linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Copyright (C) 2016 CNEX Labs

 * Initial release: Javier Gonzalez <javier@cnexlabs.com>

 *                  Matias Bjorling <matias@cnexlabs.com>

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License version

 * 2 as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * General Public License for more details.

 *

 * pblk-rl.c - pblk's rate limiter for user I/O

 *

 */

​

#include "pblk.h"

​

static void pblk_rl_kick_u_timer(struct pblk_rl *rl)

{

    mod_timer(&rl->u_timer, jiffies + msecs_to_jiffies(5000));

}

​

int pblk_rl_is_limit(struct pblk_rl *rl)

{

    int rb_space;

​

    rb_space = atomic_read(&rl->rb_space);

​

    return (rb_space == 0);

}

​

int pblk_rl_user_may_insert(struct pblk_rl *rl, int nr_entries)

{

    int rb_user_cnt = atomic_read(&rl->rb_user_cnt);

    int rb_space = atomic_read(&rl->rb_space);

​

    if (unlikely(rb_space >= 0) && (rb_space - nr_entries < 0))

        return NVM_IO_ERR;

​

    if (rb_user_cnt >= rl->rb_user_max)

        return NVM_IO_REQUEUE;

​

    return NVM_IO_OK;

}

​

void pblk_rl_inserted(struct pblk_rl *rl, int nr_entries)

{

    int rb_space = atomic_read(&rl->rb_space);

​

    if (unlikely(rb_space >= 0))

        atomic_sub(nr_entries, &rl->rb_space);

}

​

int pblk_rl_gc_may_insert(struct pblk_rl *rl, int nr_entries)

{

    int rb_gc_cnt = atomic_read(&rl->rb_gc_cnt);

    int rb_user_active;

​

    /* If there is no user I/O let GC take over space on the write buffer */