PCI: vmd: Add feature to scan BIOS-enumerated devices

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Newer VMD with device ID 0x28C1 has unique settings compared to its
predecessor where BIOS enumerates the entire VMD device tree and assigns
respective configurations.

VMD configuration BAR0 carries over from GNR legacy VMD as the mechanism
to access the configuration space of the devices owned by VMD. The size
of this window is fixed at 256 MB, where each function consumes 4 KB and
every bus consumes 1 MB.

The shadow and scratchpad registers have been relocated from the VMD
configuration space to the VMD MMIO space in VMD BAR4/BAR5, otherwise
refers to as MEMBAR2 or MSI-X bar.

VMD MSI-X remapping enable/disable is no longer supported.

On this new device, simply obtain the bus hide range and shadow register
values set by BIOS and perform a bus scan.

Also refactor vmd_enable_domain().

Signed-off-by: Nirmal Patel <nirmal.patel@linux.intel.com>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260629165025.268836-1-nirmal.patel@linux.intel.com

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Nirmal Patel 2026-06-29 16:50:25 +00:00 • committed by Bjorn Helgaas

parent dc59e4fea9

commit b030905bf5

2 changed files with 150 additions and 31 deletions

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180

drivers/pci/controller/vmd.c

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1

include/linux/pci_ids.h

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