[PATCH] perf, riscv: Wire up perf trace support for RISC-V

Björn Töpel
2024-10-24T19:04:00Z

From: Björn Töpel <bjorn@rivosinc.com>

RISC-V does not currently support perf trace, since the system call
table is not generated.

Perform the copy/paste exercise, wiring up RISC-V system call table
generation.

Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
---
tools/perf/Makefile.config | 6 ++-
tools/perf/arch/riscv/Makefile | 22 +++++++++
.../arch/riscv/entry/syscalls/mksyscalltbl | 47 +++++++++++++++++++
tools/perf/util/syscalltbl.c | 4 ++
4 files changed, 78 insertions(+), 1 deletion(-)
create mode 100755 tools/perf/arch/riscv/entry/syscalls/mksyscalltbl

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 4ddb27a48eed..1d388e71e0cc 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -31,7 +31,7 @@ $(call detected_var,SRCARCH)
ifneq ($(NO_SYSCALL_TABLE),1)
NO_SYSCALL_TABLE := 1

- ifeq ($(SRCARCH),$(filter $(SRCARCH),x86 powerpc arm64 s390 mips loongarch))
+ ifeq ($(SRCARCH),$(filter $(SRCARCH),x86 powerpc arm64 s390 mips loongarch riscv))
NO_SYSCALL_TABLE := 0
endif

@@ -83,6 +83,10 @@ ifeq ($(ARCH),mips)
LIBUNWIND_LIBS = -lunwind -lunwind-mips
endif

+ifeq ($(ARCH),riscv)
+ CFLAGS += -I$(OUTPUT)arch/riscv/include/generated
+endif
+
# So far there's only x86 and arm libdw unwind support merged in perf.
# Disable it on all other architectures in case libdw unwind
# support is detected in system. Add supported architectures
diff --git a/tools/perf/arch/riscv/Makefile b/tools/perf/arch/riscv/Makefile
index 90c3c476a242..481da4518695 100644
--- a/tools/perf/arch/riscv/Makefile
+++ b/tools/perf/arch/riscv/Makefile
@@ -4,3 +4,25 @@ endif
PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET := 1
PERF_HAVE_JITDUMP := 1
HAVE_KVM_STAT_SUPPORT := 1
+
+#
+# Syscall table generation for perf
+#
+
+out := $(OUTPUT)arch/riscv/include/generated/asm
+header := $(out)/syscalls.c
+incpath := $(srctree)/tools
+sysdef := $(srctree)/tools/arch/riscv/include/uapi/asm/unistd.h
+sysprf := $(srctree)/tools/perf/arch/riscv/entry/syscalls/
+systbl := $(sysprf)/mksyscalltbl
+
+# Create output directory if not already present
+$(shell [ -d '$(out)' ] || mkdir -p '$(out)')
+
+$(header): $(sysdef) $(systbl)
+ $(Q)$(SHELL) '$(systbl)' '$(CC)' '$(HOSTCC)' $(incpath) $(sysdef) > $@
+
+clean::
+ $(call QUIET_CLEAN, riscv) $(RM) $(header)
+
+archheaders: $(header)
diff --git a/tools/perf/arch/riscv/entry/syscalls/mksyscalltbl b/tools/perf/arch/riscv/entry/syscalls/mksyscalltbl
new file mode 100755
index 000000000000..c59f5e852b97
--- /dev/null
+++ b/tools/perf/arch/riscv/entry/syscalls/mksyscalltbl
@@ -0,0 +1,47 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# Generate system call table for perf. Derived from
+# powerpc script.
+#
+# Copyright IBM Corp. 2017
+# Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
+# Changed by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
+# Changed by: Kim Phillips <kim.phillips@arm.com>
+# Changed by: Björn Töpel <bjorn@rivosinc.com>
+
+gcc=$1
+hostcc=$2
+incpath=$3
+input=$4
+
+if ! test -r $input; then
+ echo "Could not read input file" >&2
+ exit 1
+fi
+
+create_sc_table()
+{
+ local sc nr max_nr
+
+ while read sc nr; do
+ printf "%s\n" " [$nr] = \"$sc\","
+ max_nr=$nr
+ done
+
+ echo "#define SYSCALLTBL_RISCV_MAX_ID $max_nr"
+}
+
+create_table()
+{
+ echo "#include \"$input\""
+ echo "static const char *const syscalltbl_riscv[] = {"
+ create_sc_table
+ echo "};"
+}
+
+$gcc -E -dM -x c -I $incpath/include/uapi $input \
+ |awk '$2 ~ "__NR" && $3 !~ "__NR3264_" {
+ sub("^#define __NR(3264)?_", "");
+ print | "sort -k2 -n"}' \
+ |create_table
diff --git a/tools/perf/util/syscalltbl.c b/tools/perf/util/syscalltbl.c
index 7c15dec6900d..349986f6e5f5 100644
--- a/tools/perf/util/syscalltbl.c
+++ b/tools/perf/util/syscalltbl.c
@@ -46,6 +46,10 @@ static const char *const *syscalltbl_native = syscalltbl_mips_n64;
#include <asm/syscalls.c>
const int syscalltbl_native_max_id = SYSCALLTBL_LOONGARCH_MAX_ID;
static const char *const *syscalltbl_native = syscalltbl_loongarch;
+#elif defined(__riscv)
+#include <asm/syscalls.c>
+const int syscalltbl_native_max_id = SYSCALLTBL_RISCV_MAX_ID;
+static const char *const *syscalltbl_native = syscalltbl_riscv;
#endif

struct syscall {

base-commit: c2ee9f594da826bea183ed14f2cc029c719bf4da
--
2.45.2