freebsd-dev/sys/kern/subr_bufring.c

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/*-
* Copyright (c) 2007, 2008 Kip Macy <kmacy@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/ktr.h>
#include <sys/buf_ring.h>
struct buf_ring *
buf_ring_alloc(int count, struct malloc_type *type, int flags, struct mtx *lock)
{
struct buf_ring *br;
KASSERT(powerof2(count), ("buf ring must be size power of 2"));
br = malloc(sizeof(struct buf_ring) + count*sizeof(caddr_t),
type, flags|M_ZERO);
if (br == NULL)
return (NULL);
#ifdef DEBUG_BUFRING
br->br_lock = lock;
#endif
br->br_prod_size = br->br_cons_size = count;
br->br_prod_mask = br->br_cons_mask = count-1;
br->br_prod_head = br->br_cons_head = 0;
br->br_prod_tail = br->br_cons_tail = 0;
return (br);
}
void
buf_ring_free(struct buf_ring *br, struct malloc_type *type)
{
free(br, type);
}