1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun #include <errno.h>
3*4882a593Smuzhiyun
4*4882a593Smuzhiyun #include <linux/compiler.h>
5*4882a593Smuzhiyun #include <linux/perf_event.h>
6*4882a593Smuzhiyun #include <linux/stddef.h>
7*4882a593Smuzhiyun #include <linux/types.h>
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #include <asm/barrier.h>
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun #include "event.h"
12*4882a593Smuzhiyun #include "synthetic-events.h"
13*4882a593Smuzhiyun #include "debug.h"
14*4882a593Smuzhiyun #include "tsc.h"
15*4882a593Smuzhiyun
perf_time_to_tsc(u64 ns,struct perf_tsc_conversion * tc)16*4882a593Smuzhiyun u64 perf_time_to_tsc(u64 ns, struct perf_tsc_conversion *tc)
17*4882a593Smuzhiyun {
18*4882a593Smuzhiyun u64 t, quot, rem;
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun t = ns - tc->time_zero;
21*4882a593Smuzhiyun quot = t / tc->time_mult;
22*4882a593Smuzhiyun rem = t % tc->time_mult;
23*4882a593Smuzhiyun return (quot << tc->time_shift) +
24*4882a593Smuzhiyun (rem << tc->time_shift) / tc->time_mult;
25*4882a593Smuzhiyun }
26*4882a593Smuzhiyun
tsc_to_perf_time(u64 cyc,struct perf_tsc_conversion * tc)27*4882a593Smuzhiyun u64 tsc_to_perf_time(u64 cyc, struct perf_tsc_conversion *tc)
28*4882a593Smuzhiyun {
29*4882a593Smuzhiyun u64 quot, rem;
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun if (tc->cap_user_time_short)
32*4882a593Smuzhiyun cyc = tc->time_cycles +
33*4882a593Smuzhiyun ((cyc - tc->time_cycles) & tc->time_mask);
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun quot = cyc >> tc->time_shift;
36*4882a593Smuzhiyun rem = cyc & (((u64)1 << tc->time_shift) - 1);
37*4882a593Smuzhiyun return tc->time_zero + quot * tc->time_mult +
38*4882a593Smuzhiyun ((rem * tc->time_mult) >> tc->time_shift);
39*4882a593Smuzhiyun }
40*4882a593Smuzhiyun
perf_read_tsc_conversion(const struct perf_event_mmap_page * pc,struct perf_tsc_conversion * tc)41*4882a593Smuzhiyun int perf_read_tsc_conversion(const struct perf_event_mmap_page *pc,
42*4882a593Smuzhiyun struct perf_tsc_conversion *tc)
43*4882a593Smuzhiyun {
44*4882a593Smuzhiyun u32 seq;
45*4882a593Smuzhiyun int i = 0;
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun while (1) {
48*4882a593Smuzhiyun seq = pc->lock;
49*4882a593Smuzhiyun rmb();
50*4882a593Smuzhiyun tc->time_mult = pc->time_mult;
51*4882a593Smuzhiyun tc->time_shift = pc->time_shift;
52*4882a593Smuzhiyun tc->time_zero = pc->time_zero;
53*4882a593Smuzhiyun tc->time_cycles = pc->time_cycles;
54*4882a593Smuzhiyun tc->time_mask = pc->time_mask;
55*4882a593Smuzhiyun tc->cap_user_time_zero = pc->cap_user_time_zero;
56*4882a593Smuzhiyun tc->cap_user_time_short = pc->cap_user_time_short;
57*4882a593Smuzhiyun rmb();
58*4882a593Smuzhiyun if (pc->lock == seq && !(seq & 1))
59*4882a593Smuzhiyun break;
60*4882a593Smuzhiyun if (++i > 10000) {
61*4882a593Smuzhiyun pr_debug("failed to get perf_event_mmap_page lock\n");
62*4882a593Smuzhiyun return -EINVAL;
63*4882a593Smuzhiyun }
64*4882a593Smuzhiyun }
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun if (!tc->cap_user_time_zero)
67*4882a593Smuzhiyun return -EOPNOTSUPP;
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun return 0;
70*4882a593Smuzhiyun }
71*4882a593Smuzhiyun
perf_event__synth_time_conv(const struct perf_event_mmap_page * pc,struct perf_tool * tool,perf_event__handler_t process,struct machine * machine)72*4882a593Smuzhiyun int perf_event__synth_time_conv(const struct perf_event_mmap_page *pc,
73*4882a593Smuzhiyun struct perf_tool *tool,
74*4882a593Smuzhiyun perf_event__handler_t process,
75*4882a593Smuzhiyun struct machine *machine)
76*4882a593Smuzhiyun {
77*4882a593Smuzhiyun union perf_event event = {
78*4882a593Smuzhiyun .time_conv = {
79*4882a593Smuzhiyun .header = {
80*4882a593Smuzhiyun .type = PERF_RECORD_TIME_CONV,
81*4882a593Smuzhiyun .size = sizeof(struct perf_record_time_conv),
82*4882a593Smuzhiyun },
83*4882a593Smuzhiyun },
84*4882a593Smuzhiyun };
85*4882a593Smuzhiyun struct perf_tsc_conversion tc;
86*4882a593Smuzhiyun int err;
87*4882a593Smuzhiyun
88*4882a593Smuzhiyun if (!pc)
89*4882a593Smuzhiyun return 0;
90*4882a593Smuzhiyun err = perf_read_tsc_conversion(pc, &tc);
91*4882a593Smuzhiyun if (err == -EOPNOTSUPP)
92*4882a593Smuzhiyun return 0;
93*4882a593Smuzhiyun if (err)
94*4882a593Smuzhiyun return err;
95*4882a593Smuzhiyun
96*4882a593Smuzhiyun pr_debug2("Synthesizing TSC conversion information\n");
97*4882a593Smuzhiyun
98*4882a593Smuzhiyun event.time_conv.time_mult = tc.time_mult;
99*4882a593Smuzhiyun event.time_conv.time_shift = tc.time_shift;
100*4882a593Smuzhiyun event.time_conv.time_zero = tc.time_zero;
101*4882a593Smuzhiyun event.time_conv.time_cycles = tc.time_cycles;
102*4882a593Smuzhiyun event.time_conv.time_mask = tc.time_mask;
103*4882a593Smuzhiyun event.time_conv.cap_user_time_zero = tc.cap_user_time_zero;
104*4882a593Smuzhiyun event.time_conv.cap_user_time_short = tc.cap_user_time_short;
105*4882a593Smuzhiyun
106*4882a593Smuzhiyun return process(tool, &event, NULL, machine);
107*4882a593Smuzhiyun }
108*4882a593Smuzhiyun
rdtsc(void)109*4882a593Smuzhiyun u64 __weak rdtsc(void)
110*4882a593Smuzhiyun {
111*4882a593Smuzhiyun return 0;
112*4882a593Smuzhiyun }
113