Re: [RFC 1/2] ACPI: activate&export acpi_os_get_physical_address

From: Rafael J. Wysocki
Date: Thu Apr 30 2015 - 21:21:04 EST

On Friday, May 01, 2015 03:32:29 AM Rafael J. Wysocki wrote:
> On Thursday, April 30, 2015 11:10:25 AM Darren Hart wrote:
> > On Wed, Apr 22, 2015 at 04:12:24PM +0200, Kast Bernd wrote:
> > > acpi_os_get_physical_address will be needed by an acpi driver (asus-wmi.c).
> > > Additionally it could be used by dell-laptop.c instead of directly calling virt_to_phys.
> > >
> > > acpi_os_get_physical_address gets exported and ACPI_FUTURE_USAGE is removed
> > >
> >
> > Hrm, well... this doesn't get rid of virt_to_phys, it just wraps it really. I'm
> > not sure that makes this any more acceptable than the original from Felipe - but
> > that's not my call.
> Use virt_to_phys() if you need to.
> This one is in case ACPICA needs to get the virtual-to-physical mapping (hence

More to the point, the reason why virt_to_phys() needs to be used in patch [2/2]
seems to be a nasty hack in the ASUS AML that pretty much expects us to provide
the physical address as an argument.

And I don't really understand the Matthew's comment regarding limiting
operation regions to system memory. This is about a specific operation
region (which BTW only seems to be used as a means to access system memory
at the location pointed to by the arg) in that particular method.


I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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