2 * Copyright (c) 2010 Juli Mallett <jmallett@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/systm.h>
35 #include <sys/clock.h>
36 #include <sys/kernel.h>
38 #include <sys/module.h>
39 #include <sys/random.h>
41 #include <contrib/octeon-sdk/cvmx.h>
42 #include <contrib/octeon-sdk/cvmx-rng.h>
46 * random_harvest(9) says to call it with no more than 16 bytes, but at least
47 * safe(4) seems to violate that rule.
49 #define OCTEON_RND_WORDS 2
51 struct octeon_rnd_softc {
52 uint64_t sc_entropy[OCTEON_RND_WORDS];
53 struct callout sc_callout;
56 static void octeon_rnd_identify(driver_t *drv, device_t parent);
57 static int octeon_rnd_attach(device_t dev);
58 static int octeon_rnd_probe(device_t dev);
59 static int octeon_rnd_detach(device_t dev);
61 static void octeon_rnd_harvest(void *);
63 static device_method_t octeon_rnd_methods[] = {
64 /* Device interface */
65 DEVMETHOD(device_identify, octeon_rnd_identify),
66 DEVMETHOD(device_probe, octeon_rnd_probe),
67 DEVMETHOD(device_attach, octeon_rnd_attach),
68 DEVMETHOD(device_detach, octeon_rnd_detach),
73 static driver_t octeon_rnd_driver = {
76 sizeof (struct octeon_rnd_softc)
78 static devclass_t octeon_rnd_devclass;
79 DRIVER_MODULE(rnd, nexus, octeon_rnd_driver, octeon_rnd_devclass, 0, 0);
82 octeon_rnd_identify(driver_t *drv, device_t parent)
84 BUS_ADD_CHILD(parent, 0, "rnd", 0);
88 octeon_rnd_probe(device_t dev)
90 if (device_get_unit(dev) != 0)
93 device_set_desc(dev, "Cavium Octeon Random Number Generator");
98 octeon_rnd_attach(device_t dev)
100 struct octeon_rnd_softc *sc;
102 sc = device_get_softc(dev);
103 callout_init(&sc->sc_callout, CALLOUT_MPSAFE);
104 callout_reset(&sc->sc_callout, hz * 5, octeon_rnd_harvest, sc);
112 octeon_rnd_detach(device_t dev)
114 struct octeon_rnd_softc *sc;
116 sc = device_get_softc(dev);
118 callout_stop(&sc->sc_callout);
124 octeon_rnd_harvest(void *arg)
126 struct octeon_rnd_softc *sc;
131 for (i = 0; i < OCTEON_RND_WORDS; i++)
132 sc->sc_entropy[i] = cvmx_rng_get_random64();
133 random_harvest(sc->sc_entropy, sizeof sc->sc_entropy,
134 sizeof sc->sc_entropy * 8, 0, RANDOM_PURE);
136 callout_reset(&sc->sc_callout, hz * 5, octeon_rnd_harvest, sc);