Files
cubelinux-kernel/tools/perf/arch/arm64/util/tsc.c
T
Greg Kroah-Hartman 598cf27219 Linux 6.19.3
Link: https://lore.kernel.org/r/20260217200002.683975158@linuxfoundation.org
Tested-by: Florian Fainelli <florian.fainelli@broadcom.com>
Tested-by: Takeshi Ogasawara <takeshi.ogasawara@futuring-girl.com>
Tested-by: Peter Schneider <pschneider1968@googlemail.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Salvatore Bonaccorso <carnil@debian.org>
Tested-by: Brett A C Sheffield <bacs@librecast.net>
Tested-by: Mark Brown <broonie@kernel.org>
Tested-by: Luna Jernberg <droidbittin@gmail.com>
Tested-by: Ronald Warsow <rwarsow@gmx.de>
Tested-by: Justin M. Forbes <jforbes@fedoraproject.org>
Tested-by: Ron Economos <re@w6rz.net>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-02-19 16:33:27 +01:00

22 lines
498 B
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/types.h>
#include "../../../util/tsc.h"
u64 rdtsc(void)
{
u64 val;
/*
* According to ARM DDI 0487F.c, from Armv8.0 to Armv8.5 inclusive, the
* system counter is at least 56 bits wide; from Armv8.6, the counter
* must be 64 bits wide. So the system counter could be less than 64
* bits wide and it is attributed with the flag 'cap_user_time_short'
* is true.
*/
asm volatile("mrs %0, cntvct_el0" : "=r" (val));
return val;
}