init_waitqueue_head(&wait->wait_pio);
77241056	149	atomic_set(&wait->sdma_busy, 0);
14553ca1	150	atomic_set(&wait->pio_busy, 0);
77241056 MM	151	wait->tx_limit = tx_limit;
	152	wait->sleep = sleep;
	153	wait->wakeup = wakeup;
a545f530	154	wait->sdma_drained = sdma_drained;
77241056 MM	155	}
	156
	157	/**
	158	* iowait_schedule() - initialize wait structure
	159	* @wait: wait struct to schedule
	160	* @wq: workqueue for schedule
0a226edd	161	* @cpu: cpu
77241056 MM	162	*/
	163	static inline void iowait_schedule(
	164	struct iowait *wait,
0a226edd MM	165	struct workqueue_struct *wq,
0a226edd MM	166	int cpu)
77241056	167	{
0a226edd	168	queue_work_on(cpu, wq, &wait->iowork);
77241056 MM	169	}
	170
	171	/**
	172	* iowait_sdma_drain() - wait for DMAs to drain
	173	*
	174	* @wait: iowait structure
	175	*
	176	* This will delay until the iowait sdmas have
	177	* completed.
	178	*/
	179	static inline void iowait_sdma_drain(struct iowait *wait)
	180	{
	181	wait_event(wait->wait_dma, !atomic_read(&wait->sdma_busy));
	182	}
	183
14553ca1 MM	184	/**
	185	* iowait_sdma_pending() - return sdma pending count
	186	*
	187	* @wait: iowait structure
	188	*
	189	*/
	190	static inline int iowait_sdma_pending(struct iowait *wait)
	191	{
	192	return atomic_read(&wait->sdma_busy);
	193	}
	194
	195	/**
	196	* iowait_sdma_inc - note sdma io pending
	197	* @wait: iowait structure
	198	*/
	199	static inline void iowait_sdma_inc(struct iowait *wait)
	200	{
	201	atomic_inc(&wait->sdma_busy);
	202	}
	203
	204	/**
	205	* iowait_sdma_add - add count to pending
	206	* @wait: iowait structure
	207	*/
	208	static inline void iowait_sdma_add(struct iowait *wait, int count)
	209	{
	210	atomic_add(count, &wait->sdma_busy);
	211	}
	212
	213	/**
	214	* iowait_sdma_dec - note sdma complete
	215	* @wait: iowait structure
	216	*/
	217	static inline int iowait_sdma_dec(struct iowait *wait)
	218	{
	219	return atomic_dec_and_test(&wait->sdma_busy);
	220	}
	221
	222	/**
	223	* iowait_pio_drain() - wait for pios to drain
	224	*
	225	* @wait: iowait structure
	226	*
	227	* This will delay until the iowait pios have
	228	* completed.
	229	*/
	230	static inline void iowait_pio_drain(struct iowait *wait)
	231	{
	232	wait_event_timeout(wait->wait_pio,
	233	!atomic_read(&wait->pio_busy),
	234	HZ);
	235	}
	236
	237	/**
	238	* iowait_pio_pending() - return pio pending count
	239	*
	240	* @wait: iowait structure
	241	*
	242	*/
	243	static inline int iowait_pio_pending(struct iowait *wait)
	244	{
	245	return atomic_read(&wait->pio_busy);
	246	}
	247
248	/**
249	* iowait_pio_inc - note pio pending
250	* @wait: iowait structure
251	*/
252	static inline void iowait_pio_inc(struct iowait *wait)
253	{
254	atomic_inc(&wait->pio_busy);
255	}
256
257	/**
258	* iowait_sdma_dec - note pio complete
259	* @wait: iowait structure
260	*/
261	static inline int iowait_pio_dec(struct iowait *wait)
262	{
263	return atomic_dec_and_test(&wait->pio_busy);
264	}
265
77241056 MM	266	/**
	267	* iowait_drain_wakeup() - trigger iowait_drain() waiter
	268	*
	269	* @wait: iowait structure
	270	*
	271	* This will trigger any waiters.
	272	*/
	273	static inline void iowait_drain_wakeup(struct iowait *wait)
	274	{
	275	wake_up(&wait->wait_dma);
14553ca1	276	wake_up(&wait->wait_pio);
a545f530 MM	277	if (wait->sdma_drained)
a545f530 MM	278	wait->sdma_drained(wait);
77241056 MM	279	}
77241056 MM	280
711e104d MM	281	/**
	282	* iowait_get_txhead() - get packet off of iowait list
	283	*
	284	* @wait wait struture
	285	*/
	286	static inline struct sdma_txreq iowait_get_txhead(struct iowait wait)
	287	{
	288	struct sdma_txreq *tx = NULL;
	289
	290	if (!list_empty(&wait->tx_head)) {
	291	tx = list_first_entry(
	292	&wait->tx_head,
	293	struct sdma_txreq,
	294	list);
	295	list_del_init(&tx->list);
	296	}
	297	return tx;
	298	}
	299
77241056	300	#endif