[PATCH] Make x86 Host-PCI bridge drivers honor decoded ranges

This patch adds a new API (pcib_host_res_*) that Host-PCI bridge drivers =
can=20
use to restrict allocations for child devices to a known subset of =
address=20
ranges that the bridge decodes.  Originally I tried to allocate the full=20=

ranges and use rmans just as we now do for PCI-PCI bridge windows.  =
However,=20
this broke due to the fact that all of our ACPI LPC/ISA devices attach =
at the=20
"wrong" place in the tree (they aren't behind the host-PCI bridges) and =
a=20
typical ACPI BIOS will allocate the full I/O port range to the host-PCI=20=

bridge.  We could perhaps fix this later if we relocate all the ACPI =
devices=20
that are actually ISA devices down onto an ACPI-aware ISA bus (i.e. an =
ISA bus=20
that uses ACPI to enumerate devices).  Anyway, I punted on that for now. =
=20
Instead, the current API works by using a resource_list to keep track of =
all=20
the valid address ranges.  When an allocation request is made, it simply =
tries=20
all the address ranges in turn.  I still made it honor =
hw.pci.host_mem_start=20
since the ACPI BIOSes I have seen will optionally include option ROM =
space=20
below 1MB if any ROMs are active, but we don't want to allocate that =
space for=20
a wildcard BAR operation.

I've changed the ACPI and MPTable Host-PCI bridge drivers to use this =
helper=20
API.  For ACPI we claim that bridges decode any "producer" address =
ranges in=20
the bridges _CRS.  For the MPTable I had to add logic to walk the =
extended=20
MPTable entries and use those extended entries to find the list of =
decoded=20
ranges.  I'd like to get this into 9.0 and would appreciate folks =
testing it out.

http://www.FreeBSD.org/~jhb/patches/pci_host_res.patch

--=20
John Baldwin

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