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c18ac9fbcc
The non-prefetchable MMIO aperture of a bridge can never fall outside of
the 32-bit address space. Namely, the MemoryBase and MemoryLimit fields in
PCI_BRIDGE_CONTROL_REGISTER have type UINT16, and based on the PCI-to-PCI
Bridge Architecture Spec, Chapter 3.2, the actual MMIO aperture is
determined as in:
NonPrefetchMemoryBase = (((MemoryBase & 0xFFF0u) >> 4) << 20) | 0x00000
NonPrefetchMemoryLimit = (((MemoryLimit & 0xFFF0u) >> 4) << 20) | 0xFFFFF
In "OvmfPkg/PciHotPlugInitDxe", the
"mPadding.MmioPadding.AddrSpaceGranularity" field is currently initialized
to 64. According to the above, this is useless generality: a
non-prefetchable MMIO reservation may only be satisfied from 32-bit
address space. Update the field to 32.
In practice this change makes no difference, because PciBusDxe already
enforces the 32-bit limitation when it sees "non-prefetchable" from
(SpecificFlag==0). Quoting commit 8aba40b79267 ("OvmfPkg: add
PciHotPlugInitDxe", 2016-06-30): "regardless of our request for 64-bit
MMIO reservation, it is downgraded to 32-bit".
(See the Platform Init Spec 1.6, Volume 5,
- Table 8. "ACPI 2.0 & 3.0 QWORD Address Space Descriptor Usage", and
- Table 11. "Memory Resource Flag (Resource Type = 0) Usage",
for an explanation of the "mPadding.MmioPadding" fields.)
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Marcel Apfelbaum <marcel@redhat.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Fixes: 8aba40b79267df761bd24d6874ae87f47a7bd3de
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
EDK II Project
A modern, feature-rich, cross-platform firmware development environment for the UEFI and PI specifications from www.uefi.org.
Contributions to the EDK II open source project are covered by the TianoCore Contribution Agreement 1.1
The majority of the content in the EDK II open source project uses a BSD 2-Clause License. The EDK II open source project contains the following components that are covered by additional licenses:
- AppPkg/Applications/Python/Python-2.7.2/Tools/pybench
- AppPkg/Applications/Python/Python-2.7.2
- AppPkg/Applications/Python/Python-2.7.10
- BaseTools/Source/C/BrotliCompress
- MdeModulePkg/Library/BrotliCustomDecompressLib
- OvmfPkg
- CryptoPkg/Library/OpensslLib/openssl
The EDK II Project is composed of packages. The maintainers for each package are listed in Maintainers.txt.