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(nr: flag, addr: &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(nr: flag, addr: &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(list: &wait->list);
57 init_waitqueue_head(&wait->wait_dma);
58 init_waitqueue_head(&wait->wait_pio);
59 atomic_set(v: &wait->sdma_busy, i: 0);
60 atomic_set(v: &wait->pio_busy, i: 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(list: &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(work: &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(work: &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(wait: w->iow, IOWAIT_PENDING_IB);
97 return IOWAIT_IB_SE;
98 }
99 iowait_set_flag(wait: 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

source code of linux/drivers/infiniband/hw/hfi1/iowait.c