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