Re: [PATCH v4 15/21] arm/gic: Add ACPI support for GIC preinit

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

On Sat, 23 Jan 2016, Shannon Zhao wrote:
> From: Shannon Zhao <shannon.zhao@linaro.org>
> 
> Since ACPI 6.0 defines that GIC Distributor Structure contains the GIC
> version filed, it could get GIC version from that. Then call acpi device
> initializing function to preinit GIC device.
> 
> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
> ---
> V4: use ACPI_MADT_GIC_VERSION_V* instead of GICv*
> ---
>  xen/arch/arm/gic.c | 37 +++++++++++++++++++++++++++++++++----
>  1 file changed, 33 insertions(+), 4 deletions(-)
> 
> diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
> index 43e6fa2..840075f 100644
> --- a/xen/arch/arm/gic.c
> +++ b/xen/arch/arm/gic.c
> @@ -27,6 +27,7 @@
>  #include <xen/softirq.h>
>  #include <xen/list.h>
>  #include <xen/device_tree.h>
> +#include <xen/acpi.h>
>  #include <asm/p2m.h>
>  #include <asm/domain.h>
>  #include <asm/platform.h>
> @@ -34,6 +35,7 @@
>  #include <asm/io.h>
>  #include <asm/gic.h>
>  #include <asm/vgic.h>
> +#include <asm/acpi.h>
>  
>  static void gic_restore_pending_irqs(struct vcpu *v);
>  
> @@ -228,10 +230,7 @@ int gic_irq_xlate(const u32 *intspec, unsigned int intsize,
>      return 0;
>  }
>  
> -/* Find the interrupt controller and set up the callback to translate
> - * device tree IRQ.
> - */
> -void __init gic_preinit(void)
> +static void __init gic_dt_preinit(void)
>  {
>      int rc;
>      struct dt_device_node *node;
> @@ -261,6 +260,36 @@ void __init gic_preinit(void)
>      dt_device_set_used_by(node, DOMID_XEN);
>  }
>  
> +#ifdef CONFIG_ACPI
> +static void __init gic_acpi_preinit(void)
> +{
> +    struct acpi_subtable_header *header;
> +    struct acpi_madt_generic_distributor *dist;
> +
> +    header = acpi_table_get_entry_madt(ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR, 0);
> +    if ( !header )
> +        panic("No valid GICD entries exists");
> +
> +    dist = container_of(header, struct acpi_madt_generic_distributor, header);
> +
> +    if ( acpi_device_init(DEVICE_GIC, NULL, dist->version) )
> +        panic("Unable to find compatible GIC in the ACPI table");
> +}
> +#else
> +static void __init gic_acpi_preinit(void) {}
> +#endif

Again if acpi_disabled were an #define constant, this #else would
not be needed. Provided that you remove it, you can add my Reviewed-by.


> +/* Find the interrupt controller and set up the callback to translate
> + * device tree or ACPI IRQ.
> + */
> +void __init gic_preinit(void)
> +{
> +    if ( acpi_disabled )
> +        gic_dt_preinit();
> +    else
> +        gic_acpi_preinit();
> +}
> +
>  /* Set up the GIC */
>  void __init gic_init(void)
>  {