Date: Thu, 20 Apr 2017 02:29:30 +0000 From: Dexuan Cui <decui@microsoft.com> To: John Baldwin <jhb@freebsd.org>, "freebsd-current@freebsd.org" <freebsd-current@freebsd.org> Cc: Jung-uk Kim <jkim@freebsd.org>, Yanmin Qiao <yaqia@microsoft.com> Subject: RE: Add support for ACPI Module Device ACPI0004? Message-ID: <HK2P15301MB000379C4DD8B253B3568DBCFBF1B0@HK2P15301MB0003.APCP153.PROD.OUTLOOK.COM> In-Reply-To: <3484633.CMRgrtiqef@ralph.baldwin.cx> References: <HK2P15301MB0003969B87170C0593C92EB2BF180@HK2P15301MB0003.APCP153.PROD.OUTLOOK.COM> <3484633.CMRgrtiqef@ralph.baldwin.cx>
next in thread | previous in thread | raw e-mail | index | archive | help
> From: John Baldwin [mailto:jhb@freebsd.org]
> Sent: Thursday, April 20, 2017 02:34
> > Can we add the support of "ACPI0004" with the below one-line change?
> >
> > acpi_sysres_probe(device_t dev)
> > {
> > - static char *sysres_ids[] =3D { "PNP0C01", "PNP0C02", NULL };
> > + static char *sysres_ids[] =3D { "PNP0C01", "PNP0C02", "ACPI0004", =
NULL };
> >
> Hmm, so the role of C01 and C02 is to reserve system resources, though we
> in turn allow any child of acpi0 to suballocate those ranges (since histo=
rically
> c01 and c02 tend to allocate I/O ranges that are then used by things like=
the
> EC, PS/2 keyboard controller, etc.). From my reading of ACPI0004 in the =
ACPI
> 6.1 spec it's not quite clear that ACPI0004 is like that? In particular,=
it
> seems that 004 should only allow direct children to suballocate? This
> change might work, but it will allow more devices to allocate the ranges =
in
> _CRS than otherwise.
>=20
> Do you have an acpidump from a guest system that contains an ACPI0004
> node that you can share?
>=20
> John Baldwin
Hi John,
Thanks for the help!
Please see the attached file, which is got by
"acpidump -dt | gzip -c9 > acpidump.dt.gz"
In the dump, we can see the "ACPI0004" node (VMOD) is the parent of
"VMBus" (VMBS).=20
It looks the _CRS of ACPI0004 is dynamically generated. Though we can't
see the length of the MMIO range in the dumped asl code, it does have
a 512MB MMIO range [0xFE0000000, 0xFFFFFFFFF].
It looks FreeBSD can't detect ACPI0004 automatically.
With the above one-line change, I can first find the child device=20
acpi_sysresource0 of acpi0, then call AcpiWalkResources() to get
the _CRS of acpi_sysresource0, i.e. the 512MB MMIO range.
If you think we shouldn't touch acpi_sysresource0 here, I guess
we can add a new small driver for ACPI0004, just like we added VMBus
driver as a child device of acpi0?
-- Dexuan
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?HK2P15301MB000379C4DD8B253B3568DBCFBF1B0>