selftests: Test the new RISC-V hwprobe interface

TARGETS += ptrace

TARGETS += openat2

TARGETS += resctrl

TARGETS += riscv

TARGETS += rlimits

TARGETS += rseq

TARGETS += rtc

# SPDX-License-Identifier: GPL-2.0

# Originally tools/testing/arm64/Makefile

# When ARCH not overridden for crosscompiling, lookup machine

ARCH ?= $(shell uname -m 2>/dev/null || echo not)

ifneq (,$(filter $(ARCH),riscv))

RISCV_SUBTARGETS ?= hwprobe

else

RISCV_SUBTARGETS :=

endif

CFLAGS := -Wall -O2 -g

# A proper top_srcdir is needed by KSFT(lib.mk)

top_srcdir = $(realpath ../../../../)

# Additional include paths needed by kselftest.h and local headers

CFLAGS += -I$(top_srcdir)/tools/testing/selftests/

CFLAGS += $(KHDR_INCLUDES)

export CFLAGS

export top_srcdir

all:

	@for DIR in $(RISCV_SUBTARGETS); do				\

		BUILD_TARGET=$(OUTPUT)/$$DIR;			\

		mkdir -p $$BUILD_TARGET;			\

		$(MAKE) OUTPUT=$$BUILD_TARGET -C $$DIR $@;		\

	done

install: all

	@for DIR in $(RISCV_SUBTARGETS); do				\

		BUILD_TARGET=$(OUTPUT)/$$DIR;			\

		$(MAKE) OUTPUT=$$BUILD_TARGET -C $$DIR $@;		\

	done

run_tests: all

	@for DIR in $(RISCV_SUBTARGETS); do				\

		BUILD_TARGET=$(OUTPUT)/$$DIR;			\

		$(MAKE) OUTPUT=$$BUILD_TARGET -C $$DIR $@;		\

	done

# Avoid any output on non riscv on emit_tests

emit_tests: all

	@for DIR in $(RISCV_SUBTARGETS); do				\

		BUILD_TARGET=$(OUTPUT)/$$DIR;			\

		$(MAKE) OUTPUT=$$BUILD_TARGET -C $$DIR $@;		\

	done

clean:

	@for DIR in $(RISCV_SUBTARGETS); do				\

		BUILD_TARGET=$(OUTPUT)/$$DIR;			\

		$(MAKE) OUTPUT=$$BUILD_TARGET -C $$DIR $@;		\

	done

.PHONY: all clean install run_tests emit_tests

# SPDX-License-Identifier: GPL-2.0

# Copyright (C) 2021 ARM Limited

# Originally tools/testing/arm64/abi/Makefile

TEST_GEN_PROGS := hwprobe

include ../../lib.mk

$(OUTPUT)/hwprobe: hwprobe.c sys_hwprobe.S

	$(CC) -o$@ $(CFLAGS) $(LDFLAGS) $^

// SPDX-License-Identifier: GPL-2.0-only

#include <stddef.h>

#include <asm/hwprobe.h>

/*

 * Rather than relying on having a new enough libc to define this, just do it

 * ourselves.  This way we don't need to be coupled to a new-enough libc to

 * contain the call.

 */

long riscv_hwprobe(struct riscv_hwprobe *pairs, size_t pair_count,

		   size_t cpu_count, unsigned long *cpus, unsigned int flags);

int main(int argc, char **argv)

{

	struct riscv_hwprobe pairs[8];

	unsigned long cpus;

	long out;

	/* Fake the CPU_SET ops. */

	cpus = -1;

	/*

	 * Just run a basic test: pass enough pairs to get up to the base

	 * behavior, and then check to make sure it's sane.

	 */

	for (long i = 0; i < 8; i++)

		pairs[i].key = i;

	out = riscv_hwprobe(pairs, 8, 1, &cpus, 0);

	if (out != 0)

		return -1;

	for (long i = 0; i < 4; ++i) {

		/* Fail if the kernel claims not to recognize a base key. */

		if ((i < 4) && (pairs[i].key != i))

			return -2;

		if (pairs[i].key != RISCV_HWPROBE_KEY_BASE_BEHAVIOR)

			continue;

		if (pairs[i].value & RISCV_HWPROBE_BASE_BEHAVIOR_IMA)

			continue;

		return -3;

	}

	/*

	 * This should also work with a NULL CPU set, but should not work

	 * with an improperly supplied CPU set.

	 */

	out = riscv_hwprobe(pairs, 8, 0, 0, 0);

	if (out != 0)

		return -4;

	out = riscv_hwprobe(pairs, 8, 0, &cpus, 0);

	if (out == 0)

		return -5;

	out = riscv_hwprobe(pairs, 8, 1, 0, 0);

	if (out == 0)

		return -6;

	/*

	 * Check that keys work by providing one that we know exists, and

	 * checking to make sure the resultig pair is what we asked for.

	 */

	pairs[0].key = RISCV_HWPROBE_KEY_BASE_BEHAVIOR;

	out = riscv_hwprobe(pairs, 1, 1, &cpus, 0);

	if (out != 0)

		return -7;

	if (pairs[0].key != RISCV_HWPROBE_KEY_BASE_BEHAVIOR)

		return -8;

	/*

	 * Check that an unknown key gets overwritten with -1,

	 * but doesn't block elements after it.

	 */

	pairs[0].key = 0x5555;

	pairs[1].key = 1;

	pairs[1].value = 0xAAAA;

	out = riscv_hwprobe(pairs, 2, 0, 0, 0);

	if (out != 0)

		return -9;

	if (pairs[0].key != -1)

		return -10;

	if ((pairs[1].key != 1) || (pairs[1].value == 0xAAAA))

		return -11;

	return 0;

}

/* SPDX-License-Identifier: GPL-2.0 */

/* Copyright (C) 2023 Rivos, Inc */

.text

.global riscv_hwprobe

riscv_hwprobe:

	# Put __NR_riscv_hwprobe in the syscall number register, then just shim

	# back the kernel's return.  This doesn't do any sort of errno

	# handling, the caller can deal with it.

	li a7, 258

	ecall

	ret