Re: [PATCH v3 12/17] ARM64: ACPI: Check if it runs on Xen to enable or disable ACPI

From: Stefano Stabellini
Date: Mon Jan 25 2016 - 10:32:51 EST


On Sat, 23 Jan 2016, Shannon Zhao wrote:
> From: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>

Reviewed-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>


> CC: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> ---
> 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 ||
> --
> 2.0.4
>
>