[PATCH 00/14] PCI: qcom: Simulate PCIe hotplug using 'global' interrupt

[Manivannan Sadhasivam via B4 Relay]

Hi,

This series adds support to simulate PCIe hotplug using the Qcom specific
'global' IRQ. Historically, Qcom PCIe RC controllers lack standard hotplug
support. So when an endpoint is attached to the SoC, users have to rescan the
bus manually to enumerate the device. But this can be avoided by simulating the
PCIe hotplug using Qcom specific way.

Qcom PCIe RC controllers are capable of generating the 'global' SPI interrupt
to the host CPUs. The device driver can use this event to identify events such
as PCIe link specific events, safety events etc...

One such event is the PCIe Link up event generated when an endpoint is detected
on the bus and the Link is 'up'. This event can be used to simulate the PCIe
hotplug in the Qcom SoCs.

So add support for capturing the PCIe Link up event using the 'global' interrupt
in the driver. Once the Link up event is received, the bus underneath the host
bridge is scanned to enumerate PCIe endpoint devices, thus simulating hotplug.

This series also has some cleanups to the Qcom PCIe EP controller driver for
interrupt handling.

Testing
=======

This series is tested on Qcom SM8450 based development board that has 2 SoCs
connected over PCIe.

- Mani

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
---
Manivannan Sadhasivam (14):
      PCI: qcom-ep: Drop the redundant masking of global IRQ events
      PCI: qcom-ep: Reword the error message for receiving unknown global IRQ event
      dt-bindings: PCI: pci-ep: Update Maintainers
      dt-bindings: PCI: pci-ep: Document 'linux,pci-domain' property
      dt-bindings: PCI: qcom-ep: Document "linux,pci-domain" property
      PCI: endpoint: Assign PCI domain number for endpoint controllers
      PCI: qcom-ep: Modify 'global_irq' and 'perst_irq' IRQ device names
      ARM: dts: qcom: sdx55: Add 'linux,pci-domain' to PCIe EP controller node
      ARM: dts: qcom: sdx65: Add 'linux,pci-domain' to PCIe EP controller node
      arm64: dts: qcom: sa8775p: Add 'linux,pci-domain' to PCIe EP controller nodes
      dt-bindings: PCI: qcom: Add 'global' interrupt
      dt-bindings: PCI: qcom,pcie-sm8450: Add 'global' interrupt
      PCI: qcom: Simulate PCIe hotplug using 'global' interrupt
      arm64: dts: qcom: sm8450: Add 'global' interrupt to the PCIe RC node

 Documentation/devicetree/bindings/pci/pci-ep.yaml  | 14 +++++-
 .../devicetree/bindings/pci/qcom,pcie-common.yaml  |  4 +-
 .../devicetree/bindings/pci/qcom,pcie-ep.yaml      |  1 +
 .../devicetree/bindings/pci/qcom,pcie-sm8450.yaml  | 10 ++--
 arch/arm/boot/dts/qcom/qcom-sdx55.dtsi             |  1 +
 arch/arm/boot/dts/qcom/qcom-sdx65.dtsi             |  1 +
 arch/arm64/boot/dts/qcom/sa8775p.dtsi              |  2 +
 arch/arm64/boot/dts/qcom/sm8450.dtsi               | 12 +++--
 drivers/pci/controller/dwc/pcie-qcom-ep.c          | 21 +++++++--
 drivers/pci/controller/dwc/pcie-qcom.c             | 55 ++++++++++++++++++++++
 drivers/pci/endpoint/pci-epc-core.c                |  1 +
 include/linux/pci-epc.h                            |  2 +
 12 files changed, 108 insertions(+), 16 deletions(-)
---
base-commit: 91e3b24eb7d297d9d99030800ed96944b8652eaf
change-id: 20240715-pci-qcom-hotplug-bcde1c13d91f

Best regards,
-- 
Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>