On Sunday, April 30, 2017 09:02:30 AM Sepherosa Ziehau wrote: > On Sat, Apr 29, 2017 at 12:01 AM, John Baldwin <j...@freebsd.org> wrote: > > On Friday, April 28, 2017 05:38:32 PM Sepherosa Ziehau wrote: > >> On Thu, Apr 27, 2017 at 12:14 AM, John Baldwin <j...@freebsd.org> wrote: > >> > On Wednesday, April 26, 2017 09:18:48 AM Sepherosa Ziehau wrote: > >> >> On Wed, Apr 26, 2017 at 4:36 AM, John Baldwin <j...@freebsd.org> wrote: > >> >> > On Thursday, April 20, 2017 02:29:30 AM Dexuan Cui wrote: > >> >> >> > From: John Baldwin [mailto:j...@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[] = { "PNP0C01", "PNP0C02", NULL }; > >> >> >> > > + static char *sysres_ids[] = { "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 historically > >> >> >> > 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. > >> >> >> > > >> >> >> > Do you have an acpidump from a guest system that contains an > >> >> >> > ACPI0004 > >> >> >> > node that you can share? > >> >> >> > > >> >> >> > 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). > >> >> >> 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 > >> >> >> 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? > >> >> > > >> >> > Hmmm, so looking at this, the "right" thing is probably to have a > >> >> > device > >> >> > driver for the ACPI0004 device that parses its _CRS and then allows > >> >> > its > >> >> > child devices to sub-allocate resources from the ranges in _CRS. > >> >> > However, > >> >> > this would mean make VMBus be a child of the ACPI0004 device. Suppose > >> >> > we called the ACPI0004 driver 'acpi_module' then the 'acpi_module0' > >> >> > device > >> >> > would need to create a child device for all of its child devices. > >> >> > Right > >> >> > now acpi0 also creates devices for them which is somewhat messy (acpi0 > >> >> > creates child devices anywhere in its namespace that have a valid > >> >> > _HID). > >> >> > You can find those duplicates and remove them during acpi_module0's > >> >> > attach > >> >> > routine before creating its own child device_t devices. (We associate > >> >> > a device_t with each Handle when creating device_t's for ACPI handles > >> >> > which is how you can find the old device that is a direct child of > >> >> > acpi0 > >> >> > so that it can be removed). > >> >> > >> >> The remove/reassociate vmbus part seems kinda "messy" to me. I'd just > >> >> hook up a new acpi0004 driver, and let vmbus parse the _CRS like what > >> >> we did to the hyper-v's pcib0. > >> > > >> > The acpi_pci driver used to do the remove/reassociate part. What acpi0 > >> > should probably be doing is only creating device_t nodes for immediate > >> > children. This would require an ACPI-aware isa0 for LPC devices below > >> > the ISA bus in the ACPI namespace. We haven't done that in part because > >> > BIOS vendors are not always consistent in placing LPC devices under an > >> > ISA bus. However, you otherwise have no good way to find your parent > >> > ACPI0004 device. You could perhaps find your ACPI handle, ask for its > >> > parent handle, then ask for the device_t of that handle to find the > >> > ACPI0004 device, but then you'd need to have all your bus_alloc_resource > >> > calls go to that device, not your "real" parent of acpi0, which means > >> > you can't use any of the standard bus_alloc_resource() methods like > >> > bus_alloc_resource_any() but would have to manually use > >> > BUS_ALLOC_RESOURCE > >> > with the ACPI0004 device as the explicit first argument. It is primarily > >> > the ability to let ACPI0004's driver transparently intercept all the > >> > resource allocation so it can manage that is the reason for "VMBus" > >> > to be a child of ACPI0004 rather than its sibling. > >> > >> Well, there could be more then one ACPI0004 typed devices, which could > >> not form a device tree for vmbus. > > > > Are you saing a vmbus would need resources from multiple ACPI0004 devices? > > ACPI0004 (and several other PNP ids, see dexuan's submission) is > something just like the acpi_sysresource. Not directly related to the > vmbus at all.
In the acpidump, the "vmbus" device was a direct child of ACPI0004. This is quite different from acpi_sysresource0 which can be in random places in the namespace (sometimes it is off of isab0, sometimes it is a child of isab0 or of _SB_), and thus devices that suballocate ranges it reserves (like ipmi0 or acpi_ec0) are sometimes siblings, etc. That doesn't seem to be true for ACPI004 as it is explicitly described as a container object. -- John Baldwin _______________________________________________ freebsd-current@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
