diff options
author | Łukasz Stelmach <l.stelmach@samsung.com> | 2017-12-12 17:36:05 +0100 |
---|---|---|
committer | Herbert Xu <herbert@gondor.apana.org.au> | 2017-12-22 19:52:43 +1100 |
commit | 3a5a5e5c07e35366f313a5301fe3568349ab8655 (patch) | |
tree | dec183303aff7ff09fb0a89ae3a9e5bc521237e8 /drivers/crypto/exynos-rng.c | |
parent | f76d38b26c114c5e6c8252f3c7dac42bbd69c2c3 (diff) |
crypto: exynos - Improve performance of PRNG
Use memcpy_fromio() instead of custom exynos_rng_copy_random() function
to retrieve generated numbers from the registers of PRNG.
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/crypto/exynos-rng.c')
-rw-r--r-- | drivers/crypto/exynos-rng.c | 31 |
1 files changed, 2 insertions, 29 deletions
diff --git a/drivers/crypto/exynos-rng.c b/drivers/crypto/exynos-rng.c index 825c09619eb8..dcdd444d0b3b 100644 --- a/drivers/crypto/exynos-rng.c +++ b/drivers/crypto/exynos-rng.c @@ -131,34 +131,6 @@ static int exynos_rng_set_seed(struct exynos_rng_dev *rng, } /* - * Read from output registers and put the data under 'dst' array, - * up to dlen bytes. - * - * Returns number of bytes actually stored in 'dst' (dlen - * or EXYNOS_RNG_SEED_SIZE). - */ -static unsigned int exynos_rng_copy_random(struct exynos_rng_dev *rng, - u8 *dst, unsigned int dlen) -{ - unsigned int cnt = 0; - int i, j; - u32 val; - - for (j = 0; j < EXYNOS_RNG_SEED_REGS; j++) { - val = exynos_rng_readl(rng, EXYNOS_RNG_OUT(j)); - - for (i = 0; i < 4; i++) { - dst[cnt] = val & 0xff; - val >>= 8; - if (++cnt >= dlen) - return cnt; - } - } - - return cnt; -} - -/* * Start the engine and poll for finish. Then read from output registers * filling the 'dst' buffer up to 'dlen' bytes or up to size of generated * random data (EXYNOS_RNG_SEED_SIZE). @@ -190,7 +162,8 @@ static int exynos_rng_get_random(struct exynos_rng_dev *rng, /* Clear status bit */ exynos_rng_writel(rng, EXYNOS_RNG_STATUS_RNG_DONE, EXYNOS_RNG_STATUS); - *read = exynos_rng_copy_random(rng, dst, dlen); + *read = min_t(size_t, dlen, EXYNOS_RNG_SEED_SIZE); + memcpy_fromio(dst, rng->mem + EXYNOS_RNG_OUT_BASE, *read); return 0; } |