From: Andre Przywara <andre.przywara@arm.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ard Biesheuvel <ardb@kernel.org>, Matt Mackall <mpm@selenic.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Mark Brown <broonie@kernel.org>, Will Deacon <will@kernel.org>,
Ali Saidi <alisaidi@amazon.com>,
Jon Nettleton <jon@solid-run.com>
Subject: Re: [PATCH v2] hwrng: Add Arm SMCCC TRNG based driver
Date: Wed, 21 Jul 2021 00:18:03 +0100 [thread overview]
Message-ID: <20210721001803.303dfba1@slackpad.fritz.box> (raw)
In-Reply-To: <e494866f38e9dcd2834971d3867244fb1d7e6ceb.camel@kernel.crashing.org>
On Wed, 21 Jul 2021 08:02:42 +1000
Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
Hi,
> On Tue, 2021-07-20 at 17:16 +0100, Andre Przywara wrote:
> > Yes, a similar idea was already brought up before. I think there is even
> > the potential for something like an artificial SMCCC "bus", where those
> > services presentable as devices could be auto-detected (by checking
> > known function IDs), the respective drivers would then probe
> > automatically?
>
> Sounds like a boot time killer...
How so? To be clear, at the moment there is basically just the TRNG
service we would probe for, maybe FF-A, then adding as we go. But in
any case it would be just a handful, and querying is very quick
(SMC/HVC, then just a switch/case on the other side, and ERET).
Is there any particular scenario you are concerned about? Quick
starting guests?
> can we instead describe them in DT and/or ACPI ?
I think part of the idea of SMCCC is that it does NOT need firmware
advertisement, but can instead be discovered, through a safe interface.
Cheers,
Andre
next prev parent reply other threads:[~2021-07-20 23:18 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-20 15:21 [PATCH v2] hwrng: Add Arm SMCCC TRNG based driver Andre Przywara
2021-07-20 16:03 ` Ard Biesheuvel
2021-07-20 16:16 ` Andre Przywara
2021-07-20 22:02 ` Benjamin Herrenschmidt
2021-07-20 23:18 ` Andre Przywara [this message]
2021-07-21 11:16 ` Mark Brown
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