perf test: Print result for each BPF subtest

This patch prints each sub-tests results for BPF testcases.

Before:

  # ./perf test BPF
  37: Test BPF filter                                          : Ok

After:

  # ./perf test BPF
  37: Test BPF filter                                          :
  37.1: Test basic BPF filtering                               : Ok
  37.2: Test BPF prologue generation                           : Ok

When a failure happens:

  # cat ~/.perfconfig
  [llvm]
      clang-path = "/bin/false"
  # ./perf test BPF
  37: Test BPF filter                                          :
  37.1: Test basic BPF filtering                               : Skip
  37.2: Test BPF prologue generation                           : Skip

Suggested-and-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1447749170-175898-5-git-send-email-wangnan0@huawei.com
[ Fixed up not to use .func in an anonymous union ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/tests/bpf.c b/tools/perf/tests/bpf.c
index 4efdc16..33689a0 100644
--- a/tools/perf/tests/bpf.c
+++ b/tools/perf/tests/bpf.c
@@ -215,28 +215,46 @@
 	return ret;
 }
 
-int test__bpf(int subtest __maybe_unused)
+int test__bpf_subtest_get_nr(void)
 {
-	unsigned int i;
+	return (int)ARRAY_SIZE(bpf_testcase_table);
+}
+
+const char *test__bpf_subtest_get_desc(int i)
+{
+	if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
+		return NULL;
+	return bpf_testcase_table[i].desc;
+}
+
+int test__bpf(int i)
+{
 	int err;
 
+	if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
+		return TEST_FAIL;
+
 	if (geteuid() != 0) {
 		pr_debug("Only root can run BPF test\n");
 		return TEST_SKIP;
 	}
 
-	for (i = 0; i < ARRAY_SIZE(bpf_testcase_table); i++) {
-		err = __test__bpf(i);
-
-		if (err != TEST_OK)
-			return err;
-	}
-
-	return TEST_OK;
+	err = __test__bpf(i);
+	return err;
 }
 
 #else
-int test__bpf(void)
+int test__bpf_subtest_get_nr(void)
+{
+	return 0;
+}
+
+const char *test__bpf_subtest_get_desc(int i __maybe_unused)
+{
+	return NULL;
+}
+
+int test__bpf(int i __maybe_unused)
 {
 	pr_debug("Skip BPF test because BPF support is not compiled\n");
 	return TEST_SKIP;