perf tools: Add time conversion event

Intel PT uses the time members from the perf_event_mmap_page to convert
between TSC and perf time.

Due to a lack of foresight when Intel PT was implemented, those time
members were recorded in the (implementation dependent) AUXTRACE_INFO
event, the structure of which is generally inaccessible outside of the
Intel PT decoder. However now the conversion between TSC and perf time
is needed when processing a jitdump file when Intel PT has been used for
tracing.

So add a user event to record the time members. 'perf record' will
synthesize the event if the information is available. And session
processing will put a copy of the event on the session so that tools
like 'perf inject' can easily access it.

Signed-off-by: Adrian Hunter <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/arch/x86/util/tsc.c

···
 
 	return low | ((u64)high) << 32;
 }
+
+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 time_conv_event),
+			},
+		},
+	};
+	struct perf_tsc_conversion tc;
+	int err;
+
+	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;
+
+	return process(tool, &event, NULL, machine);
+}

tools/perf/builtin-inject.c

···
 			.auxtrace_info	= perf_event__repipe_op2_synth,
 			.auxtrace	= perf_event__repipe_auxtrace,
 			.auxtrace_error	= perf_event__repipe_op2_synth,
+			.time_conv	= perf_event__repipe_op2_synth,
 			.finished_round	= perf_event__repipe_oe_synth,
 			.build_id	= perf_event__repipe_op2_synth,
 			.id_index	= perf_event__repipe_op2_synth,

tools/perf/builtin-record.c

···
 #include "util/data.h"
 #include "util/perf_regs.h"
 #include "util/auxtrace.h"
+#include "util/tsc.h"
 #include "util/parse-branch-options.h"
 #include "util/parse-regs-options.h"
 #include "util/llvm-utils.h"
···
 
 static void snapshot_sig_handler(int sig);
 
+int __weak
+perf_event__synth_time_conv(const struct perf_event_mmap_page *pc __maybe_unused,
+			    struct perf_tool *tool __maybe_unused,
+			    perf_event__handler_t process __maybe_unused,
+			    struct machine *machine __maybe_unused)
+{
+	return 0;
+}
+
 static int record__synthesize(struct record *rec)
 {
 	struct perf_session *session = rec->session;
···
 			rec->bytes_written += err;
 		}
 	}
+
+	err = perf_event__synth_time_conv(rec->evlist->mmap[0].base, tool,
+					  process_synthesized_event, machine);
+	if (err)
+		goto out;
 
 	if (rec->opts.full_auxtrace) {
 		err = perf_event__synthesize_auxtrace_info(rec->itr, tool,

tools/perf/util/event.c

···
 	[PERF_RECORD_STAT]			= "STAT",
 	[PERF_RECORD_STAT_ROUND]		= "STAT_ROUND",
 	[PERF_RECORD_EVENT_UPDATE]		= "EVENT_UPDATE",
+	[PERF_RECORD_TIME_CONV]			= "TIME_CONV",
 };
 
 const char *perf_event__name(unsigned int id)

tools/perf/util/event.h

···
 	PERF_RECORD_STAT			= 76,
 	PERF_RECORD_STAT_ROUND			= 77,
 	PERF_RECORD_EVENT_UPDATE		= 78,
+	PERF_RECORD_TIME_CONV			= 79,
 	PERF_RECORD_HEADER_MAX
 };
 
···
 	u64				time;
 };
 
+struct time_conv_event {
+	struct perf_event_header header;
+	u64 time_shift;
+	u64 time_mult;
+	u64 time_zero;
+};
+
 union perf_event {
 	struct perf_event_header	header;
 	struct mmap_event		mmap;
···
 	struct stat_config_event	stat_config;
 	struct stat_event		stat;
 	struct stat_round_event		stat_round;
+	struct time_conv_event		time_conv;
 };
 
 void perf_event__print_totals(void);

tools/perf/util/session.c

···
 		tool->stat = process_stat_stub;
 	if (tool->stat_round == NULL)
 		tool->stat_round = process_stat_round_stub;
+	if (tool->time_conv == NULL)
+		tool->time_conv = process_event_op2_stub;
 }
 
 static void swap_sample_id_all(union perf_event *event, void *data)
···
 	[PERF_RECORD_STAT]		  = perf_event__stat_swap,
 	[PERF_RECORD_STAT_ROUND]	  = perf_event__stat_round_swap,
 	[PERF_RECORD_EVENT_UPDATE]	  = perf_event__event_update_swap,
+	[PERF_RECORD_TIME_CONV]		  = perf_event__all64_swap,
 	[PERF_RECORD_HEADER_MAX]	  = NULL,
 };
 
···
 		return tool->stat(tool, event, session);
 	case PERF_RECORD_STAT_ROUND:
 		return tool->stat_round(tool, event, session);
+	case PERF_RECORD_TIME_CONV:
+		session->time_conv = event->time_conv;
+		return tool->time_conv(tool, event, session);
 	default:
 		return -EINVAL;
 	}

tools/perf/util/session.h

···
 	struct itrace_synth_opts *itrace_synth_opts;
 	struct list_head	auxtrace_index;
 	struct trace_event	tevent;
+	struct time_conv_event	time_conv;
 	bool			repipe;
 	bool			one_mmap;
 	void			*one_mmap_addr;

tools/perf/util/tool.h

···
 			id_index,
 			auxtrace_info,
 			auxtrace_error,
+			time_conv,
 			thread_map,
 			cpu_map,
 			stat_config,

tools/perf/util/tsc.h

···
 
 #include <linux/types.h>
 
+#include "event.h"
 #include "../arch/x86/util/tsc.h"
 
 u64 perf_time_to_tsc(u64 ns, struct perf_tsc_conversion *tc);
 u64 tsc_to_perf_time(u64 cyc, struct perf_tsc_conversion *tc);
 u64 rdtsc(void);
+
+struct perf_event_mmap_page;
+struct perf_tool;
+struct machine;
+
+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);
 
 #endif