xref: /titanic_41/usr/src/uts/sun4v/sys/vio_util.h (revision d29b2c4438482eb00488be49a1f5d6835f455546)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #ifndef	_VIO_UTIL_H
28 #define	_VIO_UTIL_H
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include <sys/stream.h>
33 
34 #ifdef	__cplusplus
35 extern "C" {
36 #endif
37 
38 /*
39  * A message is composed of three structures. A message block (mblk_t), a
40  * data block to which it points and a data buffer. desballoc(9F) allows
41  * the caller to specify the data buffer and a free function which will
42  * be invoked when freeb(9F) is called to free the message. This allows
43  * the user to reclaim and reuse the data buffer, as opposed to using
44  * allocb(9F) where the message block, data block and data buffer are
45  * all destroyed by freeb().
46  *
47  * Note that even with desballoc the message and data blocks are destroyed
48  * by freeb() and must be recreated. It is only the data buffer which is
49  * preserved.
50  *
51  * The caller first creates a pool of vio_mblk_t's by invoking
52  * vio_create_mblks() and specifying the number of mblks and the size of the
53  * associated data buffers. Each vio_mblk_t contains a pointer to the
54  * mblk_t, a pointer to the data buffer and a function pointer to the
55  * reclaim function. The caller is returned a pointer to the pool which is
56  * used in subsequent allocation/destroy requests.
57  *
58  * The pool is managed as a circular queue with a head and tail pointer.
59  * Allocation requests result in the head index being incremented, mblks
60  * being returned to the pool result in the tail pointer being incremented.
61  *
62  * The pool can only be destroyed when all the mblks have been returned. It
63  * is the responsibility of the caller to ensure that all vio_allocb()
64  * requests have been completed before the pool is destroyed.
65  *
66  *
67  * vio_mblk_pool_t
68  * +-------------+
69  * |    tail     |--------------------------------+
70  * +-------------+                                |
71  * |    head     |--------+                       |
72  * +-------------+        |                       |
73  * ...............        V                       V
74  * +-------------+     +-------+-------+-------+-------+
75  * |    quep     |---->| vmp_t | vmp_t | vmp_t | vmp_t |
76  * +-------------+     +-------+-------+-------+-------+
77  * |             |         |       |       |       |
78  * ...                     |       |       |       |   +------------+
79  *                         |       |       |       +-->| data block |
80  *                         |       |       |           +------------+
81  *                         |       |       |   +------------+
82  *                         |       |       +-->| data block |
83  *                         |       |           +------------+
84  *                         |       |   +------------+
85  *                         |       +-->| data block |
86  *                         |           +------------+
87  *                         |   +------------+
88  *                         +-->| data block |
89  *                             +------------+
90  *
91  */
92 
93 /* mblk pool flags */
94 #define	VMPL_FLAG_DESTROYING	0x1	/* pool is being destroyed */
95 
96 struct vio_mblk_pool;
97 
98 typedef struct vio_mblk {
99 	uint8_t			*datap;		/* data buffer */
100 	mblk_t			*mp;		/* mblk using datap */
101 	frtn_t			reclaim;	/* mblk reclaim routine */
102 	struct vio_mblk_pool 	*vmplp;		/* pointer to parent pool */
103 } vio_mblk_t;
104 
105 typedef struct vio_mblk_pool {
106 	struct vio_mblk_pool	*nextp;	/* next in a list */
107 	kmutex_t		hlock;	/* sync access to head */
108 	kmutex_t		tlock;	/* sync access to tail */
109 	vio_mblk_t		*basep;	/* base pointer to pool of vio_mblks */
110 	vio_mblk_t		**quep; /* queue of free vio_mblks */
111 	uint8_t			*datap; /* rx data buffer area */
112 	uint32_t		head;	/* queue head */
113 	uint32_t		tail;	/* queue tail */
114 	uint64_t		quelen;	/* queue len (# mblks) */
115 	uint64_t		quemask; /* quelen - 1 */
116 	size_t			mblk_size; /* data buf size of each mblk */
117 	uint32_t		flag;	/* pool-related flags */
118 } vio_mblk_pool_t;
119 
120 typedef struct vio_multi_pool {
121 	uint32_t		num_pools;	/* no. of vio mblk pools */
122 	uint32_t		tbsz;		/* allocated buffer size */
123 	uint32_t		*bufsz_tbl;	/* buffer sizes table */
124 	uint32_t		*nbuf_tbl;	/* no. of buffers table */
125 	vio_mblk_pool_t		**vmpp;		/* vio mblk pools */
126 } vio_multi_pool_t;
127 
128 int vio_create_mblks(uint64_t num_mblks,
129 			size_t mblk_size, vio_mblk_pool_t **);
130 int vio_destroy_mblks(vio_mblk_pool_t *);
131 mblk_t *vio_allocb(vio_mblk_pool_t *);
132 void vio_freeb(void *arg);
133 int vio_init_multipools(vio_multi_pool_t *vmultip, int num_pools, ...);
134 void vio_destroy_multipools(vio_multi_pool_t *vmultip, vio_mblk_pool_t **fvmp);
135 mblk_t *vio_multipool_allocb(vio_multi_pool_t *vmultip, size_t size);
136 
137 #ifdef	__cplusplus
138 }
139 #endif
140 
141 #endif	/* _VIO_UTIL_H */
142