From: Richard Henderson <richard.henderson@linaro.org>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
"open list:HARDWARE RANDOM NUMBER GENERATOR CORE"
<linux-crypto@vger.kernel.org>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v4 1/1] arm64: Implement archrandom.h for ARMv8.5-RNG
Date: Fri, 8 Nov 2019 15:52:09 +0100 [thread overview]
Message-ID: <f8c9b7e6-a0f6-211b-0003-a093d2c94e0e@linaro.org> (raw)
In-Reply-To: <CAKv+Gu8y4zwpesytU7vffSCuq8YAjWcHwFHwa_LhTW_cLiSfQw@mail.gmail.com>
On 11/8/19 3:24 PM, Ard Biesheuvel wrote:
>>> To add_interrupt_randomness(), invoked by handle_irq_event_percpu().
>>> Better if I reword the above to include the function name?
>>>
>>
>> This is one of the several places where arch_random_get_seed_long() is
>> called, so if you are going to single it out like that, it does make
>> sense to clarify that.
>>
>
> Looking more carefully at that code, it seems we call
> arch_get_random_seed_long() NR_CPUS times per second, and assuming
> that our RNDRRS sysreg will be reseeded from a resource that is shared
> between all the cores, I am now wondering if this is such a good fit
> after all, especially in the context of virtualization and
> accessibility of both sysregs all the way down to EL0.
>
> I propose we go with RNDR instead, at least for the time being, and
> once actual hardware appears, we can try to figure out how these
> pieces best fit together.
This is what I started with, based on the powerpc implementation.
I can certainly revert to that easily.
r~
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
prev parent reply other threads:[~2019-11-08 14:52 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-06 14:19 [PATCH v4 0/1] arm64: Implement archrandom.h for ARMv8.5-RNG Richard Henderson
2019-11-06 14:19 ` [PATCH v4 1/1] " Richard Henderson
2019-11-06 21:30 ` Ard Biesheuvel
2019-11-08 11:09 ` Richard Henderson
2019-11-08 13:03 ` Ard Biesheuvel
2019-11-08 14:24 ` Ard Biesheuvel
2019-11-08 14:52 ` Richard Henderson [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=f8c9b7e6-a0f6-211b-0003-a093d2c94e0e@linaro.org \
--to=richard.henderson@linaro.org \
--cc=ard.biesheuvel@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-crypto@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=maz@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).