From 3a5a5e5c07e35366f313a5301fe3568349ab8655 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C5=81ukasz=20Stelmach?= Date: Tue, 12 Dec 2017 17:36:05 +0100 Subject: crypto: exynos - Improve performance of PRNG MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Krzysztof Kozlowski Signed-off-by: Herbert Xu --- drivers/crypto/exynos-rng.c | 31 ++----------------------------- 1 file changed, 2 insertions(+), 29 deletions(-) (limited to 'drivers/crypto/exynos-rng.c') 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 @@ -130,34 +130,6 @@ static int exynos_rng_set_seed(struct exynos_rng_dev *rng, return 0; } -/* - * 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 @@ -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; } -- cgit v1.2.3