RISC-V: selftests: Add which-cpus hwprobe test

Test the RISCV_HWPROBE_WHICH_CPUS flag of hwprobe. The test also
has a command line interface in order to get the cpu list for
arbitrary hwprobe pairs.

Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231122164700.127954-10-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

tools/testing/selftests/riscv/hwprobe/Makefile

@@ -4,7 +4,7 @@
 
 CFLAGS += -I$(top_srcdir)/tools/include
 
-TEST_GEN_PROGS := hwprobe cbo
+TEST_GEN_PROGS := hwprobe cbo which-cpus
 
 include ../../lib.mk
 
@@ -13,3 +13,6 @@ $(OUTPUT)/hwprobe: hwprobe.c sys_hwprobe.S
 
 $(OUTPUT)/cbo: cbo.c sys_hwprobe.S
 	$(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^
+
+$(OUTPUT)/which-cpus: which-cpus.c sys_hwprobe.S
+	$(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^

tools/testing/selftests/riscv/hwprobe/which-cpus.c

@@ -0,0 +1,154 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2023 Ventana Micro Systems Inc.
+ *
+ * Test the RISCV_HWPROBE_WHICH_CPUS flag of hwprobe. Also provides a command
+ * line interface to get the cpu list for arbitrary hwprobe pairs.
+ */
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sched.h>
+#include <unistd.h>
+#include <assert.h>
+
+#include "hwprobe.h"
+#include "../../kselftest.h"
+
+static void help(void)
+{
+	printf("\n"
+	       "which-cpus: [-h] [<key=value> [<key=value> ...]]\n\n"
+	       "   Without parameters, tests the RISCV_HWPROBE_WHICH_CPUS flag of hwprobe.\n"
+	       "   With parameters, where each parameter is a hwprobe pair written as\n"
+	       "   <key=value>, outputs the cpulist for cpus which all match the given set\n"
+	       "   of pairs.  'key' and 'value' should be in numeric form, e.g. 4=0x3b\n");
+}
+
+static void print_cpulist(cpu_set_t *cpus)
+{
+	int start = 0, end = 0;
+
+	if (!CPU_COUNT(cpus)) {
+		printf("cpus: None\n");
+		return;
+	}
+
+	printf("cpus:");
+	for (int i = 0, c = 0; i < CPU_COUNT(cpus); i++, c++) {
+		if (start != end && !CPU_ISSET(c, cpus))
+			printf("-%d", end);
+
+		while (!CPU_ISSET(c, cpus))
+			++c;
+
+		if (i != 0 && c == end + 1) {
+			end = c;
+			continue;
+		}
+
+		printf("%c%d", i == 0 ? ' ' : ',', c);
+		start = end = c;
+	}
+	if (start != end)
+		printf("-%d", end);
+	printf("\n");
+}
+
+static void do_which_cpus(int argc, char **argv, cpu_set_t *cpus)
+{
+	struct riscv_hwprobe *pairs;
+	int nr_pairs = argc - 1;
+	char *start, *end;
+	int rc;
+
+	pairs = malloc(nr_pairs * sizeof(struct riscv_hwprobe));
+	assert(pairs);
+
+	for (int i = 0; i < nr_pairs; i++) {
+		start = argv[i + 1];
+		pairs[i].key = strtol(start, &end, 0);
+		assert(end != start && *end == '=');
+		start = end + 1;
+		pairs[i].value = strtoul(start, &end, 0);
+		assert(end != start && *end == '\0');
+	}
+
+	rc = riscv_hwprobe(pairs, nr_pairs, sizeof(cpu_set_t), (unsigned long *)cpus, RISCV_HWPROBE_WHICH_CPUS);
+	assert(rc == 0);
+	print_cpulist(cpus);
+	free(pairs);
+}
+
+int main(int argc, char **argv)
+{
+	struct riscv_hwprobe pairs[2];
+	cpu_set_t cpus_aff, cpus;
+	__u64 ext0_all;
+	long rc;
+
+	rc = sched_getaffinity(0, sizeof(cpu_set_t), &cpus_aff);
+	assert(rc == 0);
+
+	if (argc > 1) {
+		if (!strcmp(argv[1], "-h"))
+			help();
+		else
+			do_which_cpus(argc, argv, &cpus_aff);
+		return 0;
+	}
+
+	ksft_print_header();
+	ksft_set_plan(7);
+
+	pairs[0] = (struct riscv_hwprobe){ .key = RISCV_HWPROBE_KEY_BASE_BEHAVIOR, };
+	rc = riscv_hwprobe(pairs, 1, 0, NULL, 0);
+	assert(rc == 0 && pairs[0].key == RISCV_HWPROBE_KEY_BASE_BEHAVIOR &&
+	       pairs[0].value == RISCV_HWPROBE_BASE_BEHAVIOR_IMA);
+
+	pairs[0] = (struct riscv_hwprobe){ .key = RISCV_HWPROBE_KEY_IMA_EXT_0, };
+	rc = riscv_hwprobe(pairs, 1, 0, NULL, 0);
+	assert(rc == 0 && pairs[0].key == RISCV_HWPROBE_KEY_IMA_EXT_0);
+	ext0_all = pairs[0].value;
+
+	pairs[0] = (struct riscv_hwprobe){ .key = RISCV_HWPROBE_KEY_BASE_BEHAVIOR, .value = RISCV_HWPROBE_BASE_BEHAVIOR_IMA, };
+	CPU_ZERO(&cpus);
+	rc = riscv_hwprobe(pairs, 1, 0, (unsigned long *)&cpus, RISCV_HWPROBE_WHICH_CPUS);
+	ksft_test_result(rc == -EINVAL, "no cpusetsize\n");
+
+	pairs[0] = (struct riscv_hwprobe){ .key = RISCV_HWPROBE_KEY_BASE_BEHAVIOR, .value = RISCV_HWPROBE_BASE_BEHAVIOR_IMA, };
+	rc = riscv_hwprobe(pairs, 1, sizeof(cpu_set_t), NULL, RISCV_HWPROBE_WHICH_CPUS);
+	ksft_test_result(rc == -EINVAL, "NULL cpus\n");
+
+	pairs[0] = (struct riscv_hwprobe){ .key = 0xbadc0de, };
+	CPU_ZERO(&cpus);
+	rc = riscv_hwprobe(pairs, 1, sizeof(cpu_set_t), (unsigned long *)&cpus, RISCV_HWPROBE_WHICH_CPUS);
+	ksft_test_result(rc == 0 && CPU_COUNT(&cpus) == 0, "unknown key\n");
+
+	pairs[0] = (struct riscv_hwprobe){ .key = RISCV_HWPROBE_KEY_BASE_BEHAVIOR, .value = RISCV_HWPROBE_BASE_BEHAVIOR_IMA, };
+	pairs[1] = (struct riscv_hwprobe){ .key = RISCV_HWPROBE_KEY_BASE_BEHAVIOR, .value = RISCV_HWPROBE_BASE_BEHAVIOR_IMA, };
+	CPU_ZERO(&cpus);
+	rc = riscv_hwprobe(pairs, 2, sizeof(cpu_set_t), (unsigned long *)&cpus, RISCV_HWPROBE_WHICH_CPUS);
+	ksft_test_result(rc == 0, "duplicate keys\n");
+
+	pairs[0] = (struct riscv_hwprobe){ .key = RISCV_HWPROBE_KEY_BASE_BEHAVIOR, .value = RISCV_HWPROBE_BASE_BEHAVIOR_IMA, };
+	pairs[1] = (struct riscv_hwprobe){ .key = RISCV_HWPROBE_KEY_IMA_EXT_0, .value = ext0_all, };
+	CPU_ZERO(&cpus);
+	rc = riscv_hwprobe(pairs, 2, sizeof(cpu_set_t), (unsigned long *)&cpus, RISCV_HWPROBE_WHICH_CPUS);
+	ksft_test_result(rc == 0 && CPU_COUNT(&cpus) == sysconf(_SC_NPROCESSORS_ONLN), "set all cpus\n");
+
+	pairs[0] = (struct riscv_hwprobe){ .key = RISCV_HWPROBE_KEY_BASE_BEHAVIOR, .value = RISCV_HWPROBE_BASE_BEHAVIOR_IMA, };
+	pairs[1] = (struct riscv_hwprobe){ .key = RISCV_HWPROBE_KEY_IMA_EXT_0, .value = ext0_all, };
+	memcpy(&cpus, &cpus_aff, sizeof(cpu_set_t));
+	rc = riscv_hwprobe(pairs, 2, sizeof(cpu_set_t), (unsigned long *)&cpus, RISCV_HWPROBE_WHICH_CPUS);
+	ksft_test_result(rc == 0 && CPU_EQUAL(&cpus, &cpus_aff), "set all affinity cpus\n");
+
+	pairs[0] = (struct riscv_hwprobe){ .key = RISCV_HWPROBE_KEY_BASE_BEHAVIOR, .value = RISCV_HWPROBE_BASE_BEHAVIOR_IMA, };
+	pairs[1] = (struct riscv_hwprobe){ .key = RISCV_HWPROBE_KEY_IMA_EXT_0, .value = ~ext0_all, };
+	memcpy(&cpus, &cpus_aff, sizeof(cpu_set_t));
+	rc = riscv_hwprobe(pairs, 2, sizeof(cpu_set_t), (unsigned long *)&cpus, RISCV_HWPROBE_WHICH_CPUS);
+	ksft_test_result(rc == 0 && CPU_COUNT(&cpus) == 0, "clear all cpus\n");
+
+	ksft_finished();
+}