freebsd-src/sys/dev/random/nehemiah.c
Warner Losh fdafd315ad sys: Automated cleanup of cdefs and other formatting
Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by:		Netflix
2023-11-26 22:24:00 -07:00

133 lines
3.4 KiB
C

/*-
* Copyright (c) 2013-2015 Mark R V Murray
* Copyright (c) 2013 David E. O'Brien <obrien@NUXI.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
* in this position and unchanged.
* 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 ``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 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/param.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/random.h>
#include <sys/systm.h>
#include <machine/segments.h>
#include <machine/pcb.h>
#include <machine/md_var.h>
#include <machine/specialreg.h>
#include <dev/random/randomdev.h>
static u_int random_nehemiah_read(void *, u_int);
static struct random_source random_nehemiah = {
.rs_ident = "VIA Nehemiah Padlock RNG",
.rs_source = RANDOM_PURE_NEHEMIAH,
.rs_read = random_nehemiah_read
};
/* This H/W source never stores more than 8 bytes in one go */
/* ARGSUSED */
static __inline size_t
VIA_RNG_store(void *buf)
{
uint32_t retval = 0;
uint32_t rate = 0;
__asm __volatile(
"movl $0,%%edx\n\t"
".byte 0x0f, 0xa7, 0xc0"
: "=a" (retval), "+d" (rate), "+D" (buf)
:
: "memory"
);
if (rate == 0)
return (retval&0x1f);
return (0);
}
/* It is specifically allowed that buf is a multiple of sizeof(long) */
static u_int
random_nehemiah_read(void *buf, u_int c)
{
uint8_t *b;
size_t count, ret;
uint64_t tmp;
fpu_kern_enter(curthread, NULL, FPU_KERN_NORMAL | FPU_KERN_NOCTX);
b = buf;
for (count = c; count > 0; count -= ret) {
ret = MIN(VIA_RNG_store(&tmp), count);
memcpy(b, &tmp, ret);
b += ret;
}
fpu_kern_leave(curthread, NULL);
return (c);
}
static int
nehemiah_modevent(module_t mod, int type, void *unused)
{
int error = 0;
switch (type) {
case MOD_LOAD:
if (via_feature_rng & VIA_HAS_RNG) {
random_source_register(&random_nehemiah);
printf("random: fast provider: \"%s\"\n", random_nehemiah.rs_ident);
}
break;
case MOD_UNLOAD:
if (via_feature_rng & VIA_HAS_RNG) {
random_source_deregister(&random_nehemiah);
}
break;
case MOD_SHUTDOWN:
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}
static moduledata_t nehemiah_mod = {
"nehemiah",
nehemiah_modevent,
0
};
DECLARE_MODULE(nehemiah, nehemiah_mod, SI_SUB_RANDOM, SI_ORDER_FOURTH);
MODULE_VERSION(nehemiah, 1);
MODULE_DEPEND(nehemiah, random_harvestq, 1, 1, 1);