Re: [PATCH v2 1/3] ARM: tegra: basic support for Trusted Foundations

From: Stephen Warren
Date: Thu Jun 13 2013 - 15:19:39 EST


On 06/13/2013 03:12 AM, Alexandre Courbot wrote:
> Add basic support for booting secondary processors on Tegra devices
> using the Trusted Foundations secure monitor.
>
> Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/arm/tegra.txt | 11 +++++
> .../devicetree/bindings/vendor-prefixes.txt | 1 +
> arch/arm/configs/tegra_defconfig | 1 +

The defconfig change should be a separate patch, so that I can squash it
into any other defconfig updates separately from all the code changes.

> diff --git a/arch/arm/mach-tegra/firmware.c b/arch/arm/mach-tegra/firmware.c

> +void __init tegra_init_firmware(void)
> +{
> + struct device_node *node;
> +
> + if (!of_have_populated_dt())
> + return;
> +
> + node = of_find_compatible_node(NULL, NULL, "tl,trusted-foundations");
> + if (node && !IS_ENABLED(CONFIG_TEGRA_TRUSTED_FOUNDATIONS))
> + pr_warn("Trusted Foundations detected but support missing!\n");
> +#if IS_ENABLED(CONFIG_TEGRA_TRUSTED_FOUNDATIONS)
> + else if (node)
> + register_firmware_ops(&tegra_trusted_foundations_ops);
> +#endif
> +}

Is it worth continuing on in the node && !IS_ENABLED case here? After
all, we can be pretty certain that the write to the CPU reset vector is
immediately going to trap...

I suppose that perhaps without SMP, cpuidle, suspend, ... we could keep
running, but that seems a little niche.
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