arch/arm/crypto/aes-neonbs-glue.c - linux/kernel/git/viro/vfs - Git at Google

 /*
  * Bit sliced AES using NEON instructions
  *
  * Copyright (C) 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */

 #include <asm/neon.h>
 #include <crypto/aes.h>
 #include <crypto/cbc.h>
 #include <crypto/internal/simd.h>
 #include <crypto/internal/skcipher.h>
 #include <crypto/xts.h>
 #include <linux/module.h>

 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
 MODULE_LICENSE("GPL v2");

 MODULE_ALIAS_CRYPTO("ecb(aes)");
 MODULE_ALIAS_CRYPTO("cbc(aes)");
 MODULE_ALIAS_CRYPTO("ctr(aes)");
 MODULE_ALIAS_CRYPTO("xts(aes)");

 asmlinkage void aesbs_convert_key(u8 out[], u32 const rk[], int rounds);

 asmlinkage void aesbs_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[],
 				  int rounds, int blocks);
 asmlinkage void aesbs_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[],
 				  int rounds, int blocks);

 asmlinkage void aesbs_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[],
 				  int rounds, int blocks, u8 iv[]);

 asmlinkage void aesbs_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[],
 				  int rounds, int blocks, u8 ctr[], u8 final[]);

 asmlinkage void aesbs_xts_encrypt(u8 out[], u8 const in[], u8 const rk[],
 				  int rounds, int blocks, u8 iv[]);
 asmlinkage void aesbs_xts_decrypt(u8 out[], u8 const in[], u8 const rk[],
 				  int rounds, int blocks, u8 iv[]);

 asmlinkage void __aes_arm_encrypt(const u32 rk[], int rounds, const u8 in[],
 				  u8 out[]);

 struct aesbs_ctx {
 	int	rounds;
 	u8	rk[13 * (8 * AES_BLOCK_SIZE) + 32] __aligned(AES_BLOCK_SIZE);
 };

 struct aesbs_cbc_ctx {
 	struct aesbs_ctx	key;
 	u32			enc[AES_MAX_KEYLENGTH_U32];
 };

 struct aesbs_xts_ctx {
 	struct aesbs_ctx	key;
 	u32			twkey[AES_MAX_KEYLENGTH_U32];
 };

 static int aesbs_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
 			unsigned int key_len)
 {
 	struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
 	struct crypto_aes_ctx rk;
 	int err;

 	err = crypto_aes_expand_key(&rk, in_key, key_len);
 	if (err)
 		return err;

 	ctx->rounds = 6 + key_len / 4;

 	kernel_neon_begin();
 	aesbs_convert_key(ctx->rk, rk.key_enc, ctx->rounds);
 	kernel_neon_end();

 	return 0;
 }

 static int __ecb_crypt(struct skcipher_request *req,
 		       void (*fn)(u8 out[], u8 const in[], u8 const rk[],
 				  int rounds, int blocks))
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 	struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
 	struct skcipher_walk walk;
 	int err;

 	err = skcipher_walk_virt(&walk, req, true);

 	kernel_neon_begin();
 	while (walk.nbytes >= AES_BLOCK_SIZE) {
 		unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;

 		if (walk.nbytes < walk.total)
 			blocks = round_down(blocks,
 					    walk.stride / AES_BLOCK_SIZE);

 		fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->rk,
 		   ctx->rounds, blocks);
 		err = skcipher_walk_done(&walk,
 					 walk.nbytes - blocks * AES_BLOCK_SIZE);
 	}
 	kernel_neon_end();

 	return err;
 }

 static int ecb_encrypt(struct skcipher_request *req)
 {
 	return __ecb_crypt(req, aesbs_ecb_encrypt);
 }

 static int ecb_decrypt(struct skcipher_request *req)
 {
 	return __ecb_crypt(req, aesbs_ecb_decrypt);
 }

 static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
 			    unsigned int key_len)
 {
 	struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 	struct crypto_aes_ctx rk;
 	int err;

 	err = crypto_aes_expand_key(&rk, in_key, key_len);
 	if (err)
 		return err;

 	ctx->key.rounds = 6 + key_len / 4;

 	memcpy(ctx->enc, rk.key_enc, sizeof(ctx->enc));

 	kernel_neon_begin();
 	aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
 	kernel_neon_end();

 	return 0;
 }

 static void cbc_encrypt_one(struct crypto_skcipher *tfm, const u8 *src, u8 *dst)
 {
 	struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);

 	__aes_arm_encrypt(ctx->enc, ctx->key.rounds, src, dst);
 }

 static int cbc_encrypt(struct skcipher_request *req)
 {
 	return crypto_cbc_encrypt_walk(req, cbc_encrypt_one);
 }

 static int cbc_decrypt(struct skcipher_request *req)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 	struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 	struct skcipher_walk walk;
 	int err;

 	err = skcipher_walk_virt(&walk, req, true);

 	kernel_neon_begin();
 	while (walk.nbytes >= AES_BLOCK_SIZE) {
 		unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;

 		if (walk.nbytes < walk.total)
 			blocks = round_down(blocks,
 					    walk.stride / AES_BLOCK_SIZE);

 		aesbs_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
 				  ctx->key.rk, ctx->key.rounds, blocks,
 				  walk.iv);
 		err = skcipher_walk_done(&walk,
 					 walk.nbytes - blocks * AES_BLOCK_SIZE);
 	}
 	kernel_neon_end();

 	return err;
 }

 static int ctr_encrypt(struct skcipher_request *req)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 	struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
 	struct skcipher_walk walk;
 	u8 buf[AES_BLOCK_SIZE];
 	int err;

 	err = skcipher_walk_virt(&walk, req, true);

 	kernel_neon_begin();
 	while (walk.nbytes > 0) {
 		unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 		u8 *final = (walk.total % AES_BLOCK_SIZE) ? buf : NULL;

 		if (walk.nbytes < walk.total) {
 			blocks = round_down(blocks,
 					    walk.stride / AES_BLOCK_SIZE);
 			final = NULL;
 		}

 		aesbs_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
 				  ctx->rk, ctx->rounds, blocks, walk.iv, final);

 		if (final) {
 			u8 *dst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
 			u8 *src = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;

 			if (dst != src)
 				memcpy(dst, src, walk.total % AES_BLOCK_SIZE);
 			crypto_xor(dst, final, walk.total % AES_BLOCK_SIZE);

 			err = skcipher_walk_done(&walk, 0);
 			break;
 		}
 		err = skcipher_walk_done(&walk,
 					 walk.nbytes - blocks * AES_BLOCK_SIZE);
 	}
 	kernel_neon_end();

 	return err;
 }

 static int aesbs_xts_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
 			    unsigned int key_len)
 {
 	struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 	struct crypto_aes_ctx rk;
 	int err;

 	err = xts_verify_key(tfm, in_key, key_len);
 	if (err)
 		return err;

 	key_len /= 2;
 	err = crypto_aes_expand_key(&rk, in_key + key_len, key_len);
 	if (err)
 		return err;

 	memcpy(ctx->twkey, rk.key_enc, sizeof(ctx->twkey));

 	return aesbs_setkey(tfm, in_key, key_len);
 }

 static int __xts_crypt(struct skcipher_request *req,
 		       void (*fn)(u8 out[], u8 const in[], u8 const rk[],
 				  int rounds, int blocks, u8 iv[]))
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 	struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 	struct skcipher_walk walk;
 	int err;

 	err = skcipher_walk_virt(&walk, req, true);

 	__aes_arm_encrypt(ctx->twkey, ctx->key.rounds, walk.iv, walk.iv);

 	kernel_neon_begin();
 	while (walk.nbytes >= AES_BLOCK_SIZE) {
 		unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;

 		if (walk.nbytes < walk.total)
 			blocks = round_down(blocks,
 					    walk.stride / AES_BLOCK_SIZE);

 		fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->key.rk,
 		   ctx->key.rounds, blocks, walk.iv);
 		err = skcipher_walk_done(&walk,
 					 walk.nbytes - blocks * AES_BLOCK_SIZE);
 	}
 	kernel_neon_end();

 	return err;
 }

 static int xts_encrypt(struct skcipher_request *req)
 {
 	return __xts_crypt(req, aesbs_xts_encrypt);
 }

 static int xts_decrypt(struct skcipher_request *req)
 {
 	return __xts_crypt(req, aesbs_xts_decrypt);
 }

 static struct skcipher_alg aes_algs[] = { {
 	.base.cra_name		= "__ecb(aes)",
 	.base.cra_driver_name	= "__ecb-aes-neonbs",
 	.base.cra_priority	= 250,
 	.base.cra_blocksize	= AES_BLOCK_SIZE,
 	.base.cra_ctxsize	= sizeof(struct aesbs_ctx),
 	.base.cra_module	= THIS_MODULE,
 	.base.cra_flags		= CRYPTO_ALG_INTERNAL,

 	.min_keysize		= AES_MIN_KEY_SIZE,
 	.max_keysize		= AES_MAX_KEY_SIZE,
 	.walksize		= 8 * AES_BLOCK_SIZE,
 	.setkey			= aesbs_setkey,
 	.encrypt		= ecb_encrypt,
 	.decrypt		= ecb_decrypt,
 }, {
 	.base.cra_name		= "__cbc(aes)",
 	.base.cra_driver_name	= "__cbc-aes-neonbs",
 	.base.cra_priority	= 250,
 	.base.cra_blocksize	= AES_BLOCK_SIZE,
 	.base.cra_ctxsize	= sizeof(struct aesbs_cbc_ctx),
 	.base.cra_module	= THIS_MODULE,
 	.base.cra_flags		= CRYPTO_ALG_INTERNAL,

 	.min_keysize		= AES_MIN_KEY_SIZE,
 	.max_keysize		= AES_MAX_KEY_SIZE,
 	.walksize		= 8 * AES_BLOCK_SIZE,
 	.ivsize			= AES_BLOCK_SIZE,
 	.setkey			= aesbs_cbc_setkey,
 	.encrypt		= cbc_encrypt,
 	.decrypt		= cbc_decrypt,
 }, {
 	.base.cra_name		= "__ctr(aes)",
 	.base.cra_driver_name	= "__ctr-aes-neonbs",
 	.base.cra_priority	= 250,
 	.base.cra_blocksize	= 1,
 	.base.cra_ctxsize	= sizeof(struct aesbs_ctx),
 	.base.cra_module	= THIS_MODULE,
 	.base.cra_flags		= CRYPTO_ALG_INTERNAL,

 	.min_keysize		= AES_MIN_KEY_SIZE,
 	.max_keysize		= AES_MAX_KEY_SIZE,
 	.chunksize		= AES_BLOCK_SIZE,
 	.walksize		= 8 * AES_BLOCK_SIZE,
 	.ivsize			= AES_BLOCK_SIZE,
 	.setkey			= aesbs_setkey,
 	.encrypt		= ctr_encrypt,
 	.decrypt		= ctr_encrypt,
 }, {
 	.base.cra_name		= "__xts(aes)",
 	.base.cra_driver_name	= "__xts-aes-neonbs",
 	.base.cra_priority	= 250,
 	.base.cra_blocksize	= AES_BLOCK_SIZE,
 	.base.cra_ctxsize	= sizeof(struct aesbs_xts_ctx),
 	.base.cra_module	= THIS_MODULE,
 	.base.cra_flags		= CRYPTO_ALG_INTERNAL,

 	.min_keysize		= 2 * AES_MIN_KEY_SIZE,
 	.max_keysize		= 2 * AES_MAX_KEY_SIZE,
 	.walksize		= 8 * AES_BLOCK_SIZE,
 	.ivsize			= AES_BLOCK_SIZE,
 	.setkey			= aesbs_xts_setkey,
 	.encrypt		= xts_encrypt,
 	.decrypt		= xts_decrypt,
 } };

 static struct simd_skcipher_alg *aes_simd_algs[ARRAY_SIZE(aes_algs)];

 static void aes_exit(void)
 {
 	int i;

 	for (i = 0; i < ARRAY_SIZE(aes_simd_algs); i++)
 		if (aes_simd_algs[i])
 			simd_skcipher_free(aes_simd_algs[i]);

 	crypto_unregister_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
 }

 static int __init aes_init(void)
 {
 	struct simd_skcipher_alg *simd;
 	const char *basename;
 	const char *algname;
 	const char *drvname;
 	int err;
 	int i;

 	if (!(elf_hwcap & HWCAP_NEON))
 		return -ENODEV;

 	err = crypto_register_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
 	if (err)
 		return err;

 	for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
 		if (!(aes_algs[i].base.cra_flags & CRYPTO_ALG_INTERNAL))
 			continue;

 		algname = aes_algs[i].base.cra_name + 2;
 		drvname = aes_algs[i].base.cra_driver_name + 2;
 		basename = aes_algs[i].base.cra_driver_name;
 		simd = simd_skcipher_create_compat(algname, drvname, basename);
 		err = PTR_ERR(simd);
 		if (IS_ERR(simd))
 			goto unregister_simds;

 		aes_simd_algs[i] = simd;
 	}
 	return 0;

 unregister_simds:
 	aes_exit();
 	return err;
 }

 module_init(aes_init);
 module_exit(aes_exit);
	/*
	* Bit sliced AES using NEON instructions
	*
	* Copyright (C) 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	#include <asm/neon.h>
	#include <crypto/aes.h>
	#include <crypto/cbc.h>
	#include <crypto/internal/simd.h>
	#include <crypto/internal/skcipher.h>
	#include <crypto/xts.h>
	#include <linux/module.h>

	MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
	MODULE_LICENSE("GPL v2");

	MODULE_ALIAS_CRYPTO("ecb(aes)");
	MODULE_ALIAS_CRYPTO("cbc(aes)");
	MODULE_ALIAS_CRYPTO("ctr(aes)");
	MODULE_ALIAS_CRYPTO("xts(aes)");

	asmlinkage void aesbs_convert_key(u8 out[], u32 const rk[], int rounds);

	asmlinkage void aesbs_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[],
	int rounds, int blocks);
	asmlinkage void aesbs_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[],
	int rounds, int blocks);

	asmlinkage void aesbs_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[],
	int rounds, int blocks, u8 iv[]);

	asmlinkage void aesbs_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[],
	int rounds, int blocks, u8 ctr[], u8 final[]);

	asmlinkage void aesbs_xts_encrypt(u8 out[], u8 const in[], u8 const rk[],
	int rounds, int blocks, u8 iv[]);
	asmlinkage void aesbs_xts_decrypt(u8 out[], u8 const in[], u8 const rk[],
	int rounds, int blocks, u8 iv[]);

	asmlinkage void __aes_arm_encrypt(const u32 rk[], int rounds, const u8 in[],
	u8 out[]);

	struct aesbs_ctx {
	int rounds;
	u8 rk[13 * (8 * AES_BLOCK_SIZE) + 32] __aligned(AES_BLOCK_SIZE);
	};

	struct aesbs_cbc_ctx {
	struct aesbs_ctx key;
	u32 enc[AES_MAX_KEYLENGTH_U32];
	};

	struct aesbs_xts_ctx {
	struct aesbs_ctx key;
	u32 twkey[AES_MAX_KEYLENGTH_U32];
	};

	static int aesbs_setkey(struct crypto_skcipher tfm, const u8 in_key,
	unsigned int key_len)
	{
	struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
	struct crypto_aes_ctx rk;
	int err;

	err = crypto_aes_expand_key(&rk, in_key, key_len);
	if (err)
	return err;

	ctx->rounds = 6 + key_len / 4;

	kernel_neon_begin();
	aesbs_convert_key(ctx->rk, rk.key_enc, ctx->rounds);
	kernel_neon_end();

	return 0;
	}

	static int __ecb_crypt(struct skcipher_request *req,
	void (*fn)(u8 out[], u8 const in[], u8 const rk[],
	int rounds, int blocks))
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
	struct skcipher_walk walk;
	int err;

	err = skcipher_walk_virt(&walk, req, true);

	kernel_neon_begin();
	while (walk.nbytes >= AES_BLOCK_SIZE) {
	unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;

	if (walk.nbytes < walk.total)
	blocks = round_down(blocks,
	walk.stride / AES_BLOCK_SIZE);

	fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->rk,
	ctx->rounds, blocks);
	err = skcipher_walk_done(&walk,
	walk.nbytes - blocks * AES_BLOCK_SIZE);
	}
	kernel_neon_end();

	return err;
	}

	static int ecb_encrypt(struct skcipher_request *req)
	{
	return __ecb_crypt(req, aesbs_ecb_encrypt);
	}

	static int ecb_decrypt(struct skcipher_request *req)
	{
	return __ecb_crypt(req, aesbs_ecb_decrypt);
	}

	static int aesbs_cbc_setkey(struct crypto_skcipher tfm, const u8 in_key,
	unsigned int key_len)
	{
	struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
	struct crypto_aes_ctx rk;
	int err;

	err = crypto_aes_expand_key(&rk, in_key, key_len);
	if (err)
	return err;

	ctx->key.rounds = 6 + key_len / 4;

	memcpy(ctx->enc, rk.key_enc, sizeof(ctx->enc));

	kernel_neon_begin();
	aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
	kernel_neon_end();

	return 0;
	}

	static void cbc_encrypt_one(struct crypto_skcipher tfm, const u8 src, u8 *dst)
	{
	struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);

	__aes_arm_encrypt(ctx->enc, ctx->key.rounds, src, dst);
	}

	static int cbc_encrypt(struct skcipher_request *req)
	{
	return crypto_cbc_encrypt_walk(req, cbc_encrypt_one);
	}

	static int cbc_decrypt(struct skcipher_request *req)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
	struct skcipher_walk walk;
	int err;

	err = skcipher_walk_virt(&walk, req, true);

	kernel_neon_begin();
	while (walk.nbytes >= AES_BLOCK_SIZE) {
	unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;

	if (walk.nbytes < walk.total)
	blocks = round_down(blocks,
	walk.stride / AES_BLOCK_SIZE);

	aesbs_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
	ctx->key.rk, ctx->key.rounds, blocks,
	walk.iv);
	err = skcipher_walk_done(&walk,
	walk.nbytes - blocks * AES_BLOCK_SIZE);
	}
	kernel_neon_end();

	return err;
	}

	static int ctr_encrypt(struct skcipher_request *req)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
	struct skcipher_walk walk;
	u8 buf[AES_BLOCK_SIZE];
	int err;

	err = skcipher_walk_virt(&walk, req, true);

	kernel_neon_begin();
	while (walk.nbytes > 0) {
	unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
	u8 *final = (walk.total % AES_BLOCK_SIZE) ? buf : NULL;

	if (walk.nbytes < walk.total) {
	blocks = round_down(blocks,
	walk.stride / AES_BLOCK_SIZE);
	final = NULL;
	}

	aesbs_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
	ctx->rk, ctx->rounds, blocks, walk.iv, final);

	if (final) {
	u8 dst = walk.dst.virt.addr + blocks AES_BLOCK_SIZE;
	u8 src = walk.src.virt.addr + blocks AES_BLOCK_SIZE;

	if (dst != src)
	memcpy(dst, src, walk.total % AES_BLOCK_SIZE);
	crypto_xor(dst, final, walk.total % AES_BLOCK_SIZE);

	err = skcipher_walk_done(&walk, 0);
	break;
	}
	err = skcipher_walk_done(&walk,
	walk.nbytes - blocks * AES_BLOCK_SIZE);
	}
	kernel_neon_end();

	return err;
	}

	static int aesbs_xts_setkey(struct crypto_skcipher tfm, const u8 in_key,
	unsigned int key_len)
	{
	struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
	struct crypto_aes_ctx rk;
	int err;

	err = xts_verify_key(tfm, in_key, key_len);
	if (err)
	return err;

	key_len /= 2;
	err = crypto_aes_expand_key(&rk, in_key + key_len, key_len);
	if (err)
	return err;

	memcpy(ctx->twkey, rk.key_enc, sizeof(ctx->twkey));

	return aesbs_setkey(tfm, in_key, key_len);
	}

	static int __xts_crypt(struct skcipher_request *req,
	void (*fn)(u8 out[], u8 const in[], u8 const rk[],
	int rounds, int blocks, u8 iv[]))
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
	struct skcipher_walk walk;
	int err;

	err = skcipher_walk_virt(&walk, req, true);

	__aes_arm_encrypt(ctx->twkey, ctx->key.rounds, walk.iv, walk.iv);

	kernel_neon_begin();
	while (walk.nbytes >= AES_BLOCK_SIZE) {
	unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;

	if (walk.nbytes < walk.total)
	blocks = round_down(blocks,
	walk.stride / AES_BLOCK_SIZE);

	fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->key.rk,
	ctx->key.rounds, blocks, walk.iv);
	err = skcipher_walk_done(&walk,
	walk.nbytes - blocks * AES_BLOCK_SIZE);
	}
	kernel_neon_end();

	return err;
	}

	static int xts_encrypt(struct skcipher_request *req)
	{
	return __xts_crypt(req, aesbs_xts_encrypt);
	}

	static int xts_decrypt(struct skcipher_request *req)
	{
	return __xts_crypt(req, aesbs_xts_decrypt);
	}

	static struct skcipher_alg aes_algs[] = { {
	.base.cra_name = "__ecb(aes)",
	.base.cra_driver_name = "__ecb-aes-neonbs",
	.base.cra_priority = 250,
	.base.cra_blocksize = AES_BLOCK_SIZE,
	.base.cra_ctxsize = sizeof(struct aesbs_ctx),
	.base.cra_module = THIS_MODULE,
	.base.cra_flags = CRYPTO_ALG_INTERNAL,

	.min_keysize = AES_MIN_KEY_SIZE,
	.max_keysize = AES_MAX_KEY_SIZE,
	.walksize = 8 * AES_BLOCK_SIZE,
	.setkey = aesbs_setkey,
	.encrypt = ecb_encrypt,
	.decrypt = ecb_decrypt,
	}, {
	.base.cra_name = "__cbc(aes)",
	.base.cra_driver_name = "__cbc-aes-neonbs",
	.base.cra_priority = 250,
	.base.cra_blocksize = AES_BLOCK_SIZE,
	.base.cra_ctxsize = sizeof(struct aesbs_cbc_ctx),
	.base.cra_module = THIS_MODULE,
	.base.cra_flags = CRYPTO_ALG_INTERNAL,

	.min_keysize = AES_MIN_KEY_SIZE,
	.max_keysize = AES_MAX_KEY_SIZE,
	.walksize = 8 * AES_BLOCK_SIZE,
	.ivsize = AES_BLOCK_SIZE,
	.setkey = aesbs_cbc_setkey,
	.encrypt = cbc_encrypt,
	.decrypt = cbc_decrypt,
	}, {
	.base.cra_name = "__ctr(aes)",
	.base.cra_driver_name = "__ctr-aes-neonbs",
	.base.cra_priority = 250,
	.base.cra_blocksize = 1,
	.base.cra_ctxsize = sizeof(struct aesbs_ctx),
	.base.cra_module = THIS_MODULE,
	.base.cra_flags = CRYPTO_ALG_INTERNAL,

	.min_keysize = AES_MIN_KEY_SIZE,
	.max_keysize = AES_MAX_KEY_SIZE,
	.chunksize = AES_BLOCK_SIZE,
	.walksize = 8 * AES_BLOCK_SIZE,
	.ivsize = AES_BLOCK_SIZE,
	.setkey = aesbs_setkey,
	.encrypt = ctr_encrypt,
	.decrypt = ctr_encrypt,
	}, {
	.base.cra_name = "__xts(aes)",
	.base.cra_driver_name = "__xts-aes-neonbs",
	.base.cra_priority = 250,
	.base.cra_blocksize = AES_BLOCK_SIZE,
	.base.cra_ctxsize = sizeof(struct aesbs_xts_ctx),
	.base.cra_module = THIS_MODULE,
	.base.cra_flags = CRYPTO_ALG_INTERNAL,

	.min_keysize = 2 * AES_MIN_KEY_SIZE,
	.max_keysize = 2 * AES_MAX_KEY_SIZE,
	.walksize = 8 * AES_BLOCK_SIZE,
	.ivsize = AES_BLOCK_SIZE,
	.setkey = aesbs_xts_setkey,
	.encrypt = xts_encrypt,
	.decrypt = xts_decrypt,
	} };

	static struct simd_skcipher_alg *aes_simd_algs[ARRAY_SIZE(aes_algs)];

	static void aes_exit(void)
	{
	int i;

	for (i = 0; i < ARRAY_SIZE(aes_simd_algs); i++)
	if (aes_simd_algs[i])
	simd_skcipher_free(aes_simd_algs[i]);

	crypto_unregister_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
	}

	static int __init aes_init(void)
	{
	struct simd_skcipher_alg *simd;
	const char *basename;
	const char *algname;
	const char *drvname;
	int err;
	int i;

	if (!(elf_hwcap & HWCAP_NEON))
	return -ENODEV;

	err = crypto_register_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
	if (err)
	return err;

	for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
	if (!(aes_algs[i].base.cra_flags & CRYPTO_ALG_INTERNAL))
	continue;

	algname = aes_algs[i].base.cra_name + 2;
	drvname = aes_algs[i].base.cra_driver_name + 2;
	basename = aes_algs[i].base.cra_driver_name;
	simd = simd_skcipher_create_compat(algname, drvname, basename);
	err = PTR_ERR(simd);
	if (IS_ERR(simd))
	goto unregister_simds;

	aes_simd_algs[i] = simd;
	}
	return 0;

	unregister_simds:
	aes_exit();
	return err;
	}

	module_init(aes_init);
	module_exit(aes_exit);