hw/hfi1/iowait.c

0001 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
0002 /*
0003  * Copyright(c) 2018 Intel Corporation.
0004  *
0005  */
0006 #include "iowait.h"
0007 #include "trace_iowait.h"
0008
0009 /* 1 priority == 16 starve_cnt */
0010 #define IOWAIT_PRIORITY_STARVE_SHIFT 4
0011
0012 void iowait_set_flag(struct iowait *wait, u32 flag)
0013 {
0014     trace_hfi1_iowait_set(wait, flag);
0015     set_bit(flag, &wait->flags);
0016 }
0017
0018 bool iowait_flag_set(struct iowait *wait, u32 flag)
0019 {
0020     return test_bit(flag, &wait->flags);
0021 }
0022
0023 inline void iowait_clear_flag(struct iowait *wait, u32 flag)
0024 {
0025     trace_hfi1_iowait_clear(wait, flag);
0026     clear_bit(flag, &wait->flags);
0027 }
0028
0029 /*
0030  * iowait_init() - initialize wait structure
0031  * @wait: wait struct to initialize
0032  * @tx_limit: limit for overflow queuing
0033  * @func: restart function for workqueue
0034  * @sleep: sleep function for no space
0035  * @resume: wakeup function for no space
0036  *
0037  * This function initializes the iowait
0038  * structure embedded in the QP or PQ.
0039  *
0040  */
0041 void iowait_init(struct iowait *wait, u32 tx_limit,
0042          void (*func)(struct work_struct *work),
0043          void (*tidfunc)(struct work_struct *work),
0044          int (*sleep)(struct sdma_engine *sde,
0045                   struct iowait_work *wait,
0046                   struct sdma_txreq *tx,
0047                   uint seq,
0048                   bool pkts_sent),
0049          void (*wakeup)(struct iowait *wait, int reason),
0050          void (*sdma_drained)(struct iowait *wait),
0051          void (*init_priority)(struct iowait *wait))
0052 {
0053     int i;
0054
0055     wait->count = 0;
0056     INIT_LIST_HEAD(&wait->list);
0057     init_waitqueue_head(&wait->wait_dma);
0058     init_waitqueue_head(&wait->wait_pio);
0059     atomic_set(&wait->sdma_busy, 0);
0060     atomic_set(&wait->pio_busy, 0);
0061     wait->tx_limit = tx_limit;
0062     wait->sleep = sleep;
0063     wait->wakeup = wakeup;
0064     wait->sdma_drained = sdma_drained;
0065     wait->init_priority = init_priority;
0066     wait->flags = 0;
0067     for (i = 0; i < IOWAIT_SES; i++) {
0068         wait->wait[i].iow = wait;
0069         INIT_LIST_HEAD(&wait->wait[i].tx_head);
0070         if (i == IOWAIT_IB_SE)
0071             INIT_WORK(&wait->wait[i].iowork, func);
0072         else
0073             INIT_WORK(&wait->wait[i].iowork, tidfunc);
0074     }
0075 }
0076
0077 /**
0078  * iowait_cancel_work - cancel all work in iowait
0079  * @w: the iowait struct
0080  */
0081 void iowait_cancel_work(struct iowait *w)
0082 {
0083     cancel_work_sync(&iowait_get_ib_work(w)->iowork);
0084     /* Make sure that the iowork for TID RDMA is used */
0085     if (iowait_get_tid_work(w)->iowork.func)
0086         cancel_work_sync(&iowait_get_tid_work(w)->iowork);
0087 }
0088
0089 /**
0090  * iowait_set_work_flag - set work flag based on leg
0091  * @w: the iowait work struct
0092  */
0093 int iowait_set_work_flag(struct iowait_work *w)
0094 {
0095     if (w == &w->iow->wait[IOWAIT_IB_SE]) {
0096         iowait_set_flag(w->iow, IOWAIT_PENDING_IB);
0097         return IOWAIT_IB_SE;
0098     }
0099     iowait_set_flag(w->iow, IOWAIT_PENDING_TID);
0100     return IOWAIT_TID_SE;
0101 }
0102
0103 /**
0104  * iowait_priority_update_top - update the top priority entry
0105  * @w: the iowait struct
0106  * @top: a pointer to the top priority entry
0107  * @idx: the index of the current iowait in an array
0108  * @top_idx: the array index for the iowait entry that has the top priority
0109  *
0110  * This function is called to compare the priority of a given
0111  * iowait with the given top priority entry. The top index will
0112  * be returned.
0113  */
0114 uint iowait_priority_update_top(struct iowait *w,
0115                 struct iowait *top,
0116                 uint idx, uint top_idx)
0117 {
0118     u8 cnt, tcnt;
0119
0120     /* Convert priority into starve_cnt and compare the total.*/
0121     cnt = (w->priority << IOWAIT_PRIORITY_STARVE_SHIFT) + w->starved_cnt;
0122     tcnt = (top->priority << IOWAIT_PRIORITY_STARVE_SHIFT) +
0123         top->starved_cnt;
0124     if (cnt > tcnt)
0125         return idx;
0126     else
0127         return top_idx;
0128 }