target/linux/sunxi/patches-4.9/0054-crypto-sun4i-ss_support_the_Security_System_PRNG.patch

   1 From b8ae5c7387ad075ee61e8c8774ce2bca46bc9236 Mon Sep 17 00:00:00 2001
   2 From: Corentin LABBE <clabbe.montjoie@gmail.com>
   3 Date: Mon, 3 Jul 2017 20:48:48 +0200
   4 Subject: crypto: sun4i-ss - support the Security System PRNG
   5
   6 The Security System has a PRNG, this patch adds support for it via
   7 crypto_rng.
   8
   9 Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
  10 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
  11 ---
  12  drivers/crypto/Kconfig                  |  8 +++++
  13  drivers/crypto/sunxi-ss/Makefile        |  1 +
  14  drivers/crypto/sunxi-ss/sun4i-ss-core.c | 30 ++++++++++++++++++
  15  drivers/crypto/sunxi-ss/sun4i-ss-prng.c | 56 +++++++++++++++++++++++++++++++++
  16  drivers/crypto/sunxi-ss/sun4i-ss.h      | 11 +++++++
  17  5 files changed, 106 insertions(+)
  18  create mode 100644 drivers/crypto/sunxi-ss/sun4i-ss-prng.c
  19
  20 --- a/drivers/crypto/Kconfig
  21 +++ b/drivers/crypto/Kconfig
  22 @@ -538,6 +538,14 @@ config CRYPTO_DEV_SUN4I_SS
  23           To compile this driver as a module, choose M here: the module
  24           will be called sun4i-ss.
  25
  26 +config CRYPTO_DEV_SUN4I_SS_PRNG
  27 +       bool "Support for Allwinner Security System PRNG"
  28 +       depends on CRYPTO_DEV_SUN4I_SS
  29 +       select CRYPTO_RNG
  30 +       help
  31 +         Select this option if you want to provide kernel-side support for
  32 +         the Pseudo-Random Number Generator found in the Security System.
  33 +
  34  config CRYPTO_DEV_ROCKCHIP
  35         tristate "Rockchip's Cryptographic Engine driver"
  36         depends on OF && ARCH_ROCKCHIP
  37 --- a/drivers/crypto/sunxi-ss/Makefile
  38 +++ b/drivers/crypto/sunxi-ss/Makefile
  39 @@ -1,2 +1,3 @@
  40  obj-$(CONFIG_CRYPTO_DEV_SUN4I_SS) += sun4i-ss.o
  41  sun4i-ss-y += sun4i-ss-core.o sun4i-ss-hash.o sun4i-ss-cipher.o
  42 +sun4i-ss-$(CONFIG_CRYPTO_DEV_SUN4I_SS_PRNG) += sun4i-ss-prng.o
  43 --- a/drivers/crypto/sunxi-ss/sun4i-ss-core.c
  44 +++ b/drivers/crypto/sunxi-ss/sun4i-ss-core.c
  45 @@ -214,6 +214,23 @@ static struct sun4i_ss_alg_template ss_a
  46                 }
  47         }
  48  },
  49 +#ifdef CONFIG_CRYPTO_DEV_SUN4I_SS_PRNG
  50 +{
  51 +       .type = CRYPTO_ALG_TYPE_RNG,
  52 +       .alg.rng = {
  53 +               .base = {
  54 +                       .cra_name               = "stdrng",
  55 +                       .cra_driver_name        = "sun4i_ss_rng",
  56 +                       .cra_priority           = 300,
  57 +                       .cra_ctxsize            = 0,
  58 +                       .cra_module             = THIS_MODULE,
  59 +               },
  60 +               .generate               = sun4i_ss_prng_generate,
  61 +               .seed                   = sun4i_ss_prng_seed,
  62 +               .seedsize               = SS_SEED_LEN / BITS_PER_BYTE,
  63 +       }
  64 +},
  65 +#endif
  66  };
  67
  68  static int sun4i_ss_probe(struct platform_device *pdev)
  69 @@ -356,6 +373,13 @@ static int sun4i_ss_probe(struct platfor
  70                                 goto error_alg;
  71                         }
  72                         break;
  73 +               case CRYPTO_ALG_TYPE_RNG:
  74 +                       err = crypto_register_rng(&ss_algs[i].alg.rng);
  75 +                       if (err) {
  76 +                               dev_err(ss->dev, "Fail to register %s\n",
  77 +                                       ss_algs[i].alg.rng.base.cra_name);
  78 +                       }
  79 +                       break;
  80                 }
  81         }
  82         platform_set_drvdata(pdev, ss);
  83 @@ -370,6 +394,9 @@ error_alg:
  84                 case CRYPTO_ALG_TYPE_AHASH:
  85                         crypto_unregister_ahash(&ss_algs[i].alg.hash);
  86                         break;
  87 +               case CRYPTO_ALG_TYPE_RNG:
  88 +                       crypto_unregister_rng(&ss_algs[i].alg.rng);
  89 +                       break;
  90                 }
  91         }
  92         if (ss->reset)
  93 @@ -394,6 +421,9 @@ static int sun4i_ss_remove(struct platfo
  94                 case CRYPTO_ALG_TYPE_AHASH:
  95                         crypto_unregister_ahash(&ss_algs[i].alg.hash);
  96                         break;
  97 +               case CRYPTO_ALG_TYPE_RNG:
  98 +                       crypto_unregister_rng(&ss_algs[i].alg.rng);
  99 +                       break;
 100                 }
 101         }
 102
 103 --- /dev/null
 104 +++ b/drivers/crypto/sunxi-ss/sun4i-ss-prng.c
 105 @@ -0,0 +1,56 @@
 106 +#include "sun4i-ss.h"
 107 +
 108 +int sun4i_ss_prng_seed(struct crypto_rng *tfm, const u8 *seed,
 109 +                      unsigned int slen)
 110 +{
 111 +       struct sun4i_ss_alg_template *algt;
 112 +       struct rng_alg *alg = crypto_rng_alg(tfm);
 113 +
 114 +       algt = container_of(alg, struct sun4i_ss_alg_template, alg.rng);
 115 +       memcpy(algt->ss->seed, seed, slen);
 116 +
 117 +       return 0;
 118 +}
 119 +
 120 +int sun4i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
 121 +                          unsigned int slen, u8 *dst, unsigned int dlen)
 122 +{
 123 +       struct sun4i_ss_alg_template *algt;
 124 +       struct rng_alg *alg = crypto_rng_alg(tfm);
 125 +       int i;
 126 +       u32 v;
 127 +       u32 *data = (u32 *)dst;
 128 +       const u32 mode = SS_OP_PRNG | SS_PRNG_CONTINUE | SS_ENABLED;
 129 +       size_t len;
 130 +       struct sun4i_ss_ctx *ss;
 131 +       unsigned int todo = (dlen / 4) * 4;
 132 +
 133 +       algt = container_of(alg, struct sun4i_ss_alg_template, alg.rng);
 134 +       ss = algt->ss;
 135 +
 136 +       spin_lock(&ss->slock);
 137 +
 138 +       writel(mode, ss->base + SS_CTL);
 139 +
 140 +       while (todo > 0) {
 141 +               /* write the seed */
 142 +               for (i = 0; i < SS_SEED_LEN / BITS_PER_LONG; i++)
 143 +                       writel(ss->seed[i], ss->base + SS_KEY0 + i * 4);
 144 +
 145 +               /* Read the random data */
 146 +               len = min_t(size_t, SS_DATA_LEN / BITS_PER_BYTE, todo);
 147 +               readsl(ss->base + SS_TXFIFO, data, len / 4);
 148 +               data += len / 4;
 149 +               todo -= len;
 150 +
 151 +               /* Update the seed */
 152 +               for (i = 0; i < SS_SEED_LEN / BITS_PER_LONG; i++) {
 153 +                       v = readl(ss->base + SS_KEY0 + i * 4);
 154 +                       ss->seed[i] = v;
 155 +               }
 156 +       }
 157 +
 158 +       writel(0, ss->base + SS_CTL);
 159 +       spin_unlock(&ss->slock);
 160 +       return dlen;
 161 +}
 162 --- a/drivers/crypto/sunxi-ss/sun4i-ss.h
 163 +++ b/drivers/crypto/sunxi-ss/sun4i-ss.h
 164 @@ -30,6 +30,7 @@
 165  #include <crypto/aes.h>
 166  #include <crypto/des.h>
 167  #include <crypto/internal/rng.h>
 168 +#include <crypto/rng.h>
 169
 170  #define SS_CTL            0x00
 171  #define SS_KEY0           0x04
 172 @@ -125,6 +126,9 @@
 173  #define SS_RXFIFO_EMP_INT_ENABLE       (1 << 2)
 174  #define SS_TXFIFO_AVA_INT_ENABLE       (1 << 0)
 175
 176 +#define SS_SEED_LEN 192
 177 +#define SS_DATA_LEN 160
 178 +
 179  struct sun4i_ss_ctx {
 180         void __iomem *base;
 181         int irq;
 182 @@ -134,6 +138,9 @@ struct sun4i_ss_ctx {
 183         struct device *dev;
 184         struct resource *res;
 185         spinlock_t slock; /* control the use of the device */
 186 +#ifdef CONFIG_CRYPTO_DEV_SUN4I_SS_PRNG
 187 +       u32 seed[SS_SEED_LEN / BITS_PER_LONG];
 188 +#endif
 189  };
 190
 191  struct sun4i_ss_alg_template {
 192 @@ -142,6 +149,7 @@ struct sun4i_ss_alg_template {
 193         union {
 194                 struct crypto_alg crypto;
 195                 struct ahash_alg hash;
 196 +               struct rng_alg rng;
 197         } alg;
 198         struct sun4i_ss_ctx *ss;
 199  };
 200 @@ -199,3 +207,6 @@ int sun4i_ss_des_setkey(struct crypto_ab
 201                         unsigned int keylen);
 202  int sun4i_ss_des3_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
 203                          unsigned int keylen);
 204 +int sun4i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
 205 +                          unsigned int slen, u8 *dst, unsigned int dlen);
 206 +int sun4i_ss_prng_seed(struct crypto_rng *tfm, const u8 *seed, unsigned int slen);