Date: Sat, 26 Mar 2016 12:56:24 +0000
From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
To: Shannon Zhao <shannon.zhao@linaro.org>
CC: <linux-arm-kernel@lists.infradead.org>, <stefano.stabellini@citrix.com>,
        <david.vrabel@citrix.com>, <devicetree@vger.kernel.org>,
        <linux-efi@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <catalin.marinas@arm.com>, <will.deacon@arm.com>,
        <julien.grall@arm.com>, <peter.huangpeng@huawei.com>,
        <xen-devel@lists.xen.org>, <zhaoshenglong@huawei.com>
Subject: Re: [PATCH v7 12/17] ARM64: ACPI: Check if it runs on Xen to enable
 or disable ACPI
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 <1458830676-27075-13-git-send-email-shannon.zhao@linaro.org>
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Will, Catalin,

are you OK with this change?
The series is almost ready to go in, I would like to tie up the loose ends.

Thanks,

Stefano

On Thu, 24 Mar 2016, Shannon Zhao wrote:
> When it's a Xen domain0 booting with ACPI, it will supply a /chosen and
> a /hypervisor node in DT. So check if it needs to enable ACPI.
> 
> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> Acked-by: Hanjun Guo <hanjun.guo@linaro.org>
> ---
>  arch/arm64/kernel/acpi.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> index d1ce8e2..4e92be0 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -67,10 +67,13 @@ static int __init dt_scan_depth1_nodes(unsigned long node,
>  {
>  	/*
>  	 * Return 1 as soon as we encounter a node at depth 1 that is
> -	 * not the /chosen node.
> +	 * not the /chosen node, or /hypervisor node when running on Xen.
>  	 */
> -	if (depth == 1 && (strcmp(uname, "chosen") != 0))
> -		return 1;
> +	if (depth == 1 && (strcmp(uname, "chosen") != 0)) {
> +		if (!xen_initial_domain() || (strcmp(uname, "hypervisor") != 0))
> +			return 1;
> +	}
> +
>  	return 0;
>  }
>  
> @@ -184,7 +187,8 @@ void __init acpi_boot_table_init(void)
>  	/*
>  	 * Enable ACPI instead of device tree unless
>  	 * - ACPI has been disabled explicitly (acpi=off), or
> -	 * - the device tree is not empty (it has more than just a /chosen node)
> +	 * - the device tree is not empty (it has more than just a /chosen node,
> +	 *   and a /hypervisor node when running on Xen)
>  	 *   and ACPI has not been force enabled (acpi=force)
>  	 */
>  	if (param_acpi_off ||
> -- 
> 2.1.4
>