arm/arm64: add spinlock torture test

This is port of the test in virtualopensystems tcg_baremetal_tests.
Signed-off-by: Andrew Jones <drjones@redhat.com>
[Rename test to spinlock-test. Use atomics by default. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arm/spinlock-test.c

+#include <libcflat.h>
+#include <asm/smp.h>
+#include <asm/cpumask.h>
+#include <asm/barrier.h>
+
+#define LOOP_SIZE 10000000
+
+struct lock_ops {
+	void (*lock)(int *v);
+	void (*unlock)(int *v);
+};
+static struct lock_ops lock_ops;
+
+static void gcc_builtin_lock(int *lock_var)
+{
+	while (__sync_lock_test_and_set(lock_var, 1));
+}
+static void gcc_builtin_unlock(int *lock_var)
+{
+	__sync_lock_release(lock_var);
+}
+static void none_lock(int *lock_var)
+{
+	while (*lock_var != 0);
+	*lock_var = 1;
+}
+static void none_unlock(int *lock_var)
+{
+	*lock_var = 0;
+}
+
+static int global_a, global_b;
+static int global_lock;
+
+static cpumask_t smp_test_complete;
+
+static void test_spinlock(void)
+{
+	int i, errors = 0;
+	int cpu = smp_processor_id();
+
+	printf("CPU%d online\n", cpu);
+
+	for (i = 0; i < LOOP_SIZE; i++) {
+
+		lock_ops.lock(&global_lock);
+
+		if (global_a == (cpu + 1) % 2) {
+			global_a = 1;
+			global_b = 0;
+		} else {
+			global_a = 0;
+			global_b = 1;
+		}
+
+		if (global_a == global_b)
+			errors++;
+
+		lock_ops.unlock(&global_lock);
+	}
+	report("CPU%d: Done - Errors: %d\n", errors == 0, cpu, errors);
+
+	cpumask_set_cpu(cpu, &smp_test_complete);
+	if (cpu != 0)
+		halt();
+}
+
+int main(int argc, char **argv)
+{
+	int cpu;
+
+	if (argc && strcmp(argv[0], "bad") != 0) {
+		lock_ops.lock = gcc_builtin_lock;
+		lock_ops.unlock = gcc_builtin_unlock;
+	} else {
+		lock_ops.lock = none_lock;
+		lock_ops.unlock = none_unlock;
+	}
+
+	for_each_present_cpu(cpu) {
+		if (cpu == 0)
+			continue;
+		smp_boot_secondary(cpu, test_spinlock);
+	}
+
+	test_spinlock();
+
+	while (!cpumask_full(&smp_test_complete))
+		cpu_relax();
+
+	return report_summary();
+}

config/config-arm-common.mak

@@ -10,7 +10,8 @@ ifeq ($(LOADADDR),)
 endif
 
 tests-common = \
-	$(TEST_DIR)/selftest.flat
+	$(TEST_DIR)/selftest.flat \
+	$(TEST_DIR)/spinlock-test.flat
 
 all: test_cases
 
@@ -70,3 +71,4 @@ generated_files = $(asm-offsets)
 test_cases: $(generated_files) $(tests-common) $(tests)
 
 $(TEST_DIR)/selftest.elf: $(cstart.o) $(TEST_DIR)/selftest.o
+$(TEST_DIR)/spinlock-test.elf: $(cstart.o) $(TEST_DIR)/spinlock-test.o