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> --- Changes in v2: - Added CONFIG_PCI_DOMAINS_GENERIC guard for domain_nr - Switched to dev_WARN_ONCE() for unhandled interrupts - Squashed the 'linux,pci-domain' bindings patches into one - Link to v1: https://lore.kernel.org/r/20240715-pci-qcom-hotplug-v1-0-5f3765cc873a@xxxxxxxxxx --- Manivannan Sadhasivam (13): 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 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 | 10 ++++ include/linux/pci-epc.h | 2 + 12 files changed, 116 insertions(+), 17 deletions(-) --- base-commit: 91e3b24eb7d297d9d99030800ed96944b8652eaf change-id: 20240715-pci-qcom-hotplug-bcde1c13d91f Best regards, -- Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
