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

   1// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
   2/*
   3 * Copyright(c) 2018 Intel Corporation.
   4 *
   5 */
   6#include "iowait.h"
   7#include "trace_iowait.h"
   8
   9/* 1 priority == 16 starve_cnt */
  10#define IOWAIT_PRIORITY_STARVE_SHIFT 4
  11
  12void iowait_set_flag(struct iowait *wait, u32 flag)
  13{
  14        trace_hfi1_iowait_set(wait, flag);
  15        set_bit(flag, &wait->flags);
  16}
  17
  18bool iowait_flag_set(struct iowait *wait, u32 flag)
  19{
  20        return test_bit(flag, &wait->flags);
  21}
  22
  23inline void iowait_clear_flag(struct iowait *wait, u32 flag)
  24{
  25        trace_hfi1_iowait_clear(wait, flag);
  26        clear_bit(flag, &wait->flags);
  27}
  28
  29/*
  30 * iowait_init() - initialize wait structure
  31 * @wait: wait struct to initialize
  32 * @tx_limit: limit for overflow queuing
  33 * @func: restart function for workqueue
  34 * @sleep: sleep function for no space
  35 * @resume: wakeup function for no space
  36 *
  37 * This function initializes the iowait
  38 * structure embedded in the QP or PQ.
  39 *
  40 */
  41void iowait_init(struct iowait *wait, u32 tx_limit,
  42                 void (*func)(struct work_struct *work),
  43                 void (*tidfunc)(struct work_struct *work),
  44                 int (*sleep)(struct sdma_engine *sde,
  45                              struct iowait_work *wait,
  46                              struct sdma_txreq *tx,
  47                              uint seq,
  48                              bool pkts_sent),
  49                 void (*wakeup)(struct iowait *wait, int reason),
  50                 void (*sdma_drained)(struct iowait *wait),
  51                 void (*init_priority)(struct iowait *wait))
  52{
  53        int i;
  54
  55        wait->count = 0;
  56        INIT_LIST_HEAD(&wait->list);
  57        init_waitqueue_head(&wait->wait_dma);
  58        init_waitqueue_head(&wait->wait_pio);
  59        atomic_set(&wait->sdma_busy, 0);
  60        atomic_set(&wait->pio_busy, 0);
  61        wait->tx_limit = tx_limit;
  62        wait->sleep = sleep;
  63        wait->wakeup = wakeup;
  64        wait->sdma_drained = sdma_drained;
  65        wait->init_priority = init_priority;
  66        wait->flags = 0;
  67        for (i = 0; i < IOWAIT_SES; i++) {
  68                wait->wait[i].iow = wait;
  69                INIT_LIST_HEAD(&wait->wait[i].tx_head);
  70                if (i == IOWAIT_IB_SE)
  71                        INIT_WORK(&wait->wait[i].iowork, func);
  72                else
  73                        INIT_WORK(&wait->wait[i].iowork, tidfunc);
  74        }
  75}
  76
  77/**
  78 * iowait_cancel_work - cancel all work in iowait
  79 * @w: the iowait struct
  80 */
  81void iowait_cancel_work(struct iowait *w)
  82{
  83        cancel_work_sync(&iowait_get_ib_work(w)->iowork);
  84        /* Make sure that the iowork for TID RDMA is used */
  85        if (iowait_get_tid_work(w)->iowork.func)
  86                cancel_work_sync(&iowait_get_tid_work(w)->iowork);
  87}
  88
  89/**
  90 * iowait_set_work_flag - set work flag based on leg
  91 * @w: the iowait work struct
  92 */
  93int iowait_set_work_flag(struct iowait_work *w)
  94{
  95        if (w == &w->iow->wait[IOWAIT_IB_SE]) {
  96                iowait_set_flag(w->iow, IOWAIT_PENDING_IB);
  97                return IOWAIT_IB_SE;
  98        }
  99        iowait_set_flag(w->iow, IOWAIT_PENDING_TID);
 100        return IOWAIT_TID_SE;
 101}
 102
 103/**
 104 * iowait_priority_update_top - update the top priority entry
 105 * @w: the iowait struct
 106 * @top: a pointer to the top priority entry
 107 * @idx: the index of the current iowait in an array
 108 * @top_idx: the array index for the iowait entry that has the top priority
 109 *
 110 * This function is called to compare the priority of a given
 111 * iowait with the given top priority entry. The top index will
 112 * be returned.
 113 */
 114uint iowait_priority_update_top(struct iowait *w,
 115                                struct iowait *top,
 116                                uint idx, uint top_idx)
 117{
 118        u8 cnt, tcnt;
 119
 120        /* Convert priority into starve_cnt and compare the total.*/
 121        cnt = (w->priority << IOWAIT_PRIORITY_STARVE_SHIFT) + w->starved_cnt;
 122        tcnt = (top->priority << IOWAIT_PRIORITY_STARVE_SHIFT) +
 123                top->starved_cnt;
 124        if (cnt > tcnt)
 125                return idx;
 126        else
 127                return top_idx;
 128}
 129