[mirror_ubuntu-bionic-kernel.git] / arch / powerpc / crypto / aes-spe-glue.c

/*
 * 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 <stockhausen@collogia.de>
 *
 * 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>
#include <crypto/xts.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)
{
	disable_kernel_spe();
	/* 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);
	int err;

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

	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");
Commit	Line	Data
8a28a1a8 MS	1	/*
	2	* Glue code for AES implementation for SPE instructions (PPC)
	3	*
	4	* Based on generic implementation. The assembler module takes care
	5	* about the SPE registers so it can run from interrupt context.
	6	*
	7	* Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
	8	*
	9	* This program is free software; you can redistribute it and/or modify it
	10	* under the terms of the GNU General Public License as published by the Free
	11	* Software Foundation; either version 2 of the License, or (at your option)
	12	* any later version.
	13	*
	14	*/
	15
	16	#include <crypto/aes.h>
	17	#include <linux/module.h>
	18	#include <linux/init.h>
	19	#include <linux/types.h>
	20	#include <linux/errno.h>
	21	#include <linux/crypto.h>
	22	#include <asm/byteorder.h>
	23	#include <asm/switch_to.h>
	24	#include <crypto/algapi.h>
49abc0d2	25	#include <crypto/xts.h>
8a28a1a8 MS	26
	27	/*
	28	* MAX_BYTES defines the number of bytes that are allowed to be processed
	29	* between preempt_disable() and preempt_enable(). e500 cores can issue two
	30	* instructions per clock cycle using one 32/64 bit unit (SU1) and one 32
	31	* bit unit (SU2). One of these can be a memory access that is executed via
	32	* a single load and store unit (LSU). XTS-AES-256 takes ~780 operations per
	33	* 16 byte block block or 25 cycles per byte. Thus 768 bytes of input data
	34	* will need an estimated maximum of 20,000 cycles. Headroom for cache misses
	35	* included. Even with the low end model clocked at 667 MHz this equals to a
	36	* critical time window of less than 30us. The value has been choosen to
	37	* process a 512 byte disk block in one or a large 1400 bytes IPsec network
	38	* packet in two runs.
	39	*
	40	*/
	41	#define MAX_BYTES 768
	42
	43	struct ppc_aes_ctx {
	44	u32 key_enc[AES_MAX_KEYLENGTH_U32];
	45	u32 key_dec[AES_MAX_KEYLENGTH_U32];
	46	u32 rounds;
	47	};
	48
	49	struct ppc_xts_ctx {
	50	u32 key_enc[AES_MAX_KEYLENGTH_U32];
	51	u32 key_dec[AES_MAX_KEYLENGTH_U32];
	52	u32 key_twk[AES_MAX_KEYLENGTH_U32];
	53	u32 rounds;
	54	};
	55
	56	extern void ppc_encrypt_aes(u8 out, const u8 in, u32 *key_enc, u32 rounds);
	57	extern void ppc_decrypt_aes(u8 out, const u8 in, u32 *key_dec, u32 rounds);
	58	extern void ppc_encrypt_ecb(u8 out, const u8 in, u32 *key_enc, u32 rounds,
	59	u32 bytes);
	60	extern void ppc_decrypt_ecb(u8 out, const u8 in, u32 *key_dec, u32 rounds,
	61	u32 bytes);
	62	extern void ppc_encrypt_cbc(u8 out, const u8 in, u32 *key_enc, u32 rounds,
	63	u32 bytes, u8 *iv);
	64	extern void ppc_decrypt_cbc(u8 out, const u8 in, u32 *key_dec, u32 rounds,
	65	u32 bytes, u8 *iv);
	66	extern void ppc_crypt_ctr (u8 out, const u8 in, u32 *key_enc, u32 rounds,
	67	u32 bytes, u8 *iv);
	68	extern void ppc_encrypt_xts(u8 out, const u8 in, u32 *key_enc, u32 rounds,
	69	u32 bytes, u8 iv, u32 key_twk);
	70	extern void ppc_decrypt_xts(u8 out, const u8 in, u32 *key_dec, u32 rounds,
	71	u32 bytes, u8 iv, u32 key_twk);
	72
	73	extern void ppc_expand_key_128(u32 key_enc, const u8 key);
	74	extern void ppc_expand_key_192(u32 key_enc, const u8 key);
	75	extern void ppc_expand_key_256(u32 key_enc, const u8 key);
	76
	77	extern void ppc_generate_decrypt_key(u32 key_dec,u32 key_enc,
	78	unsigned int key_len);
	79
	80	static void spe_begin(void)
	81	{
	82	/* disable preemption and save users SPE registers if required */
	83	preempt_disable();
	84	enable_kernel_spe();
	85	}
	86
	87	static void spe_end(void)
	88	{
dc4fbba1	89	disable_kernel_spe();
8a28a1a8 MS	90	/* reenable preemption */
	91	preempt_enable();
	92	}
	93
	94	static int ppc_aes_setkey(struct crypto_tfm tfm, const u8 in_key,
	95	unsigned int key_len)
	96	{
	97	struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);
	98
	99	if (key_len != AES_KEYSIZE_128 &&
	100	key_len != AES_KEYSIZE_192 &&
	101	key_len != AES_KEYSIZE_256) {
	102	tfm->crt_flags \|= CRYPTO_TFM_RES_BAD_KEY_LEN;
	103	return -EINVAL;
	104	}
	105
	106	switch (key_len) {
	107	case AES_KEYSIZE_128:
	108	ctx->rounds = 4;
	109	ppc_expand_key_128(ctx->key_enc, in_key);
	110	break;
	111	case AES_KEYSIZE_192:
	112	ctx->rounds = 5;
	113	ppc_expand_key_192(ctx->key_enc, in_key);
	114	break;
	115	case AES_KEYSIZE_256:
	116	ctx->rounds = 6;
	117	ppc_expand_key_256(ctx->key_enc, in_key);
	118	break;
	119	}
	120
	121	ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len);
	122
	123	return 0;
	124	}
	125
	126	static int ppc_xts_setkey(struct crypto_tfm tfm, const u8 in_key,
	127	unsigned int key_len)
	128	{
	129	struct ppc_xts_ctx *ctx = crypto_tfm_ctx(tfm);
28856a9e SM	130	int err;
	131
	132	err = xts_check_key(tfm, in_key, key_len);
	133	if (err)
	134	return err;
8a28a1a8 MS	135
	136	key_len >>= 1;
	137
	138	if (key_len != AES_KEYSIZE_128 &&
	139	key_len != AES_KEYSIZE_192 &&
	140	key_len != AES_KEYSIZE_256) {
	141	tfm->crt_flags \|= CRYPTO_TFM_RES_BAD_KEY_LEN;
	142	return -EINVAL;
	143	}
	144
	145	switch (key_len) {
	146	case AES_KEYSIZE_128:
	147	ctx->rounds = 4;
	148	ppc_expand_key_128(ctx->key_enc, in_key);
	149	ppc_expand_key_128(ctx->key_twk, in_key + AES_KEYSIZE_128);
	150	break;
	151	case AES_KEYSIZE_192:
	152	ctx->rounds = 5;
	153	ppc_expand_key_192(ctx->key_enc, in_key);
	154	ppc_expand_key_192(ctx->key_twk, in_key + AES_KEYSIZE_192);
	155	break;
	156	case AES_KEYSIZE_256:
	157	ctx->rounds = 6;
	158	ppc_expand_key_256(ctx->key_enc, in_key);
	159	ppc_expand_key_256(ctx->key_twk, in_key + AES_KEYSIZE_256);
	160	break;
	161	}
	162
	163	ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len);
	164
	165	return 0;
	166	}
	167
	168	static void ppc_aes_encrypt(struct crypto_tfm tfm, u8 out, const u8 *in)
	169	{
	170	struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);
	171
	172	spe_begin();
	173	ppc_encrypt_aes(out, in, ctx->key_enc, ctx->rounds);
	174	spe_end();
	175	}
	176
	177	static void ppc_aes_decrypt(struct crypto_tfm tfm, u8 out, const u8 *in)
	178	{
	179	struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);
	180
	181	spe_begin();
	182	ppc_decrypt_aes(out, in, ctx->key_dec, ctx->rounds);
	183	spe_end();
	184	}
	185
	186	static int ppc_ecb_encrypt(struct blkcipher_desc desc, struct scatterlist dst,
	187	struct scatterlist *src, unsigned int nbytes)
	188	{
	189	struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	190	struct blkcipher_walk walk;
	191	unsigned int ubytes;
	192	int err;
	193
	194	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	195	blkcipher_walk_init(&walk, dst, src, nbytes);
	196	err = blkcipher_walk_virt(desc, &walk);
	197
	198	while ((nbytes = walk.nbytes)) {
199	ubytes = nbytes > MAX_BYTES ?
200	nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
201	nbytes -= ubytes;
202
203	spe_begin();
204	ppc_encrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr,
205	ctx->key_enc, ctx->rounds, nbytes);
206	spe_end();
207
208	err = blkcipher_walk_done(desc, &walk, ubytes);
209	}
210
211	return err;
212	}
213
214	static int ppc_ecb_decrypt(struct blkcipher_desc desc, struct scatterlist dst,
215	struct scatterlist *src, unsigned int nbytes)
216	{
217	struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
218	struct blkcipher_walk walk;
219	unsigned int ubytes;
220	int err;
221
222	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
223	blkcipher_walk_init(&walk, dst, src, nbytes);
224	err = blkcipher_walk_virt(desc, &walk);
225
226	while ((nbytes = walk.nbytes)) {
227	ubytes = nbytes > MAX_BYTES ?
228	nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
229	nbytes -= ubytes;
230
231	spe_begin();
232	ppc_decrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr,
233	ctx->key_dec, ctx->rounds, nbytes);
234	spe_end();
235
236	err = blkcipher_walk_done(desc, &walk, ubytes);
237	}
238
239	return err;
240	}
241
242	static int ppc_cbc_encrypt(struct blkcipher_desc desc, struct scatterlist dst,
243	struct scatterlist *src, unsigned int nbytes)
244	{
245	struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
246	struct blkcipher_walk walk;
247	unsigned int ubytes;
248	int err;
249
250	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
251	blkcipher_walk_init(&walk, dst, src, nbytes);
252	err = blkcipher_walk_virt(desc, &walk);
253
254	while ((nbytes = walk.nbytes)) {
255	ubytes = nbytes > MAX_BYTES ?
256	nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
257	nbytes -= ubytes;
258
259	spe_begin();
260	ppc_encrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr,
261	ctx->key_enc, ctx->rounds, nbytes, walk.iv);
262	spe_end();
263
264	err = blkcipher_walk_done(desc, &walk, ubytes);
265	}
266
267	return err;
268	}
269
270	static int ppc_cbc_decrypt(struct blkcipher_desc desc, struct scatterlist dst,
271	struct scatterlist *src, unsigned int nbytes)
272	{
273	struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
274	struct blkcipher_walk walk;
275	unsigned int ubytes;
276	int err;
277
278	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
279	blkcipher_walk_init(&walk, dst, src, nbytes);
280	err = blkcipher_walk_virt(desc, &walk);
281
282	while ((nbytes = walk.nbytes)) {
283	ubytes = nbytes > MAX_BYTES ?
284	nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
285	nbytes -= ubytes;
286
287	spe_begin();
288	ppc_decrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr,
289	ctx->key_dec, ctx->rounds, nbytes, walk.iv);
290	spe_end();
291
292	err = blkcipher_walk_done(desc, &walk, ubytes);
293	}
294
295	return err;
296	}
297
298	static int ppc_ctr_crypt(struct blkcipher_desc desc, struct scatterlist dst,
299	struct scatterlist *src, unsigned int nbytes)
300	{
301	struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
302	struct blkcipher_walk walk;
303	unsigned int pbytes, ubytes;
304	int err;
305
306	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
307	blkcipher_walk_init(&walk, dst, src, nbytes);
308	err = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);
309
310	while ((pbytes = walk.nbytes)) {
311	pbytes = pbytes > MAX_BYTES ? MAX_BYTES : pbytes;
312	pbytes = pbytes == nbytes ?
313	nbytes : pbytes & ~(AES_BLOCK_SIZE - 1);
314	ubytes = walk.nbytes - pbytes;
315
316	spe_begin();
317	ppc_crypt_ctr(walk.dst.virt.addr, walk.src.virt.addr,
318	ctx->key_enc, ctx->rounds, pbytes , walk.iv);
319	spe_end();
320
321	nbytes -= pbytes;
322	err = blkcipher_walk_done(desc, &walk, ubytes);
323	}
324
325	return err;
326	}
327
328	static int ppc_xts_encrypt(struct blkcipher_desc desc, struct scatterlist dst,
329	struct scatterlist *src, unsigned int nbytes)
330	{
331	struct ppc_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
332	struct blkcipher_walk walk;
333	unsigned int ubytes;
334	int err;
335	u32 *twk;
336
337	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
338	blkcipher_walk_init(&walk, dst, src, nbytes);
339	err = blkcipher_walk_virt(desc, &walk);
340	twk = ctx->key_twk;
341
342	while ((nbytes = walk.nbytes)) {
343	ubytes = nbytes > MAX_BYTES ?
344	nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
345	nbytes -= ubytes;
346
347	spe_begin();
348	ppc_encrypt_xts(walk.dst.virt.addr, walk.src.virt.addr,
349	ctx->key_enc, ctx->rounds, nbytes, walk.iv, twk);
350	spe_end();
351
352	twk = NULL;
353	err = blkcipher_walk_done(desc, &walk, ubytes);
354	}
355
356	return err;
357	}
358
359	static int ppc_xts_decrypt(struct blkcipher_desc desc, struct scatterlist dst,
360	struct scatterlist *src, unsigned int nbytes)
361	{
362	struct ppc_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
363	struct blkcipher_walk walk;
364	unsigned int ubytes;
365	int err;
366	u32 *twk;
367
368	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
369	blkcipher_walk_init(&walk, dst, src, nbytes);
370	err = blkcipher_walk_virt(desc, &walk);
371	twk = ctx->key_twk;
372
373	while ((nbytes = walk.nbytes)) {
374	ubytes = nbytes > MAX_BYTES ?
375	nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
376	nbytes -= ubytes;
377
378	spe_begin();
379	ppc_decrypt_xts(walk.dst.virt.addr, walk.src.virt.addr,
380	ctx->key_dec, ctx->rounds, nbytes, walk.iv, twk);
381	spe_end();
382
383	twk = NULL;
384	err = blkcipher_walk_done(desc, &walk, ubytes);
385	}
386
387	return err;
388	}
389
390	/*
391	* Algorithm definitions. Disabling alignment (cra_alignmask=0) was chosen
392	* because the e500 platform can handle unaligned reads/writes very efficently.
393	* This improves IPsec thoughput by another few percent. Additionally we assume
394	* that AES context is always aligned to at least 8 bytes because it is created
395	* with kmalloc() in the crypto infrastructure
396	*
397	*/
398	static struct crypto_alg aes_algs[] = { {
399	.cra_name = "aes",
400	.cra_driver_name = "aes-ppc-spe",
401	.cra_priority = 300,
402	.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
403	.cra_blocksize = AES_BLOCK_SIZE,
404	.cra_ctxsize = sizeof(struct ppc_aes_ctx),
405	.cra_alignmask = 0,
406	.cra_module = THIS_MODULE,
407	.cra_u = {
408	.cipher = {
409	.cia_min_keysize = AES_MIN_KEY_SIZE,
410	.cia_max_keysize = AES_MAX_KEY_SIZE,
411	.cia_setkey = ppc_aes_setkey,
412	.cia_encrypt = ppc_aes_encrypt,
413	.cia_decrypt = ppc_aes_decrypt
414	}
415	}
416	}, {
417	.cra_name = "ecb(aes)",
418	.cra_driver_name = "ecb-ppc-spe",
419	.cra_priority = 300,
420	.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
421	.cra_blocksize = AES_BLOCK_SIZE,
422	.cra_ctxsize = sizeof(struct ppc_aes_ctx),
423	.cra_alignmask = 0,
424	.cra_type = &crypto_blkcipher_type,
425	.cra_module = THIS_MODULE,
426	.cra_u = {
427	.blkcipher = {
428	.min_keysize = AES_MIN_KEY_SIZE,
429	.max_keysize = AES_MAX_KEY_SIZE,
430	.ivsize = AES_BLOCK_SIZE,
431	.setkey = ppc_aes_setkey,
432	.encrypt = ppc_ecb_encrypt,
433	.decrypt = ppc_ecb_decrypt,
434	}
435	}
436	}, {
437	.cra_name = "cbc(aes)",
438	.cra_driver_name = "cbc-ppc-spe",
439	.cra_priority = 300,
440	.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
441	.cra_blocksize = AES_BLOCK_SIZE,
442	.cra_ctxsize = sizeof(struct ppc_aes_ctx),
443	.cra_alignmask = 0,
444	.cra_type = &crypto_blkcipher_type,
445	.cra_module = THIS_MODULE,
446	.cra_u = {
447	.blkcipher = {
448	.min_keysize = AES_MIN_KEY_SIZE,
449	.max_keysize = AES_MAX_KEY_SIZE,
450	.ivsize = AES_BLOCK_SIZE,
451	.setkey = ppc_aes_setkey,
452	.encrypt = ppc_cbc_encrypt,
453	.decrypt = ppc_cbc_decrypt,
454	}
455	}
456	}, {
457	.cra_name = "ctr(aes)",
458	.cra_driver_name = "ctr-ppc-spe",
459	.cra_priority = 300,
460	.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
461	.cra_blocksize = 1,
462	.cra_ctxsize = sizeof(struct ppc_aes_ctx),
463	.cra_alignmask = 0,
464	.cra_type = &crypto_blkcipher_type,
465	.cra_module = THIS_MODULE,
466	.cra_u = {
467	.blkcipher = {
468	.min_keysize = AES_MIN_KEY_SIZE,
469	.max_keysize = AES_MAX_KEY_SIZE,
470	.ivsize = AES_BLOCK_SIZE,
471	.setkey = ppc_aes_setkey,
472	.encrypt = ppc_ctr_crypt,
473	.decrypt = ppc_ctr_crypt,
474	}
475	}
476	}, {
477	.cra_name = "xts(aes)",
478	.cra_driver_name = "xts-ppc-spe",
479	.cra_priority = 300,
480	.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
481	.cra_blocksize = AES_BLOCK_SIZE,
482	.cra_ctxsize = sizeof(struct ppc_xts_ctx),
483	.cra_alignmask = 0,
484	.cra_type = &crypto_blkcipher_type,
485	.cra_module = THIS_MODULE,
486	.cra_u = {
487	.blkcipher = {
488	.min_keysize = AES_MIN_KEY_SIZE * 2,
489	.max_keysize = AES_MAX_KEY_SIZE * 2,
490	.ivsize = AES_BLOCK_SIZE,
491	.setkey = ppc_xts_setkey,
492	.encrypt = ppc_xts_encrypt,
493	.decrypt = ppc_xts_decrypt,
494	}
495	}
496	} };
497
498	static int __init ppc_aes_mod_init(void)
499	{
500	return crypto_register_algs(aes_algs, ARRAY_SIZE(aes_algs));
501	}
502
503	static void __exit ppc_aes_mod_fini(void)
504	{
505	crypto_unregister_algs(aes_algs, ARRAY_SIZE(aes_algs));
506	}
507
508	module_init(ppc_aes_mod_init);
509	module_exit(ppc_aes_mod_fini);
510
511	MODULE_LICENSE("GPL");
512	MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS, SPE optimized");
513
514	MODULE_ALIAS_CRYPTO("aes");
515	MODULE_ALIAS_CRYPTO("ecb(aes)");
516	MODULE_ALIAS_CRYPTO("cbc(aes)");
517	MODULE_ALIAS_CRYPTO("ctr(aes)");
518	MODULE_ALIAS_CRYPTO("xts(aes)");
519	MODULE_ALIAS_CRYPTO("aes-ppc-spe");