NetBSD-5.0.2/sys/arch/x86/pci/pchb_rnd.c
/* $NetBSD: pchb_rnd.c,v 1.8 2008/03/04 15:33:06 cube Exp $ */
/*
* Copyright (c) 2000 Michael Shalayeff
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Michael Shalayeff.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*
* from OpenBSD: pchb.c,v 1.23 2000/10/23 20:07:30 deraadt Exp
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: pchb_rnd.c,v 1.8 2008/03/04 15:33:06 cube Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/time.h>
#include <machine/bus.h>
#include <dev/pci/pcivar.h>
#include <dev/pci/pcireg.h>
#include <dev/pci/pcidevs.h>
#include <arch/x86/pci/i82802reg.h>
#include <arch/x86/pci/pchbvar.h>
static void pchb_rnd_callout(void *v);
#define PCHB_RNG_RETRIES 1000
#define PCHB_RNG_MIN_SAMPLES 10
void
pchb_detach_rnd(struct pchb_softc *sc)
{
uint8_t reg8;
if (!sc->sc_rnd_attached)
return;
/* pch is polled for entropy, so no estimate is available. */
rnd_detach_source(&sc->sc_rnd_source);
callout_stop(&sc->sc_rnd_ch);
callout_destroy(&sc->sc_rnd_ch);
/* Disable the RNG. */
reg8 = bus_space_read_1(sc->sc_st, sc->sc_sh, I82802_RNG_HWST);
bus_space_write_1(sc->sc_st, sc->sc_sh, I82802_RNG_HWST,
reg8 & ~I82802_RNG_HWST_ENABLE);
bus_space_unmap(sc->sc_st, sc->sc_sh, I82802_IOSIZE);
sc->sc_rnd_attached = false;
}
void
pchb_attach_rnd(struct pchb_softc *sc, struct pci_attach_args *pa)
{
int i, j, count_ff;
uint8_t reg8;
if (PCI_VENDOR(pa->pa_id) != PCI_VENDOR_INTEL)
return;
switch (PCI_PRODUCT(pa->pa_id)) {
#if defined(__i386__)
/* Old chipsets which only support IA32 CPUs. */
case PCI_PRODUCT_INTEL_82810E_MCH:
case PCI_PRODUCT_INTEL_82810_DC100_MCH:
case PCI_PRODUCT_INTEL_82810_MCH:
case PCI_PRODUCT_INTEL_82815_DC100_HUB:
case PCI_PRODUCT_INTEL_82815_NOAGP_HUB:
case PCI_PRODUCT_INTEL_82815_NOGRAPH_HUB:
case PCI_PRODUCT_INTEL_82815_FULL_HUB:
case PCI_PRODUCT_INTEL_82820_MCH:
case PCI_PRODUCT_INTEL_82840_HB:
case PCI_PRODUCT_INTEL_82845_HB:
case PCI_PRODUCT_INTEL_82850_HB:
case PCI_PRODUCT_INTEL_82860_HB:
case PCI_PRODUCT_INTEL_82865_HB:
case PCI_PRODUCT_INTEL_82875P_HB:
#endif /* defined((__i386__) */
/* New chipsets which support EM64T CPUs. */
case PCI_PRODUCT_INTEL_82915G_HB:
case PCI_PRODUCT_INTEL_82915GM_HB:
case PCI_PRODUCT_INTEL_82925X_HB:
case PCI_PRODUCT_INTEL_82945P_MCH:
case PCI_PRODUCT_INTEL_82955X_HB:
break;
default:
return;
}
sc->sc_st = pa->pa_memt;
if (bus_space_map(sc->sc_st, I82802_IOBASE, I82802_IOSIZE, 0,
&sc->sc_sh) != 0) {
/*
* Unable to map control registers, punt,
* but don't bother issuing a warning.
*/
return;
}
reg8 = bus_space_read_1(sc->sc_st, sc->sc_sh,
I82802_RNG_HWST);
if ((reg8 & I82802_RNG_HWST_PRESENT) == 0) {
/*
* Random number generator is not present.
*/
bus_space_unmap(sc->sc_st, sc->sc_sh, I82802_IOSIZE);
return;
}
/* Enable the RNG. */
bus_space_write_1(sc->sc_st, sc->sc_sh,
I82802_RNG_HWST, reg8 | I82802_RNG_HWST_ENABLE);
reg8 = bus_space_read_1(sc->sc_st, sc->sc_sh, I82802_RNG_HWST);
if ((reg8 & I82802_RNG_HWST_ENABLE) == 0) {
/*
* Couldn't enable the RNG.
*/
bus_space_unmap(sc->sc_st, sc->sc_sh, I82802_IOSIZE);
return;
}
/* Check to see if we can read data from the RNG. */
count_ff = 0;
for (j = 0; j < PCHB_RNG_MIN_SAMPLES; ++j) {
for (i = 0; i < PCHB_RNG_RETRIES; i++) {
reg8 = bus_space_read_1(sc->sc_st, sc->sc_sh,
I82802_RNG_RNGST);
if (!(reg8 & I82802_RNG_RNGST_DATAV)) {
delay(10);
continue;
}
reg8 = bus_space_read_1(sc->sc_st, sc->sc_sh,
I82802_RNG_DATA);
break;
}
if (i == PCHB_RNG_RETRIES) {
bus_space_unmap(sc->sc_st, sc->sc_sh, I82802_IOSIZE);
aprint_verbose_dev(sc->sc_dev,
"timeout reading test samples, RNG disabled.\n");
return;
}
if (reg8 == 0xff)
++count_ff;
}
if (count_ff == PCHB_RNG_MIN_SAMPLES) {
bus_space_unmap(sc->sc_st, sc->sc_sh, I82802_IOSIZE);
aprint_verbose_dev(sc->sc_dev,
"returns constant 0xff stream, RNG disabled.\n");
return;
}
/*
* Should test entropy source to ensure
* that it passes the Statistical Random
* Number Generator Tests in section 4.11.1,
* FIPS PUB 140-1.
*
* http://csrc.nist.gov/fips/fips1401.htm
*/
aprint_normal_dev(sc->sc_dev, "random number generator enabled\n");
callout_init(&sc->sc_rnd_ch, 0);
/* pch is polled for entropy, so no estimate is available. */
rnd_attach_source(&sc->sc_rnd_source, device_xname(sc->sc_dev),
RND_TYPE_RNG, RND_FLAG_NO_ESTIMATE);
sc->sc_rnd_i = sizeof(sc->sc_rnd_ax);
pchb_rnd_callout(sc);
sc->sc_rnd_attached = true;
}
static void
pchb_rnd_callout(void *v)
{
struct pchb_softc *sc = v;
if ((bus_space_read_1(sc->sc_st, sc->sc_sh, I82802_RNG_RNGST) &
I82802_RNG_RNGST_DATAV) != 0) {
sc->sc_rnd_ax = (sc->sc_rnd_ax << NBBY) |
bus_space_read_1(sc->sc_st, sc->sc_sh, I82802_RNG_DATA);
if (--sc->sc_rnd_i == 0) {
sc->sc_rnd_i = sizeof(sc->sc_rnd_ax);
rnd_add_data(&sc->sc_rnd_source, &sc->sc_rnd_ax,
sizeof(sc->sc_rnd_ax),
sizeof(sc->sc_rnd_ax) * NBBY);
}
}
callout_reset(&sc->sc_rnd_ch, 1, pchb_rnd_callout, sc);
}