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