arch/powerpc/crypto/aes.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * AES routines supporting VMX instructions on the Power 8
   4  *
   5  * Copyright (C) 2015 International Business Machines Inc.
   6  *
   7  * Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com>
   8  */
   9
  10 #include <linux/types.h>
  11 #include <linux/err.h>
  12 #include <linux/crypto.h>
  13 #include <linux/delay.h>
  14 #include <asm/simd.h>
  15 #include <asm/switch_to.h>
  16 #include <crypto/aes.h>
  17 #include <crypto/internal/cipher.h>
  18 #include <crypto/internal/simd.h>
  19
  20 #include "aesp8-ppc.h"
  21
  22 struct p8_aes_ctx {
  23         struct crypto_cipher *fallback;
  24         struct aes_key enc_key;
  25         struct aes_key dec_key;
  26 };
  27
  28 static int p8_aes_init(struct crypto_tfm *tfm)
  29 {
  30         const char *alg = crypto_tfm_alg_name(tfm);
  31         struct crypto_cipher *fallback;
  32         struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
  33
  34         fallback = crypto_alloc_cipher(alg, 0, CRYPTO_ALG_NEED_FALLBACK);
  35         if (IS_ERR(fallback)) {
  36                 printk(KERN_ERR
  37                        "Failed to allocate transformation for '%s': %ld\n",
  38                        alg, PTR_ERR(fallback));
  39                 return PTR_ERR(fallback);
  40         }
  41
  42         crypto_cipher_set_flags(fallback,
  43                                 crypto_cipher_get_flags((struct
  44                                                          crypto_cipher *)
  45                                                         tfm));
  46         ctx->fallback = fallback;
  47
  48         return 0;
  49 }
  50
  51 static void p8_aes_exit(struct crypto_tfm *tfm)
  52 {
  53         struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
  54
  55         if (ctx->fallback) {
  56                 crypto_free_cipher(ctx->fallback);
  57                 ctx->fallback = NULL;
  58         }
  59 }
  60
  61 static int p8_aes_setkey(struct crypto_tfm *tfm, const u8 *key,
  62                          unsigned int keylen)
  63 {
  64         int ret;
  65         struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
  66
  67         preempt_disable();
  68         pagefault_disable();
  69         enable_kernel_vsx();
  70         ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
  71         ret |= aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
  72         disable_kernel_vsx();
  73         pagefault_enable();
  74         preempt_enable();
  75
  76         ret |= crypto_cipher_setkey(ctx->fallback, key, keylen);
  77
  78         return ret ? -EINVAL : 0;
  79 }
  80
  81 static void p8_aes_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
  82 {
  83         struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
  84
  85         if (!crypto_simd_usable()) {
  86                 crypto_cipher_encrypt_one(ctx->fallback, dst, src);
  87         } else {
  88                 preempt_disable();
  89                 pagefault_disable();
  90                 enable_kernel_vsx();
  91                 aes_p8_encrypt(src, dst, &ctx->enc_key);
  92                 disable_kernel_vsx();
  93                 pagefault_enable();
  94                 preempt_enable();
  95         }
  96 }
  97
  98 static void p8_aes_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
  99 {
 100         struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
 101
 102         if (!crypto_simd_usable()) {
 103                 crypto_cipher_decrypt_one(ctx->fallback, dst, src);
 104         } else {
 105                 preempt_disable();
 106                 pagefault_disable();
 107                 enable_kernel_vsx();
 108                 aes_p8_decrypt(src, dst, &ctx->dec_key);
 109                 disable_kernel_vsx();
 110                 pagefault_enable();
 111                 preempt_enable();
 112         }
 113 }
 114
 115 struct crypto_alg p8_aes_alg = {
 116         .cra_name = "aes",
 117         .cra_driver_name = "p8_aes",
 118         .cra_module = THIS_MODULE,
 119         .cra_priority = 1000,
 120         .cra_type = NULL,
 121         .cra_flags = CRYPTO_ALG_TYPE_CIPHER | CRYPTO_ALG_NEED_FALLBACK,
 122         .cra_alignmask = 0,
 123         .cra_blocksize = AES_BLOCK_SIZE,
 124         .cra_ctxsize = sizeof(struct p8_aes_ctx),
 125         .cra_init = p8_aes_init,
 126         .cra_exit = p8_aes_exit,
 127         .cra_cipher = {
 128                        .cia_min_keysize = AES_MIN_KEY_SIZE,
 129                        .cia_max_keysize = AES_MAX_KEY_SIZE,
 130                        .cia_setkey = p8_aes_setkey,
 131                        .cia_encrypt = p8_aes_encrypt,
 132                        .cia_decrypt = p8_aes_decrypt,
 133         },
 134 };