Re: [Xen-devel] [PATCH v2 07/17] libxl/arm: Construct ACPI GTDT table

[Julien Grall <julien.grall@xxxxxxx>]

Hi,

On 23/06/16 16:00, Stefano Stabellini wrote:
> On Thu, 23 Jun 2016, Shannon Zhao wrote:
[...]

> > +static void make_acpi_gtdt(libxl__gc *gc, struct xc_dom_image *dom)
> > +{
> > +    struct acpi_table_gtdt *gtdt;
> > +    size_t size = sizeof(*gtdt);
> > +
> > +    gtdt = libxl__zalloc(gc, size);
> > +
> > +    gtdt->non_secure_el1_interrupt = GUEST_TIMER_PHYS_NS_PPI;
> > +    gtdt->non_secure_el1_flags =
> > +                             (ACPI_LEVEL_SENSITIVE << ACPI_GTDT_INTERRUPT_MODE)
> > +                             |(ACPI_ACTIVE_LOW << 
> > ACPI_GTDT_INTERRUPT_POLARITY);
> > +    gtdt->virtual_timer_interrupt = GUEST_TIMER_VIRT_PPI;
> > +    gtdt->virtual_timer_flags =
> > +                             (ACPI_LEVEL_SENSITIVE << ACPI_GTDT_INTERRUPT_MODE)
> > +                             |(ACPI_ACTIVE_LOW << 
> > ACPI_GTDT_INTERRUPT_POLARITY);
> > +
> > +    make_acpi_header(&gtdt->header, "GTDT", size, 2);
> > +
> > +    acpitables[GTDT].table = gtdt;
> > +    acpitables[GTDT].size = size;
> > +    /* Align to 64bit. */
> > +    dom->acpitable_size += ROUNDUP(acpitables[GTDT].size, 3);
> > +}
> Many of this tables look pretty much static. Any reason why we can't
> define them and initialize them on an header somewhere like:
>
>      struct acpi_gtdt xen_acpi_gtdt {
>          .non_secure_el1_interrupt = GUEST_TIMER_PHYS_NS_PPI;
>          .non_secure_el1_flags = (ACPI_LEVEL_SENSITIVE << ACPI_GTDT_INTERRUPT_MODE) | 
> (ACPI_ACTIVE_LOW << ACPI_GTDT_INTERRUPT_POLARITY);
>          .virtual_timer_interrupt = GUEST_TIMER_VIRT_PPI;
>          .virtual_timer_flags = (ACPI_LEVEL_SENSITIVE << 
> ACPI_GTDT_INTERRUPT_MODE)|(ACPI_ACTIVE_LOW << ACPI_GTDT_INTERRUPT_POLARITY);
>      };
>
> it would make the code shorter and easier to read.
I agree with Stefano on this point.

> >   int libxl__prepare_acpi(libxl__gc *gc, libxl_domain_build_info *info,
> >                           libxl__domain_build_state *state,
> >                           struct xc_dom_image *dom)
> > @@ -132,6 +159,7 @@ int libxl__prepare_acpi(libxl__gc *gc, 
> > libxl_domain_build_info *info,
> >
> >       make_acpi_rsdp(gc, dom);
> >       make_acpi_xsdt(gc, dom);
> > +    make_acpi_gtdt(gc, dom);
> >
> >       return 0;
> >   }
> > --
> > 2.0.4
Regards,

--
Julien Grall

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