From: Marc Zyngier <maz@kernel.org>
To: Mark Brown <broonie@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 3/4] arm64: Require that system registers at all visible ELs be initialized
Date: Thu, 08 Apr 2021 18:02:19 +0100 [thread overview]
Message-ID: <87r1jkogkk.wl-maz@kernel.org> (raw)
In-Reply-To: <20210401180942.35815-4-broonie@kernel.org>
On Thu, 01 Apr 2021 19:09:41 +0100,
Mark Brown <broonie@kernel.org> wrote:
>
> Currently we require that software at a higher exception level initialise
> all registers at the exception level the kernel will be entered prior to
> starting the kernel in order to ensure that there is nothing uninitialised
> which could result in an UNKNOWN state while running the kernel. The
> expectation is that the software running at the highest exception levels
> will be tightly coupled to the system and can ensure that all available
> features are appropriately initialised and that the kernel can initialise
> anything else.
>
> There is a gap here in the case where new registers are added to lower
> exception levels that require initialisation but the kernel does not yet
> understand them. Extend the requirement to also include exception levels
> below the one where the kernel is entered to cover this.
>
> Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
> Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
M.
--
Without deviation from the norm, progress is not possible.
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next prev parent reply other threads:[~2021-04-08 17:18 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-01 18:09 [PATCH v2 0/4] arm64: Booting clarifications and fine grained traps setup Mark Brown
2021-04-01 18:09 ` [PATCH v2 1/4] arm64: Document requirements for fine grained traps at boot Mark Brown
2021-04-08 17:00 ` Marc Zyngier
2021-04-01 18:09 ` [PATCH v2 2/4] arm64: Disable fine grained traps on boot Mark Brown
2021-04-08 17:00 ` Marc Zyngier
2021-04-01 18:09 ` [PATCH v2 3/4] arm64: Require that system registers at all visible ELs be initialized Mark Brown
2021-04-08 17:02 ` Marc Zyngier [this message]
2021-04-01 18:09 ` [PATCH v2 4/4] arm64: Document values for system registers on boot Mark Brown
2021-04-08 17:16 ` Marc Zyngier
2021-04-08 17:33 ` Mark Brown
2021-04-08 17:59 ` (subset) [PATCH v2 0/4] arm64: Booting clarifications and fine grained traps setup Catalin Marinas
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