1// SPDX-License-Identifier: GPL-2.0
 
 
 
 
 2#include <linux/compiler.h>
 
 
 3#include <linux/types.h>
 4
 
 
 
 
 
 5#include "tsc.h"
 6
 7u64 perf_time_to_tsc(u64 ns, struct perf_tsc_conversion *tc)
 8{
 9	u64 t, quot, rem;
10
11	t = ns - tc->time_zero;
12	quot = t / tc->time_mult;
13	rem  = t % tc->time_mult;
14	return (quot << tc->time_shift) +
15	       (rem << tc->time_shift) / tc->time_mult;
16}
17
18u64 tsc_to_perf_time(u64 cyc, struct perf_tsc_conversion *tc)
19{
20	u64 quot, rem;
21
 
 
 
 
22	quot = cyc >> tc->time_shift;
23	rem  = cyc & (((u64)1 << tc->time_shift) - 1);
24	return tc->time_zero + quot * tc->time_mult +
25	       ((rem * tc->time_mult) >> tc->time_shift);
26}
27
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
28u64 __weak rdtsc(void)
29{
30	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
31}

  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
 18u64 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
 29u64 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
 43int 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
 74int 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);
 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
111u64 __weak rdtsc(void)
112{
113	return 0;
114}
115
116size_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}