LXR linux/drivers/crypto/vmx/aes.c

   1/**
   2 * AES routines supporting VMX instructions on the Power 8
   3 *
   4 * Copyright (C) 2015 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: Marcelo Henrique Cerri <mhcerri@br.ibm.com>
  20 */
  21
  22#include <linux/types.h>
  23#include <linux/err.h>
  24#include <linux/crypto.h>
  25#include <linux/delay.h>
  26#include <linux/hardirq.h>
  27#include <asm/switch_to.h>
  28#include <crypto/aes.h>
  29
  30#include "aesp8-ppc.h"
  31
  32struct p8_aes_ctx {
  33        struct crypto_cipher *fallback;
  34        struct aes_key enc_key;
  35        struct aes_key dec_key;
  36};
  37
  38static int p8_aes_init(struct crypto_tfm *tfm)
  39{
  40        const char *alg = crypto_tfm_alg_name(tfm);
  41        struct crypto_cipher *fallback;
  42        struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
  43
  44        fallback = crypto_alloc_cipher(alg, 0, CRYPTO_ALG_NEED_FALLBACK);
  45        if (IS_ERR(fallback)) {
  46                printk(KERN_ERR
  47                       "Failed to allocate transformation for '%s': %ld\n",
  48                       alg, PTR_ERR(fallback));
  49                return PTR_ERR(fallback);
  50        }
  51
  52        crypto_cipher_set_flags(fallback,
  53                                crypto_cipher_get_flags((struct
  54                                                         crypto_cipher *)
  55                                                        tfm));
  56        ctx->fallback = fallback;
  57
  58        return 0;
  59}
  60
  61static void p8_aes_exit(struct crypto_tfm *tfm)
  62{
  63        struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
  64
  65        if (ctx->fallback) {
  66                crypto_free_cipher(ctx->fallback);
  67                ctx->fallback = NULL;
  68        }
  69}
  70
  71static int p8_aes_setkey(struct crypto_tfm *tfm, const u8 *key,
  72                         unsigned int keylen)
  73{
  74        int ret;
  75        struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
  76
  77        preempt_disable();
  78        pagefault_disable();
  79        enable_kernel_vsx();
  80        ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
  81        ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
  82        disable_kernel_vsx();
  83        pagefault_enable();
  84        preempt_enable();
  85
  86        ret += crypto_cipher_setkey(ctx->fallback, key, keylen);
  87        return ret;
  88}
  89
  90static void p8_aes_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
  91{
  92        struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
  93
  94        if (in_interrupt()) {
  95                crypto_cipher_encrypt_one(ctx->fallback, dst, src);
  96        } else {
  97                preempt_disable();
  98                pagefault_disable();
  99                enable_kernel_vsx();
 100                aes_p8_encrypt(src, dst, &ctx->enc_key);
 101                disable_kernel_vsx();
 102                pagefault_enable();
 103                preempt_enable();
 104        }
 105}
 106
 107static void p8_aes_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
 108{
 109        struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
 110
 111        if (in_interrupt()) {
 112                crypto_cipher_decrypt_one(ctx->fallback, dst, src);
 113        } else {
 114                preempt_disable();
 115                pagefault_disable();
 116                enable_kernel_vsx();
 117                aes_p8_decrypt(src, dst, &ctx->dec_key);
 118                disable_kernel_vsx();
 119                pagefault_enable();
 120                preempt_enable();
 121        }
 122}
 123
 124struct crypto_alg p8_aes_alg = {
 125        .cra_name = "aes",
 126        .cra_driver_name = "p8_aes",
 127        .cra_module = THIS_MODULE,
 128        .cra_priority = 1000,
 129        .cra_type = NULL,
 130        .cra_flags = CRYPTO_ALG_TYPE_CIPHER | CRYPTO_ALG_NEED_FALLBACK,
 131        .cra_alignmask = 0,
 132        .cra_blocksize = AES_BLOCK_SIZE,
 133        .cra_ctxsize = sizeof(struct p8_aes_ctx),
 134        .cra_init = p8_aes_init,
 135        .cra_exit = p8_aes_exit,
 136        .cra_cipher = {
 137                       .cia_min_keysize = AES_MIN_KEY_SIZE,
 138                       .cia_max_keysize = AES_MAX_KEY_SIZE,
 139                       .cia_setkey = p8_aes_setkey,
 140                       .cia_encrypt = p8_aes_encrypt,
 141                       .cia_decrypt = p8_aes_decrypt,
 142        },
 143};
 144