xref: /netbsd/sys/sys/rndsource.h (revision 85859e7e)
1 /*	$NetBSD: rndsource.h,v 1.9 2023/07/16 10:36:11 riastradh Exp $	*/
2 
3 /*-
4  * Copyright (c) 2019 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Taylor R. Campbell.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #ifndef	_SYS_RNDSOURCE_H
33 #define	_SYS_RNDSOURCE_H
34 
35 #ifndef _KERNEL			/* XXX */
36 #error <sys/rndsource.h> is meant for kernel consumers only.
37 #endif
38 
39 #include <sys/types.h>
40 #include <sys/queue.h>
41 #include <sys/rndio.h>
42 #include <sys/rngtest.h>
43 
44 struct percpu;
45 
46 /*
47  * struct rnd_delta_estimator
48  *
49  *	State for the time-delta entropy estimation model.
50  */
51 typedef struct rnd_delta_estimator {
52 	uint64_t	x;
53 	uint64_t	dx;
54 	uint64_t	d2x;
55 	uint64_t	insamples;
56 	uint64_t	outbits;
57 } rnd_delta_t;
58 
59 /*
60  * struct krndsource
61  *
62  *	State for an entropy source.  To be allocated by a driver for a
63  *	hardware entropy source, and treated as opaque.
64  *
65  *	There are a number of unused fields in order to preserve ABI
66  *	compatibility with the old implementation.
67  */
68 struct krndsource {
69 	LIST_ENTRY(krndsource) list;	/* the linked list */
70 	char		name[16];	/* device name */
71 	rnd_delta_t	time_delta;	/* time samples added while cold */
72 	rnd_delta_t	value_delta;	/* value samples added whiel cold */
73 	uint32_t	total;		/* number of bits added while cold */
74 	uint32_t	type;		/* type, RND_TYPE_* */
75 	uint32_t	flags;		/* flags, RND_FLAG_* */
76 	void		*state;		/* percpu (struct rndsource_cpu *) */
77 	size_t		test_cnt;	/* unused */
78 	void		(*get)(size_t, void *);	/* pool wants N bytes (badly) */
79 	void		*getarg;	/* argument to get-function */
80 	void		(*enable)(struct krndsource *, bool); /* unused */
81 	rngtest_t	*test;		/* unused */
82 	unsigned	refcnt;		/* unused */
83 };
84 
85 typedef struct krndsource krndsource_t;
86 
87 void	rndsource_setcb(struct krndsource *, void (*)(size_t, void *), void *);
88 void	rnd_attach_source(struct krndsource *, const char *, uint32_t,
89 	    uint32_t);
90 void	rnd_detach_source(struct krndsource *);
91 
92 void	_rnd_add_uint32(struct krndsource *, uint32_t); /* legacy */
93 void	_rnd_add_uint64(struct krndsource *, uint64_t); /* legacy */
94 
95 void	rnd_add_uint32(struct krndsource *, uint32_t);
96 void	rnd_add_data(struct krndsource *, const void *, uint32_t, uint32_t);
97 void	rnd_add_data_sync(struct krndsource *, const void *, uint32_t,
98 	    uint32_t);
99 
100 #endif	/* _SYS_RNDSOURCE_H */
101