octeon_rnd.c revision 257338
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: head/sys/mips/cavium/octeon_rnd.c 257338 2013-10-29 14:07:31Z nwhitehorn $ 27 */ 28 29#include <sys/cdefs.h> 30__FBSDID("$FreeBSD: head/sys/mips/cavium/octeon_rnd.c 257338 2013-10-29 14:07:31Z nwhitehorn $"); 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 46struct octeon_rnd_softc { 47 uint64_t sc_entropy[OCTEON_RND_WORDS]; 48 struct callout sc_callout; 49}; 50 51static void octeon_rnd_identify(driver_t *drv, device_t parent); 52static int octeon_rnd_attach(device_t dev); 53static int octeon_rnd_probe(device_t dev); 54static int octeon_rnd_detach(device_t dev); 55 56static void octeon_rnd_harvest(void *); 57 58static 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 68static driver_t octeon_rnd_driver = { 69 "rnd", 70 octeon_rnd_methods, 71 sizeof (struct octeon_rnd_softc) 72}; 73static devclass_t octeon_rnd_devclass; 74DRIVER_MODULE(rnd, nexus, octeon_rnd_driver, octeon_rnd_devclass, 0, 0); 75 76static void 77octeon_rnd_identify(driver_t *drv, device_t parent) 78{ 79 BUS_ADD_CHILD(parent, 0, "rnd", 0); 80} 81 82static int 83octeon_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 92static int 93octeon_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, CALLOUT_MPSAFE); 99 callout_reset(&sc->sc_callout, hz * 5, octeon_rnd_harvest, sc); 100 101 cvmx_rng_enable(); 102 103 return (0); 104} 105 106static int 107octeon_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 118static void 119octeon_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 random_harvest(sc->sc_entropy, sizeof sc->sc_entropy, 129 (sizeof(sc->sc_entropy)*8)/2, RANDOM_PURE_OCTEON); 130 131 callout_reset(&sc->sc_callout, hz * 5, octeon_rnd_harvest, sc); 132} 133