Message-ID: <Z7F2wdG99A0na-ie@gondor.apana.org.au>
Date: Sun, 16 Feb 2025 13:25:21 +0800
From: Herbert Xu <herbert@...dor.apana.org.au>
To: Nicolas Frattaroli <nicolas.frattaroli@...labora.com>
Cc: Philipp Zabel <p.zabel@...gutronix.de>, Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Heiko Stuebner <heiko@...ech.de>,
	Olivia Mackall <olivia@...enic.com>,
	Daniel Golle <daniel@...rotopia.org>,
	Aurelien Jarno <aurelien@...el32.net>,
	Sebastian Reichel <sebastian.reichel@...labora.com>,
	kernel@...labora.com, devicetree@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-rockchip@...ts.infradead.org, linux-kernel@...r.kernel.org,
	linux-crypto@...r.kernel.org,
	XiaoDong Huang <derrick.huang@...k-chips.com>,
	Conor Dooley <conor.dooley@...rochip.com>,
	Lin Jinhan <troy.lin@...k-chips.com>
Subject: Re: [PATCH v2 0/7] RK3588 Hardware Random Number Generator Driver

On Tue, Feb 04, 2025 at 04:35:45PM +0100, Nicolas Frattaroli wrote:
> This series adds support for the Rockchip RK3588's standalone hardware
> random number generator to the existing mainline rockchip-rng driver.
> 
> The RK3588 has several hardware random number generators, one in each
> the secure-world and non-secure-world crypto accelerator, and one
> standalone one in each the secure-world and non-secure-world, so 4
> hwrngs in total. This series adds support for the standalone hwrng,
> which is an entirely new IP on this SoC and distinct from the one in the
> Crypto IP.
> 
> The decision to integrate this into the existing rockchip-rng driver was
> made based on a few factors:
> 
> 1. The driver is fairly small.
> 2. While not much code is shared, some code is, specifically relating to
>    power management, the hwrng interface and the probe function.
> 3. I don't want users to figure out why "CONFIG_HW_RANDOM_ROCKCHIP"
>    doesn't enable the RK3588 one, and I really don't see a reason to
>    build without both of them considering the other RK3588 TRNG (for
>    which there is not yet a driver iirc) *does* share code with the
>    existing rockchip-rng driver.
> 
> Here are the rngtest5 results from this new driver on my board:
> 
>   user@...ian-rockchip-rock5b-rk3588:~$ cat /sys/class/misc/hw_random/rng_current 
>   rockchip-rng
>   user@...ian-rockchip-rock5b-rk3588:~$ sudo cat /dev/hwrng | rngtest -c 10000 
>   [...]
>   rngtest: bits received from input: 200000032
>   rngtest: FIPS 140-2 successes: 9990
>   rngtest: FIPS 140-2 failures: 10
>   rngtest: FIPS 140-2(2001-10-10) Monobit: 1
>   rngtest: FIPS 140-2(2001-10-10) Poker: 0
>   rngtest: FIPS 140-2(2001-10-10) Runs: 5
>   rngtest: FIPS 140-2(2001-10-10) Long run: 4
>   rngtest: FIPS 140-2(2001-10-10) Continuous run: 0
>   rngtest: input channel speed: (min=212.255; avg=29089.272; max=19531250.000)Kibits/s
>   rngtest: FIPS tests speed: (min=64.005; avg=102.494; max=153.818)Mibits/s
>   rngtest: Program run time: 11292340 microseconds
> 
> As you can see, the quality of the entropy is quite good, and the
> throughput is an acceptable 29 Mibit/s.
> 
> The series starts out with two patches for the bindings. The bindings
> are separate from the rockchip,rk3568-rng bindings, as the required
> properties differ. The SCMI reset ID numbers are needed because mainline
> uses a different reset numbering scheme, but TF-A uses the downstream
> numbering scheme as far as I know. The TRNG must be reset through SCMI.
> 
> Next up are two cleanup patches for the existing driver. Even if a
> decision is made to split the drivers for whatever reason, these two
> patches should be used in the rk3568-rng driver as they get rid of small
> peculiarities in the code without meaningfully changing how the driver
> works.
> 
> Next up is the main driver patch that adds support for the new TRNG. As
> the driver was developed by reading the downstream vendor code for this
> particular device and reworking it, I've included the downstream vendor
> developer who wrote the driver as a Co-developed-by tag with their
> existing downstream sign-off.
> 
> The penultimate patch adds the node to the rk3588-base.dtsi, and
> enables it.
> 
> The final patch adds myself to the MAINTAINERS of this driver and these
> bindings.
> 
> Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@...labora.com>
> ---
> Changes in v2:
> - Drop mailmap patch
> - driver: restore the OF matching to how it was, and change soc_data to
>   const
> - dts: get rid of the board specific DTS enablement and instead enable
>   it in rk3588-base
> - bindings: drop the change of adding myself to maintainers from the
>   bindings patch, make it a separate patch
> - bindings: get rid of the comments
> - bindings: set status = "okay" in the example
> - bindings: make interrupts property required
> - Add a patch to add me to the MAINTAINERS for this driver/binding
> - Link to v1: https://lore.kernel.org/r/20250130-rk3588-trng-submission-v1-0-97ff76568e49@collabora.com
> 
> ---
> Nicolas Frattaroli (7):
>       dt-bindings: reset: Add SCMI reset IDs for RK3588
>       dt-bindings: rng: add binding for Rockchip RK3588 RNG
>       hwrng: rockchip: store dev pointer in driver struct
>       hwrng: rockchip: eliminate some unnecessary dereferences
>       hwrng: rockchip: add support for rk3588's standalone TRNG
>       arm64: dts: rockchip: Add rng node to RK3588
>       MAINTAINERS: add Nicolas Frattaroli to rockchip-rng maintainers
> 
>  .../bindings/rng/rockchip,rk3588-rng.yaml          |  60 +++++
>  MAINTAINERS                                        |   2 +
>  arch/arm64/boot/dts/rockchip/rk3588-base.dtsi      |   9 +
>  drivers/char/hw_random/Kconfig                     |   3 +-
>  drivers/char/hw_random/rockchip-rng.c              | 250 ++++++++++++++++++---
>  include/dt-bindings/reset/rockchip,rk3588-cru.h    |  41 +++-
>  6 files changed, 335 insertions(+), 30 deletions(-)
> ---
> base-commit: 72deda0abee6e705ae71a93f69f55e33be5bca5c
> change-id: 20250130-rk3588-trng-submission-055255c96689
> 
> Best regards,
> -- 
> Nicolas Frattaroli <nicolas.frattaroli@...labora.com>

Patches 1-5,7 applied.  Thanks.
-- 
Email: Herbert Xu <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

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