[PATCH 00/16] PCI: MSI parent domain conversion
Bjorn Helgaas
helgaas at kernel.org
Thu Jul 3 10:28:01 PDT 2025
On Thu, Jun 26, 2025 at 04:47:50PM +0200, Nam Cao wrote:
> The initial implementation of PCI/MSI interrupt domains in the hierarchical
> interrupt domain model used a shortcut by providing a global PCI/MSI
> domain.
>
> This works because the PCI/MSI[X] hardware is standardized and uniform, but
> it violates the basic design principle of hierarchical interrupt domains:
> Each hardware block involved in the interrupt delivery chain should have a
> separate interrupt domain.
>
> For PCI/MSI[X], the interrupt controller is per PCI device and not a global
> made-up entity.
>
> Unsurprisingly, the shortcut turned out to have downsides as it does not
> allow dynamic allocation of interrupt vectors after initialization and it
> prevents supporting IMS on PCI. For further details, see:
>
> https://lore.kernel.org/lkml/20221111120501.026511281@linutronix.de/
>
> The solution is implementing per device MSI domains, this means the
> entities which provide global PCI/MSI domain so far have to implement MSI
> parent domain functionality instead.
>
> This series converts the PCI controller drivers to implement MSI parent
> domain.
>
> drivers/pci/Kconfig | 1 +
> drivers/pci/controller/Kconfig | 11 +
> drivers/pci/controller/dwc/Kconfig | 1 +
> .../pci/controller/dwc/pcie-designware-host.c | 68 ++----
> drivers/pci/controller/dwc/pcie-designware.h | 1 -
> drivers/pci/controller/mobiveil/Kconfig | 1 +
> .../controller/mobiveil/pcie-mobiveil-host.c | 42 ++--
> .../pci/controller/mobiveil/pcie-mobiveil.h | 1 -
> drivers/pci/controller/pci-aardvark.c | 59 ++---
> drivers/pci/controller/pci-hyperv.c | 98 ++++++--
> drivers/pci/controller/pcie-altera-msi.c | 44 ++--
> drivers/pci/controller/pcie-brcmstb.c | 44 ++--
> drivers/pci/controller/pcie-iproc-msi.c | 45 ++--
> drivers/pci/controller/pcie-mediatek-gen3.c | 67 ++---
> drivers/pci/controller/pcie-mediatek.c | 46 ++--
> drivers/pci/controller/pcie-rcar-host.c | 69 ++----
> drivers/pci/controller/pcie-xilinx-dma-pl.c | 48 ++--
> drivers/pci/controller/pcie-xilinx-nwl.c | 45 ++--
> drivers/pci/controller/pcie-xilinx.c | 55 +++--
> drivers/pci/controller/plda/Kconfig | 1 +
> drivers/pci/controller/plda/pcie-plda-host.c | 44 ++--
> drivers/pci/controller/plda/pcie-plda.h | 1 -
> drivers/pci/controller/vmd.c | 229 +++++++++---------
> 23 files changed, 504 insertions(+), 517 deletions(-)
Looks good to me, thanks! I think Mani will probably pick this up.
I might have included the specific "legacy MSI domain" thing you're
replacing. It looks like you're replacing pci_msi_create_irq_domain()
with msi_create_parent_irq_domain()?
Minor merge conflict in pcie-mediatek-gen3.c with dcbea1c7e94e ("PCI:
mediatek-gen3: Use dev_fwnode() for irq_domain_create_linear()"). No
problem, we can easily fix that up.
The "++i" in vmd.c stuck out to me since "i++" is so much more common.
Acked-by: Bjorn Helgaas <bhelgaas at google.com>
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