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/*-
* Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
* Copyright (c) 2016 The FreeBSD Foundation
* All rights reserved.
*
* Portions of this software were developed by Konstantin Belousov
* under sponsorship from the FreeBSD Foundation.
*
* 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>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include "namespace.h"
#include <sys/elf.h>
#include <sys/fcntl.h>
#include <sys/mman.h>
#include <sys/time.h>
#include <sys/vdso.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include "un-namespace.h"
#include <machine/cpufunc.h>
#include <machine/specialreg.h>
#include <dev/acpica/acpi_hpet.h>
#include "libc_private.h"
static void
lfence_mb(void)
{
#if defined(__i386__)
static int lfence_works = -1;
u_int cpuid_supported, p[4];
if (lfence_works == -1) {
__asm __volatile(
" pushfl\n"
" popl %%eax\n"
" movl %%eax,%%ecx\n"
" xorl $0x200000,%%eax\n"
" pushl %%eax\n"
" popfl\n"
" pushfl\n"
" popl %%eax\n"
" xorl %%eax,%%ecx\n"
" je 1f\n"
" movl $1,%0\n"
" jmp 2f\n"
"1: movl $0,%0\n"
"2:\n"
: "=r" (cpuid_supported) : : "eax", "ecx", "cc");
if (cpuid_supported) {
__asm __volatile(
" pushl %%ebx\n"
" cpuid\n"
" movl %%ebx,%1\n"
" popl %%ebx\n"
: "=a" (p[0]), "=r" (p[1]), "=c" (p[2]), "=d" (p[3])
: "0" (0x1));
lfence_works = (p[3] & CPUID_SSE2) != 0;
} else
lfence_works = 0;
}
if (lfence_works == 1)
lfence();
#elif defined(__amd64__)
lfence();
#else
#error "arch"
#endif
}
static u_int
__vdso_gettc_rdtsc_low(const struct vdso_timehands *th)
{
u_int rv;
lfence_mb();
__asm __volatile("rdtsc; shrd %%cl, %%edx, %0"
: "=a" (rv) : "c" (th->th_x86_shift) : "edx");
return (rv);
}
static u_int
__vdso_rdtsc32(void)
{
lfence_mb();
return (rdtsc32());
}
static char *hpet_dev_map = NULL;
static uint32_t hpet_idx = 0xffffffff;
static void
__vdso_init_hpet(uint32_t u)
{
static const char devprefix[] = "/dev/hpet";
char devname[64], *c, *c1, t;
int fd;
c1 = c = stpcpy(devname, devprefix);
u = hpet_idx;
do {
*c++ = u % 10 + '0';
u /= 10;
} while (u != 0);
*c = '\0';
for (c--; c1 != c; c1++, c--) {
t = *c1;
*c1 = *c;
*c = t;
}
fd = _open(devname, O_RDONLY);
if (fd == -1) {
hpet_dev_map = MAP_FAILED;
return;
}
if (hpet_dev_map != NULL && hpet_dev_map != MAP_FAILED)
munmap(hpet_dev_map, PAGE_SIZE);
hpet_dev_map = mmap(NULL, PAGE_SIZE, PROT_READ, MAP_SHARED, fd, 0);
_close(fd);
}
#pragma weak __vdso_gettc
int
__vdso_gettc(const struct vdso_timehands *th, u_int *tc)
{
uint32_t tmp;
switch (th->th_algo) {
case VDSO_TH_ALGO_X86_TSC:
*tc = th->th_x86_shift > 0 ? __vdso_gettc_rdtsc_low(th) :
__vdso_rdtsc32();
return (0);
case VDSO_TH_ALGO_X86_HPET:
tmp = th->th_x86_hpet_idx;
if (hpet_dev_map == NULL || tmp != hpet_idx) {
hpet_idx = tmp;
__vdso_init_hpet(hpet_idx);
}
if (hpet_dev_map == MAP_FAILED)
return (ENOSYS);
*tc = *(volatile uint32_t *)(hpet_dev_map + HPET_MAIN_COUNTER);
return (0);
default:
return (ENOSYS);
}
}
#pragma weak __vdso_gettimekeep
int
__vdso_gettimekeep(struct vdso_timekeep **tk)
{
return (_elf_aux_info(AT_TIMEKEEP, tk, sizeof(*tk)));
}
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