Re: [PATCH v3 0/4] Assorted changes for Exynos PRNG driver

[Herbert Xu]

On Tue, Dec 12, 2017 at 05:36:03PM +0100, Łukasz Stelmach wrote:
> Hello,
> 
> This is a series of patches for exynos-rng driver I've decided to
> create after adding support for Exynos5250+ chips. They do not
> strictly depend on each other, but I think it is better to send them
> as a single patch-set.
> 
> The driver requires appropriate DT configuration introduced in
> 
> https://patchwork.kernel.org/patch/10106797/
> 
> Patch #1 Add support for PRNG in Exynos5250+ SoCs
> 
> Patch #2 Improve output performance by using memcpy() rather than a
> custom function to retrieve random bytes from registers. Rearrange
> the loop for polling the hardware.
> 
> Patch #3 Reseed the PRNG after reading 2^16 bytes. Simmilar approach
> is implemented in DRBG. (Thanks Stephan Mueller)
> 
> Patch #4 Introduce locking to prevent simultaneous access to the
> hardware from more than one thread/process.
> 
> Changes since v2:

All applied.  Thanks.
-- 
Email: Herbert Xu 
Home Page: http://gondor.apana.org.au/~herbert/
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[PATCH v3 0/4] Assorted changes for Exynos PRNG driver

[Łukasz Stelmach]

Hello,

This is a series of patches for exynos-rng driver I've decided to
create after adding support for Exynos5250+ chips. They do not
strictly depend on each other, but I think it is better to send them
as a single patch-set.

The driver requires appropriate DT configuration introduced in

https://patchwork.kernel.org/patch/10106797/

Patch #1 Add support for PRNG in Exynos5250+ SoCs

Patch #2 Improve output performance by using memcpy() rather than a
custom function to retrieve random bytes from registers. Rearrange
the loop for polling the hardware.

Patch #3 Reseed the PRNG after reading 2^16 bytes. Simmilar approach
is implemented in DRBG. (Thanks Stephan Mueller)

Patch #4 Introduce locking to prevent simultaneous access to the
hardware from more than one thread/process.

Changes since v2:

- Remove changes in the loop polling the status register in
  exynos_rng_get_random(). Thanks Krzysztof Kozłowski.
- Remove the check for valid values of rng->type from
  exynos_rng_probe(). The function wouldn't be called with values other
  than mentioned in exynos_rng_dt_match array.
- Applied changes to the commit message of patch #3 requested by Stephan
  Mueller.

Changes since v1:

- Added Patch #4.
- Extended commit message for patch #3.
- Changed exynos_prng_type enum and a define according to Krzysztof Kozłowski's
  recommendations.
- Brought back cpu_relax() in a rearranged loop in
  exynos_rng_get_random().
- Moved an assignment of the read valuea away from an error path.
- Removed dev_info() reporting hardware presence from
  exynos_rng_probe().

Łukasz Stelmach (4):
  crypto: exynos - Support Exynos5250+ SoCs
  crypto: exynos - Improve performance of PRNG
  crypto: exynos - Reseed PRNG after generating 2^16 random bytes
  crypto: exynos - Introduce mutex to prevent concurrent access to
hardware

 .../bindings/crypto/samsung,exynos-rng4.txt|  4 +-
 drivers/crypto/exynos-rng.c| 94 ++
 2 files changed, 62 insertions(+), 36 deletions(-)

-- 
2.11.0