130 lines
3.3 KiB
C
130 lines
3.3 KiB
C
/*-
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*
|
|
* Copyright 2020 Conrad Meyer <cem@FreeBSD.org>. 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.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 CONTRIBUTORS 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 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.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
#include <sys/param.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/pcpu.h>
|
|
#include <sys/prng.h>
|
|
#include <sys/smp.h>
|
|
#include <sys/systm.h>
|
|
|
|
#if !PCG_HAS_128BIT_OPS
|
|
/* On 32-bit platforms, gang together two 32-bit generators. */
|
|
typedef struct {
|
|
pcg32u_random_t states[2];
|
|
} pcg64u_random_t;
|
|
|
|
static inline void
|
|
pcg64u_srandom_r(pcg64u_random_t *state64, uint64_t seed)
|
|
{
|
|
pcg32u_srandom_r(&state64->states[0], seed);
|
|
pcg32u_srandom_r(&state64->states[1], seed);
|
|
}
|
|
|
|
static inline uint64_t
|
|
pcg64u_random_r(pcg64u_random_t *state64)
|
|
{
|
|
return ((((uint64_t)pcg32u_random_r(&state64->states[0])) << 32) |
|
|
pcg32u_random_r(&state64->states[1]));
|
|
}
|
|
|
|
static inline uint64_t
|
|
pcg64u_boundedrand_r(pcg64u_random_t *state64, uint64_t bound)
|
|
{
|
|
uint64_t threshold = -bound % bound;
|
|
for (;;) {
|
|
uint64_t r = pcg64u_random_r(state64);
|
|
if (r >= threshold)
|
|
return (r % bound);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
DPCPU_DEFINE_STATIC(pcg32u_random_t, pcpu_prng32_state);
|
|
DPCPU_DEFINE_STATIC(pcg64u_random_t, pcpu_prng64_state);
|
|
|
|
static void
|
|
prng_init(void *dummy __unused)
|
|
{
|
|
pcg32u_random_t *state;
|
|
pcg64u_random_t *state64;
|
|
int i;
|
|
|
|
CPU_FOREACH(i) {
|
|
state = DPCPU_ID_PTR(i, pcpu_prng32_state);
|
|
pcg32u_srandom_r(state, 1);
|
|
state64 = DPCPU_ID_PTR(i, pcpu_prng64_state);
|
|
pcg64u_srandom_r(state64, 1);
|
|
}
|
|
}
|
|
SYSINIT(prng_init, SI_SUB_CPU, SI_ORDER_ANY, prng_init, NULL);
|
|
|
|
uint32_t
|
|
prng32(void)
|
|
{
|
|
uint32_t r;
|
|
|
|
critical_enter();
|
|
r = pcg32u_random_r(DPCPU_PTR(pcpu_prng32_state));
|
|
critical_exit();
|
|
return (r);
|
|
}
|
|
|
|
uint32_t
|
|
prng32_bounded(uint32_t bound)
|
|
{
|
|
uint32_t r;
|
|
|
|
critical_enter();
|
|
r = pcg32u_boundedrand_r(DPCPU_PTR(pcpu_prng32_state), bound);
|
|
critical_exit();
|
|
return (r);
|
|
}
|
|
|
|
uint64_t
|
|
prng64(void)
|
|
{
|
|
uint64_t r;
|
|
|
|
critical_enter();
|
|
r = pcg64u_random_r(DPCPU_PTR(pcpu_prng64_state));
|
|
critical_exit();
|
|
return (r);
|
|
}
|
|
|
|
uint64_t
|
|
prng64_bounded(uint64_t bound)
|
|
{
|
|
uint64_t r;
|
|
|
|
critical_enter();
|
|
r = pcg64u_boundedrand_r(DPCPU_PTR(pcpu_prng64_state), bound);
|
|
critical_exit();
|
|
return (r);
|
|
}
|