drivers/crypto/nx/nx-aes-cbc.c

   1 /**
   2  * AES CBC routines supporting the Power 7+ Nest Accelerators driver
   3  *
   4  * Copyright (C) 2011-2012 International Business Machines Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 only.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  *
  19  * Author: Kent Yoder <yoder1@us.ibm.com>
  20  */
  21
  22 #include <crypto/aes.h>
  23 #include <crypto/algapi.h>
  24 #include <linux/module.h>
  25 #include <linux/types.h>
  26 #include <linux/crypto.h>
  27 #include <asm/vio.h>
  28
  29 #include "nx_csbcpb.h"
  30 #include "nx.h"
  31
  32
  33 static int cbc_aes_nx_set_key(struct crypto_tfm *tfm,
  34                               const u8          *in_key,
  35                               unsigned int       key_len)
  36 {
  37         struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(tfm);
  38         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
  39
  40         nx_ctx_init(nx_ctx, HCOP_FC_AES);
  41
  42         switch (key_len) {
  43         case AES_KEYSIZE_128:
  44                 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
  45                 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
  46                 break;
  47         case AES_KEYSIZE_192:
  48                 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_192);
  49                 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192];
  50                 break;
  51         case AES_KEYSIZE_256:
  52                 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_256);
  53                 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_256];
  54                 break;
  55         default:
  56                 return -EINVAL;
  57         }
  58
  59         csbcpb->cpb.hdr.mode = NX_MODE_AES_CBC;
  60         memcpy(csbcpb->cpb.aes_cbc.key, in_key, key_len);
  61
  62         return 0;
  63 }
  64
  65 static int cbc_aes_nx_crypt(struct blkcipher_desc *desc,
  66                             struct scatterlist    *dst,
  67                             struct scatterlist    *src,
  68                             unsigned int           nbytes,
  69                             int                    enc)
  70 {
  71         struct nx_crypto_ctx *nx_ctx = crypto_blkcipher_ctx(desc->tfm);
  72         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
  73         unsigned long irq_flags;
  74         unsigned int processed = 0, to_process;
  75         u32 max_sg_len;
  76         int rc;
  77
  78         spin_lock_irqsave(&nx_ctx->lock, irq_flags);
  79
  80         max_sg_len = min_t(u32, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
  81                            nx_ctx->ap->sglen);
  82
  83         if (enc)
  84                 NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
  85         else
  86                 NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
  87
  88         do {
  89                 to_process = min_t(u64, nbytes - processed,
  90                                    nx_ctx->ap->databytelen);
  91                 to_process = min_t(u64, to_process,
  92                                    NX_PAGE_SIZE * (max_sg_len - 1));
  93                 to_process = to_process & ~(AES_BLOCK_SIZE - 1);
  94
  95                 rc = nx_build_sg_lists(nx_ctx, desc, dst, src, to_process,
  96                                        processed, csbcpb->cpb.aes_cbc.iv);
  97                 if (rc)
  98                         goto out;
  99
 100                 if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
 101                         rc = -EINVAL;
 102                         goto out;
 103                 }
 104
 105                 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
 106                                    desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 107                 if (rc)
 108                         goto out;
 109
 110                 memcpy(desc->info, csbcpb->cpb.aes_cbc.cv, AES_BLOCK_SIZE);
 111                 atomic_inc(&(nx_ctx->stats->aes_ops));
 112                 atomic64_add(csbcpb->csb.processed_byte_count,
 113                              &(nx_ctx->stats->aes_bytes));
 114
 115                 processed += to_process;
 116         } while (processed < nbytes);
 117 out:
 118         spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 119         return rc;
 120 }
 121
 122 static int cbc_aes_nx_encrypt(struct blkcipher_desc *desc,
 123                               struct scatterlist    *dst,
 124                               struct scatterlist    *src,
 125                               unsigned int           nbytes)
 126 {
 127         return cbc_aes_nx_crypt(desc, dst, src, nbytes, 1);
 128 }
 129
 130 static int cbc_aes_nx_decrypt(struct blkcipher_desc *desc,
 131                               struct scatterlist    *dst,
 132                               struct scatterlist    *src,
 133                               unsigned int           nbytes)
 134 {
 135         return cbc_aes_nx_crypt(desc, dst, src, nbytes, 0);
 136 }
 137
 138 struct crypto_alg nx_cbc_aes_alg = {
 139         .cra_name        = "cbc(aes)",
 140         .cra_driver_name = "cbc-aes-nx",
 141         .cra_priority    = 300,
 142         .cra_flags       = CRYPTO_ALG_TYPE_BLKCIPHER,
 143         .cra_blocksize   = AES_BLOCK_SIZE,
 144         .cra_ctxsize     = sizeof(struct nx_crypto_ctx),
 145         .cra_type        = &crypto_blkcipher_type,
 146         .cra_alignmask   = 0xf,
 147         .cra_module      = THIS_MODULE,
 148         .cra_init        = nx_crypto_ctx_aes_cbc_init,
 149         .cra_exit        = nx_crypto_ctx_exit,
 150         .cra_blkcipher = {
 151                 .min_keysize = AES_MIN_KEY_SIZE,
 152                 .max_keysize = AES_MAX_KEY_SIZE,
 153                 .ivsize      = AES_BLOCK_SIZE,
 154                 .setkey      = cbc_aes_nx_set_key,
 155                 .encrypt     = cbc_aes_nx_encrypt,
 156                 .decrypt     = cbc_aes_nx_decrypt,
 157         }
 158 };