// SPDX-License-Identifier: GPL-2.0 #include <errno.h> #include <inttypes.h> #include <string.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; } size_t perf_event__fprintf_time_conv(union perf_event *event, FILE *fp) { struct perf_record_time_conv *tc = (struct perf_record_time_conv *)event; size_t ret; ret = fprintf(fp, "\n... Time Shift %" PRI_lu64 "\n", tc->time_shift); ret += fprintf(fp, "... Time Muliplier %" PRI_lu64 "\n", tc->time_mult); ret += fprintf(fp, "... Time Zero %" PRI_lu64 "\n", tc->time_zero); /* * The event TIME_CONV was extended for the fields from "time_cycles" * when supported cap_user_time_short, for backward compatibility, * prints the extended fields only if they are contained in the event. */ if (event_contains(*tc, time_cycles)) { ret += fprintf(fp, "... Time Cycles %" PRI_lu64 "\n", tc->time_cycles); ret += fprintf(fp, "... Time Mask %#" PRI_lx64 "\n", tc->time_mask); ret += fprintf(fp, "... Cap Time Zero %" PRId32 "\n", tc->cap_user_time_zero); ret += fprintf(fp, "... Cap Time Short %" PRId32 "\n", tc->cap_user_time_short); } return ret; }