1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2010 Juli Mallett <[email protected]>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/bus.h>
37 #include <sys/clock.h>
38 #include <sys/kernel.h>
39 #include <sys/lock.h>
40 #include <sys/module.h>
41 #include <sys/random.h>
42
43 #include <contrib/octeon-sdk/cvmx.h>
44 #include <contrib/octeon-sdk/cvmx-rng.h>
45
46 #define OCTEON_RND_WORDS 2
47
48 struct octeon_rnd_softc {
49 uint64_t sc_entropy[OCTEON_RND_WORDS];
50 struct callout sc_callout;
51 };
52
53 static void octeon_rnd_identify(driver_t *drv, device_t parent);
54 static int octeon_rnd_attach(device_t dev);
55 static int octeon_rnd_probe(device_t dev);
56 static int octeon_rnd_detach(device_t dev);
57
58 static void octeon_rnd_harvest(void *);
59
60 static device_method_t octeon_rnd_methods[] = {
61 /* Device interface */
62 DEVMETHOD(device_identify, octeon_rnd_identify),
63 DEVMETHOD(device_probe, octeon_rnd_probe),
64 DEVMETHOD(device_attach, octeon_rnd_attach),
65 DEVMETHOD(device_detach, octeon_rnd_detach),
66 { 0, 0 }
67 };
68
69 static driver_t octeon_rnd_driver = {
70 "rnd",
71 octeon_rnd_methods,
72 sizeof (struct octeon_rnd_softc)
73 };
74 static devclass_t octeon_rnd_devclass;
75 DRIVER_MODULE(rnd, nexus, octeon_rnd_driver, octeon_rnd_devclass, 0, 0);
76
77 static void
octeon_rnd_identify(driver_t * drv,device_t parent)78 octeon_rnd_identify(driver_t *drv, device_t parent)
79 {
80 BUS_ADD_CHILD(parent, 0, "rnd", 0);
81 }
82
83 static int
octeon_rnd_probe(device_t dev)84 octeon_rnd_probe(device_t dev)
85 {
86 if (device_get_unit(dev) != 0)
87 return (ENXIO);
88
89 device_set_desc(dev, "Cavium Octeon Random Number Generator");
90 return (BUS_PROBE_NOWILDCARD);
91 }
92
93 static int
octeon_rnd_attach(device_t dev)94 octeon_rnd_attach(device_t dev)
95 {
96 struct octeon_rnd_softc *sc;
97
98 sc = device_get_softc(dev);
99 callout_init(&sc->sc_callout, 1);
100 callout_reset(&sc->sc_callout, hz * 5, octeon_rnd_harvest, sc);
101
102 cvmx_rng_enable();
103
104 return (0);
105 }
106
107 static int
octeon_rnd_detach(device_t dev)108 octeon_rnd_detach(device_t dev)
109 {
110 struct octeon_rnd_softc *sc;
111
112 sc = device_get_softc(dev);
113
114 callout_stop(&sc->sc_callout);
115
116 return (0);
117 }
118
119 static void
octeon_rnd_harvest(void * arg)120 octeon_rnd_harvest(void *arg)
121 {
122 struct octeon_rnd_softc *sc;
123 unsigned i;
124
125 sc = arg;
126
127 for (i = 0; i < OCTEON_RND_WORDS; i++)
128 sc->sc_entropy[i] = cvmx_rng_get_random64();
129 /* MarkM: FIX!! Check that this does not swamp the harvester! */
130 random_harvest_queue(sc->sc_entropy, sizeof sc->sc_entropy, RANDOM_PURE_OCTEON);
131
132 callout_reset(&sc->sc_callout, hz * 5, octeon_rnd_harvest, sc);
133 }
134