143 lines · c
1// SPDX-License-Identifier: GPL-2.02#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 const 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}143