linux/drivers/infiniband/hw/hfi1/iowait.c

127 lines
3.2 KiB
C

// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
/*
* Copyright(c) 2018 Intel Corporation.
*
*/
#include "iowait.h"
#include "trace_iowait.h"
/* 1 priority == 16 starve_cnt */
#define IOWAIT_PRIORITY_STARVE_SHIFT 4
void iowait_set_flag(struct iowait *wait, u32 flag)
{
trace_hfi1_iowait_set(wait, flag);
set_bit(flag, &wait->flags);
}
bool iowait_flag_set(struct iowait *wait, u32 flag)
{
return test_bit(flag, &wait->flags);
}
inline void iowait_clear_flag(struct iowait *wait, u32 flag)
{
trace_hfi1_iowait_clear(wait, flag);
clear_bit(flag, &wait->flags);
}
/**
* 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.
*
*/
void iowait_init(struct iowait *wait, u32 tx_limit,
void (*func)(struct work_struct *work),
void (*tidfunc)(struct work_struct *work),
int (*sleep)(struct sdma_engine *sde,
struct iowait_work *wait,
struct sdma_txreq *tx,
uint seq,
bool pkts_sent),
void (*wakeup)(struct iowait *wait, int reason),
void (*sdma_drained)(struct iowait *wait),
void (*init_priority)(struct iowait *wait))
{
int i;
wait->count = 0;
INIT_LIST_HEAD(&wait->list);
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;
wait->init_priority = init_priority;
wait->flags = 0;
for (i = 0; i < IOWAIT_SES; i++) {
wait->wait[i].iow = wait;
INIT_LIST_HEAD(&wait->wait[i].tx_head);
if (i == IOWAIT_IB_SE)
INIT_WORK(&wait->wait[i].iowork, func);
else
INIT_WORK(&wait->wait[i].iowork, tidfunc);
}
}
/**
* iowait_cancel_work - cancel all work in iowait
* @w: the iowait struct
*/
void iowait_cancel_work(struct iowait *w)
{
cancel_work_sync(&iowait_get_ib_work(w)->iowork);
cancel_work_sync(&iowait_get_tid_work(w)->iowork);
}
/**
* iowait_set_work_flag - set work flag based on leg
* @w - the iowait work struct
*/
int iowait_set_work_flag(struct iowait_work *w)
{
if (w == &w->iow->wait[IOWAIT_IB_SE]) {
iowait_set_flag(w->iow, IOWAIT_PENDING_IB);
return IOWAIT_IB_SE;
}
iowait_set_flag(w->iow, IOWAIT_PENDING_TID);
return IOWAIT_TID_SE;
}
/**
* iowait_priority_update_top - update the top priority entry
* @w: the iowait struct
* @top: a pointer to the top priority entry
* @idx: the index of the current iowait in an array
* @top_idx: the array index for the iowait entry that has the top priority
*
* This function is called to compare the priority of a given
* iowait with the given top priority entry. The top index will
* be returned.
*/
uint iowait_priority_update_top(struct iowait *w,
struct iowait *top,
uint idx, uint top_idx)
{
u8 cnt, tcnt;
/* Convert priority into starve_cnt and compare the total.*/
cnt = (w->priority << IOWAIT_PRIORITY_STARVE_SHIFT) + w->starved_cnt;
tcnt = (top->priority << IOWAIT_PRIORITY_STARVE_SHIFT) +
top->starved_cnt;
if (cnt > tcnt)
return idx;
else
return top_idx;
}