// 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;
}