arch/powerpc/crypto/aes-spe-glue.c - kernel/common - Git at Google

 /*
  * Glue code for AES implementation for SPE instructions (PPC)
  *
  * Based on generic implementation. The assembler module takes care
  * about the SPE registers so it can run from interrupt context.
  *
  * Copyright (c) 2015 Markus Stockhausen <[email protected]>
  *
  * 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.
  *
  */

 #include <crypto/aes.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/crypto.h>
 #include <asm/byteorder.h>
 #include <asm/switch_to.h>
 #include <crypto/algapi.h>

 /*
  * MAX_BYTES defines the number of bytes that are allowed to be processed
  * between preempt_disable() and preempt_enable(). e500 cores can issue two
  * instructions per clock cycle using one 32/64 bit unit (SU1) and one 32
  * bit unit (SU2). One of these can be a memory access that is executed via
  * a single load and store unit (LSU). XTS-AES-256 takes ~780 operations per
  * 16 byte block block or 25 cycles per byte. Thus 768 bytes of input data
  * will need an estimated maximum of 20,000 cycles. Headroom for cache misses
  * included. Even with the low end model clocked at 667 MHz this equals to a
  * critical time window of less than 30us. The value has been choosen to
  * process a 512 byte disk block in one or a large 1400 bytes IPsec network
  * packet in two runs.
  *
  */
 #define MAX_BYTES 768

 struct ppc_aes_ctx {
 	u32 key_enc[AES_MAX_KEYLENGTH_U32];
 	u32 key_dec[AES_MAX_KEYLENGTH_U32];
 	u32 rounds;
 };

 struct ppc_xts_ctx {
 	u32 key_enc[AES_MAX_KEYLENGTH_U32];
 	u32 key_dec[AES_MAX_KEYLENGTH_U32];
 	u32 key_twk[AES_MAX_KEYLENGTH_U32];
 	u32 rounds;
 };

 extern void ppc_encrypt_aes(u8 *out, const u8 *in, u32 *key_enc, u32 rounds);
 extern void ppc_decrypt_aes(u8 *out, const u8 *in, u32 *key_dec, u32 rounds);
 extern void ppc_encrypt_ecb(u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
 			    u32 bytes);
 extern void ppc_decrypt_ecb(u8 *out, const u8 *in, u32 *key_dec, u32 rounds,
 			    u32 bytes);
 extern void ppc_encrypt_cbc(u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
 			    u32 bytes, u8 *iv);
 extern void ppc_decrypt_cbc(u8 *out, const u8 *in, u32 *key_dec, u32 rounds,
 			    u32 bytes, u8 *iv);
 extern void ppc_crypt_ctr  (u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
 			    u32 bytes, u8 *iv);
 extern void ppc_encrypt_xts(u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
 			    u32 bytes, u8 *iv, u32 *key_twk);
 extern void ppc_decrypt_xts(u8 *out, const u8 *in, u32 *key_dec, u32 rounds,
 			    u32 bytes, u8 *iv, u32 *key_twk);

 extern void ppc_expand_key_128(u32 *key_enc, const u8 *key);
 extern void ppc_expand_key_192(u32 *key_enc, const u8 *key);
 extern void ppc_expand_key_256(u32 *key_enc, const u8 *key);

 extern void ppc_generate_decrypt_key(u32 *key_dec,u32 *key_enc,
 				     unsigned int key_len);

 static void spe_begin(void)
 {
 	/* disable preemption and save users SPE registers if required */
 	preempt_disable();
 	enable_kernel_spe();
 }

 static void spe_end(void)
 {
 	/* reenable preemption */
 	preempt_enable();
 }

 static int ppc_aes_setkey(struct crypto_tfm *tfm, const u8 *in_key,
 		unsigned int key_len)
 {
 	struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);

 	if (key_len != AES_KEYSIZE_128 &&
 	    key_len != AES_KEYSIZE_192 &&
 	    key_len != AES_KEYSIZE_256) {
 		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 		return -EINVAL;
 	}

 	switch (key_len) {
 	case AES_KEYSIZE_128:
 		ctx->rounds = 4;
 		ppc_expand_key_128(ctx->key_enc, in_key);
 		break;
 	case AES_KEYSIZE_192:
 		ctx->rounds = 5;
 		ppc_expand_key_192(ctx->key_enc, in_key);
 		break;
 	case AES_KEYSIZE_256:
 		ctx->rounds = 6;
 		ppc_expand_key_256(ctx->key_enc, in_key);
 		break;
 	}

 	ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len);

 	return 0;
 }

 static int ppc_xts_setkey(struct crypto_tfm *tfm, const u8 *in_key,
 		   unsigned int key_len)
 {
 	struct ppc_xts_ctx *ctx = crypto_tfm_ctx(tfm);

 	key_len >>= 1;

 	if (key_len != AES_KEYSIZE_128 &&
 	    key_len != AES_KEYSIZE_192 &&
 	    key_len != AES_KEYSIZE_256) {
 		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 		return -EINVAL;
 	}

 	switch (key_len) {
 	case AES_KEYSIZE_128:
 		ctx->rounds = 4;
 		ppc_expand_key_128(ctx->key_enc, in_key);
 		ppc_expand_key_128(ctx->key_twk, in_key + AES_KEYSIZE_128);
 		break;
 	case AES_KEYSIZE_192:
 		ctx->rounds = 5;
 		ppc_expand_key_192(ctx->key_enc, in_key);
 		ppc_expand_key_192(ctx->key_twk, in_key + AES_KEYSIZE_192);
 		break;
 	case AES_KEYSIZE_256:
 		ctx->rounds = 6;
 		ppc_expand_key_256(ctx->key_enc, in_key);
 		ppc_expand_key_256(ctx->key_twk, in_key + AES_KEYSIZE_256);
 		break;
 	}

 	ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len);

 	return 0;
 }

 static void ppc_aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 {
 	struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);

 	spe_begin();
 	ppc_encrypt_aes(out, in, ctx->key_enc, ctx->rounds);
 	spe_end();
 }

 static void ppc_aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 {
 	struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);

 	spe_begin();
 	ppc_decrypt_aes(out, in, ctx->key_dec, ctx->rounds);
 	spe_end();
 }

 static int ppc_ecb_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 			   struct scatterlist *src, unsigned int nbytes)
 {
 	struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 	struct blkcipher_walk walk;
 	unsigned int ubytes;
 	int err;

 	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);

 	while ((nbytes = walk.nbytes)) {
 		ubytes = nbytes > MAX_BYTES ?
 			 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
 		nbytes -= ubytes;

 		spe_begin();
 		ppc_encrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr,
 				ctx->key_enc, ctx->rounds, nbytes);
 		spe_end();

 		err = blkcipher_walk_done(desc, &walk, ubytes);
 	}

 	return err;
 }

 static int ppc_ecb_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 			   struct scatterlist *src, unsigned int nbytes)
 {
 	struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 	struct blkcipher_walk walk;
 	unsigned int ubytes;
 	int err;

 	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);

 	while ((nbytes = walk.nbytes)) {
 		ubytes = nbytes > MAX_BYTES ?
 			 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
 		nbytes -= ubytes;

 		spe_begin();
 		ppc_decrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr,
 				ctx->key_dec, ctx->rounds, nbytes);
 		spe_end();

 		err = blkcipher_walk_done(desc, &walk, ubytes);
 	}

 	return err;
 }

 static int ppc_cbc_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 			   struct scatterlist *src, unsigned int nbytes)
 {
 	struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 	struct blkcipher_walk walk;
 	unsigned int ubytes;
 	int err;

 	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);

 	while ((nbytes = walk.nbytes)) {
 		ubytes = nbytes > MAX_BYTES ?
 			 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
 		nbytes -= ubytes;

 		spe_begin();
 		ppc_encrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr,
 				ctx->key_enc, ctx->rounds, nbytes, walk.iv);
 		spe_end();

 		err = blkcipher_walk_done(desc, &walk, ubytes);
 	}

 	return err;
 }

 static int ppc_cbc_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 			   struct scatterlist *src, unsigned int nbytes)
 {
 	struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 	struct blkcipher_walk walk;
 	unsigned int ubytes;
 	int err;

 	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);

 	while ((nbytes = walk.nbytes)) {
 		ubytes = nbytes > MAX_BYTES ?
 			 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
 		nbytes -= ubytes;

 		spe_begin();
 		ppc_decrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr,
 				ctx->key_dec, ctx->rounds, nbytes, walk.iv);
 		spe_end();

 		err = blkcipher_walk_done(desc, &walk, ubytes);
 	}

 	return err;
 }

 static int ppc_ctr_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 			 struct scatterlist *src, unsigned int nbytes)
 {
 	struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 	struct blkcipher_walk walk;
 	unsigned int pbytes, ubytes;
 	int err;

 	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);

 	while ((pbytes = walk.nbytes)) {
 		pbytes = pbytes > MAX_BYTES ? MAX_BYTES : pbytes;
 		pbytes = pbytes == nbytes ?
 			 nbytes : pbytes & ~(AES_BLOCK_SIZE - 1);
 		ubytes = walk.nbytes - pbytes;

 		spe_begin();
 		ppc_crypt_ctr(walk.dst.virt.addr, walk.src.virt.addr,
 			      ctx->key_enc, ctx->rounds, pbytes , walk.iv);
 		spe_end();

 		nbytes -= pbytes;
 		err = blkcipher_walk_done(desc, &walk, ubytes);
 	}

 	return err;
 }

 static int ppc_xts_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 			   struct scatterlist *src, unsigned int nbytes)
 {
 	struct ppc_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 	struct blkcipher_walk walk;
 	unsigned int ubytes;
 	int err;
 	u32 *twk;

 	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);
 	twk = ctx->key_twk;

 	while ((nbytes = walk.nbytes)) {
 		ubytes = nbytes > MAX_BYTES ?
 			 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
 		nbytes -= ubytes;

 		spe_begin();
 		ppc_encrypt_xts(walk.dst.virt.addr, walk.src.virt.addr,
 				ctx->key_enc, ctx->rounds, nbytes, walk.iv, twk);
 		spe_end();

 		twk = NULL;
 		err = blkcipher_walk_done(desc, &walk, ubytes);
 	}

 	return err;
 }

 static int ppc_xts_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 			   struct scatterlist *src, unsigned int nbytes)
 {
 	struct ppc_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 	struct blkcipher_walk walk;
 	unsigned int ubytes;
 	int err;
 	u32 *twk;

 	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);
 	twk = ctx->key_twk;

 	while ((nbytes = walk.nbytes)) {
 		ubytes = nbytes > MAX_BYTES ?
 			 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
 		nbytes -= ubytes;

 		spe_begin();
 		ppc_decrypt_xts(walk.dst.virt.addr, walk.src.virt.addr,
 				ctx->key_dec, ctx->rounds, nbytes, walk.iv, twk);
 		spe_end();

 		twk = NULL;
 		err = blkcipher_walk_done(desc, &walk, ubytes);
 	}

 	return err;
 }

 /*
  * Algorithm definitions. Disabling alignment (cra_alignmask=0) was chosen
  * because the e500 platform can handle unaligned reads/writes very efficently.
  * This improves IPsec thoughput by another few percent. Additionally we assume
  * that AES context is always aligned to at least 8 bytes because it is created
  * with kmalloc() in the crypto infrastructure
  *
  */
 static struct crypto_alg aes_algs[] = { {
 	.cra_name		=	"aes",
 	.cra_driver_name	=	"aes-ppc-spe",
 	.cra_priority		=	300,
 	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
 	.cra_blocksize		=	AES_BLOCK_SIZE,
 	.cra_ctxsize		=	sizeof(struct ppc_aes_ctx),
 	.cra_alignmask		=	0,
 	.cra_module		=	THIS_MODULE,
 	.cra_u			=	{
 		.cipher = {
 			.cia_min_keysize	=	AES_MIN_KEY_SIZE,
 			.cia_max_keysize	=	AES_MAX_KEY_SIZE,
 			.cia_setkey		=	ppc_aes_setkey,
 			.cia_encrypt		=	ppc_aes_encrypt,
 			.cia_decrypt		=	ppc_aes_decrypt
 		}
 	}
 }, {
 	.cra_name		=	"ecb(aes)",
 	.cra_driver_name	=	"ecb-ppc-spe",
 	.cra_priority		=	300,
 	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
 	.cra_blocksize		=	AES_BLOCK_SIZE,
 	.cra_ctxsize		=	sizeof(struct ppc_aes_ctx),
 	.cra_alignmask		=	0,
 	.cra_type		=	&crypto_blkcipher_type,
 	.cra_module		=	THIS_MODULE,
 	.cra_u = {
 		.blkcipher = {
 			.min_keysize		=	AES_MIN_KEY_SIZE,
 			.max_keysize		=	AES_MAX_KEY_SIZE,
 			.ivsize			=	AES_BLOCK_SIZE,
 			.setkey			=	ppc_aes_setkey,
 			.encrypt		=	ppc_ecb_encrypt,
 			.decrypt		=	ppc_ecb_decrypt,
 		}
 	}
 }, {
 	.cra_name		=	"cbc(aes)",
 	.cra_driver_name	=	"cbc-ppc-spe",
 	.cra_priority		=	300,
 	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
 	.cra_blocksize		=	AES_BLOCK_SIZE,
 	.cra_ctxsize		=	sizeof(struct ppc_aes_ctx),
 	.cra_alignmask		=	0,
 	.cra_type		=	&crypto_blkcipher_type,
 	.cra_module		=	THIS_MODULE,
 	.cra_u = {
 		.blkcipher = {
 			.min_keysize		=	AES_MIN_KEY_SIZE,
 			.max_keysize		=	AES_MAX_KEY_SIZE,
 			.ivsize			=	AES_BLOCK_SIZE,
 			.setkey			=	ppc_aes_setkey,
 			.encrypt		=	ppc_cbc_encrypt,
 			.decrypt		=	ppc_cbc_decrypt,
 		}
 	}
 }, {
 	.cra_name		=	"ctr(aes)",
 	.cra_driver_name	=	"ctr-ppc-spe",
 	.cra_priority		=	300,
 	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
 	.cra_blocksize		=	1,
 	.cra_ctxsize		=	sizeof(struct ppc_aes_ctx),
 	.cra_alignmask		=	0,
 	.cra_type		=	&crypto_blkcipher_type,
 	.cra_module		=	THIS_MODULE,
 	.cra_u = {
 		.blkcipher = {
 			.min_keysize		=	AES_MIN_KEY_SIZE,
 			.max_keysize		=	AES_MAX_KEY_SIZE,
 			.ivsize			=	AES_BLOCK_SIZE,
 			.setkey			=	ppc_aes_setkey,
 			.encrypt		=	ppc_ctr_crypt,
 			.decrypt		=	ppc_ctr_crypt,
 		}
 	}
 }, {
 	.cra_name		=	"xts(aes)",
 	.cra_driver_name	=	"xts-ppc-spe",
 	.cra_priority		=	300,
 	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
 	.cra_blocksize		=	AES_BLOCK_SIZE,
 	.cra_ctxsize		=	sizeof(struct ppc_xts_ctx),
 	.cra_alignmask		=	0,
 	.cra_type		=	&crypto_blkcipher_type,
 	.cra_module		=	THIS_MODULE,
 	.cra_u = {
 		.blkcipher = {
 			.min_keysize		=	AES_MIN_KEY_SIZE * 2,
 			.max_keysize		=	AES_MAX_KEY_SIZE * 2,
 			.ivsize			=	AES_BLOCK_SIZE,
 			.setkey			=	ppc_xts_setkey,
 			.encrypt		=	ppc_xts_encrypt,
 			.decrypt		=	ppc_xts_decrypt,
 		}
 	}
 } };

 static int __init ppc_aes_mod_init(void)
 {
 	return crypto_register_algs(aes_algs, ARRAY_SIZE(aes_algs));
 }

 static void __exit ppc_aes_mod_fini(void)
 {
 	crypto_unregister_algs(aes_algs, ARRAY_SIZE(aes_algs));
 }

 module_init(ppc_aes_mod_init);
 module_exit(ppc_aes_mod_fini);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS, SPE optimized");

 MODULE_ALIAS_CRYPTO("aes");
 MODULE_ALIAS_CRYPTO("ecb(aes)");
 MODULE_ALIAS_CRYPTO("cbc(aes)");
 MODULE_ALIAS_CRYPTO("ctr(aes)");
 MODULE_ALIAS_CRYPTO("xts(aes)");
 MODULE_ALIAS_CRYPTO("aes-ppc-spe");
	/*
	* Glue code for AES implementation for SPE instructions (PPC)
	*
	* Based on generic implementation. The assembler module takes care
	* about the SPE registers so it can run from interrupt context.
	*
	* Copyright (c) 2015 Markus Stockhausen <[email protected]>
	*
	* 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.
	*
	*/

	#include <crypto/aes.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/types.h>
	#include <linux/errno.h>
	#include <linux/crypto.h>
	#include <asm/byteorder.h>
	#include <asm/switch_to.h>
	#include <crypto/algapi.h>

	/*
	* MAX_BYTES defines the number of bytes that are allowed to be processed
	* between preempt_disable() and preempt_enable(). e500 cores can issue two
	* instructions per clock cycle using one 32/64 bit unit (SU1) and one 32
	* bit unit (SU2). One of these can be a memory access that is executed via
	* a single load and store unit (LSU). XTS-AES-256 takes ~780 operations per
	* 16 byte block block or 25 cycles per byte. Thus 768 bytes of input data
	* will need an estimated maximum of 20,000 cycles. Headroom for cache misses
	* included. Even with the low end model clocked at 667 MHz this equals to a
	* critical time window of less than 30us. The value has been choosen to
	* process a 512 byte disk block in one or a large 1400 bytes IPsec network
	* packet in two runs.
	*
	*/
	#define MAX_BYTES 768

	struct ppc_aes_ctx {
	u32 key_enc[AES_MAX_KEYLENGTH_U32];
	u32 key_dec[AES_MAX_KEYLENGTH_U32];
	u32 rounds;
	};

	struct ppc_xts_ctx {
	u32 key_enc[AES_MAX_KEYLENGTH_U32];
	u32 key_dec[AES_MAX_KEYLENGTH_U32];
	u32 key_twk[AES_MAX_KEYLENGTH_U32];
	u32 rounds;
	};

	extern void ppc_encrypt_aes(u8 out, const u8 in, u32 *key_enc, u32 rounds);
	extern void ppc_decrypt_aes(u8 out, const u8 in, u32 *key_dec, u32 rounds);
	extern void ppc_encrypt_ecb(u8 out, const u8 in, u32 *key_enc, u32 rounds,
	u32 bytes);
	extern void ppc_decrypt_ecb(u8 out, const u8 in, u32 *key_dec, u32 rounds,
	u32 bytes);
	extern void ppc_encrypt_cbc(u8 out, const u8 in, u32 *key_enc, u32 rounds,
	u32 bytes, u8 *iv);
	extern void ppc_decrypt_cbc(u8 out, const u8 in, u32 *key_dec, u32 rounds,
	u32 bytes, u8 *iv);
	extern void ppc_crypt_ctr (u8 out, const u8 in, u32 *key_enc, u32 rounds,
	u32 bytes, u8 *iv);
	extern void ppc_encrypt_xts(u8 out, const u8 in, u32 *key_enc, u32 rounds,
	u32 bytes, u8 iv, u32 key_twk);
	extern void ppc_decrypt_xts(u8 out, const u8 in, u32 *key_dec, u32 rounds,
	u32 bytes, u8 iv, u32 key_twk);

	extern void ppc_expand_key_128(u32 key_enc, const u8 key);
	extern void ppc_expand_key_192(u32 key_enc, const u8 key);
	extern void ppc_expand_key_256(u32 key_enc, const u8 key);

	extern void ppc_generate_decrypt_key(u32 key_dec,u32 key_enc,
	unsigned int key_len);

	static void spe_begin(void)
	{
	/* disable preemption and save users SPE registers if required */
	preempt_disable();
	enable_kernel_spe();
	}

	static void spe_end(void)
	{
	/* reenable preemption */
	preempt_enable();
	}

	static int ppc_aes_setkey(struct crypto_tfm tfm, const u8 in_key,
	unsigned int key_len)
	{
	struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);

	if (key_len != AES_KEYSIZE_128 &&
	key_len != AES_KEYSIZE_192 &&
	key_len != AES_KEYSIZE_256) {
	tfm->crt_flags \|= CRYPTO_TFM_RES_BAD_KEY_LEN;
	return -EINVAL;
	}

	switch (key_len) {
	case AES_KEYSIZE_128:
	ctx->rounds = 4;
	ppc_expand_key_128(ctx->key_enc, in_key);
	break;
	case AES_KEYSIZE_192:
	ctx->rounds = 5;
	ppc_expand_key_192(ctx->key_enc, in_key);
	break;
	case AES_KEYSIZE_256:
	ctx->rounds = 6;
	ppc_expand_key_256(ctx->key_enc, in_key);
	break;
	}

	ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len);

	return 0;
	}

	static int ppc_xts_setkey(struct crypto_tfm tfm, const u8 in_key,
	unsigned int key_len)
	{
	struct ppc_xts_ctx *ctx = crypto_tfm_ctx(tfm);

	key_len >>= 1;

	if (key_len != AES_KEYSIZE_128 &&
	key_len != AES_KEYSIZE_192 &&
	key_len != AES_KEYSIZE_256) {
	tfm->crt_flags \|= CRYPTO_TFM_RES_BAD_KEY_LEN;
	return -EINVAL;
	}

	switch (key_len) {
	case AES_KEYSIZE_128:
	ctx->rounds = 4;
	ppc_expand_key_128(ctx->key_enc, in_key);
	ppc_expand_key_128(ctx->key_twk, in_key + AES_KEYSIZE_128);
	break;
	case AES_KEYSIZE_192:
	ctx->rounds = 5;
	ppc_expand_key_192(ctx->key_enc, in_key);
	ppc_expand_key_192(ctx->key_twk, in_key + AES_KEYSIZE_192);
	break;
	case AES_KEYSIZE_256:
	ctx->rounds = 6;
	ppc_expand_key_256(ctx->key_enc, in_key);
	ppc_expand_key_256(ctx->key_twk, in_key + AES_KEYSIZE_256);
	break;
	}

	ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len);

	return 0;
	}

	static void ppc_aes_encrypt(struct crypto_tfm tfm, u8 out, const u8 *in)
	{
	struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);

	spe_begin();
	ppc_encrypt_aes(out, in, ctx->key_enc, ctx->rounds);
	spe_end();
	}

	static void ppc_aes_decrypt(struct crypto_tfm tfm, u8 out, const u8 *in)
	{
	struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);

	spe_begin();
	ppc_decrypt_aes(out, in, ctx->key_dec, ctx->rounds);
	spe_end();
	}

	static int ppc_ecb_encrypt(struct blkcipher_desc desc, struct scatterlist dst,
	struct scatterlist *src, unsigned int nbytes)
	{
	struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk walk;
	unsigned int ubytes;
	int err;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while ((nbytes = walk.nbytes)) {
	ubytes = nbytes > MAX_BYTES ?
	nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
	nbytes -= ubytes;

	spe_begin();
	ppc_encrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr,
	ctx->key_enc, ctx->rounds, nbytes);
	spe_end();

	err = blkcipher_walk_done(desc, &walk, ubytes);
	}

	return err;
	}

	static int ppc_ecb_decrypt(struct blkcipher_desc desc, struct scatterlist dst,
	struct scatterlist *src, unsigned int nbytes)
	{
	struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk walk;
	unsigned int ubytes;
	int err;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while ((nbytes = walk.nbytes)) {
	ubytes = nbytes > MAX_BYTES ?
	nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
	nbytes -= ubytes;

	spe_begin();
	ppc_decrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr,
	ctx->key_dec, ctx->rounds, nbytes);
	spe_end();

	err = blkcipher_walk_done(desc, &walk, ubytes);
	}

	return err;
	}

	static int ppc_cbc_encrypt(struct blkcipher_desc desc, struct scatterlist dst,
	struct scatterlist *src, unsigned int nbytes)
	{
	struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk walk;
	unsigned int ubytes;
	int err;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while ((nbytes = walk.nbytes)) {
	ubytes = nbytes > MAX_BYTES ?
	nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
	nbytes -= ubytes;

	spe_begin();
	ppc_encrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr,
	ctx->key_enc, ctx->rounds, nbytes, walk.iv);
	spe_end();

	err = blkcipher_walk_done(desc, &walk, ubytes);
	}

	return err;
	}

	static int ppc_cbc_decrypt(struct blkcipher_desc desc, struct scatterlist dst,
	struct scatterlist *src, unsigned int nbytes)
	{
	struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk walk;
	unsigned int ubytes;
	int err;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while ((nbytes = walk.nbytes)) {
	ubytes = nbytes > MAX_BYTES ?
	nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
	nbytes -= ubytes;

	spe_begin();
	ppc_decrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr,
	ctx->key_dec, ctx->rounds, nbytes, walk.iv);
	spe_end();

	err = blkcipher_walk_done(desc, &walk, ubytes);
	}

	return err;
	}

	static int ppc_ctr_crypt(struct blkcipher_desc desc, struct scatterlist dst,
	struct scatterlist *src, unsigned int nbytes)
	{
	struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk walk;
	unsigned int pbytes, ubytes;
	int err;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);

	while ((pbytes = walk.nbytes)) {
	pbytes = pbytes > MAX_BYTES ? MAX_BYTES : pbytes;
	pbytes = pbytes == nbytes ?
	nbytes : pbytes & ~(AES_BLOCK_SIZE - 1);
	ubytes = walk.nbytes - pbytes;

	spe_begin();
	ppc_crypt_ctr(walk.dst.virt.addr, walk.src.virt.addr,
	ctx->key_enc, ctx->rounds, pbytes , walk.iv);
	spe_end();

	nbytes -= pbytes;
	err = blkcipher_walk_done(desc, &walk, ubytes);
	}

	return err;
	}

	static int ppc_xts_encrypt(struct blkcipher_desc desc, struct scatterlist dst,
	struct scatterlist *src, unsigned int nbytes)
	{
	struct ppc_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk walk;
	unsigned int ubytes;
	int err;
	u32 *twk;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);
	twk = ctx->key_twk;

	while ((nbytes = walk.nbytes)) {
	ubytes = nbytes > MAX_BYTES ?
	nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
	nbytes -= ubytes;

	spe_begin();
	ppc_encrypt_xts(walk.dst.virt.addr, walk.src.virt.addr,
	ctx->key_enc, ctx->rounds, nbytes, walk.iv, twk);
	spe_end();

	twk = NULL;
	err = blkcipher_walk_done(desc, &walk, ubytes);
	}

	return err;
	}

	static int ppc_xts_decrypt(struct blkcipher_desc desc, struct scatterlist dst,
	struct scatterlist *src, unsigned int nbytes)
	{
	struct ppc_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk walk;
	unsigned int ubytes;
	int err;
	u32 *twk;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);
	twk = ctx->key_twk;

	while ((nbytes = walk.nbytes)) {
	ubytes = nbytes > MAX_BYTES ?
	nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
	nbytes -= ubytes;

	spe_begin();
	ppc_decrypt_xts(walk.dst.virt.addr, walk.src.virt.addr,
	ctx->key_dec, ctx->rounds, nbytes, walk.iv, twk);
	spe_end();

	twk = NULL;
	err = blkcipher_walk_done(desc, &walk, ubytes);
	}

	return err;
	}

	/*
	* Algorithm definitions. Disabling alignment (cra_alignmask=0) was chosen
	* because the e500 platform can handle unaligned reads/writes very efficently.
	* This improves IPsec thoughput by another few percent. Additionally we assume
	* that AES context is always aligned to at least 8 bytes because it is created
	* with kmalloc() in the crypto infrastructure
	*
	*/
	static struct crypto_alg aes_algs[] = { {
	.cra_name = "aes",
	.cra_driver_name = "aes-ppc-spe",
	.cra_priority = 300,
	.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
	.cra_blocksize = AES_BLOCK_SIZE,
	.cra_ctxsize = sizeof(struct ppc_aes_ctx),
	.cra_alignmask = 0,
	.cra_module = THIS_MODULE,
	.cra_u = {
	.cipher = {
	.cia_min_keysize = AES_MIN_KEY_SIZE,
	.cia_max_keysize = AES_MAX_KEY_SIZE,
	.cia_setkey = ppc_aes_setkey,
	.cia_encrypt = ppc_aes_encrypt,
	.cia_decrypt = ppc_aes_decrypt
	}
	}
	}, {
	.cra_name = "ecb(aes)",
	.cra_driver_name = "ecb-ppc-spe",
	.cra_priority = 300,
	.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize = AES_BLOCK_SIZE,
	.cra_ctxsize = sizeof(struct ppc_aes_ctx),
	.cra_alignmask = 0,
	.cra_type = &crypto_blkcipher_type,
	.cra_module = THIS_MODULE,
	.cra_u = {
	.blkcipher = {
	.min_keysize = AES_MIN_KEY_SIZE,
	.max_keysize = AES_MAX_KEY_SIZE,
	.ivsize = AES_BLOCK_SIZE,
	.setkey = ppc_aes_setkey,
	.encrypt = ppc_ecb_encrypt,
	.decrypt = ppc_ecb_decrypt,
	}
	}
	}, {
	.cra_name = "cbc(aes)",
	.cra_driver_name = "cbc-ppc-spe",
	.cra_priority = 300,
	.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize = AES_BLOCK_SIZE,
	.cra_ctxsize = sizeof(struct ppc_aes_ctx),
	.cra_alignmask = 0,
	.cra_type = &crypto_blkcipher_type,
	.cra_module = THIS_MODULE,
	.cra_u = {
	.blkcipher = {
	.min_keysize = AES_MIN_KEY_SIZE,
	.max_keysize = AES_MAX_KEY_SIZE,
	.ivsize = AES_BLOCK_SIZE,
	.setkey = ppc_aes_setkey,
	.encrypt = ppc_cbc_encrypt,
	.decrypt = ppc_cbc_decrypt,
	}
	}
	}, {
	.cra_name = "ctr(aes)",
	.cra_driver_name = "ctr-ppc-spe",
	.cra_priority = 300,
	.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize = 1,
	.cra_ctxsize = sizeof(struct ppc_aes_ctx),
	.cra_alignmask = 0,
	.cra_type = &crypto_blkcipher_type,
	.cra_module = THIS_MODULE,
	.cra_u = {
	.blkcipher = {
	.min_keysize = AES_MIN_KEY_SIZE,
	.max_keysize = AES_MAX_KEY_SIZE,
	.ivsize = AES_BLOCK_SIZE,
	.setkey = ppc_aes_setkey,
	.encrypt = ppc_ctr_crypt,
	.decrypt = ppc_ctr_crypt,
	}
	}
	}, {
	.cra_name = "xts(aes)",
	.cra_driver_name = "xts-ppc-spe",
	.cra_priority = 300,
	.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize = AES_BLOCK_SIZE,
	.cra_ctxsize = sizeof(struct ppc_xts_ctx),
	.cra_alignmask = 0,
	.cra_type = &crypto_blkcipher_type,
	.cra_module = THIS_MODULE,
	.cra_u = {
	.blkcipher = {
	.min_keysize = AES_MIN_KEY_SIZE * 2,
	.max_keysize = AES_MAX_KEY_SIZE * 2,
	.ivsize = AES_BLOCK_SIZE,
	.setkey = ppc_xts_setkey,
	.encrypt = ppc_xts_encrypt,
	.decrypt = ppc_xts_decrypt,
	}
	}
	} };

	static int __init ppc_aes_mod_init(void)
	{
	return crypto_register_algs(aes_algs, ARRAY_SIZE(aes_algs));
	}

	static void __exit ppc_aes_mod_fini(void)
	{
	crypto_unregister_algs(aes_algs, ARRAY_SIZE(aes_algs));
	}

	module_init(ppc_aes_mod_init);
	module_exit(ppc_aes_mod_fini);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS, SPE optimized");

	MODULE_ALIAS_CRYPTO("aes");
	MODULE_ALIAS_CRYPTO("ecb(aes)");
	MODULE_ALIAS_CRYPTO("cbc(aes)");
	MODULE_ALIAS_CRYPTO("ctr(aes)");
	MODULE_ALIAS_CRYPTO("xts(aes)");
	MODULE_ALIAS_CRYPTO("aes-ppc-spe");