1 files changed, 13 insertions, 88 deletions

diff --git a/arch/s390/crypto/chacha-glue.c b/arch/s390/crypto/chacha-glue.c
index 0c68191f2aa4..b3ffaa555385 100644
--- a/arch/s390/crypto/chacha-glue.c
+++ b/arch/s390/crypto/chacha-glue.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * s390 ChaCha stream cipher.
+ * ChaCha stream cipher (s390 optimized)
  *
  * Copyright IBM Corp. 2021
  */
@@ -8,9 +8,7 @@
 #define KMSG_COMPONENT "chacha_s390"
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
-#include <crypto/internal/chacha.h>
-#include <crypto/internal/skcipher.h>
-#include <crypto/algapi.h>
+#include <crypto/chacha.h>
 #include <linux/cpufeature.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -18,50 +16,6 @@
 #include <asm/fpu.h>
 #include "chacha-s390.h"
 
-static void chacha20_crypt_s390(u32 *state, u8 *dst, const u8 *src,
-				unsigned int nbytes, const u32 *key,
-				u32 *counter)
-{
-	DECLARE_KERNEL_FPU_ONSTACK32(vxstate);
-
-	kernel_fpu_begin(&vxstate, KERNEL_VXR);
-	chacha20_vx(dst, src, nbytes, key, counter);
-	kernel_fpu_end(&vxstate, KERNEL_VXR);
-
-	*counter += round_up(nbytes, CHACHA_BLOCK_SIZE) / CHACHA_BLOCK_SIZE;
-}
-
-static int chacha20_s390(struct skcipher_request *req)
-{
-	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
-	struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
-	u32 state[CHACHA_STATE_WORDS] __aligned(16);
-	struct skcipher_walk walk;
-	unsigned int nbytes;
-	int rc;
-
-	rc = skcipher_walk_virt(&walk, req, false);
-	chacha_init(state, ctx->key, req->iv);
-
-	while (walk.nbytes > 0) {
-		nbytes = walk.nbytes;
-		if (nbytes < walk.total)
-			nbytes = round_down(nbytes, walk.stride);
-
-		if (nbytes <= CHACHA_BLOCK_SIZE) {
-			chacha_crypt_generic(state, walk.dst.virt.addr,
-					     walk.src.virt.addr, nbytes,
-					     ctx->nrounds);
-		} else {
-			chacha20_crypt_s390(state, walk.dst.virt.addr,
-					    walk.src.virt.addr, nbytes,
-					    &state[4], &state[12]);
-		}
-		rc = skcipher_walk_done(&walk, walk.nbytes - nbytes);
-	}
-	return rc;
-}
-
 void hchacha_block_arch(const u32 *state, u32 *stream, int nrounds)
 {
 	/* TODO: implement hchacha_block_arch() in assembly */
@@ -76,32 +30,20 @@ void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src,
 	 * it cannot handle a block of data or less, but otherwise
 	 * it can handle data of arbitrary size
 	 */
-	if (bytes <= CHACHA_BLOCK_SIZE || nrounds != 20 || !cpu_has_vx())
+	if (bytes <= CHACHA_BLOCK_SIZE || nrounds != 20 || !cpu_has_vx()) {
 		chacha_crypt_generic(state, dst, src, bytes, nrounds);
-	else
-		chacha20_crypt_s390(state, dst, src, bytes,
-				    &state[4], &state[12]);
-}
-EXPORT_SYMBOL(chacha_crypt_arch);
+	} else {
+		DECLARE_KERNEL_FPU_ONSTACK32(vxstate);
 
-static struct skcipher_alg chacha_algs[] = {
-	{
-		.base.cra_name		= "chacha20",
-		.base.cra_driver_name	= "chacha20-s390",
-		.base.cra_priority	= 900,
-		.base.cra_blocksize	= 1,
-		.base.cra_ctxsize	= sizeof(struct chacha_ctx),
-		.base.cra_module	= THIS_MODULE,
+		kernel_fpu_begin(&vxstate, KERNEL_VXR);
+		chacha20_vx(dst, src, bytes, &state[4], &state[12]);
+		kernel_fpu_end(&vxstate, KERNEL_VXR);
 
-		.min_keysize		= CHACHA_KEY_SIZE,
-		.max_keysize		= CHACHA_KEY_SIZE,
-		.ivsize			= CHACHA_IV_SIZE,
-		.chunksize		= CHACHA_BLOCK_SIZE,
-		.setkey			= chacha20_setkey,
-		.encrypt		= chacha20_s390,
-		.decrypt		= chacha20_s390,
+		state[12] += round_up(bytes, CHACHA_BLOCK_SIZE) /
+			     CHACHA_BLOCK_SIZE;
 	}
-};
+}
+EXPORT_SYMBOL(chacha_crypt_arch);
 
 bool chacha_is_arch_optimized(void)
 {
@@ -109,22 +51,5 @@ bool chacha_is_arch_optimized(void)
 }
 EXPORT_SYMBOL(chacha_is_arch_optimized);
 
-static int __init chacha_mod_init(void)
-{
-	return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ?
-		crypto_register_skciphers(chacha_algs, ARRAY_SIZE(chacha_algs)) : 0;
-}
-
-static void __exit chacha_mod_fini(void)
-{
-	if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER))
-		crypto_unregister_skciphers(chacha_algs, ARRAY_SIZE(chacha_algs));
-}
-
-arch_initcall(chacha_mod_init);
-module_exit(chacha_mod_fini);
-
-MODULE_DESCRIPTION("ChaCha20 stream cipher");
+MODULE_DESCRIPTION("ChaCha stream cipher (s390 optimized)");
 MODULE_LICENSE("GPL v2");
-
-MODULE_ALIAS_CRYPTO("chacha20");