499 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			499 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
| #ifndef _HFI1_IOWAIT_H
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| #define _HFI1_IOWAIT_H
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| /*
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|  * Copyright(c) 2015 - 2018 Intel Corporation.
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|  *
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|  * This file is provided under a dual BSD/GPLv2 license.  When using or
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|  * redistributing this file, you may do so under either license.
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|  *
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|  * GPL LICENSE SUMMARY
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of version 2 of the GNU General Public License as
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|  * published by the Free Software Foundation.
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|  *
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|  * This program is distributed in the hope that it will be useful, but
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|  * WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * General Public License for more details.
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|  *
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|  * BSD LICENSE
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions
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|  * are met:
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|  *
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|  *  - Redistributions of source code must retain the above copyright
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|  *    notice, this list of conditions and the following disclaimer.
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|  *  - Redistributions in binary form must reproduce the above copyright
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|  *    notice, this list of conditions and the following disclaimer in
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|  *    the documentation and/or other materials provided with the
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|  *    distribution.
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|  *  - Neither the name of Intel Corporation nor the names of its
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|  *    contributors may be used to endorse or promote products derived
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|  *    from this software without specific prior written permission.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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|  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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|  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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|  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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|  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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|  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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|  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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|  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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|  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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|  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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|  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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|  *
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|  */
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| 
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| #include <linux/list.h>
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| #include <linux/workqueue.h>
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| #include <linux/wait.h>
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| #include <linux/sched.h>
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| 
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| #include "sdma_txreq.h"
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| 
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| /*
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|  * typedef (*restart_t)() - restart callback
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|  * @work: pointer to work structure
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|  */
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| typedef void (*restart_t)(struct work_struct *work);
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| 
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| #define IOWAIT_PENDING_IB  0x0
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| #define IOWAIT_PENDING_TID 0x1
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| 
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| /*
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|  * A QP can have multiple Send Engines (SEs).
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|  *
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|  * The current use case is for supporting a TID RDMA
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|  * packet build/xmit mechanism independent from verbs.
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|  */
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| #define IOWAIT_SES 2
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| #define IOWAIT_IB_SE 0
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| #define IOWAIT_TID_SE 1
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| 
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| struct sdma_txreq;
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| struct sdma_engine;
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| /**
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|  * @iowork: the work struct
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|  * @tx_head: list of prebuilt packets
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|  * @iow: the parent iowait structure
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|  *
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|  * This structure is the work item (process) specific
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|  * details associated with the each of the two SEs of the
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|  * QP.
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|  *
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|  * The workstruct and the queued TXs are unique to each
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|  * SE.
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|  */
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| struct iowait;
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| struct iowait_work {
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| 	struct work_struct iowork;
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| 	struct list_head tx_head;
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| 	struct iowait *iow;
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| };
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| 
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| /**
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|  * @list: used to add/insert into QP/PQ wait lists
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|  * @tx_head: overflow list of sdma_txreq's
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|  * @sleep: no space callback
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|  * @wakeup: space callback wakeup
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|  * @sdma_drained: sdma count drained
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|  * @init_priority: callback to manipulate priority
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|  * @lock: lock protected head of wait queue
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|  * @iowork: workqueue overhead
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|  * @wait_dma: wait for sdma_busy == 0
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|  * @wait_pio: wait for pio_busy == 0
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|  * @sdma_busy: # of packets in flight
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|  * @count: total number of descriptors in tx_head'ed list
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|  * @tx_limit: limit for overflow queuing
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|  * @tx_count: number of tx entry's in tx_head'ed list
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|  * @flags: wait flags (one per QP)
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|  * @wait: SE array for multiple legs
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|  *
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|  * This is to be embedded in user's state structure
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|  * (QP or PQ).
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|  *
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|  * The sleep and wakeup members are a
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|  * bit misnamed.   They do not strictly
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|  * speaking sleep or wake up, but they
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|  * are callbacks for the ULP to implement
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|  * what ever queuing/dequeuing of
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|  * the embedded iowait and its containing struct
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|  * when a resource shortage like SDMA ring space
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|  * or PIO credit space is seen.
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|  *
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|  * Both potentially have locks help
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|  * so sleeping is not allowed and it is not
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|  * supported to submit txreqs from the wakeup
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|  * call directly because of lock conflicts.
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|  *
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|  * The wait_dma member along with the iow
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|  *
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|  * The lock field is used by waiters to record
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|  * the seqlock_t that guards the list head.
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|  * Waiters explicity know that, but the destroy
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|  * code that unwaits QPs does not.
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|  */
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| struct iowait {
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| 	struct list_head list;
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| 	int (*sleep)(
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| 		struct sdma_engine *sde,
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| 		struct iowait_work *wait,
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| 		struct sdma_txreq *tx,
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| 		uint seq,
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| 		bool pkts_sent
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| 		);
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| 	void (*wakeup)(struct iowait *wait, int reason);
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| 	void (*sdma_drained)(struct iowait *wait);
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| 	void (*init_priority)(struct iowait *wait);
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| 	seqlock_t *lock;
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| 	wait_queue_head_t wait_dma;
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| 	wait_queue_head_t wait_pio;
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| 	atomic_t sdma_busy;
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| 	atomic_t pio_busy;
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| 	u32 count;
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| 	u32 tx_limit;
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| 	u32 tx_count;
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| 	u8 starved_cnt;
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| 	u8 priority;
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| 	unsigned long flags;
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| 	struct iowait_work wait[IOWAIT_SES];
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| };
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| 
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| #define SDMA_AVAIL_REASON 0
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| 
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| void iowait_set_flag(struct iowait *wait, u32 flag);
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| bool iowait_flag_set(struct iowait *wait, u32 flag);
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| void iowait_clear_flag(struct iowait *wait, u32 flag);
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| 
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| void iowait_init(struct iowait *wait, u32 tx_limit,
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| 		 void (*func)(struct work_struct *work),
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| 		 void (*tidfunc)(struct work_struct *work),
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| 		 int (*sleep)(struct sdma_engine *sde,
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| 			      struct iowait_work *wait,
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| 			      struct sdma_txreq *tx,
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| 			      uint seq,
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| 			      bool pkts_sent),
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| 		 void (*wakeup)(struct iowait *wait, int reason),
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| 		 void (*sdma_drained)(struct iowait *wait),
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| 		 void (*init_priority)(struct iowait *wait));
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| 
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| /**
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|  * iowait_schedule() - schedule the default send engine work
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|  * @wait: wait struct to schedule
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|  * @wq: workqueue for schedule
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|  * @cpu: cpu
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|  */
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| static inline bool iowait_schedule(struct iowait *wait,
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| 				   struct workqueue_struct *wq, int cpu)
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| {
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| 	return !!queue_work_on(cpu, wq, &wait->wait[IOWAIT_IB_SE].iowork);
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| }
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| 
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| /**
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|  * iowait_tid_schedule - schedule the tid SE
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|  * @wait: the iowait structure
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|  * @wq: the work queue
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|  * @cpu: the cpu
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|  */
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| static inline bool iowait_tid_schedule(struct iowait *wait,
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| 				       struct workqueue_struct *wq, int cpu)
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| {
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| 	return !!queue_work_on(cpu, wq, &wait->wait[IOWAIT_TID_SE].iowork);
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| }
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| 
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| /**
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|  * iowait_sdma_drain() - wait for DMAs to drain
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|  *
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|  * @wait: iowait structure
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|  *
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|  * This will delay until the iowait sdmas have
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|  * completed.
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|  */
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| static inline void iowait_sdma_drain(struct iowait *wait)
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| {
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| 	wait_event(wait->wait_dma, !atomic_read(&wait->sdma_busy));
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| }
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| 
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| /**
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|  * iowait_sdma_pending() - return sdma pending count
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|  *
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|  * @wait: iowait structure
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|  *
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|  */
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| static inline int iowait_sdma_pending(struct iowait *wait)
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| {
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| 	return atomic_read(&wait->sdma_busy);
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| }
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| 
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| /**
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|  * iowait_sdma_inc - note sdma io pending
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|  * @wait: iowait structure
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|  */
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| static inline void iowait_sdma_inc(struct iowait *wait)
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| {
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| 	atomic_inc(&wait->sdma_busy);
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| }
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| 
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| /**
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|  * iowait_sdma_add - add count to pending
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|  * @wait: iowait structure
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|  */
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| static inline void iowait_sdma_add(struct iowait *wait, int count)
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| {
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| 	atomic_add(count, &wait->sdma_busy);
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| }
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| 
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| /**
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|  * iowait_sdma_dec - note sdma complete
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|  * @wait: iowait structure
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|  */
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| static inline int iowait_sdma_dec(struct iowait *wait)
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| {
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| 	if (!wait)
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| 		return 0;
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| 	return atomic_dec_and_test(&wait->sdma_busy);
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| }
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| 
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| /**
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|  * iowait_pio_drain() - wait for pios to drain
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|  *
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|  * @wait: iowait structure
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|  *
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|  * This will delay until the iowait pios have
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|  * completed.
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|  */
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| static inline void iowait_pio_drain(struct iowait *wait)
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| {
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| 	wait_event_timeout(wait->wait_pio,
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| 			   !atomic_read(&wait->pio_busy),
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| 			   HZ);
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| }
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| 
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| /**
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|  * iowait_pio_pending() - return pio pending count
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|  *
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|  * @wait: iowait structure
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|  *
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|  */
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| static inline int iowait_pio_pending(struct iowait *wait)
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| {
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| 	return atomic_read(&wait->pio_busy);
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| }
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| 
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| /**
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|  * iowait_pio_inc - note pio pending
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|  * @wait: iowait structure
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|  */
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| static inline void iowait_pio_inc(struct iowait *wait)
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| {
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| 	atomic_inc(&wait->pio_busy);
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| }
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| 
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| /**
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|  * iowait_pio_dec - note pio complete
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|  * @wait: iowait structure
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|  */
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| static inline int iowait_pio_dec(struct iowait *wait)
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| {
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| 	if (!wait)
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| 		return 0;
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| 	return atomic_dec_and_test(&wait->pio_busy);
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| }
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| 
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| /**
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|  * iowait_drain_wakeup() - trigger iowait_drain() waiter
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|  *
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|  * @wait: iowait structure
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|  *
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|  * This will trigger any waiters.
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|  */
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| static inline void iowait_drain_wakeup(struct iowait *wait)
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| {
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| 	wake_up(&wait->wait_dma);
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| 	wake_up(&wait->wait_pio);
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| 	if (wait->sdma_drained)
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| 		wait->sdma_drained(wait);
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| }
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| 
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| /**
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|  * iowait_get_txhead() - get packet off of iowait list
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|  *
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|  * @wait iowait_work struture
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|  */
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| static inline struct sdma_txreq *iowait_get_txhead(struct iowait_work *wait)
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| {
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| 	struct sdma_txreq *tx = NULL;
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| 
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| 	if (!list_empty(&wait->tx_head)) {
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| 		tx = list_first_entry(
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| 			&wait->tx_head,
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| 			struct sdma_txreq,
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| 			list);
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| 		list_del_init(&tx->list);
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| 	}
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| 	return tx;
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| }
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| 
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| static inline u16 iowait_get_desc(struct iowait_work *w)
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| {
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| 	u16 num_desc = 0;
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| 	struct sdma_txreq *tx = NULL;
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| 
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| 	if (!list_empty(&w->tx_head)) {
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| 		tx = list_first_entry(&w->tx_head, struct sdma_txreq,
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| 				      list);
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| 		num_desc = tx->num_desc;
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| 		if (tx->flags & SDMA_TXREQ_F_VIP)
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| 			w->iow->priority++;
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| 	}
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| 	return num_desc;
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| }
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| 
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| static inline u32 iowait_get_all_desc(struct iowait *w)
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| {
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| 	u32 num_desc = 0;
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| 
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| 	num_desc = iowait_get_desc(&w->wait[IOWAIT_IB_SE]);
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| 	num_desc += iowait_get_desc(&w->wait[IOWAIT_TID_SE]);
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| 	return num_desc;
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| }
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| 
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| static inline void iowait_update_priority(struct iowait_work *w)
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| {
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| 	struct sdma_txreq *tx = NULL;
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| 
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| 	if (!list_empty(&w->tx_head)) {
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| 		tx = list_first_entry(&w->tx_head, struct sdma_txreq,
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| 				      list);
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| 		if (tx->flags & SDMA_TXREQ_F_VIP)
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| 			w->iow->priority++;
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| 	}
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| }
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| 
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| static inline void iowait_update_all_priority(struct iowait *w)
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| {
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| 	iowait_update_priority(&w->wait[IOWAIT_IB_SE]);
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| 	iowait_update_priority(&w->wait[IOWAIT_TID_SE]);
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| }
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| 
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| static inline void iowait_init_priority(struct iowait *w)
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| {
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| 	w->priority = 0;
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| 	if (w->init_priority)
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| 		w->init_priority(w);
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| }
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| 
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| static inline void iowait_get_priority(struct iowait *w)
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| {
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| 	iowait_init_priority(w);
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| 	iowait_update_all_priority(w);
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| }
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| 
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| /**
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|  * iowait_queue - Put the iowait on a wait queue
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|  * @pkts_sent: have some packets been sent before queuing?
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|  * @w: the iowait struct
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|  * @wait_head: the wait queue
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|  *
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|  * This function is called to insert an iowait struct into a
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|  * wait queue after a resource (eg, sdma descriptor or pio
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|  * buffer) is run out.
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|  */
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| static inline void iowait_queue(bool pkts_sent, struct iowait *w,
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| 				struct list_head *wait_head)
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| {
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| 	/*
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| 	 * To play fair, insert the iowait at the tail of the wait queue if it
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| 	 * has already sent some packets; Otherwise, put it at the head.
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| 	 * However, if it has priority packets to send, also put it at the
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| 	 * head.
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| 	 */
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| 	if (pkts_sent)
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| 		w->starved_cnt = 0;
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| 	else
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| 		w->starved_cnt++;
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| 
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| 	if (w->priority > 0 || !pkts_sent)
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| 		list_add(&w->list, wait_head);
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| 	else
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| 		list_add_tail(&w->list, wait_head);
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| }
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| 
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| /**
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|  * iowait_starve_clear - clear the wait queue's starve count
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|  * @pkts_sent: have some packets been sent?
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|  * @w: the iowait struct
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|  *
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|  * This function is called to clear the starve count. If no
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|  * packets have been sent, the starve count will not be cleared.
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|  */
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| static inline void iowait_starve_clear(bool pkts_sent, struct iowait *w)
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| {
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| 	if (pkts_sent)
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| 		w->starved_cnt = 0;
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| }
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| 
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| /* Update the top priority index */
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| uint iowait_priority_update_top(struct iowait *w,
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| 				struct iowait *top,
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| 				uint idx, uint top_idx);
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| 
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| /**
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|  * iowait_packet_queued() - determine if a packet is queued
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|  * @wait: the iowait_work structure
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|  */
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| static inline bool iowait_packet_queued(struct iowait_work *wait)
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| {
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| 	return !list_empty(&wait->tx_head);
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| }
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| 
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| /**
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|  * inc_wait_count - increment wait counts
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|  * @w: the log work struct
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|  * @n: the count
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|  */
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| static inline void iowait_inc_wait_count(struct iowait_work *w, u16 n)
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| {
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| 	if (!w)
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| 		return;
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| 	w->iow->tx_count++;
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| 	w->iow->count += n;
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| }
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| 
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| /**
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|  * iowait_get_tid_work - return iowait_work for tid SE
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|  * @w: the iowait struct
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|  */
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| static inline struct iowait_work *iowait_get_tid_work(struct iowait *w)
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| {
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| 	return &w->wait[IOWAIT_TID_SE];
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| }
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| 
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| /**
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|  * iowait_get_ib_work - return iowait_work for ib SE
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|  * @w: the iowait struct
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|  */
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| static inline struct iowait_work *iowait_get_ib_work(struct iowait *w)
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| {
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| 	return &w->wait[IOWAIT_IB_SE];
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| }
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| 
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| /**
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|  * iowait_ioww_to_iow - return iowait given iowait_work
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|  * @w: the iowait_work struct
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|  */
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| static inline struct iowait *iowait_ioww_to_iow(struct iowait_work *w)
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| {
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| 	if (likely(w))
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| 		return w->iow;
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| 	return NULL;
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| }
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| 
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| void iowait_cancel_work(struct iowait *w);
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| int iowait_set_work_flag(struct iowait_work *w);
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| 
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| #endif
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