Merge tag 'linux-kselftest-kunit-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull more Kunit updates from Shuah Khan:

 - add Kunit to kernel_init() and remove KUnit from init calls entirely.

   This addresses the concern that Kunit would not work correctly during
   late init phase.

 - add a linker section where KUnit can put references to its test
   suites.

   This is the first step in transitioning to dispatching all KUnit
   tests from a centralized executor rather than having each as its own
   separate late_initcall.

 - add a centralized executor to dispatch tests rather than relying on
   late_initcall to schedule each test suite separately. Centralized
   execution is for built-in tests only; modules will execute tests when
   loaded.

 - convert bitfield test to use KUnit framework

 - Documentation updates for naming guidelines and how
   kunit_test_suite() works.

 - add test plan to KUnit TAP format

* tag 'linux-kselftest-kunit-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  lib: kunit: Fix compilation test when using TEST_BIT_FIELD_COMPILE
  lib: kunit: add bitfield test conversion to KUnit
  Documentation: kunit: add a brief blurb about kunit_test_suite
  kunit: test: add test plan to KUnit TAP format
  init: main: add KUnit to kernel init
  kunit: test: create a single centralized executor for all tests
  vmlinux.lds.h: add linker section for KUnit test suites
  Documentation: kunit: Add naming guidelines

3 files changed, 46 insertions, 13 deletions

diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile
index 724b94311ca3..c49f4ffb6273 100644
--- a/lib/kunit/Makefile
+++ b/lib/kunit/Makefile
@@ -3,7 +3,8 @@ obj-$(CONFIG_KUNIT) +=			kunit.o
 kunit-objs +=				test.o \
 					string-stream.o \
 					assert.o \
-					try-catch.o
+					try-catch.o \
+					executor.o
 
 ifeq ($(CONFIG_KUNIT_DEBUGFS),y)
 kunit-objs +=				debugfs.o
diff --git a/lib/kunit/executor.c b/lib/kunit/executor.c
new file mode 100644
index 000000000000..a95742a4ece7
--- /dev/null
+++ b/lib/kunit/executor.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <kunit/test.h>
+
+/*
+ * These symbols point to the .kunit_test_suites section and are defined in
+ * include/asm-generic/vmlinux.lds.h, and consequently must be extern.
+ */
+extern struct kunit_suite * const * const __kunit_suites_start[];
+extern struct kunit_suite * const * const __kunit_suites_end[];
+
+#if IS_BUILTIN(CONFIG_KUNIT)
+
+static void kunit_print_tap_header(void)
+{
+	struct kunit_suite * const * const *suites, * const *subsuite;
+	int num_of_suites = 0;
+
+	for (suites = __kunit_suites_start;
+	     suites < __kunit_suites_end;
+	     suites++)
+		for (subsuite = *suites; *subsuite != NULL; subsuite++)
+			num_of_suites++;
+
+	pr_info("TAP version 14\n");
+	pr_info("1..%d\n", num_of_suites);
+}
+
+int kunit_run_all_tests(void)
+{
+	struct kunit_suite * const * const *suites;
+
+	kunit_print_tap_header();
+
+	for (suites = __kunit_suites_start;
+	     suites < __kunit_suites_end;
+	     suites++)
+			__kunit_test_suites_init(*suites);
+
+	return 0;
+}
+
+#endif /* IS_BUILTIN(CONFIG_KUNIT) */
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index dcc35fd30d95..750704abe89a 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -16,16 +16,6 @@
 #include "string-stream.h"
 #include "try-catch-impl.h"
 
-static void kunit_print_tap_version(void)
-{
-	static bool kunit_has_printed_tap_version;
-
-	if (!kunit_has_printed_tap_version) {
-		pr_info("TAP version 14\n");
-		kunit_has_printed_tap_version = true;
-	}
-}
-
 /*
  * Append formatted message to log, size of which is limited to
  * KUNIT_LOG_SIZE bytes (including null terminating byte).
@@ -65,7 +55,6 @@ EXPORT_SYMBOL_GPL(kunit_suite_num_test_cases);
 
 static void kunit_print_subtest_start(struct kunit_suite *suite)
 {
-	kunit_print_tap_version();
 	kunit_log(KERN_INFO, suite, KUNIT_SUBTEST_INDENT "# Subtest: %s",
 		  suite->name);
 	kunit_log(KERN_INFO, suite, KUNIT_SUBTEST_INDENT "1..%zd",
@@ -381,7 +370,7 @@ static void kunit_init_suite(struct kunit_suite *suite)
 	kunit_debugfs_create_suite(suite);
 }
 
-int __kunit_test_suites_init(struct kunit_suite **suites)
+int __kunit_test_suites_init(struct kunit_suite * const * const suites)
 {
 	unsigned int i;