diff options
Diffstat (limited to 'lib/libc/i386/sys/__vdso_gettc.c')
-rw-r--r-- | lib/libc/i386/sys/__vdso_gettc.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/lib/libc/i386/sys/__vdso_gettc.c b/lib/libc/i386/sys/__vdso_gettc.c new file mode 100644 index 0000000..4419141 --- /dev/null +++ b/lib/libc/i386/sys/__vdso_gettc.c @@ -0,0 +1,50 @@ +/*- + * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org> + * + * 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/types.h> +#include <sys/time.h> +#include <sys/vdso.h> +#include <machine/cpufunc.h> + +static u_int +__vdso_gettc_low(const struct vdso_timehands *th) +{ + uint32_t rv; + + __asm __volatile("rdtsc; shrd %%cl, %%edx, %0" + : "=a" (rv) : "c" (th->th_x86_shift) : "edx"); + return (rv); +} + +#pragma weak __vdso_gettc +u_int +__vdso_gettc(const struct vdso_timehands *th) +{ + + return (th->th_x86_shift > 0 ? __vdso_gettc_low(th) : rdtsc32()); +} |