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
  12 void iowait_set_flag(struct iowait *wait, u32 flag)
  13 {
  14         trace_hfi1_iowait_set(wait, flag);
  15         set_bit(flag, &wait->flags);
  16 }
  17
  18 bool iowait_flag_set(struct iowait *wait, u32 flag)
  19 {
  20         return test_bit(flag, &wait->flags);
  21 }
  22
  23 inline 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  */
  41 void 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  */
  81 void iowait_cancel_work(struct iowait *w)
  82 {
  83         cancel_work_sync(&iowait_get_ib_work(w)->iowork);
  84         cancel_work_sync(&iowait_get_tid_work(w)->iowork);
  85 }
  86
  87 /**
  88  * iowait_set_work_flag - set work flag based on leg
  89  * @w - the iowait work struct
  90  */
  91 int iowait_set_work_flag(struct iowait_work *w)
  92 {
  93         if (w == &w->iow->wait[IOWAIT_IB_SE]) {
  94                 iowait_set_flag(w->iow, IOWAIT_PENDING_IB);
  95                 return IOWAIT_IB_SE;
  96         }
  97         iowait_set_flag(w->iow, IOWAIT_PENDING_TID);
  98         return IOWAIT_TID_SE;
  99 }
 100
 101 /**
 102  * iowait_priority_update_top - update the top priority entry
 103  * @w: the iowait struct
 104  * @top: a pointer to the top priority entry
 105  * @idx: the index of the current iowait in an array
 106  * @top_idx: the array index for the iowait entry that has the top priority
 107  *
 108  * This function is called to compare the priority of a given
 109  * iowait with the given top priority entry. The top index will
 110  * be returned.
 111  */
 112 uint iowait_priority_update_top(struct iowait *w,
 113                                 struct iowait *top,
 114                                 uint idx, uint top_idx)
 115 {
 116         u8 cnt, tcnt;
 117
 118         /* Convert priority into starve_cnt and compare the total.*/
 119         cnt = (w->priority << IOWAIT_PRIORITY_STARVE_SHIFT) + w->starved_cnt;
 120         tcnt = (top->priority << IOWAIT_PRIORITY_STARVE_SHIFT) +
 121                 top->starved_cnt;
 122         if (cnt > tcnt)
 123                 return idx;
 124         else
 125                 return top_idx;
 126 }