/*
* Copyright (c) 2014-2017 Richard Braun.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*
*
* System counters.
*
* This module provides 64-bits general-purpose counters that can be
* accessed and modified atomically from any context.
*/
#ifndef _KERN_SYSCNT_H
#define _KERN_SYSCNT_H
#include
#include
#include
#include
#include
/*
* Size of the buffer storing a system counter name.
*/
#define SYSCNT_NAME_SIZE 32
#include
/*
* System counter.
*/
struct syscnt;
/*
* Initialize and register the given counter.
*
* The counter is set to 0.
*/
void syscnt_register(struct syscnt *syscnt, const char *name);
#ifdef ATOMIC_HAVE_64B_OPS
static inline void
syscnt_set(struct syscnt *syscnt, uint64_t value)
{
atomic_store(&syscnt->value, value, ATOMIC_RELAXED);
}
static inline void
syscnt_add(struct syscnt *syscnt, int64_t delta)
{
atomic_add(&syscnt->value, delta, ATOMIC_RELAXED);
}
static inline uint64_t
syscnt_read(const struct syscnt *syscnt)
{
return atomic_load((uint64_t *)&syscnt->value, ATOMIC_RELAXED);
}
#else /* ATOMIC_HAVE_64B_OPS */
static inline void
syscnt_set(struct syscnt *syscnt, uint64_t value)
{
unsigned long flags;
spinlock_lock_intr_save(&syscnt->lock, &flags);
syscnt->value = value;
spinlock_unlock_intr_restore(&syscnt->lock, flags);
}
static inline void
syscnt_add(struct syscnt *syscnt, int64_t delta)
{
unsigned long flags;
spinlock_lock_intr_save(&syscnt->lock, &flags);
syscnt->value += delta;
spinlock_unlock_intr_restore(&syscnt->lock, flags);
}
static inline uint64_t
syscnt_read(struct syscnt *syscnt)
{
unsigned long flags;
uint64_t value;
spinlock_lock_intr_save(&syscnt->lock, &flags);
value = syscnt->value;
spinlock_unlock_intr_restore(&syscnt->lock, flags);
return value;
}
#endif /* ATOMIC_HAVE_64B_OPS */
static inline void
syscnt_inc(struct syscnt *syscnt)
{
syscnt_add(syscnt, 1);
}
static inline void
syscnt_dec(struct syscnt *syscnt)
{
syscnt_add(syscnt, -1);
}
/*
* Display system counters.
*
* A prefix can be used to filter the output, where only counters with the
* given prefix are displayed. If NULL, all counters are reported.
*/
void syscnt_info(const char *prefix);
/*
* This init operation provides :
* - registration of system counters
* - module fully initialized
*/
INIT_OP_DECLARE(syscnt_setup);
#endif /* _KERN_SYSCNT_H */