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

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2#include "sun4i-ss.h"
   3
   4int 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
  16int 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}
  70