[PATCH v7 04/14] perf test: Add asm pureloop test tool

[carsten . haitzler]

From: Carsten Haitzler <carsten.haitzler@xxxxxxx>

Add test tool to be driven by further test scripts. This tool is pure
arm64 ASM with no libc usage to ensure it is the same exact
binary/code every time so it can also be re-used for many uses. It
just loops for a given fixed number of loops.

Signed-off-by: Carsten Haitzler <carsten.haitzler@xxxxxxx>
---
 tools/perf/tests/shell/coresight/Makefile     |  3 +-
 .../shell/coresight/asm_pure_loop/.gitignore  |  1 +
 .../shell/coresight/asm_pure_loop/Makefile    | 34 +++++++++++++++++++
 .../coresight/asm_pure_loop/asm_pure_loop.S   | 28 +++++++++++++++
 4 files changed, 65 insertions(+), 1 deletion(-)
 create mode 100644 tools/perf/tests/shell/coresight/asm_pure_loop/.gitignore
 create mode 100644 tools/perf/tests/shell/coresight/asm_pure_loop/Makefile
 create mode 100644 tools/perf/tests/shell/coresight/asm_pure_loop/asm_pure_loop.S

diff --git a/tools/perf/tests/shell/coresight/Makefile b/tools/perf/tests/shell/coresight/Makefile
index 3b816bb4ced3..d4f868d55773 100644
--- a/tools/perf/tests/shell/coresight/Makefile
+++ b/tools/perf/tests/shell/coresight/Makefile
@@ -4,7 +4,8 @@ include ../../../../../tools/scripts/Makefile.include
 include ../../../../../tools/scripts/Makefile.arch
 include ../../../../../tools/scripts/utilities.mak
 
-SUBDIRS =
+SUBDIRS = \
+	asm_pure_loop
 
 all: $(SUBDIRS)
 $(SUBDIRS):
diff --git a/tools/perf/tests/shell/coresight/asm_pure_loop/.gitignore b/tools/perf/tests/shell/coresight/asm_pure_loop/.gitignore
new file mode 100644
index 000000000000..468673ac32e8
--- /dev/null
+++ b/tools/perf/tests/shell/coresight/asm_pure_loop/.gitignore
@@ -0,0 +1 @@
+asm_pure_loop
diff --git a/tools/perf/tests/shell/coresight/asm_pure_loop/Makefile b/tools/perf/tests/shell/coresight/asm_pure_loop/Makefile
new file mode 100644
index 000000000000..206849e92bc9
--- /dev/null
+++ b/tools/perf/tests/shell/coresight/asm_pure_loop/Makefile
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: GPL-2.0
+# Carsten Haitzler <carsten.haitzler@xxxxxxx>, 2021
+
+include ../Makefile.miniconfig
+
+# Binary to produce
+BIN=asm_pure_loop
+# Any linking/libraries needed for the binary - empty if none needed
+LIB=
+
+all: $(BIN)
+
+$(BIN): $(BIN).S
+ifdef CORESIGHT
+ifeq ($(ARCH),arm64)
+# Build line - this is raw asm with no libc to have an always exact binary
+	$(Q)$(CC) $(BIN).S -nostdlib -static -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
diff --git a/tools/perf/tests/shell/coresight/asm_pure_loop/asm_pure_loop.S b/tools/perf/tests/shell/coresight/asm_pure_loop/asm_pure_loop.S
new file mode 100644
index 000000000000..75cf084a927d
--- /dev/null
+++ b/tools/perf/tests/shell/coresight/asm_pure_loop/asm_pure_loop.S
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Tamas Zsoldos <tamas.zsoldos@xxxxxxx>, 2021 */
+
+.globl _start
+_start:
+	mov	x0, 0x0000ffff
+	mov	x1, xzr
+loop:
+	nop
+	nop
+	cbnz	x1, noskip
+	nop
+	nop
+	adrp	x2, skip
+	add 	x2, x2, :lo12:skip
+	br	x2
+	nop
+	nop
+noskip:
+	nop
+	nop
+skip:
+	sub	x0, x0, 1
+	cbnz	x0, loop
+
+	mov	x0, #0
+	mov	x8, #93 // __NR_exit syscall
+	svc	#0
-- 
2.32.0