4 #include <linux/perf_event.h>
6 #include "../../perf.h"
7 #include <linux/types.h>
8 #include "../../util/debug.h"
9 #include "../../util/tsc.h"
12 int perf_read_tsc_conversion(const struct perf_event_mmap_page *pc,
13 struct perf_tsc_conversion *tc)
15 bool cap_user_time_zero;
22 tc->time_mult = pc->time_mult;
23 tc->time_shift = pc->time_shift;
24 tc->time_zero = pc->time_zero;
25 cap_user_time_zero = pc->cap_user_time_zero;
27 if (pc->lock == seq && !(seq & 1))
30 pr_debug("failed to get perf_event_mmap_page lock\n");
35 if (!cap_user_time_zero)
43 unsigned int low, high;
45 asm volatile("rdtsc" : "=a" (low), "=d" (high));
47 return low | ((u64)high) << 32;