1/*-
2 * Copyright (c) 2014 Chelsio Communications, Inc.
3 * All rights reserved.
4 * Written by: Navdeep Parhar <np@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD$
28 *
29 */
30
31#ifndef __NET_MP_RING_H
32#define __NET_MP_RING_H
33
34#ifndef _KERNEL
35#error "no user-serviceable parts inside"
36#endif
37
38struct ifmp_ring;
39typedef u_int (*mp_ring_drain_t)(struct ifmp_ring *, u_int, u_int);
40typedef u_int (*mp_ring_can_drain_t)(struct ifmp_ring *);
41typedef void (*mp_ring_serial_t)(struct ifmp_ring *);
42
43#if defined(__powerpc__) || defined(__mips__) || defined(__i386__) || defined(__HAIKU__)
44#define MP_RING_NO_64BIT_ATOMICS
45#endif
46
47struct ifmp_ring {
48	volatile uint64_t	state __aligned(CACHE_LINE_SIZE);
49
50	int			size __aligned(CACHE_LINE_SIZE);
51	void *			cookie;
52	struct malloc_type *	mt;
53	mp_ring_drain_t		drain;
54	mp_ring_can_drain_t	can_drain;	/* cheap, may be unreliable */
55	counter_u64_t		enqueues;
56	counter_u64_t		drops;
57	counter_u64_t		starts;
58	counter_u64_t		stalls;
59	counter_u64_t		restarts;	/* recovered after stalling */
60	counter_u64_t		abdications;
61#ifdef MP_RING_NO_64BIT_ATOMICS
62	struct mtx		lock;
63#endif
64	void * volatile		items[
65#if __GNUC__ < 3
66	0
67#else
68#endif
69	] __aligned(CACHE_LINE_SIZE);
70};
71
72int ifmp_ring_alloc(struct ifmp_ring **, int, void *, mp_ring_drain_t,
73    mp_ring_can_drain_t, struct malloc_type *, int);
74void ifmp_ring_free(struct ifmp_ring *);
75int ifmp_ring_enqueue(struct ifmp_ring *, void **, int, int, int);
76void ifmp_ring_check_drainage(struct ifmp_ring *, int);
77void ifmp_ring_reset_stats(struct ifmp_ring *);
78int ifmp_ring_is_idle(struct ifmp_ring *);
79int ifmp_ring_is_stalled(struct ifmp_ring *r);
80#endif
81