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| // 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;
| }
|
|
