Re: [PATCH 2/7] crypto: stm32 - add new algorithms support

From: Thomas BOURGOIN
Date: Thu Jul 13 2023 - 04:03:40 EST


Hi Linus,

On 7/13/23 00:56, Linus Walleij wrote:
Yes this fixes the bug and the tests pass fine 😄

Great news

I wonder why SHA1 was affected? Same codepath?

Yes the number of CSR to save is the same for SHA256 and SHA1. You can look at the 'Context swapping' chapter (47.3.3) in the reference manual for UX500. There is a note at the end telling that you do not have to save all 54 register if you do HASH operation, only 38 are necessary :
> If the context swap does not involve HMAC operations, registers cs_rk0 to cs_rk7 and
cs_rh0 to cs_rh7 can be ignored
Best regards,

Thomas