xref: /openbmc/linux/arch/x86/kernel/trace_clock.c (revision 0da85d1e)
1 /*
2  * X86 trace clocks
3  */
4 #include <asm/trace_clock.h>
5 #include <asm/barrier.h>
6 #include <asm/msr.h>
7 
8 /*
9  * trace_clock_x86_tsc(): A clock that is just the cycle counter.
10  *
11  * Unlike the other clocks, this is not in nanoseconds.
12  */
13 u64 notrace trace_clock_x86_tsc(void)
14 {
15 	u64 ret;
16 
17 	rdtsc_barrier();
18 	rdtscll(ret);
19 
20 	return ret;
21 }
22