drivers/crypto/allwinner/sun4i-ss/sun4i-ss-prng.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 #include "sun4i-ss.h"
   3
   4 int sun4i_ss_prng_seed(struct crypto_rng *tfm, const u8 *seed,
   5                        unsigned int slen)
   6 {
   7         struct sun4i_ss_alg_template *algt;
   8         struct rng_alg *alg = crypto_rng_alg(tfm);
   9
  10         algt = container_of(alg, struct sun4i_ss_alg_template, alg.rng);
  11         memcpy(algt->ss->seed, seed, slen);
  12
  13         return 0;
  14 }
  15
  16 int sun4i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
  17                            unsigned int slen, u8 *dst, unsigned int dlen)
  18 {
  19         struct sun4i_ss_alg_template *algt;
  20         struct rng_alg *alg = crypto_rng_alg(tfm);
  21         int i, err;
  22         u32 v;
  23         u32 *data = (u32 *)dst;
  24         const u32 mode = SS_OP_PRNG | SS_PRNG_CONTINUE | SS_ENABLED;
  25         size_t len;
  26         struct sun4i_ss_ctx *ss;
  27         unsigned int todo = (dlen / 4) * 4;
  28
  29         algt = container_of(alg, struct sun4i_ss_alg_template, alg.rng);
  30         ss = algt->ss;
  31
  32         err = pm_runtime_resume_and_get(ss->dev);
  33         if (err < 0)
  34                 return err;
  35
  36         if (IS_ENABLED(CONFIG_CRYPTO_DEV_SUN4I_SS_DEBUG)) {
  37                 algt->stat_req++;
  38                 algt->stat_bytes += todo;
  39         }
  40
  41         spin_lock_bh(&ss->slock);
  42
  43         writel(mode, ss->base + SS_CTL);
  44
  45         while (todo > 0) {
  46                 /* write the seed */
  47                 for (i = 0; i < SS_SEED_LEN / BITS_PER_LONG; i++)
  48                         writel(ss->seed[i], ss->base + SS_KEY0 + i * 4);
  49
  50                 /* Read the random data */
  51                 len = min_t(size_t, SS_DATA_LEN / BITS_PER_BYTE, todo);
  52                 readsl(ss->base + SS_TXFIFO, data, len / 4);
  53                 data += len / 4;
  54                 todo -= len;
  55
  56                 /* Update the seed */
  57                 for (i = 0; i < SS_SEED_LEN / BITS_PER_LONG; i++) {
  58                         v = readl(ss->base + SS_KEY0 + i * 4);
  59                         ss->seed[i] = v;
  60                 }
  61         }
  62
  63         writel(0, ss->base + SS_CTL);
  64         spin_unlock_bh(&ss->slock);
  65
  66         pm_runtime_put(ss->dev);
  67
  68         return 0;
  69 }