[PATCH 10/13] ARM64: ACPI: Check if it runs on Xen to enable or disable ACPI

[Stefano Stabellini]

On Tue, 17 Nov 2015, shannon.zhao at linaro.org wrote:
> From: Shannon Zhao <shannon.zhao at linaro.org>
> 
> 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 at 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 19de753..7b67426 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -62,10 +62,13 @@ 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 to Xen initial domain that is not
> +	 * either /chosen or /hypervisor node.

* not the /chosen node, or /hypervisor node when running on Xen.

>  	 */
>  	if (depth == 1 && (strcmp(uname, "chosen") != 0))
> -		return 1;
> +		if (!xen_initial_domain() || (strcmp(uname, "hypervisor") != 0))
> +			return 1;

Please add { } around the inner if statement.


>  	return 0;
>  }
>  
> @@ -179,8 +182,9 @@ 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)
> -	 *   and ACPI has not been force enabled (acpi=force)
> +	 * - the device tree is not empty (it has more than just a /chosen node
> +	 *   or to Xen initial domain it has more than a /chosen node and
> +	 *   /hypervisor node) and ACPI has not been force enabled (acpi=force)

the device tree is not empty (it has more than just a /chosen node, and
an /hypervisor node when running on Xen


>  	 */
>  	if (param_acpi_off ||
>  	    (!param_acpi_force && of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
> -- 
> 2.1.0
>