drivers/crypto/padlock-aes.c - kernel/msm-4.19 - Gitiles

 /*
  * Cryptographic API.
  *
  * Support for VIA PadLock hardware crypto engine.
  *
  * Copyright (c) 2004  Michal Ludvig <michal@logix.cz>
  *
  * Key expansion routine taken from crypto/aes_generic.c
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * ---------------------------------------------------------------------------
  * Copyright (c) 2002, Dr Brian Gladman <brg@gladman.me.uk>, Worcester, UK.
  * All rights reserved.
  *
  * LICENSE TERMS
  *
  * The free distribution and use of this software in both source and binary
  * form is allowed (with or without changes) provided that:
  *
  *   1. distributions of this source code include the above copyright
  *      notice, this list of conditions and the following disclaimer;
  *
  *   2. distributions in binary form include the above copyright
  *      notice, this list of conditions and the following disclaimer
  *      in the documentation and/or other associated materials;
  *
  *   3. the copyright holder's name is not used to endorse products
  *      built using this software without specific written permission.
  *
  * ALTERNATIVELY, provided that this notice is retained in full, this product
  * may be distributed under the terms of the GNU General Public License (GPL),
  * in which case the provisions of the GPL apply INSTEAD OF those given above.
  *
  * DISCLAIMER
  *
  * This software is provided 'as is' with no explicit or implied warranties
  * in respect of its properties, including, but not limited to, correctness
  * and/or fitness for purpose.
  * ---------------------------------------------------------------------------
  */

 #include <crypto/algapi.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <asm/byteorder.h>
 #include "padlock.h"

 #define AES_MIN_KEY_SIZE	16	/* in uint8_t units */
 #define AES_MAX_KEY_SIZE	32	/* ditto */
 #define AES_BLOCK_SIZE		16	/* ditto */
 #define AES_EXTENDED_KEY_SIZE	64	/* in uint32_t units */
 #define AES_EXTENDED_KEY_SIZE_B	(AES_EXTENDED_KEY_SIZE * sizeof(uint32_t))

 /* Control word. */
 struct cword {
 	unsigned int __attribute__ ((__packed__))
 		rounds:4,
 		algo:3,
 		keygen:1,
 		interm:1,
 		encdec:1,
 		ksize:2;
 } __attribute__ ((__aligned__(PADLOCK_ALIGNMENT)));

 /* Whenever making any changes to the following
  * structure *make sure* you keep E, d_data
  * and cword aligned on 16 Bytes boundaries!!! */
 struct aes_ctx {
 	struct {
 		struct cword encrypt;
 		struct cword decrypt;
 	} cword;
 	u32 *D;
 	int key_length;
 	u32 E[AES_EXTENDED_KEY_SIZE]
 		__attribute__ ((__aligned__(PADLOCK_ALIGNMENT)));
 	u32 d_data[AES_EXTENDED_KEY_SIZE]
 		__attribute__ ((__aligned__(PADLOCK_ALIGNMENT)));
 };

 /* ====== Key management routines ====== */

 static inline uint32_t
 generic_rotr32 (const uint32_t x, const unsigned bits)
 {
 	const unsigned n = bits % 32;
 	return (x >> n) | (x << (32 - n));
 }

 static inline uint32_t
 generic_rotl32 (const uint32_t x, const unsigned bits)
 {
 	const unsigned n = bits % 32;
 	return (x << n) | (x >> (32 - n));
 }

 #define rotl generic_rotl32
 #define rotr generic_rotr32

 /*
  * #define byte(x, nr) ((unsigned char)((x) >> (nr*8)))
  */
 static inline uint8_t
 byte(const uint32_t x, const unsigned n)
 {
 	return x >> (n << 3);
 }

 #define E_KEY ctx->E
 #define D_KEY ctx->D

 static uint8_t pow_tab[256];
 static uint8_t log_tab[256];
 static uint8_t sbx_tab[256];
 static uint8_t isb_tab[256];
 static uint32_t rco_tab[10];
 static uint32_t ft_tab[4][256];
 static uint32_t it_tab[4][256];

 static uint32_t fl_tab[4][256];
 static uint32_t il_tab[4][256];

 static inline uint8_t
 f_mult (uint8_t a, uint8_t b)
 {
 	uint8_t aa = log_tab[a], cc = aa + log_tab[b];

 	return pow_tab[cc + (cc < aa ? 1 : 0)];
 }

 #define ff_mult(a,b)    (a && b ? f_mult(a, b) : 0)

 #define f_rn(bo, bi, n, k)					\
     bo[n] =  ft_tab[0][byte(bi[n],0)] ^				\
              ft_tab[1][byte(bi[(n + 1) & 3],1)] ^		\
              ft_tab[2][byte(bi[(n + 2) & 3],2)] ^		\
              ft_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n)

 #define i_rn(bo, bi, n, k)					\
     bo[n] =  it_tab[0][byte(bi[n],0)] ^				\
              it_tab[1][byte(bi[(n + 3) & 3],1)] ^		\
              it_tab[2][byte(bi[(n + 2) & 3],2)] ^		\
              it_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n)

 #define ls_box(x)				\
     ( fl_tab[0][byte(x, 0)] ^			\
       fl_tab[1][byte(x, 1)] ^			\
       fl_tab[2][byte(x, 2)] ^			\
       fl_tab[3][byte(x, 3)] )

 #define f_rl(bo, bi, n, k)					\
     bo[n] =  fl_tab[0][byte(bi[n],0)] ^				\
              fl_tab[1][byte(bi[(n + 1) & 3],1)] ^		\
              fl_tab[2][byte(bi[(n + 2) & 3],2)] ^		\
              fl_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n)

 #define i_rl(bo, bi, n, k)					\
     bo[n] =  il_tab[0][byte(bi[n],0)] ^				\
              il_tab[1][byte(bi[(n + 3) & 3],1)] ^		\
              il_tab[2][byte(bi[(n + 2) & 3],2)] ^		\
              il_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n)

 static void
 gen_tabs (void)
 {
 	uint32_t i, t;
 	uint8_t p, q;

 	/* log and power tables for GF(2**8) finite field with
 	   0x011b as modular polynomial - the simplest prmitive
 	   root is 0x03, used here to generate the tables */

 	for (i = 0, p = 1; i < 256; ++i) {
 		pow_tab[i] = (uint8_t) p;
 		log_tab[p] = (uint8_t) i;

 		p ^= (p << 1) ^ (p & 0x80 ? 0x01b : 0);
 	}

 	log_tab[1] = 0;

 	for (i = 0, p = 1; i < 10; ++i) {
 		rco_tab[i] = p;

 		p = (p << 1) ^ (p & 0x80 ? 0x01b : 0);
 	}

 	for (i = 0; i < 256; ++i) {
 		p = (i ? pow_tab[255 - log_tab[i]] : 0);
 		q = ((p >> 7) | (p << 1)) ^ ((p >> 6) | (p << 2));
 		p ^= 0x63 ^ q ^ ((q >> 6) | (q << 2));
 		sbx_tab[i] = p;
 		isb_tab[p] = (uint8_t) i;
 	}

 	for (i = 0; i < 256; ++i) {
 		p = sbx_tab[i];

 		t = p;
 		fl_tab[0][i] = t;
 		fl_tab[1][i] = rotl (t, 8);
 		fl_tab[2][i] = rotl (t, 16);
 		fl_tab[3][i] = rotl (t, 24);

 		t = ((uint32_t) ff_mult (2, p)) |
 		    ((uint32_t) p << 8) |
 		    ((uint32_t) p << 16) | ((uint32_t) ff_mult (3, p) << 24);

 		ft_tab[0][i] = t;
 		ft_tab[1][i] = rotl (t, 8);
 		ft_tab[2][i] = rotl (t, 16);
 		ft_tab[3][i] = rotl (t, 24);

 		p = isb_tab[i];

 		t = p;
 		il_tab[0][i] = t;
 		il_tab[1][i] = rotl (t, 8);
 		il_tab[2][i] = rotl (t, 16);
 		il_tab[3][i] = rotl (t, 24);

 		t = ((uint32_t) ff_mult (14, p)) |
 		    ((uint32_t) ff_mult (9, p) << 8) |
 		    ((uint32_t) ff_mult (13, p) << 16) |
 		    ((uint32_t) ff_mult (11, p) << 24);

 		it_tab[0][i] = t;
 		it_tab[1][i] = rotl (t, 8);
 		it_tab[2][i] = rotl (t, 16);
 		it_tab[3][i] = rotl (t, 24);
 	}
 }

 #define star_x(x) (((x) & 0x7f7f7f7f) << 1) ^ ((((x) & 0x80808080) >> 7) * 0x1b)

 #define imix_col(y,x)       \
     u   = star_x(x);        \
     v   = star_x(u);        \
     w   = star_x(v);        \
     t   = w ^ (x);          \
    (y)  = u ^ v ^ w;        \
    (y) ^= rotr(u ^ t,  8) ^ \
           rotr(v ^ t, 16) ^ \
           rotr(t,24)

 /* initialise the key schedule from the user supplied key */

 #define loop4(i)                                    \
 {   t = rotr(t,  8); t = ls_box(t) ^ rco_tab[i];    \
     t ^= E_KEY[4 * i];     E_KEY[4 * i + 4] = t;    \
     t ^= E_KEY[4 * i + 1]; E_KEY[4 * i + 5] = t;    \
     t ^= E_KEY[4 * i + 2]; E_KEY[4 * i + 6] = t;    \
     t ^= E_KEY[4 * i + 3]; E_KEY[4 * i + 7] = t;    \
 }

 #define loop6(i)                                    \
 {   t = rotr(t,  8); t = ls_box(t) ^ rco_tab[i];    \
     t ^= E_KEY[6 * i];     E_KEY[6 * i + 6] = t;    \
     t ^= E_KEY[6 * i + 1]; E_KEY[6 * i + 7] = t;    \
     t ^= E_KEY[6 * i + 2]; E_KEY[6 * i + 8] = t;    \
     t ^= E_KEY[6 * i + 3]; E_KEY[6 * i + 9] = t;    \
     t ^= E_KEY[6 * i + 4]; E_KEY[6 * i + 10] = t;   \
     t ^= E_KEY[6 * i + 5]; E_KEY[6 * i + 11] = t;   \
 }

 #define loop8(i)                                    \
 {   t = rotr(t,  8); ; t = ls_box(t) ^ rco_tab[i];  \
     t ^= E_KEY[8 * i];     E_KEY[8 * i + 8] = t;    \
     t ^= E_KEY[8 * i + 1]; E_KEY[8 * i + 9] = t;    \
     t ^= E_KEY[8 * i + 2]; E_KEY[8 * i + 10] = t;   \
     t ^= E_KEY[8 * i + 3]; E_KEY[8 * i + 11] = t;   \
     t  = E_KEY[8 * i + 4] ^ ls_box(t);    \
     E_KEY[8 * i + 12] = t;                \
     t ^= E_KEY[8 * i + 5]; E_KEY[8 * i + 13] = t;   \
     t ^= E_KEY[8 * i + 6]; E_KEY[8 * i + 14] = t;   \
     t ^= E_KEY[8 * i + 7]; E_KEY[8 * i + 15] = t;   \
 }

 /* Tells whether the ACE is capable to generate
    the extended key for a given key_len. */
 static inline int
 aes_hw_extkey_available(uint8_t key_len)
 {
 	/* TODO: We should check the actual CPU model/stepping
 	         as it's possible that the capability will be
 	         added in the next CPU revisions. */
 	if (key_len == 16)
 		return 1;
 	return 0;
 }

 static inline struct aes_ctx *aes_ctx_common(void *ctx)
 {
 	unsigned long addr = (unsigned long)ctx;
 	unsigned long align = PADLOCK_ALIGNMENT;

 	if (align <= crypto_tfm_ctx_alignment())
 		align = 1;
 	return (struct aes_ctx *)ALIGN(addr, align);
 }

 static inline struct aes_ctx *aes_ctx(struct crypto_tfm *tfm)
 {
 	return aes_ctx_common(crypto_tfm_ctx(tfm));
 }

 static inline struct aes_ctx *blk_aes_ctx(struct crypto_blkcipher *tfm)
 {
 	return aes_ctx_common(crypto_blkcipher_ctx(tfm));
 }

 static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 		       unsigned int key_len)
 {
 	struct aes_ctx *ctx = aes_ctx(tfm);
 	const __le32 *key = (const __le32 *)in_key;
 	u32 *flags = &tfm->crt_flags;
 	uint32_t i, t, u, v, w;
 	uint32_t P[AES_EXTENDED_KEY_SIZE];
 	uint32_t rounds;

 	if (key_len % 8) {
 		*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 		return -EINVAL;
 	}

 	ctx->key_length = key_len;

 	/*
 	 * If the hardware is capable of generating the extended key
 	 * itself we must supply the plain key for both encryption
 	 * and decryption.
 	 */
 	ctx->D = ctx->E;

 	E_KEY[0] = le32_to_cpu(key[0]);
 	E_KEY[1] = le32_to_cpu(key[1]);
 	E_KEY[2] = le32_to_cpu(key[2]);
 	E_KEY[3] = le32_to_cpu(key[3]);

 	/* Prepare control words. */
 	memset(&ctx->cword, 0, sizeof(ctx->cword));

 	ctx->cword.decrypt.encdec = 1;
 	ctx->cword.encrypt.rounds = 10 + (key_len - 16) / 4;
 	ctx->cword.decrypt.rounds = ctx->cword.encrypt.rounds;
 	ctx->cword.encrypt.ksize = (key_len - 16) / 8;
 	ctx->cword.decrypt.ksize = ctx->cword.encrypt.ksize;

 	/* Don't generate extended keys if the hardware can do it. */
 	if (aes_hw_extkey_available(key_len))
 		return 0;

 	ctx->D = ctx->d_data;
 	ctx->cword.encrypt.keygen = 1;
 	ctx->cword.decrypt.keygen = 1;

 	switch (key_len) {
 	case 16:
 		t = E_KEY[3];
 		for (i = 0; i < 10; ++i)
 			loop4 (i);
 		break;

 	case 24:
 		E_KEY[4] = le32_to_cpu(key[4]);
 		t = E_KEY[5] = le32_to_cpu(key[5]);
 		for (i = 0; i < 8; ++i)
 			loop6 (i);
 		break;

 	case 32:
 		E_KEY[4] = le32_to_cpu(key[4]);
 		E_KEY[5] = le32_to_cpu(key[5]);
 		E_KEY[6] = le32_to_cpu(key[6]);
 		t = E_KEY[7] = le32_to_cpu(key[7]);
 		for (i = 0; i < 7; ++i)
 			loop8 (i);
 		break;
 	}

 	D_KEY[0] = E_KEY[0];
 	D_KEY[1] = E_KEY[1];
 	D_KEY[2] = E_KEY[2];
 	D_KEY[3] = E_KEY[3];

 	for (i = 4; i < key_len + 24; ++i) {
 		imix_col (D_KEY[i], E_KEY[i]);
 	}

 	/* PadLock needs a different format of the decryption key. */
 	rounds = 10 + (key_len - 16) / 4;

 	for (i = 0; i < rounds; i++) {
 		P[((i + 1) * 4) + 0] = D_KEY[((rounds - i - 1) * 4) + 0];
 		P[((i + 1) * 4) + 1] = D_KEY[((rounds - i - 1) * 4) + 1];
 		P[((i + 1) * 4) + 2] = D_KEY[((rounds - i - 1) * 4) + 2];
 		P[((i + 1) * 4) + 3] = D_KEY[((rounds - i - 1) * 4) + 3];
 	}

 	P[0] = E_KEY[(rounds * 4) + 0];
 	P[1] = E_KEY[(rounds * 4) + 1];
 	P[2] = E_KEY[(rounds * 4) + 2];
 	P[3] = E_KEY[(rounds * 4) + 3];

 	memcpy(D_KEY, P, AES_EXTENDED_KEY_SIZE_B);

 	return 0;
 }

 /* ====== Encryption/decryption routines ====== */

 /* These are the real call to PadLock. */
 static inline void padlock_xcrypt(const u8 *input, u8 *output, void *key,
 				  void *control_word)
 {
 	asm volatile (".byte 0xf3,0x0f,0xa7,0xc8"	/* rep xcryptecb */
 		      : "+S"(input), "+D"(output)
 		      : "d"(control_word), "b"(key), "c"(1));
 }

 static void aes_crypt_copy(const u8 *in, u8 *out, u32 *key, struct cword *cword)
 {
 	u8 buf[AES_BLOCK_SIZE * 2 + PADLOCK_ALIGNMENT - 1];
 	u8 *tmp = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);

 	memcpy(tmp, in, AES_BLOCK_SIZE);
 	padlock_xcrypt(tmp, out, key, cword);
 }

 static inline void aes_crypt(const u8 *in, u8 *out, u32 *key,
 			     struct cword *cword)
 {
 	asm volatile ("pushfl; popfl");

 	/* padlock_xcrypt requires at least two blocks of data. */
 	if (unlikely(!(((unsigned long)in ^ (PAGE_SIZE - AES_BLOCK_SIZE)) &
 		       (PAGE_SIZE - 1)))) {
 		aes_crypt_copy(in, out, key, cword);
 		return;
 	}

 	padlock_xcrypt(in, out, key, cword);
 }

 static inline void padlock_xcrypt_ecb(const u8 *input, u8 *output, void *key,
 				      void *control_word, u32 count)
 {
 	if (count == 1) {
 		aes_crypt(input, output, key, control_word);
 		return;
 	}

 	asm volatile ("pushfl; popfl");		/* enforce key reload. */
 	asm volatile ("test $1, %%cl;"
 		      "je 1f;"
 		      "lea -1(%%ecx), %%eax;"
 		      "mov $1, %%ecx;"
 		      ".byte 0xf3,0x0f,0xa7,0xc8;"	/* rep xcryptecb */
 		      "mov %%eax, %%ecx;"
 		      "1:"
 		      ".byte 0xf3,0x0f,0xa7,0xc8"	/* rep xcryptecb */
 		      : "+S"(input), "+D"(output)
 		      : "d"(control_word), "b"(key), "c"(count)
 		      : "ax");
 }

 static inline u8 *padlock_xcrypt_cbc(const u8 *input, u8 *output, void *key,
 				     u8 *iv, void *control_word, u32 count)
 {
 	/* Enforce key reload. */
 	asm volatile ("pushfl; popfl");
 	/* rep xcryptcbc */
 	asm volatile (".byte 0xf3,0x0f,0xa7,0xd0"
 		      : "+S" (input), "+D" (output), "+a" (iv)
 		      : "d" (control_word), "b" (key), "c" (count));
 	return iv;
 }

 static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 {
 	struct aes_ctx *ctx = aes_ctx(tfm);
 	aes_crypt(in, out, ctx->E, &ctx->cword.encrypt);
 }

 static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 {
 	struct aes_ctx *ctx = aes_ctx(tfm);
 	aes_crypt(in, out, ctx->D, &ctx->cword.decrypt);
 }

 static struct crypto_alg aes_alg = {
 	.cra_name		=	"aes",
 	.cra_driver_name	=	"aes-padlock",
 	.cra_priority		=	PADLOCK_CRA_PRIORITY,
 	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
 	.cra_blocksize		=	AES_BLOCK_SIZE,
 	.cra_ctxsize		=	sizeof(struct aes_ctx),
 	.cra_alignmask		=	PADLOCK_ALIGNMENT - 1,
 	.cra_module		=	THIS_MODULE,
 	.cra_list		=	LIST_HEAD_INIT(aes_alg.cra_list),
 	.cra_u			=	{
 		.cipher = {
 			.cia_min_keysize	=	AES_MIN_KEY_SIZE,
 			.cia_max_keysize	=	AES_MAX_KEY_SIZE,
 			.cia_setkey	   	= 	aes_set_key,
 			.cia_encrypt	 	=	aes_encrypt,
 			.cia_decrypt	  	=	aes_decrypt,
 		}
 	}
 };

 static int ecb_aes_encrypt(struct blkcipher_desc *desc,
 			   struct scatterlist *dst, struct scatterlist *src,
 			   unsigned int nbytes)
 {
 	struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
 	struct blkcipher_walk walk;
 	int err;

 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);

 	while ((nbytes = walk.nbytes)) {
 		padlock_xcrypt_ecb(walk.src.virt.addr, walk.dst.virt.addr,
 				   ctx->E, &ctx->cword.encrypt,
 				   nbytes / AES_BLOCK_SIZE);
 		nbytes &= AES_BLOCK_SIZE - 1;
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}

 	return err;
 }

 static int ecb_aes_decrypt(struct blkcipher_desc *desc,
 			   struct scatterlist *dst, struct scatterlist *src,
 			   unsigned int nbytes)
 {
 	struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
 	struct blkcipher_walk walk;
 	int err;

 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);

 	while ((nbytes = walk.nbytes)) {
 		padlock_xcrypt_ecb(walk.src.virt.addr, walk.dst.virt.addr,
 				   ctx->D, &ctx->cword.decrypt,
 				   nbytes / AES_BLOCK_SIZE);
 		nbytes &= AES_BLOCK_SIZE - 1;
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}

 	return err;
 }

 static struct crypto_alg ecb_aes_alg = {
 	.cra_name		=	"ecb(aes)",
 	.cra_driver_name	=	"ecb-aes-padlock",
 	.cra_priority		=	PADLOCK_COMPOSITE_PRIORITY,
 	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
 	.cra_blocksize		=	AES_BLOCK_SIZE,
 	.cra_ctxsize		=	sizeof(struct aes_ctx),
 	.cra_alignmask		=	PADLOCK_ALIGNMENT - 1,
 	.cra_type		=	&crypto_blkcipher_type,
 	.cra_module		=	THIS_MODULE,
 	.cra_list		=	LIST_HEAD_INIT(ecb_aes_alg.cra_list),
 	.cra_u			=	{
 		.blkcipher = {
 			.min_keysize		=	AES_MIN_KEY_SIZE,
 			.max_keysize		=	AES_MAX_KEY_SIZE,
 			.setkey	   		= 	aes_set_key,
 			.encrypt		=	ecb_aes_encrypt,
 			.decrypt		=	ecb_aes_decrypt,
 		}
 	}
 };

 static int cbc_aes_encrypt(struct blkcipher_desc *desc,
 			   struct scatterlist *dst, struct scatterlist *src,
 			   unsigned int nbytes)
 {
 	struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
 	struct blkcipher_walk walk;
 	int err;

 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);

 	while ((nbytes = walk.nbytes)) {
 		u8 *iv = padlock_xcrypt_cbc(walk.src.virt.addr,
 					    walk.dst.virt.addr, ctx->E,
 					    walk.iv, &ctx->cword.encrypt,
 					    nbytes / AES_BLOCK_SIZE);
 		memcpy(walk.iv, iv, AES_BLOCK_SIZE);
 		nbytes &= AES_BLOCK_SIZE - 1;
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}

 	return err;
 }

 static int cbc_aes_decrypt(struct blkcipher_desc *desc,
 			   struct scatterlist *dst, struct scatterlist *src,
 			   unsigned int nbytes)
 {
 	struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
 	struct blkcipher_walk walk;
 	int err;

 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);

 	while ((nbytes = walk.nbytes)) {
 		padlock_xcrypt_cbc(walk.src.virt.addr, walk.dst.virt.addr,
 				   ctx->D, walk.iv, &ctx->cword.decrypt,
 				   nbytes / AES_BLOCK_SIZE);
 		nbytes &= AES_BLOCK_SIZE - 1;
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}

 	return err;
 }

 static struct crypto_alg cbc_aes_alg = {
 	.cra_name		=	"cbc(aes)",
 	.cra_driver_name	=	"cbc-aes-padlock",
 	.cra_priority		=	PADLOCK_COMPOSITE_PRIORITY,
 	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
 	.cra_blocksize		=	AES_BLOCK_SIZE,
 	.cra_ctxsize		=	sizeof(struct aes_ctx),
 	.cra_alignmask		=	PADLOCK_ALIGNMENT - 1,
 	.cra_type		=	&crypto_blkcipher_type,
 	.cra_module		=	THIS_MODULE,
 	.cra_list		=	LIST_HEAD_INIT(cbc_aes_alg.cra_list),
 	.cra_u			=	{
 		.blkcipher = {
 			.min_keysize		=	AES_MIN_KEY_SIZE,
 			.max_keysize		=	AES_MAX_KEY_SIZE,
 			.ivsize			=	AES_BLOCK_SIZE,
 			.setkey	   		= 	aes_set_key,
 			.encrypt		=	cbc_aes_encrypt,
 			.decrypt		=	cbc_aes_decrypt,
 		}
 	}
 };

 static int __init padlock_init(void)
 {
 	int ret;

 	if (!cpu_has_xcrypt) {
 		printk(KERN_ERR PFX "VIA PadLock not detected.\n");
 		return -ENODEV;
 	}

 	if (!cpu_has_xcrypt_enabled) {
 		printk(KERN_ERR PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
 		return -ENODEV;
 	}

 	gen_tabs();
 	if ((ret = crypto_register_alg(&aes_alg)))
 		goto aes_err;

 	if ((ret = crypto_register_alg(&ecb_aes_alg)))
 		goto ecb_aes_err;

 	if ((ret = crypto_register_alg(&cbc_aes_alg)))
 		goto cbc_aes_err;

 	printk(KERN_NOTICE PFX "Using VIA PadLock ACE for AES algorithm.\n");

 out:
 	return ret;

 cbc_aes_err:
 	crypto_unregister_alg(&ecb_aes_alg);
 ecb_aes_err:
 	crypto_unregister_alg(&aes_alg);
 aes_err:
 	printk(KERN_ERR PFX "VIA PadLock AES initialization failed.\n");
 	goto out;
 }

 static void __exit padlock_fini(void)
 {
 	crypto_unregister_alg(&cbc_aes_alg);
 	crypto_unregister_alg(&ecb_aes_alg);
 	crypto_unregister_alg(&aes_alg);
 }

 module_init(padlock_init);
 module_exit(padlock_fini);

 MODULE_DESCRIPTION("VIA PadLock AES algorithm support");
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Michal Ludvig");

 MODULE_ALIAS("aes");
	/*
	* Cryptographic API.
	*
	* Support for VIA PadLock hardware crypto engine.
	*
	* Copyright (c) 2004 Michal Ludvig <michal@logix.cz>
	*
	* Key expansion routine taken from crypto/aes_generic.c
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* ---------------------------------------------------------------------------
	* Copyright (c) 2002, Dr Brian Gladman <brg@gladman.me.uk>, Worcester, UK.
	* All rights reserved.
	*
	* LICENSE TERMS
	*
	* The free distribution and use of this software in both source and binary
	* form is allowed (with or without changes) provided that:
	*
	* 1. distributions of this source code include the above copyright
	* notice, this list of conditions and the following disclaimer;
	*
	* 2. distributions in binary form include the above copyright
	* notice, this list of conditions and the following disclaimer
	* in the documentation and/or other associated materials;
	*
	* 3. the copyright holder's name is not used to endorse products
	* built using this software without specific written permission.
	*
	* ALTERNATIVELY, provided that this notice is retained in full, this product
	* may be distributed under the terms of the GNU General Public License (GPL),
	* in which case the provisions of the GPL apply INSTEAD OF those given above.
	*
	* DISCLAIMER
	*
	* This software is provided 'as is' with no explicit or implied warranties
	* in respect of its properties, including, but not limited to, correctness
	* and/or fitness for purpose.
	* ---------------------------------------------------------------------------
	*/

	#include <crypto/algapi.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/types.h>
	#include <linux/errno.h>
	#include <linux/interrupt.h>
	#include <linux/kernel.h>
	#include <asm/byteorder.h>
	#include "padlock.h"

	#define AES_MIN_KEY_SIZE 16 /* in uint8_t units */
	#define AES_MAX_KEY_SIZE 32 /* ditto */
	#define AES_BLOCK_SIZE 16 /* ditto */
	#define AES_EXTENDED_KEY_SIZE 64 /* in uint32_t units */
	#define AES_EXTENDED_KEY_SIZE_B (AES_EXTENDED_KEY_SIZE * sizeof(uint32_t))

	/* Control word. */
	struct cword {
	unsigned int __attribute__ ((__packed__))
	rounds:4,
	algo:3,
	keygen:1,
	interm:1,
	encdec:1,
	ksize:2;
	} __attribute__ ((__aligned__(PADLOCK_ALIGNMENT)));

	/* Whenever making any changes to the following
	* structure make sure you keep E, d_data
	* and cword aligned on 16 Bytes boundaries!!! */
	struct aes_ctx {
	struct {
	struct cword encrypt;
	struct cword decrypt;
	} cword;
	u32 *D;
	int key_length;
	u32 E[AES_EXTENDED_KEY_SIZE]
	__attribute__ ((__aligned__(PADLOCK_ALIGNMENT)));
	u32 d_data[AES_EXTENDED_KEY_SIZE]
	__attribute__ ((__aligned__(PADLOCK_ALIGNMENT)));
	};

	/* ====== Key management routines ====== */

	static inline uint32_t
	generic_rotr32 (const uint32_t x, const unsigned bits)
	{
	const unsigned n = bits % 32;
	return (x >> n) \| (x << (32 - n));
	}

	static inline uint32_t
	generic_rotl32 (const uint32_t x, const unsigned bits)
	{
	const unsigned n = bits % 32;
	return (x << n) \| (x >> (32 - n));
	}

	#define rotl generic_rotl32
	#define rotr generic_rotr32

	/*
	* #define byte(x, nr) ((unsigned char)((x) >> (nr*8)))
	*/
	static inline uint8_t
	byte(const uint32_t x, const unsigned n)
	{
	return x >> (n << 3);
	}

	#define E_KEY ctx->E
	#define D_KEY ctx->D

	static uint8_t pow_tab[256];
	static uint8_t log_tab[256];
	static uint8_t sbx_tab[256];
	static uint8_t isb_tab[256];
	static uint32_t rco_tab[10];
	static uint32_t ft_tab[4][256];
	static uint32_t it_tab[4][256];

	static uint32_t fl_tab[4][256];
	static uint32_t il_tab[4][256];

	static inline uint8_t
	f_mult (uint8_t a, uint8_t b)
	{
	uint8_t aa = log_tab[a], cc = aa + log_tab[b];

	return pow_tab[cc + (cc < aa ? 1 : 0)];
	}

	#define ff_mult(a,b) (a && b ? f_mult(a, b) : 0)

	#define f_rn(bo, bi, n, k) \
	bo[n] = ft_tab[0][byte(bi[n],0)] ^ \
	ft_tab[1][byte(bi[(n + 1) & 3],1)] ^ \
	ft_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
	ft_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n)

	#define i_rn(bo, bi, n, k) \
	bo[n] = it_tab[0][byte(bi[n],0)] ^ \
	it_tab[1][byte(bi[(n + 3) & 3],1)] ^ \
	it_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
	it_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n)

	#define ls_box(x) \
	( fl_tab[0][byte(x, 0)] ^ \
	fl_tab[1][byte(x, 1)] ^ \
	fl_tab[2][byte(x, 2)] ^ \
	fl_tab[3][byte(x, 3)] )

	#define f_rl(bo, bi, n, k) \
	bo[n] = fl_tab[0][byte(bi[n],0)] ^ \
	fl_tab[1][byte(bi[(n + 1) & 3],1)] ^ \
	fl_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
	fl_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n)

	#define i_rl(bo, bi, n, k) \
	bo[n] = il_tab[0][byte(bi[n],0)] ^ \
	il_tab[1][byte(bi[(n + 3) & 3],1)] ^ \
	il_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
	il_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n)

	static void
	gen_tabs (void)
	{
	uint32_t i, t;
	uint8_t p, q;

	/* log and power tables for GF(2**8) finite field with
	0x011b as modular polynomial - the simplest prmitive
	root is 0x03, used here to generate the tables */

	for (i = 0, p = 1; i < 256; ++i) {
	pow_tab[i] = (uint8_t) p;
	log_tab[p] = (uint8_t) i;

	p ^= (p << 1) ^ (p & 0x80 ? 0x01b : 0);
	}

	log_tab[1] = 0;

	for (i = 0, p = 1; i < 10; ++i) {
	rco_tab[i] = p;

	p = (p << 1) ^ (p & 0x80 ? 0x01b : 0);
	}

	for (i = 0; i < 256; ++i) {
	p = (i ? pow_tab[255 - log_tab[i]] : 0);
	q = ((p >> 7) \| (p << 1)) ^ ((p >> 6) \| (p << 2));
	p ^= 0x63 ^ q ^ ((q >> 6) \| (q << 2));
	sbx_tab[i] = p;
	isb_tab[p] = (uint8_t) i;
	}

	for (i = 0; i < 256; ++i) {
	p = sbx_tab[i];

	t = p;
	fl_tab[0][i] = t;
	fl_tab[1][i] = rotl (t, 8);
	fl_tab[2][i] = rotl (t, 16);
	fl_tab[3][i] = rotl (t, 24);

	t = ((uint32_t) ff_mult (2, p)) \|
	((uint32_t) p << 8) \|
	((uint32_t) p << 16) \| ((uint32_t) ff_mult (3, p) << 24);

	ft_tab[0][i] = t;
	ft_tab[1][i] = rotl (t, 8);
	ft_tab[2][i] = rotl (t, 16);
	ft_tab[3][i] = rotl (t, 24);

	p = isb_tab[i];

	t = p;
	il_tab[0][i] = t;
	il_tab[1][i] = rotl (t, 8);
	il_tab[2][i] = rotl (t, 16);
	il_tab[3][i] = rotl (t, 24);

	t = ((uint32_t) ff_mult (14, p)) \|
	((uint32_t) ff_mult (9, p) << 8) \|
	((uint32_t) ff_mult (13, p) << 16) \|
	((uint32_t) ff_mult (11, p) << 24);

	it_tab[0][i] = t;
	it_tab[1][i] = rotl (t, 8);
	it_tab[2][i] = rotl (t, 16);
	it_tab[3][i] = rotl (t, 24);
	}
	}

	#define star_x(x) (((x) & 0x7f7f7f7f) << 1) ^ ((((x) & 0x80808080) >> 7) * 0x1b)

	#define imix_col(y,x) \
	u = star_x(x); \
	v = star_x(u); \
	w = star_x(v); \
	t = w ^ (x); \
	(y) = u ^ v ^ w; \
	(y) ^= rotr(u ^ t, 8) ^ \
	rotr(v ^ t, 16) ^ \
	rotr(t,24)

	/* initialise the key schedule from the user supplied key */

	#define loop4(i) \
	{ t = rotr(t, 8); t = ls_box(t) ^ rco_tab[i]; \
	t ^= E_KEY[4 * i]; E_KEY[4 * i + 4] = t; \
	t ^= E_KEY[4 * i + 1]; E_KEY[4 * i + 5] = t; \
	t ^= E_KEY[4 * i + 2]; E_KEY[4 * i + 6] = t; \
	t ^= E_KEY[4 * i + 3]; E_KEY[4 * i + 7] = t; \
	}

	#define loop6(i) \
	{ t = rotr(t, 8); t = ls_box(t) ^ rco_tab[i]; \
	t ^= E_KEY[6 * i]; E_KEY[6 * i + 6] = t; \
	t ^= E_KEY[6 * i + 1]; E_KEY[6 * i + 7] = t; \
	t ^= E_KEY[6 * i + 2]; E_KEY[6 * i + 8] = t; \
	t ^= E_KEY[6 * i + 3]; E_KEY[6 * i + 9] = t; \
	t ^= E_KEY[6 * i + 4]; E_KEY[6 * i + 10] = t; \
	t ^= E_KEY[6 * i + 5]; E_KEY[6 * i + 11] = t; \
	}

	#define loop8(i) \
	{ t = rotr(t, 8); ; t = ls_box(t) ^ rco_tab[i]; \
	t ^= E_KEY[8 * i]; E_KEY[8 * i + 8] = t; \
	t ^= E_KEY[8 * i + 1]; E_KEY[8 * i + 9] = t; \
	t ^= E_KEY[8 * i + 2]; E_KEY[8 * i + 10] = t; \
	t ^= E_KEY[8 * i + 3]; E_KEY[8 * i + 11] = t; \
	t = E_KEY[8 * i + 4] ^ ls_box(t); \
	E_KEY[8 * i + 12] = t; \
	t ^= E_KEY[8 * i + 5]; E_KEY[8 * i + 13] = t; \
	t ^= E_KEY[8 * i + 6]; E_KEY[8 * i + 14] = t; \
	t ^= E_KEY[8 * i + 7]; E_KEY[8 * i + 15] = t; \
	}

	/* Tells whether the ACE is capable to generate
	the extended key for a given key_len. */
	static inline int
	aes_hw_extkey_available(uint8_t key_len)
	{
	/* TODO: We should check the actual CPU model/stepping
	as it's possible that the capability will be
	added in the next CPU revisions. */
	if (key_len == 16)
	return 1;
	return 0;
	}

	static inline struct aes_ctx aes_ctx_common(void ctx)
	{
	unsigned long addr = (unsigned long)ctx;
	unsigned long align = PADLOCK_ALIGNMENT;

	if (align <= crypto_tfm_ctx_alignment())
	align = 1;
	return (struct aes_ctx *)ALIGN(addr, align);
	}

	static inline struct aes_ctx aes_ctx(struct crypto_tfm tfm)
	{
	return aes_ctx_common(crypto_tfm_ctx(tfm));
	}

	static inline struct aes_ctx blk_aes_ctx(struct crypto_blkcipher tfm)
	{
	return aes_ctx_common(crypto_blkcipher_ctx(tfm));
	}

	static int aes_set_key(struct crypto_tfm tfm, const u8 in_key,
	unsigned int key_len)
	{
	struct aes_ctx *ctx = aes_ctx(tfm);
	const __le32 key = (const __le32 )in_key;
	u32 *flags = &tfm->crt_flags;
	uint32_t i, t, u, v, w;
	uint32_t P[AES_EXTENDED_KEY_SIZE];
	uint32_t rounds;

	if (key_len % 8) {
	*flags \|= CRYPTO_TFM_RES_BAD_KEY_LEN;
	return -EINVAL;
	}

	ctx->key_length = key_len;

	/*
	* If the hardware is capable of generating the extended key
	* itself we must supply the plain key for both encryption
	* and decryption.
	*/
	ctx->D = ctx->E;

	E_KEY[0] = le32_to_cpu(key[0]);
	E_KEY[1] = le32_to_cpu(key[1]);
	E_KEY[2] = le32_to_cpu(key[2]);
	E_KEY[3] = le32_to_cpu(key[3]);

	/* Prepare control words. */
	memset(&ctx->cword, 0, sizeof(ctx->cword));

	ctx->cword.decrypt.encdec = 1;
	ctx->cword.encrypt.rounds = 10 + (key_len - 16) / 4;
	ctx->cword.decrypt.rounds = ctx->cword.encrypt.rounds;
	ctx->cword.encrypt.ksize = (key_len - 16) / 8;
	ctx->cword.decrypt.ksize = ctx->cword.encrypt.ksize;

	/* Don't generate extended keys if the hardware can do it. */
	if (aes_hw_extkey_available(key_len))
	return 0;

	ctx->D = ctx->d_data;
	ctx->cword.encrypt.keygen = 1;
	ctx->cword.decrypt.keygen = 1;

	switch (key_len) {
	case 16:
	t = E_KEY[3];
	for (i = 0; i < 10; ++i)
	loop4 (i);
	break;

	case 24:
	E_KEY[4] = le32_to_cpu(key[4]);
	t = E_KEY[5] = le32_to_cpu(key[5]);
	for (i = 0; i < 8; ++i)
	loop6 (i);
	break;

	case 32:
	E_KEY[4] = le32_to_cpu(key[4]);
	E_KEY[5] = le32_to_cpu(key[5]);
	E_KEY[6] = le32_to_cpu(key[6]);
	t = E_KEY[7] = le32_to_cpu(key[7]);
	for (i = 0; i < 7; ++i)
	loop8 (i);
	break;
	}

	D_KEY[0] = E_KEY[0];
	D_KEY[1] = E_KEY[1];
	D_KEY[2] = E_KEY[2];
	D_KEY[3] = E_KEY[3];

	for (i = 4; i < key_len + 24; ++i) {
	imix_col (D_KEY[i], E_KEY[i]);
	}

	/* PadLock needs a different format of the decryption key. */
	rounds = 10 + (key_len - 16) / 4;

	for (i = 0; i < rounds; i++) {
	P[((i + 1) * 4) + 0] = D_KEY[((rounds - i - 1) * 4) + 0];
	P[((i + 1) * 4) + 1] = D_KEY[((rounds - i - 1) * 4) + 1];
	P[((i + 1) * 4) + 2] = D_KEY[((rounds - i - 1) * 4) + 2];
	P[((i + 1) * 4) + 3] = D_KEY[((rounds - i - 1) * 4) + 3];
	}

	P[0] = E_KEY[(rounds * 4) + 0];
	P[1] = E_KEY[(rounds * 4) + 1];
	P[2] = E_KEY[(rounds * 4) + 2];
	P[3] = E_KEY[(rounds * 4) + 3];

	memcpy(D_KEY, P, AES_EXTENDED_KEY_SIZE_B);

	return 0;
	}

	/* ====== Encryption/decryption routines ====== */

	/* These are the real call to PadLock. */
	static inline void padlock_xcrypt(const u8 input, u8 output, void *key,
	void *control_word)
	{
	asm volatile (".byte 0xf3,0x0f,0xa7,0xc8" /* rep xcryptecb */
	: "+S"(input), "+D"(output)
	: "d"(control_word), "b"(key), "c"(1));
	}

	static void aes_crypt_copy(const u8 in, u8 out, u32 key, struct cword cword)
	{
	u8 buf[AES_BLOCK_SIZE * 2 + PADLOCK_ALIGNMENT - 1];
	u8 *tmp = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);

	memcpy(tmp, in, AES_BLOCK_SIZE);
	padlock_xcrypt(tmp, out, key, cword);
	}

	static inline void aes_crypt(const u8 in, u8 out, u32 *key,
	struct cword *cword)
	{
	asm volatile ("pushfl; popfl");

	/* padlock_xcrypt requires at least two blocks of data. */
	if (unlikely(!(((unsigned long)in ^ (PAGE_SIZE - AES_BLOCK_SIZE)) &
	(PAGE_SIZE - 1)))) {
	aes_crypt_copy(in, out, key, cword);
	return;
	}

	padlock_xcrypt(in, out, key, cword);
	}

	static inline void padlock_xcrypt_ecb(const u8 input, u8 output, void *key,
	void *control_word, u32 count)
	{
	if (count == 1) {
	aes_crypt(input, output, key, control_word);
	return;
	}

	asm volatile ("pushfl; popfl"); /* enforce key reload. */
	asm volatile ("test $1, %%cl;"
	"je 1f;"
	"lea -1(%%ecx), %%eax;"
	"mov $1, %%ecx;"
	".byte 0xf3,0x0f,0xa7,0xc8;" /* rep xcryptecb */
	"mov %%eax, %%ecx;"
	"1:"
	".byte 0xf3,0x0f,0xa7,0xc8" /* rep xcryptecb */
	: "+S"(input), "+D"(output)
	: "d"(control_word), "b"(key), "c"(count)
	: "ax");
	}

	static inline u8 padlock_xcrypt_cbc(const u8 input, u8 output, void key,
	u8 iv, void control_word, u32 count)
	{
	/* Enforce key reload. */
	asm volatile ("pushfl; popfl");
	/* rep xcryptcbc */
	asm volatile (".byte 0xf3,0x0f,0xa7,0xd0"
	: "+S" (input), "+D" (output), "+a" (iv)
	: "d" (control_word), "b" (key), "c" (count));
	return iv;
	}

	static void aes_encrypt(struct crypto_tfm tfm, u8 out, const u8 *in)
	{
	struct aes_ctx *ctx = aes_ctx(tfm);
	aes_crypt(in, out, ctx->E, &ctx->cword.encrypt);
	}

	static void aes_decrypt(struct crypto_tfm tfm, u8 out, const u8 *in)
	{
	struct aes_ctx *ctx = aes_ctx(tfm);
	aes_crypt(in, out, ctx->D, &ctx->cword.decrypt);
	}

	static struct crypto_alg aes_alg = {
	.cra_name = "aes",
	.cra_driver_name = "aes-padlock",
	.cra_priority = PADLOCK_CRA_PRIORITY,
	.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
	.cra_blocksize = AES_BLOCK_SIZE,
	.cra_ctxsize = sizeof(struct aes_ctx),
	.cra_alignmask = PADLOCK_ALIGNMENT - 1,
	.cra_module = THIS_MODULE,
	.cra_list = LIST_HEAD_INIT(aes_alg.cra_list),
	.cra_u = {
	.cipher = {
	.cia_min_keysize = AES_MIN_KEY_SIZE,
	.cia_max_keysize = AES_MAX_KEY_SIZE,
	.cia_setkey = aes_set_key,
	.cia_encrypt = aes_encrypt,
	.cia_decrypt = aes_decrypt,
	}
	}
	};

	static int ecb_aes_encrypt(struct blkcipher_desc *desc,
	struct scatterlist dst, struct scatterlist src,
	unsigned int nbytes)
	{
	struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
	struct blkcipher_walk walk;
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while ((nbytes = walk.nbytes)) {
	padlock_xcrypt_ecb(walk.src.virt.addr, walk.dst.virt.addr,
	ctx->E, &ctx->cword.encrypt,
	nbytes / AES_BLOCK_SIZE);
	nbytes &= AES_BLOCK_SIZE - 1;
	err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	return err;
	}

	static int ecb_aes_decrypt(struct blkcipher_desc *desc,
	struct scatterlist dst, struct scatterlist src,
	unsigned int nbytes)
	{
	struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
	struct blkcipher_walk walk;
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while ((nbytes = walk.nbytes)) {
	padlock_xcrypt_ecb(walk.src.virt.addr, walk.dst.virt.addr,
	ctx->D, &ctx->cword.decrypt,
	nbytes / AES_BLOCK_SIZE);
	nbytes &= AES_BLOCK_SIZE - 1;
	err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	return err;
	}

	static struct crypto_alg ecb_aes_alg = {
	.cra_name = "ecb(aes)",
	.cra_driver_name = "ecb-aes-padlock",
	.cra_priority = PADLOCK_COMPOSITE_PRIORITY,
	.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize = AES_BLOCK_SIZE,
	.cra_ctxsize = sizeof(struct aes_ctx),
	.cra_alignmask = PADLOCK_ALIGNMENT - 1,
	.cra_type = &crypto_blkcipher_type,
	.cra_module = THIS_MODULE,
	.cra_list = LIST_HEAD_INIT(ecb_aes_alg.cra_list),
	.cra_u = {
	.blkcipher = {
	.min_keysize = AES_MIN_KEY_SIZE,
	.max_keysize = AES_MAX_KEY_SIZE,
	.setkey = aes_set_key,
	.encrypt = ecb_aes_encrypt,
	.decrypt = ecb_aes_decrypt,
	}
	}
	};

	static int cbc_aes_encrypt(struct blkcipher_desc *desc,
	struct scatterlist dst, struct scatterlist src,
	unsigned int nbytes)
	{
	struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
	struct blkcipher_walk walk;
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while ((nbytes = walk.nbytes)) {
	u8 *iv = padlock_xcrypt_cbc(walk.src.virt.addr,
	walk.dst.virt.addr, ctx->E,
	walk.iv, &ctx->cword.encrypt,
	nbytes / AES_BLOCK_SIZE);
	memcpy(walk.iv, iv, AES_BLOCK_SIZE);
	nbytes &= AES_BLOCK_SIZE - 1;
	err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	return err;
	}

	static int cbc_aes_decrypt(struct blkcipher_desc *desc,
	struct scatterlist dst, struct scatterlist src,
	unsigned int nbytes)
	{
	struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
	struct blkcipher_walk walk;
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while ((nbytes = walk.nbytes)) {
	padlock_xcrypt_cbc(walk.src.virt.addr, walk.dst.virt.addr,
	ctx->D, walk.iv, &ctx->cword.decrypt,
	nbytes / AES_BLOCK_SIZE);
	nbytes &= AES_BLOCK_SIZE - 1;
	err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	return err;
	}

	static struct crypto_alg cbc_aes_alg = {
	.cra_name = "cbc(aes)",
	.cra_driver_name = "cbc-aes-padlock",
	.cra_priority = PADLOCK_COMPOSITE_PRIORITY,
	.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize = AES_BLOCK_SIZE,
	.cra_ctxsize = sizeof(struct aes_ctx),
	.cra_alignmask = PADLOCK_ALIGNMENT - 1,
	.cra_type = &crypto_blkcipher_type,
	.cra_module = THIS_MODULE,
	.cra_list = LIST_HEAD_INIT(cbc_aes_alg.cra_list),
	.cra_u = {
	.blkcipher = {
	.min_keysize = AES_MIN_KEY_SIZE,
	.max_keysize = AES_MAX_KEY_SIZE,
	.ivsize = AES_BLOCK_SIZE,
	.setkey = aes_set_key,
	.encrypt = cbc_aes_encrypt,
	.decrypt = cbc_aes_decrypt,
	}
	}
	};

	static int __init padlock_init(void)
	{
	int ret;

	if (!cpu_has_xcrypt) {
	printk(KERN_ERR PFX "VIA PadLock not detected.\n");
	return -ENODEV;
	}

	if (!cpu_has_xcrypt_enabled) {
	printk(KERN_ERR PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
	return -ENODEV;
	}

	gen_tabs();
	if ((ret = crypto_register_alg(&aes_alg)))
	goto aes_err;

	if ((ret = crypto_register_alg(&ecb_aes_alg)))
	goto ecb_aes_err;

	if ((ret = crypto_register_alg(&cbc_aes_alg)))
	goto cbc_aes_err;

	printk(KERN_NOTICE PFX "Using VIA PadLock ACE for AES algorithm.\n");

	out:
	return ret;

	cbc_aes_err:
	crypto_unregister_alg(&ecb_aes_alg);
	ecb_aes_err:
	crypto_unregister_alg(&aes_alg);
	aes_err:
	printk(KERN_ERR PFX "VIA PadLock AES initialization failed.\n");
	goto out;
	}

	static void __exit padlock_fini(void)
	{
	crypto_unregister_alg(&cbc_aes_alg);
	crypto_unregister_alg(&ecb_aes_alg);
	crypto_unregister_alg(&aes_alg);
	}

	module_init(padlock_init);
	module_exit(padlock_fini);

	MODULE_DESCRIPTION("VIA PadLock AES algorithm support");
	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Michal Ludvig");

	MODULE_ALIAS("aes");