LXR linux/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/cipher.h>
  18#include <crypto/internal/simd.h>
  19
  20#include "aesp8-ppc.h"
  21
  22struct p8_aes_ctx {
  23        struct crypto_cipher *fallback;
  24        struct aes_key enc_key;
  25        struct aes_key dec_key;
  26};
  27
  28static 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
  51static 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
  61static 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
  81static 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
  98static 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
 115struct 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};
 135