From: catalin.marinas@arm•com (Catalin Marinas)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 9/9] arm64: Add new cpu-return-addr device tree binding
Date: Wed, 27 Aug 2014 09:30:22 +0100 [thread overview]
Message-ID: <20140827083022.GE6968@arm.com> (raw)
In-Reply-To: <4192d403bb9703063c59a052293faa19d38d2f02.1408736066.git.geoff@infradead.org>
On Fri, Aug 22, 2014 at 08:49:17PM +0100, Geoff Levand wrote:
> Add a new arm64 device tree binding cpu-return-addr. This binding is recomended
> for all ARM v8 CPUs that have an "enable-method" property value of "spin-table".
> The value is a 64 bit physical address that secondary CPU execution will transfer
> to upon CPU shutdown.
>
> Signed-off-by: Geoff Levand <geoff@infradead•org>
> ---
> Documentation/devicetree/bindings/arm/cpus.txt | 25 +++++++++++++++++++++++++
> 1 file changed, 25 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt
> index 1fe72a0..42d5d5f 100644
> --- a/Documentation/devicetree/bindings/arm/cpus.txt
> +++ b/Documentation/devicetree/bindings/arm/cpus.txt
> @@ -201,6 +201,15 @@ nodes to be present and contain the properties described below.
> property identifying a 64-bit zero-initialised
> memory location.
>
> + - cpu-return-addr
> + Usage: recomended for all ARM v8 CPUs that have an
> + "enable-method" property value of "spin-table".
> + Value type: <prop-encoded-array>
> + Definition:
> + # On ARM v8 64-bit systems must be a two cell property.
> + The value is a 64 bit physical address that secondary
> + CPU execution will transfer to upon CPU shutdown.
As I've been away for most of the past four weeks, I haven't read all
the threads around this topic. But I don't think we ended up with a
clearly agreed recommendation for cpu-return-addr. If we do, we also
need to be clear on what state the CPU should be in when returned to
such address (ELx, MMU, caches).
In general, if we need returning to firmware I would strongly recommend
PSCI but I know there is the Applied board which does not have EL3, so
something like this may work. But we need to get them into discussion as
well since I assume cpu-return-addr would be a firmware provided
address.
--
Catalin
next prev parent reply other threads:[~2014-08-27 8:30 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-22 19:49 [PATCH 0/9] arm64: minor fixups and enhancements Geoff Levand
2014-08-22 19:49 ` [PATCH 1/9] arm64: Fix efi kernel entry Geoff Levand
2014-08-26 15:55 ` Catalin Marinas
2014-08-26 16:19 ` Ard Biesheuvel
2014-08-26 18:42 ` Geoff Levand
2014-08-22 19:49 ` [PATCH 7/9] arm64: Add atomic macros to assembler.h Geoff Levand
2014-08-26 16:05 ` Catalin Marinas
2014-08-26 19:40 ` Geoff Levand
2014-08-27 8:25 ` Catalin Marinas
2014-08-22 19:49 ` [PATCH 3/9] arm64: Remove unneeded extern keyword Geoff Levand
2014-08-26 16:11 ` Mark Rutland
2014-08-22 19:49 ` [PATCH 5/9] arm64: Fix include header order in vmlinux.lds.S Geoff Levand
2014-08-26 16:27 ` Mark Rutland
2014-08-26 19:27 ` Geoff Levand
2014-08-27 8:24 ` Catalin Marinas
2014-08-29 21:53 ` Geoff Levand
2014-08-22 19:49 ` [PATCH 2/9] arm64: Fix INVALID_HWID definition Geoff Levand
2014-08-26 15:57 ` Catalin Marinas
2014-08-26 18:18 ` Geoff Levand
2014-08-27 8:21 ` Catalin Marinas
2014-08-26 16:31 ` Mark Rutland
2014-08-26 17:38 ` Geoff Levand
2014-08-22 19:49 ` [PATCH 4/9] arm64: Remove unused variable in head.S Geoff Levand
2014-08-27 8:40 ` Will Deacon
2014-08-22 19:49 ` [PATCH 6/9] arm64: Add new routine local_disable Geoff Levand
2014-08-26 16:04 ` Catalin Marinas
2014-08-26 16:23 ` Mark Rutland
2014-08-22 19:49 ` [PATCH 8/9] arm64: Add missing AT() macros to vmlinux.lds.S Geoff Levand
2014-08-26 16:08 ` Catalin Marinas
2014-08-26 19:33 ` Geoff Levand
2014-08-27 6:53 ` AKASHI Takahiro
2014-08-22 19:49 ` [PATCH 9/9] arm64: Add new cpu-return-addr device tree binding Geoff Levand
2014-08-27 8:30 ` Catalin Marinas [this message]
2014-08-29 21:45 ` Geoff Levand
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