crypto: null - remove the default null skcipher

crypto_get_default_null_skcipher() and
crypto_put_default_null_skcipher() are no longer used, so remove them.

Signed-off-by: Eric Biggers <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

crypto/crypto_null.c

···
 #include <crypto/internal/skcipher.h>
 #include <linux/init.h>
 #include <linux/module.h>
-#include <linux/spinlock.h>
 #include <linux/string.h>
-
-static DEFINE_SPINLOCK(crypto_default_null_skcipher_lock);
-static struct crypto_sync_skcipher *crypto_default_null_skcipher;
-static int crypto_default_null_skcipher_refcnt;
 
 static int null_init(struct shash_desc *desc)
 {
···
 
 MODULE_ALIAS_CRYPTO("digest_null");
 MODULE_ALIAS_CRYPTO("cipher_null");
-
-struct crypto_sync_skcipher *crypto_get_default_null_skcipher(void)
-{
-	struct crypto_sync_skcipher *ntfm = NULL;
-	struct crypto_sync_skcipher *tfm;
-
-	spin_lock_bh(&crypto_default_null_skcipher_lock);
-	tfm = crypto_default_null_skcipher;
-
-	if (!tfm) {
-		spin_unlock_bh(&crypto_default_null_skcipher_lock);
-
-		ntfm = crypto_alloc_sync_skcipher("ecb(cipher_null)", 0, 0);
-		if (IS_ERR(ntfm))
-			return ntfm;
-
-		spin_lock_bh(&crypto_default_null_skcipher_lock);
-		tfm = crypto_default_null_skcipher;
-		if (!tfm) {
-			tfm = ntfm;
-			ntfm = NULL;
-			crypto_default_null_skcipher = tfm;
-		}
-	}
-
-	crypto_default_null_skcipher_refcnt++;
-	spin_unlock_bh(&crypto_default_null_skcipher_lock);
-
-	crypto_free_sync_skcipher(ntfm);
-
-	return tfm;
-}
-EXPORT_SYMBOL_GPL(crypto_get_default_null_skcipher);
-
-void crypto_put_default_null_skcipher(void)
-{
-	struct crypto_sync_skcipher *tfm = NULL;
-
-	spin_lock_bh(&crypto_default_null_skcipher_lock);
-	if (!--crypto_default_null_skcipher_refcnt) {
-		tfm = crypto_default_null_skcipher;
-		crypto_default_null_skcipher = NULL;
-	}
-	spin_unlock_bh(&crypto_default_null_skcipher_lock);
-
-	crypto_free_sync_skcipher(tfm);
-}
-EXPORT_SYMBOL_GPL(crypto_put_default_null_skcipher);
 
 static int __init crypto_null_mod_init(void)
 {

include/crypto/null.h

···
 #define NULL_DIGEST_SIZE	0
 #define NULL_IV_SIZE		0
 
-struct crypto_sync_skcipher *crypto_get_default_null_skcipher(void);
-void crypto_put_default_null_skcipher(void);
-
 #endif