crypto: api - compile out crypto_boot_test_finished when tests disabled

The crypto_boot_test_finished static key is unnecessary when self-tests
are disabled in the kconfig, so optimize it out accordingly, along with
the entirety of crypto_start_tests().  This mainly avoids the overhead
of an unnecessary static_branch_enable() on every boot.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/algapi.c

@@ -454,7 +454,7 @@ int crypto_register_alg(struct crypto_alg *alg)
 	down_write(&crypto_alg_sem);
 	larval = __crypto_register_alg(alg, &algs_to_put);
 	if (!IS_ERR_OR_NULL(larval)) {
-		test_started = static_key_enabled(&crypto_boot_test_finished);
+		test_started = crypto_boot_test_finished();
 		larval->test_started = test_started;
 	}
 	up_write(&crypto_alg_sem);
@@ -1253,6 +1253,9 @@ EXPORT_SYMBOL_GPL(crypto_stats_skcipher_decrypt);
 
 static void __init crypto_start_tests(void)
 {
+	if (IS_ENABLED(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS))
+		return;
+
 	for (;;) {
 		struct crypto_larval *larval = NULL;
 		struct crypto_alg *q;
@@ -1286,7 +1289,7 @@ static void __init crypto_start_tests(void)
 		crypto_wait_for_test(larval);
 	}
 
-	static_branch_enable(&crypto_boot_test_finished);
+	set_crypto_boot_test_finished();
 }
 
 static int __init crypto_algapi_init(void)

crypto/api.c

@@ -31,8 +31,10 @@ EXPORT_SYMBOL_GPL(crypto_alg_sem);
 BLOCKING_NOTIFIER_HEAD(crypto_chain);
 EXPORT_SYMBOL_GPL(crypto_chain);
 
-DEFINE_STATIC_KEY_FALSE(crypto_boot_test_finished);
-EXPORT_SYMBOL_GPL(crypto_boot_test_finished);
+#ifndef CONFIG_CRYPTO_MANAGER_DISABLE_TESTS
+DEFINE_STATIC_KEY_FALSE(__crypto_boot_test_finished);
+EXPORT_SYMBOL_GPL(__crypto_boot_test_finished);
+#endif
 
 static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg);
 
@@ -202,7 +204,7 @@ static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
 	struct crypto_larval *larval = (void *)alg;
 	long timeout;
 
-	if (!static_branch_likely(&crypto_boot_test_finished))
+	if (!crypto_boot_test_finished())
 		crypto_start_test(larval);
 
 	timeout = wait_for_completion_killable_timeout(

crypto/internal.h

@@ -47,7 +47,25 @@ extern struct list_head crypto_alg_list;
 extern struct rw_semaphore crypto_alg_sem;
 extern struct blocking_notifier_head crypto_chain;
 
-DECLARE_STATIC_KEY_FALSE(crypto_boot_test_finished);
+#ifdef CONFIG_CRYPTO_MANAGER_DISABLE_TESTS
+static inline bool crypto_boot_test_finished(void)
+{
+	return true;
+}
+static inline void set_crypto_boot_test_finished(void)
+{
+}
+#else
+DECLARE_STATIC_KEY_FALSE(__crypto_boot_test_finished);
+static inline bool crypto_boot_test_finished(void)
+{
+	return static_branch_likely(&__crypto_boot_test_finished);
+}
+static inline void set_crypto_boot_test_finished(void)
+{
+	static_branch_enable(&__crypto_boot_test_finished);
+}
+#endif /* !CONFIG_CRYPTO_MANAGER_DISABLE_TESTS */
 
 #ifdef CONFIG_PROC_FS
 void __init crypto_init_proc(void);