Is there much point to the PCDs after this? Even before, the benefit was minimal. I think there was the idea that they could allow you to get the base address without having to include the platform specific include files. (OvmfPlatforms.h)
Another idea could be to go ahead and convert it to a dynamic PCD, and use it wherever possible. But, it doesn't seem all that important either way. I'd prefer to either drop the PCDs, or make 1 dynamic PCD. What do you think? -Jordan On 2016-05-09 17:37:29, Laszlo Ersek wrote: > Short version: > - Each PCIe downstream port can host only one device. > - Each PCIe downstream port is represented as a PCI bridge. > - If a PCI device needs an IO BAR, then the non-root bridge it is on > will at least need 0x1000 IO ports (required by the PCI spec), for > accommodating the IO BARs of all of the devices on it. > - Consequently, each IO BAR requiring device in a PCIe downstream port > eats up 0x1000 from the limited PCI IO Port aperture (current size: > 0x4000). > - The long term solution is to move away from IO BARs (for example, > legacy-free virtio-1.0 devices use MMIO BARs only). > - Until then, we can push down PMBASE from 0xB000 to 0x0600 on Q35 (same > as SeaBIOS does), and then push down the base of the PCI IO Port > aperture from 0xC000 to 0x6000, increasing its size from 0x4000 to > 0xA000. > > Long version: > - https://bugzilla.redhat.com/show_bug.cgi?id=1333238 > > Public branch: > - https://github.com/lersek/edk2/commits/grow_portspace_bz1333238 > > Cc: Jordan Justen <[email protected]> > > Thanks > Laszlo > > Laszlo Ersek (6): > OvmfPkg: rename PcdAcpiPmBaseAddress to PcdPiix4AcpiPmBaseAddress > OvmfPkg: add and use industry standard macro PIIX4_PMBA_MASK > OvmfPkg: introduce PcdIch9AcpiPmBaseAddress > OvmfPkg: determine PMBA value dependent on host bridge device ID > OvmfPkg/PlatformPei: set PCI IO port aperture dynamically > OvmfPkg/PlatformPei: provide 10 * 4KB of PCI IO Port space on Q35 > > OvmfPkg/OvmfPkg.dec | 16 ++++--- > OvmfPkg/OvmfPkgIa32.dsc | 2 + > OvmfPkg/OvmfPkgIa32X64.dsc | 2 + > OvmfPkg/OvmfPkgX64.dsc | 2 + > OvmfPkg/Library/AcpiTimerLib/BaseAcpiTimerLib.inf | 5 +- > OvmfPkg/Library/AcpiTimerLib/BaseRomAcpiTimerLib.inf | 5 +- > OvmfPkg/Library/ResetSystemLib/ResetSystemLib.inf | 5 +- > OvmfPkg/PlatformPei/PlatformPei.inf | 3 +- > OvmfPkg/Include/IndustryStandard/I440FxPiix4.h | 2 + > OvmfPkg/Library/AcpiTimerLib/BaseAcpiTimerLib.c | 10 +++- > OvmfPkg/Library/AcpiTimerLib/BaseRomAcpiTimerLib.c | 10 +++- > OvmfPkg/Library/ResetSystemLib/ResetSystemLib.c | 22 ++++++++- > OvmfPkg/PlatformPei/Platform.c | 48 > +++++++++++++++----- > 13 files changed, 101 insertions(+), 31 deletions(-) > > -- > 1.8.3.1 > _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
