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

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