perf tools: Add coresight etm PMU record capabilities

Coresight ETMs are IP blocks used to perform HW assisted tracing on a
CPU core.  This patch introduce the required auxiliary API functions
allowing the perf core to interact with a tracer.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1474041004-13956-4-git-send-email-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

MAINTAINERS

@@ -1124,6 +1124,10 @@ F:	Documentation/trace/coresight.txt
 F:	Documentation/devicetree/bindings/arm/coresight.txt
 F:	Documentation/ABI/testing/sysfs-bus-coresight-devices-*
 F:	tools/perf/arch/arm/util/pmu.c
+F:	tools/perf/arch/arm/util/auxtrace.c
+F:	tools/perf/arch/arm/util/cs-etm.c
+F:	tools/perf/arch/arm/util/cs-etm.h
+F:	tools/perf/util/cs-etm.h
 
 ARM/CORGI MACHINE SUPPORT
 M:	Richard Purdie <rpurdie@rpsys.net>

tools/perf/arch/arm/util/Build

@@ -3,4 +3,4 @@ libperf-$(CONFIG_DWARF) += dwarf-regs.o
 libperf-$(CONFIG_LOCAL_LIBUNWIND)    += unwind-libunwind.o
 libperf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
 
-libperf-$(CONFIG_AUXTRACE) += pmu.o
+libperf-$(CONFIG_AUXTRACE) += pmu.o auxtrace.o cs-etm.o

tools/perf/arch/arm/util/auxtrace.c

@@ -0,0 +1,54 @@
+/*
+ * Copyright(C) 2015 Linaro Limited. All rights reserved.
+ * Author: Mathieu Poirier <mathieu.poirier@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdbool.h>
+#include <linux/coresight-pmu.h>
+
+#include "../../util/auxtrace.h"
+#include "../../util/evlist.h"
+#include "../../util/pmu.h"
+#include "cs-etm.h"
+
+struct auxtrace_record
+*auxtrace_record__init(struct perf_evlist *evlist, int *err)
+{
+	struct perf_pmu	*cs_etm_pmu;
+	struct perf_evsel *evsel;
+	bool found_etm = false;
+
+	cs_etm_pmu = perf_pmu__find(CORESIGHT_ETM_PMU_NAME);
+
+	if (evlist) {
+		evlist__for_each_entry(evlist, evsel) {
+			if (cs_etm_pmu &&
+			    evsel->attr.type == cs_etm_pmu->type)
+				found_etm = true;
+		}
+	}
+
+	if (found_etm)
+		return cs_etm_record_init(err);
+
+	/*
+	 * Clear 'err' even if we haven't found a cs_etm event - that way perf
+	 * record can still be used even if tracers aren't present.  The NULL
+	 * return value will take care of telling the infrastructure HW tracing
+	 * isn't available.
+	 */
+	*err = 0;
+	return NULL;
+}

tools/perf/arch/arm/util/cs-etm.h

@@ -0,0 +1,23 @@
+/*
+ * Copyright(C) 2015 Linaro Limited. All rights reserved.
+ * Author: Mathieu Poirier <mathieu.poirier@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef INCLUDE__PERF_CS_ETM_H__
+#define INCLUDE__PERF_CS_ETM_H__
+
+struct auxtrace_record *cs_etm_record_init(int *err);
+
+#endif

tools/perf/arch/arm64/util/Build

@@ -1,4 +1,6 @@
 libperf-$(CONFIG_DWARF)     += dwarf-regs.o
 libperf-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o
 
-libperf-$(CONFIG_AUXTRACE) += ../../arm/util/pmu.o
+libperf-$(CONFIG_AUXTRACE) += ../../arm/util/pmu.o \
+			      ../../arm/util/auxtrace.o \
+			      ../../arm/util/cs-etm.o

tools/perf/util/auxtrace.c

@@ -892,6 +892,7 @@ int perf_event__process_auxtrace_info(struct perf_tool *tool __maybe_unused,
 		return intel_pt_process_auxtrace_info(event, session);
 	case PERF_AUXTRACE_INTEL_BTS:
 		return intel_bts_process_auxtrace_info(event, session);
+	case PERF_AUXTRACE_CS_ETM:
 	case PERF_AUXTRACE_UNKNOWN:
 	default:
 		return -EINVAL;

tools/perf/util/auxtrace.h

@@ -41,6 +41,7 @@ enum auxtrace_type {
 	PERF_AUXTRACE_UNKNOWN,
 	PERF_AUXTRACE_INTEL_PT,
 	PERF_AUXTRACE_INTEL_BTS,
+	PERF_AUXTRACE_CS_ETM,
 };
 
 enum itrace_period_type {

tools/perf/util/cs-etm.h

@@ -0,0 +1,74 @@
+/*
+ * Copyright(C) 2015 Linaro Limited. All rights reserved.
+ * Author: Mathieu Poirier <mathieu.poirier@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef INCLUDE__UTIL_PERF_CS_ETM_H__
+#define INCLUDE__UTIL_PERF_CS_ETM_H__
+
+/* Versionning header in case things need tro change in the future.  That way
+ * decoding of old snapshot is still possible.
+ */
+enum {
+	/* Starting with 0x0 */
+	CS_HEADER_VERSION_0,
+	/* PMU->type (32 bit), total # of CPUs (32 bit) */
+	CS_PMU_TYPE_CPUS,
+	CS_ETM_SNAPSHOT,
+	CS_HEADER_VERSION_0_MAX,
+};
+
+/* Beginning of header common to both ETMv3 and V4 */
+enum {
+	CS_ETM_MAGIC,
+	CS_ETM_CPU,
+};
+
+/* ETMv3/PTM metadata */
+enum {
+	/* Dynamic, configurable parameters */
+	CS_ETM_ETMCR = CS_ETM_CPU + 1,
+	CS_ETM_ETMTRACEIDR,
+	/* RO, taken from sysFS */
+	CS_ETM_ETMCCER,
+	CS_ETM_ETMIDR,
+	CS_ETM_PRIV_MAX,
+};
+
+/* ETMv4 metadata */
+enum {
+	/* Dynamic, configurable parameters */
+	CS_ETMV4_TRCCONFIGR = CS_ETM_CPU + 1,
+	CS_ETMV4_TRCTRACEIDR,
+	/* RO, taken from sysFS */
+	CS_ETMV4_TRCIDR0,
+	CS_ETMV4_TRCIDR1,
+	CS_ETMV4_TRCIDR2,
+	CS_ETMV4_TRCIDR8,
+	CS_ETMV4_TRCAUTHSTATUS,
+	CS_ETMV4_PRIV_MAX,
+};
+
+#define KiB(x) ((x) * 1024)
+#define MiB(x) ((x) * 1024 * 1024)
+
+#define CS_ETM_HEADER_SIZE (CS_HEADER_VERSION_0_MAX * sizeof(u64))
+
+static const u64 __perf_cs_etmv3_magic   = 0x3030303030303030ULL;
+static const u64 __perf_cs_etmv4_magic   = 0x4040404040404040ULL;
+#define CS_ETMV3_PRIV_SIZE (CS_ETM_PRIV_MAX * sizeof(u64))
+#define CS_ETMV4_PRIV_SIZE (CS_ETMV4_PRIV_MAX * sizeof(u64))
+
+#endif