cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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iowait.c (3414B)

      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}