freebsd-src/sys/kern/subr_bufring.c
Kip Macy db7f0b974f - bump __FreeBSD version to reflect added buf_ring, memory barriers,
and ifnet functions

- add memory barriers to <machine/atomic.h>
- update drivers to only conditionally define their own

- add lockless producer / consumer ring buffer
- remove ring buffer implementation from cxgb and update its callers

- add if_transmit(struct ifnet *ifp, struct mbuf *m) to ifnet to
  allow drivers to efficiently manage multiple hardware queues
  (i.e. not serialize all packets through one ifq)
- expose if_qflush to allow drivers to flush any driver managed queues

This work was supported by Bitgravity Inc. and Chelsio Inc.
2008-11-22 05:55:56 +00:00

69 lines
2.3 KiB
C

/**************************************************************************
*
* 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. The name of Kip Macy nor the names of other
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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);
}