text: /**
   * AES CBC routines supporting the Power 7+ Nest Accelerators driver
   *
   * Copyright (C) 2011-2012 International Business Machines Inc.
   *
   * 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; version 2 only.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   *
   * Author: Kent Yoder <yoder1@us.ibm.com>
   */
  
  #include <crypto/aes.h>
  #include <crypto/algapi.h>
  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/crypto.h>
  #include <asm/vio.h>
  
  #include "nx_csbcpb.h"
  #include "nx.h"
  
  
  static int cbc_aes_nx_set_key(struct crypto_tfm *tfm,
  			      const u8          *in_key,
  			      unsigned int       key_len)
  {
  	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(tfm);
  	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
  
  	nx_ctx_init(nx_ctx, HCOP_FC_AES);
  
  	switch (key_len) {
  	case AES_KEYSIZE_128:
  		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
  		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
  		break;
  	case AES_KEYSIZE_192:
  		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_192);
  		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192];
  		break;
  	case AES_KEYSIZE_256:
  		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_256);
  		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_256];
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	csbcpb->cpb.hdr.mode = NX_MODE_AES_CBC;
  	memcpy(csbcpb->cpb.aes_cbc.key, in_key, key_len);
  
  	return 0;
  }
  
  static int cbc_aes_nx_crypt(struct blkcipher_desc *desc,
  			    struct scatterlist    *dst,
  			    struct scatterlist    *src,
  			    unsigned int           nbytes,
  			    int                    enc)
  {
  	struct nx_crypto_ctx *nx_ctx = crypto_blkcipher_ctx(desc->tfm);
  	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
  	int rc;
  
  	if (nbytes > nx_ctx->ap->databytelen)
  		return -EINVAL;
  
  	if (enc)
  		NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
  	else
  		NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
  
  	rc = nx_build_sg_lists(nx_ctx, desc, dst, src, nbytes,
  			       csbcpb->cpb.aes_cbc.iv);
  	if (rc)
  		goto out;
  
  	if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
  		rc = -EINVAL;
  		goto out;
  	}
  
  	rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
  			   desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
  	if (rc)
  		goto out;
  
  	atomic_inc(&(nx_ctx->stats->aes_ops));
  	atomic64_add(csbcpb->csb.processed_byte_count,
  		     &(nx_ctx->stats->aes_bytes));
  out:
  	return rc;
  }
  
  static int cbc_aes_nx_encrypt(struct blkcipher_desc *desc,
  			      struct scatterlist    *dst,
  			      struct scatterlist    *src,
  			      unsigned int           nbytes)
  {
  	return cbc_aes_nx_crypt(desc, dst, src, nbytes, 1);
  }
  
  static int cbc_aes_nx_decrypt(struct blkcipher_desc *desc,
  			      struct scatterlist    *dst,
  			      struct scatterlist    *src,
  			      unsigned int           nbytes)
  {
  	return cbc_aes_nx_crypt(desc, dst, src, nbytes, 0);
  }
  
  struct crypto_alg nx_cbc_aes_alg = {
  	.cra_name        = "cbc(aes)",
  	.cra_driver_name = "cbc-aes-nx",
  	.cra_priority    = 300,
  	.cra_flags       = CRYPTO_ALG_TYPE_BLKCIPHER,
  	.cra_blocksize   = AES_BLOCK_SIZE,
  	.cra_ctxsize     = sizeof(struct nx_crypto_ctx),
  	.cra_type        = &crypto_blkcipher_type,
  	.cra_alignmask   = 0xf,
  	.cra_module      = THIS_MODULE,
  	.cra_init        = nx_crypto_ctx_aes_cbc_init,
  	.cra_exit        = nx_crypto_ctx_exit,
  	.cra_blkcipher = {
  		.min_keysize = AES_MIN_KEY_SIZE,
  		.max_keysize = AES_MAX_KEY_SIZE,
  		.ivsize      = AES_BLOCK_SIZE,
  		.setkey      = cbc_aes_nx_set_key,
  		.encrypt     = cbc_aes_nx_encrypt,
  		.decrypt     = cbc_aes_nx_decrypt,
  	}
  };
  