xref: /freebsd/sys/net/mp_ring.h (revision 2a58b312)
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 
38 struct ifmp_ring;
39 typedef u_int (*mp_ring_drain_t)(struct ifmp_ring *, u_int, u_int);
40 typedef u_int (*mp_ring_can_drain_t)(struct ifmp_ring *);
41 typedef void (*mp_ring_serial_t)(struct ifmp_ring *);
42 
43 #if defined(__powerpc__) || defined(__i386__)
44 #define MP_RING_NO_64BIT_ATOMICS
45 #endif
46 
47 struct 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[] __aligned(CACHE_LINE_SIZE);
65 };
66 
67 int ifmp_ring_alloc(struct ifmp_ring **, int, void *, mp_ring_drain_t,
68     mp_ring_can_drain_t, struct malloc_type *, int);
69 void ifmp_ring_free(struct ifmp_ring *);
70 int ifmp_ring_enqueue(struct ifmp_ring *, void **, int, int, int);
71 void ifmp_ring_check_drainage(struct ifmp_ring *, int);
72 void ifmp_ring_reset_stats(struct ifmp_ring *);
73 int ifmp_ring_is_idle(struct ifmp_ring *);
74 int ifmp_ring_is_stalled(struct ifmp_ring *r);
75 #endif
76