[PATCH 0/3] crypto: hw_random - Add new Exynos RNG driver

From: Krzysztof Kozlowski
Date: Fri Mar 24 2017 - 10:25:43 EST


Hi,

This is a follow up of my questions around exynos-rng [1].

The existing exynos-rng has many issues. The most important one is that
it is a pseudo RNG device but uses hw_random interface which does not allow
proper seeding.

The RNG module on Exynos4 requires seeding. On newer SoCs (like Exynos5420)
it can seed itself from a true RNG. Converting the existing driver
to use TRNG would effectively drop support for Exynos4 and break
compatibility with existing users.

Instead I decided to convert it to crypto API. In the future I hope
to add support for seeding from TRNG module.

Tested with app [2].

Patches are independent. I will take the defconfig changes (2/3 and 3/3)
through samsung-soc tree.

Best regards,
Krzysztof

[1] https://www.spinics.net/lists/arm-kernel/msg569641.html
[2] https://www.spinics.net/lists/arm-kernel/msg571184.html

Krzysztof Kozlowski (3):
crypto: hw_random - Add new Exynos RNG driver
ARM: exynos_defconfig: Enable Exynos RNG and user-space crypto API
ARM: multi_v7_defconfig: Enable Exynos RNG and user-space crypto API

MAINTAINERS | 8 +
arch/arm/configs/exynos_defconfig | 6 +
arch/arm/configs/multi_v7_defconfig | 6 +
drivers/char/hw_random/Kconfig | 14 --
drivers/char/hw_random/Makefile | 1 -
drivers/char/hw_random/exynos-rng.c | 231 ---------------------------
drivers/crypto/Kconfig | 15 ++
drivers/crypto/Makefile | 1 +
drivers/crypto/exynos-rng.c | 306 ++++++++++++++++++++++++++++++++++++
9 files changed, 342 insertions(+), 246 deletions(-)
delete mode 100644 drivers/char/hw_random/exynos-rng.c
create mode 100644 drivers/crypto/exynos-rng.c

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2.9.3