83 lines
1.6 KiB
C
Executable file
83 lines
1.6 KiB
C
Executable file
// SPDX-License-Identifier: GPL-2.0
|
|
#include <stdbool.h>
|
|
#include <errno.h>
|
|
|
|
#include <linux/stddef.h>
|
|
#include <linux/perf_event.h>
|
|
|
|
#include "../../perf.h"
|
|
#include <linux/types.h>
|
|
#include "../../util/debug.h"
|
|
#include "../../util/tsc.h"
|
|
|
|
int perf_read_tsc_conversion(const struct perf_event_mmap_page *pc,
|
|
struct perf_tsc_conversion *tc)
|
|
{
|
|
bool cap_user_time_zero;
|
|
u32 seq;
|
|
int i = 0;
|
|
|
|
while (1) {
|
|
seq = pc->lock;
|
|
rmb();
|
|
tc->time_mult = pc->time_mult;
|
|
tc->time_shift = pc->time_shift;
|
|
tc->time_zero = pc->time_zero;
|
|
cap_user_time_zero = pc->cap_user_time_zero;
|
|
rmb();
|
|
if (pc->lock == seq && !(seq & 1))
|
|
break;
|
|
if (++i > 10000) {
|
|
pr_debug("failed to get perf_event_mmap_page lock\n");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
if (!cap_user_time_zero)
|
|
return -EOPNOTSUPP;
|
|
|
|
return 0;
|
|
}
|
|
|
|
u64 rdtsc(void)
|
|
{
|
|
unsigned int low, high;
|
|
|
|
asm volatile("rdtsc" : "=a" (low), "=d" (high));
|
|
|
|
return low | ((u64)high) << 32;
|
|
}
|
|
|
|
int perf_event__synth_time_conv(const struct perf_event_mmap_page *pc,
|
|
struct perf_tool *tool,
|
|
perf_event__handler_t process,
|
|
struct machine *machine)
|
|
{
|
|
union perf_event event = {
|
|
.time_conv = {
|
|
.header = {
|
|
.type = PERF_RECORD_TIME_CONV,
|
|
.size = sizeof(struct time_conv_event),
|
|
},
|
|
},
|
|
};
|
|
struct perf_tsc_conversion tc;
|
|
int err;
|
|
|
|
if (!pc)
|
|
return 0;
|
|
err = perf_read_tsc_conversion(pc, &tc);
|
|
if (err == -EOPNOTSUPP)
|
|
return 0;
|
|
if (err)
|
|
return err;
|
|
|
|
pr_debug2("Synthesizing TSC conversion information\n");
|
|
|
|
event.time_conv.time_mult = tc.time_mult;
|
|
event.time_conv.time_shift = tc.time_shift;
|
|
event.time_conv.time_zero = tc.time_zero;
|
|
|
|
return process(tool, &event, NULL, machine);
|
|
}
|