perf test coresight: Add thread loop test tool

Add test tool to be driven by further test scripts. This is a simple C
based loop with threads test to drive from scripts that can output TIDs
for tracking/checking.

Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Carsten Haitzler <carsten.haitzler@arm.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: coresight@lists.linaro.org
Link: https://lore.kernel.org/r/20220909152803.2317006-9-carsten.haitzler@foss.arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/shell/coresight/Makefile

@@ -6,7 +6,8 @@ include ../../../../../tools/scripts/utilities.mak
 
 SUBDIRS = \
 	asm_pure_loop \
-	memcpy_thread
+	memcpy_thread \
+	thread_loop
 
 all: $(SUBDIRS)
 $(SUBDIRS):

tools/perf/tests/shell/coresight/thread_loop/.gitignore

@@ -0,0 +1 @@
+thread_loop

tools/perf/tests/shell/coresight/thread_loop/Makefile

@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: GPL-2.0
+# Carsten Haitzler <carsten.haitzler@arm.com>, 2021
+include ../Makefile.miniconfig
+
+# Binary to produce
+BIN=thread_loop
+# Any linking/libraries needed for the binary - empty if none needed
+LIB=-pthread
+
+all: $(BIN)
+
+$(BIN): $(BIN).c
+ifdef CORESIGHT
+ifeq ($(ARCH),arm64)
+# Build line
+	$(Q)$(CC) $(BIN).c -o $(BIN) $(LIB)
+endif
+endif
+
+install-tests: all
+ifdef CORESIGHT
+ifeq ($(ARCH),arm64)
+# Install the test tool in the right place
+	$(call QUIET_INSTALL, tests) \
+		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(perfexec_instdir_SQ)/$(INSTDIR_SUB)/$(BIN)'; \
+		$(INSTALL) $(BIN) '$(DESTDIR_SQ)$(perfexec_instdir_SQ)/$(INSTDIR_SUB)/$(BIN)/$(BIN)'
+endif
+endif
+
+clean:
+	$(Q)$(RM) -f $(BIN)
+
+.PHONY: all clean install-tests

tools/perf/tests/shell/coresight/thread_loop/thread_loop.c

@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0
+// Carsten Haitzler <carsten.haitzler@arm.com>, 2021
+
+// define this for gettid()
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <pthread.h>
+#include <sys/syscall.h>
+#ifndef SYS_gettid
+// gettid is 178 on arm64
+# define SYS_gettid 178
+#endif
+#define gettid() syscall(SYS_gettid)
+
+struct args {
+	unsigned int loops;
+	pthread_t th;
+	void *ret;
+};
+
+static void *thrfn(void *arg)
+{
+	struct args *a = arg;
+	int i = 0, len = a->loops;
+
+	if (getenv("SHOW_TID")) {
+		unsigned long long tid = gettid();
+
+		printf("%llu\n", tid);
+	}
+	asm volatile(
+		"loop:\n"
+		"add %[i], %[i], #1\n"
+		"cmp %[i], %[len]\n"
+		"blt loop\n"
+		: /* out */
+		: /* in */ [i] "r" (i), [len] "r" (len)
+		: /* clobber */
+	);
+	return (void *)(long)i;
+}
+
+static pthread_t new_thr(void *(*fn) (void *arg), void *arg)
+{
+	pthread_t t;
+	pthread_attr_t attr;
+
+	pthread_attr_init(&attr);
+	pthread_create(&t, &attr, fn, arg);
+	return t;
+}
+
+int main(int argc, char **argv)
+{
+	unsigned int i, len, thr;
+	pthread_t threads[256];
+	struct args args[256];
+
+	if (argc < 3) {
+		printf("ERR: %s [numthreads] [numloops (millions)]\n", argv[0]);
+		exit(1);
+	}
+
+	thr = atoi(argv[1]);
+	if ((thr < 1) || (thr > 256)) {
+		printf("ERR: threads 1-256\n");
+		exit(1);
+	}
+	len = atoi(argv[2]);
+	if ((len < 1) || (len > 4000)) {
+		printf("ERR: max loops 4000 (millions)\n");
+		exit(1);
+	}
+	len *= 1000000;
+	for (i = 0; i < thr; i++) {
+		args[i].loops = len;
+		args[i].th = new_thr(thrfn, &(args[i]));
+	}
+	for (i = 0; i < thr; i++)
+		pthread_join(args[i].th, &(args[i].ret));
+	return 0;
+}