1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/compiler.h> 3 #include <linux/types.h> 4 5 #include "tsc.h" 6 7 u64 perf_time_to_tsc(u64 ns, struct perf_tsc_conversion *tc) 8 { 9 u64 t, quot, rem; 10 11 t = ns - tc->time_zero; 12 quot = t / tc->time_mult; 13 rem = t % tc->time_mult; 14 return (quot << tc->time_shift) + 15 (rem << tc->time_shift) / tc->time_mult; 16 } 17 18 u64 tsc_to_perf_time(u64 cyc, struct perf_tsc_conversion *tc) 19 { 20 u64 quot, rem; 21 22 quot = cyc >> tc->time_shift; 23 rem = cyc & (((u64)1 << tc->time_shift) - 1); 24 return tc->time_zero + quot * tc->time_mult + 25 ((rem * tc->time_mult) >> tc->time_shift); 26 } 27 28 u64 __weak rdtsc(void) 29 { 30 return 0; 31 } 32