Re: [PATCH v2 2/3] x86/acpi: take rsdp address for boot params if available

[Ingo Molnar <mingo@kernel.org>]

* Juergen Gross <jgross@suse.com> wrote:

> On 08/12/17 08:05, Ingo Molnar wrote:
> > 
> > * Juergen Gross <jgross@suse.com> wrote:
> 
> ...
> 
> > acpi_physical_address acpi_arch_get_root_pointer(void)
> > {
> > 	return boot_params.hdr.acpi_rsdp_addr;
> > }
> > 
> > 4)
> > 
> > Add this to arch/x86/include/asm/acpi.h:
> > 
> > extern acpi_physical_address acpi_arch_get_root_pointer(void);
> 
> Uuh, this leads to problems for files including <asm/acpi.h> directly:
> acpi_physical_address won't be defined, and including <acpi/actypes.h>
> from arch/x86/include/asm/acpi.h will lead to:
> 
> #error unknown ACPI_MACHINE_WIDTH
> 
> This can only be avoided by including <linux/acpi.h> from <asm/acpi.h>
> which seems to be the wrong layering.
> 
> So I could:
> 
> a) modify the sources including <asm/acpi.h> to use <linux/acpi.h>
>    instead
> b) don't use acpi_physical_address but either u64 or unsigned long.
> c) ?
> 
> What would be your preference?

Would it help if you put the prototype into linux/acpi.h perhaps? It's a generic 
facility in principle, even if only used by x86 at the moment.

Thanks,

	Ingo