1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
|
// SPDX-License-Identifier: GPL-2.0
#include <errno.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,
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;
}
|
