1 | // SPDX-License-Identifier: GPL-2.0 |
2 | #include <errno.h> |
3 | #include <inttypes.h> |
4 | #include <string.h> |
5 | |
6 | #include <linux/compiler.h> |
7 | #include <linux/perf_event.h> |
8 | #include <linux/stddef.h> |
9 | #include <linux/types.h> |
10 | |
11 | #include <asm/barrier.h> |
12 | |
13 | #include "event.h" |
14 | #include "synthetic-events.h" |
15 | #include "debug.h" |
16 | #include "tsc.h" |
17 | |
18 | u64 perf_time_to_tsc(u64 ns, struct perf_tsc_conversion *tc) |
19 | { |
20 | u64 t, quot, rem; |
21 | |
22 | t = ns - tc->time_zero; |
23 | quot = t / tc->time_mult; |
24 | rem = t % tc->time_mult; |
25 | return (quot << tc->time_shift) + |
26 | (rem << tc->time_shift) / tc->time_mult; |
27 | } |
28 | |
29 | u64 tsc_to_perf_time(u64 cyc, struct perf_tsc_conversion *tc) |
30 | { |
31 | u64 quot, rem; |
32 | |
33 | if (tc->cap_user_time_short) |
34 | cyc = tc->time_cycles + |
35 | ((cyc - tc->time_cycles) & tc->time_mask); |
36 | |
37 | quot = cyc >> tc->time_shift; |
38 | rem = cyc & (((u64)1 << tc->time_shift) - 1); |
39 | return tc->time_zero + quot * tc->time_mult + |
40 | ((rem * tc->time_mult) >> tc->time_shift); |
41 | } |
42 | |
43 | int perf_read_tsc_conversion(const struct perf_event_mmap_page *pc, |
44 | struct perf_tsc_conversion *tc) |
45 | { |
46 | u32 seq; |
47 | int i = 0; |
48 | |
49 | while (1) { |
50 | seq = pc->lock; |
51 | rmb(); |
52 | tc->time_mult = pc->time_mult; |
53 | tc->time_shift = pc->time_shift; |
54 | tc->time_zero = pc->time_zero; |
55 | tc->time_cycles = pc->time_cycles; |
56 | tc->time_mask = pc->time_mask; |
57 | tc->cap_user_time_zero = pc->cap_user_time_zero; |
58 | tc->cap_user_time_short = pc->cap_user_time_short; |
59 | rmb(); |
60 | if (pc->lock == seq && !(seq & 1)) |
61 | break; |
62 | if (++i > 10000) { |
63 | pr_debug("failed to get perf_event_mmap_page lock\n" ); |
64 | return -EINVAL; |
65 | } |
66 | } |
67 | |
68 | if (!tc->cap_user_time_zero) |
69 | return -EOPNOTSUPP; |
70 | |
71 | return 0; |
72 | } |
73 | |
74 | int perf_event__synth_time_conv(const struct perf_event_mmap_page *pc, |
75 | struct perf_tool *tool, |
76 | perf_event__handler_t process, |
77 | struct machine *machine) |
78 | { |
79 | union perf_event event = { |
80 | .time_conv = { |
81 | .header = { |
82 | .type = PERF_RECORD_TIME_CONV, |
83 | .size = sizeof(struct perf_record_time_conv), |
84 | }, |
85 | }, |
86 | }; |
87 | struct perf_tsc_conversion tc; |
88 | int err; |
89 | |
90 | if (!pc) |
91 | return 0; |
92 | err = perf_read_tsc_conversion(pc, tc: &tc); |
93 | if (err == -EOPNOTSUPP) |
94 | return 0; |
95 | if (err) |
96 | return err; |
97 | |
98 | pr_debug2("Synthesizing TSC conversion information\n" ); |
99 | |
100 | event.time_conv.time_mult = tc.time_mult; |
101 | event.time_conv.time_shift = tc.time_shift; |
102 | event.time_conv.time_zero = tc.time_zero; |
103 | event.time_conv.time_cycles = tc.time_cycles; |
104 | event.time_conv.time_mask = tc.time_mask; |
105 | event.time_conv.cap_user_time_zero = tc.cap_user_time_zero; |
106 | event.time_conv.cap_user_time_short = tc.cap_user_time_short; |
107 | |
108 | return process(tool, &event, NULL, machine); |
109 | } |
110 | |
111 | u64 __weak rdtsc(void) |
112 | { |
113 | return 0; |
114 | } |
115 | |
116 | size_t perf_event__fprintf_time_conv(union perf_event *event, FILE *fp) |
117 | { |
118 | struct perf_record_time_conv *tc = (struct perf_record_time_conv *)event; |
119 | size_t ret; |
120 | |
121 | ret = fprintf(fp, "\n... Time Shift %" PRI_lu64 "\n" , tc->time_shift); |
122 | ret += fprintf(fp, "... Time Muliplier %" PRI_lu64 "\n" , tc->time_mult); |
123 | ret += fprintf(fp, "... Time Zero %" PRI_lu64 "\n" , tc->time_zero); |
124 | |
125 | /* |
126 | * The event TIME_CONV was extended for the fields from "time_cycles" |
127 | * when supported cap_user_time_short, for backward compatibility, |
128 | * prints the extended fields only if they are contained in the event. |
129 | */ |
130 | if (event_contains(*tc, time_cycles)) { |
131 | ret += fprintf(fp, "... Time Cycles %" PRI_lu64 "\n" , |
132 | tc->time_cycles); |
133 | ret += fprintf(fp, "... Time Mask %#" PRI_lx64 "\n" , |
134 | tc->time_mask); |
135 | ret += fprintf(fp, "... Cap Time Zero %" PRId32 "\n" , |
136 | tc->cap_user_time_zero); |
137 | ret += fprintf(fp, "... Cap Time Short %" PRId32 "\n" , |
138 | tc->cap_user_time_short); |
139 | } |
140 | |
141 | return ret; |
142 | } |
143 | |