- data->cyc2ns_mul =
- DIV_ROUND_CLOSEST(NSEC_PER_MSEC << CYC2NS_SCALE_FACTOR,
- cpu_khz);
- data->cyc2ns_shift = CYC2NS_SCALE_FACTOR;
+ clocks_calc_mult_shift(&data->cyc2ns_mul, &data->cyc2ns_shift, cpu_khz,
+ NSEC_PER_MSEC, 0);
+
+ /*
+ * cyc2ns_shift is exported via arch_perf_update_userpage() where it is
+ * not expected to be greater than 31 due to the original published
+ * conversion algorithm shifting a 32-bit value (now specifies a 64-bit
+ * value) - refer perf_event_mmap_page documentation in perf_event.h.
+ */
+ if (data->cyc2ns_shift == 32) {
+ data->cyc2ns_shift = 31;
+ data->cyc2ns_mul >>= 1;
+ }
+