From 6a34c928c2ac9fce926b1348d61dae34262e3f77 Mon Sep 17 00:00:00 2001 From: Wilco Dijkstra Date: Thu, 1 Jul 2021 15:42:05 +0100 Subject: AArch64: Add hp-timing.h Add hp-timing.h using the cntvct_el0 counter. Return timing in nanoseconds so it is fully compatible with generic hp-timing. Don't set HP_TIMING_INLINE in the dynamic linker since it adds unnecessary overheads and some ancient kernels may not handle emulating cntcvt correctly. Currently cntvct_el0 is only used for timing in the benchtests. Reviewed-by: Szabolcs Nagy --- sysdeps/aarch64/hp-timing.h | 47 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 sysdeps/aarch64/hp-timing.h diff --git a/sysdeps/aarch64/hp-timing.h b/sysdeps/aarch64/hp-timing.h new file mode 100644 index 0000000000..f9822e725c --- /dev/null +++ b/sysdeps/aarch64/hp-timing.h @@ -0,0 +1,47 @@ +/* High precision, low overhead timing functions. AArch64 version. + Copyright (C) 2021 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#ifndef _HP_TIMING_H +#define _HP_TIMING_H 1 + +#include +#include +#include +#include + +/* Don't use inline timer in ld.so. */ +#if IS_IN(rtld) +# define HP_TIMING_INLINE (0) +#else +# define HP_TIMING_INLINE (1) +#endif + +typedef uint64_t hp_timing_t; + +#define HP_TIMING_NOW(var) \ + __asm__ __volatile__ ("isb; mrs %0, cntvct_el0" : "=r" (var)) + +/* Compute elapsed time in nanoseconds. */ +#undef HP_TIMING_DIFF +#define HP_TIMING_DIFF(Diff, Start, End) \ +({ hp_timing_t freq; \ + __asm__ __volatile__ ("mrs %0, cntfrq_el0" : "=r" (freq)); \ + (Diff) = ((End) - (Start)) * (UINT64_C(1000000000) / freq); \ +}) + +#endif /* hp-timing.h */ -- cgit 1.4.1