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