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// SPDX-License-Identifier: GPL-2.0
#include <errno.h>
#include <inttypes.h>
#include <string.h>
#include <linux/compiler.h>
#include <linux/perf_event.h>
#include <linux/stddef.h>
#include <linux/types.h>
#include <asm/barrier.h>
#include "event.h"
#include "synthetic-events.h"
#include "debug.h"
#include "tsc.h"
u64 perf_time_to_tsc(u64 ns, struct perf_tsc_conversion *tc)
{
u64 t, quot, rem;
t = ns - tc->time_zero;
quot = t / tc->time_mult;
rem = t % tc->time_mult;
return (quot << tc->time_shift) +
(rem << tc->time_shift) / tc->time_mult;
}
u64 tsc_to_perf_time(u64 cyc, struct perf_tsc_conversion *tc)
{
u64 quot, rem;
if (tc->cap_user_time_short)
cyc = tc->time_cycles +
((cyc - tc->time_cycles) & tc->time_mask);
quot = cyc >> tc->time_shift;
rem = cyc & (((u64)1 << tc->time_shift) - 1);
return tc->time_zero + quot * tc->time_mult +
((rem * tc->time_mult) >> tc->time_shift);
}
int perf_read_tsc_conversion(const struct perf_event_mmap_page *pc,
struct perf_tsc_conversion *tc)
{
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;
tc->time_cycles = pc->time_cycles;
tc->time_mask = pc->time_mask;
tc->cap_user_time_zero = pc->cap_user_time_zero;
tc->cap_user_time_short = pc->cap_user_time_short;
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 (!tc->cap_user_time_zero)
return -EOPNOTSUPP;
return 0;
}
int perf_event__synth_time_conv(const struct perf_event_mmap_page *pc,
const 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 perf_record_time_conv),
},
},
};
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;
event.time_conv.time_cycles = tc.time_cycles;
event.time_conv.time_mask = tc.time_mask;
event.time_conv.cap_user_time_zero = tc.cap_user_time_zero;
event.time_conv.cap_user_time_short = tc.cap_user_time_short;
return process(tool, &event, NULL, machine);
}
u64 __weak rdtsc(void)
{
return 0;
}
size_t perf_event__fprintf_time_conv(union perf_event *event, FILE *fp)
{
struct perf_record_time_conv *tc = (struct perf_record_time_conv *)event;
size_t ret;
ret = fprintf(fp, "\n... Time Shift %" PRI_lu64 "\n", tc->time_shift);
ret += fprintf(fp, "... Time Muliplier %" PRI_lu64 "\n", tc->time_mult);
ret += fprintf(fp, "... Time Zero %" PRI_lu64 "\n", tc->time_zero);
/*
* The event TIME_CONV was extended for the fields from "time_cycles"
* when supported cap_user_time_short, for backward compatibility,
* prints the extended fields only if they are contained in the event.
*/
if (event_contains(*tc, time_cycles)) {
ret += fprintf(fp, "... Time Cycles %" PRI_lu64 "\n",
tc->time_cycles);
ret += fprintf(fp, "... Time Mask %#" PRI_lx64 "\n",
tc->time_mask);
ret += fprintf(fp, "... Cap Time Zero %" PRId32 "\n",
tc->cap_user_time_zero);
ret += fprintf(fp, "... Cap Time Short %" PRId32 "\n",
tc->cap_user_time_short);
}
return ret;
}
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