crypto: x86/aes-ni - remove special handling of AES in PCBC mode

For historical reasons, the AES-NI based implementation of the PCBC
chaining mode uses a special FPU chaining mode wrapper template to
amortize the FPU start/stop overhead over multiple blocks.

When this FPU wrapper was introduced, it supported widely used
chaining modes such as XTS and CTR (as well as LRW), but currently,
PCBC is the only remaining user.

Since there are no known users of pcbc(aes) in the kernel, let's remove
this special driver, and rely on the generic pcbc driver to encapsulate
the AES-NI core cipher.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

arch/x86/crypto/aesni-intel_glue.c

@@ -1253,22 +1253,6 @@ static struct skcipher_alg aesni_skciphers[] = {
 static
 struct simd_skcipher_alg *aesni_simd_skciphers[ARRAY_SIZE(aesni_skciphers)];
 
-static struct {
-	const char *algname;
-	const char *drvname;
-	const char *basename;
-	struct simd_skcipher_alg *simd;
-} aesni_simd_skciphers2[] = {
-#if (defined(MODULE) && IS_ENABLED(CONFIG_CRYPTO_PCBC)) || \
-    IS_BUILTIN(CONFIG_CRYPTO_PCBC)
-	{
-		.algname	= "pcbc(aes)",
-		.drvname	= "pcbc-aes-aesni",
-		.basename	= "fpu(pcbc(__aes-aesni))",
-	},
-#endif
-};
-
 #ifdef CONFIG_X86_64
 static int generic_gcmaes_set_key(struct crypto_aead *aead, const u8 *key,
 				  unsigned int key_len)
@@ -1422,10 +1406,6 @@ static void aesni_free_simds(void)
 	for (i = 0; i < ARRAY_SIZE(aesni_simd_skciphers) &&
 		    aesni_simd_skciphers[i]; i++)
 		simd_skcipher_free(aesni_simd_skciphers[i]);
-
-	for (i = 0; i < ARRAY_SIZE(aesni_simd_skciphers2); i++)
-		if (aesni_simd_skciphers2[i].simd)
-			simd_skcipher_free(aesni_simd_skciphers2[i].simd);
 }
 
 static int __init aesni_init(void)
@@ -1499,18 +1479,6 @@ static int __init aesni_init(void)
 		aesni_simd_skciphers[i] = simd;
 	}
 
-	for (i = 0; i < ARRAY_SIZE(aesni_simd_skciphers2); i++) {
-		algname = aesni_simd_skciphers2[i].algname;
-		drvname = aesni_simd_skciphers2[i].drvname;
-		basename = aesni_simd_skciphers2[i].basename;
-		simd = simd_skcipher_create_compat(algname, drvname, basename);
-		err = PTR_ERR(simd);
-		if (IS_ERR(simd))
-			continue;
-
-		aesni_simd_skciphers2[i].simd = simd;
-	}
-
 	return 0;
 
 unregister_simds: