On Thursday 13 January 2022 11:49:38 Stefan Roese wrote:
> From: Bharat Kumar Gogada <bharat.kumar.gogada@xxxxxxxxxx>
>
> As per section 6.2.4.1.2, 6.2.6 in PCIe r4.0 (and later versions),
> platform-specific System Errors like AER can be delivered via platform-
> specific interrupt lines.
>
> This patch adds the init_platform_service_irqs() hook to struct
> pci_host_bridge, making it possible that platforms may implement this
> function to hook IRQs for these platform-specific System Errors, like
> AER.
>
> If these platform-specific service IRQs have been successfully
> installed via pcie_init_platform_service_irqs(),
> pcie_init_service_irqs() is skipped.
>
> Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xxxxxxxxxx>
> Signed-off-by: Stefan Roese <sr@xxxxxxx>
> Cc: Bjorn Helgaas <helgaas@xxxxxxxxxx>
> Cc: Pali Rohár <pali@xxxxxxxxxx>
> Cc: Michal Simek <michal.simek@xxxxxxxxxx>
> ---
> drivers/pci/pcie/portdrv_core.c | 43 ++++++++++++++++++++++++++++++++-
> include/linux/pci.h | 2 ++
> 2 files changed, 44 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
> index bda630889f95..4dab74ff4368 100644
> --- a/drivers/pci/pcie/portdrv_core.c
> +++ b/drivers/pci/pcie/portdrv_core.c
> @@ -190,6 +190,31 @@ static int pcie_init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
> return 0;
> }
>
> +/**
> + * pcie_init_platform_service_irqs - initialize platform service irqs for
> + * platform-specific System Errors
> + * @dev: PCI Express port to handle
> + * @irqs: Array of irqs to populate
> + * @mask: Bitmask of capabilities
> + *
> + * Return value: true/false for platforms service irqs installed or not
> + */
> +static bool pcie_init_platform_service_irqs(struct pci_dev *dev,
> + int *irqs, int mask)
> +{
> + struct pci_host_bridge *bridge;
> +
> + if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
I think that this check is not needed as it is done before calling
pcie_init_platform_service_irqs() function.
> + bridge = pci_find_host_bridge(dev->bus);
> + if (bridge && bridge->init_platform_service_irqs) {
> + bridge->init_platform_service_irqs(dev, irqs, mask);
> + return true;
Suggestion: What about "return bridge->init_platform_service_irqs(...);" ?
This could allow callback function to fail...
> + }
> + }
> +
> + return false;
> +}
> +
> /**
> * get_port_device_capability - discover capabilities of a PCI Express port
> * @dev: PCI Express port to examine
> @@ -318,6 +343,7 @@ int pcie_port_device_register(struct pci_dev *dev)
> int irqs[PCIE_PORT_DEVICE_MAXSERVICES] = {
> [0 ... PCIE_PORT_DEVICE_MAXSERVICES-1] = -1
> };
> + bool plat_irqs;
>
> /* Enable PCI Express port device */
> status = pci_enable_device(dev);
> @@ -342,7 +368,22 @@ int pcie_port_device_register(struct pci_dev *dev)
> irq_services |= PCIE_PORT_SERVICE_DPC;
> irq_services &= capabilities;
>
> - if (irq_services) {
> + /*
> + * Some platforms have dedicated interrupts from root complex to
> + * interrupt controller for PCIe platform-specific System Errors
> + * like AER/PME etc., check if the platform registered with any such
> + * IRQ.
> + */
> + if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
> + plat_irqs = pcie_init_platform_service_irqs(dev, irqs,
> + capabilities);
> + }
> +
> + /*
> + * Only install service irqs, when the platform-specific hook was
> + * unsuccessful
> + */
> + if (irq_services && !plat_irqs) {
> /*
> * Initialize service IRQs. Don't use service devices that
> * require interrupts if there is no way to generate them.
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 18a75c8e615c..a0bcc8062b91 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -554,6 +554,8 @@ struct pci_host_bridge {
> u8 (*swizzle_irq)(struct pci_dev *, u8 *); /* Platform IRQ swizzler */
> int (*map_irq)(const struct pci_dev *, u8, u8);
> void (*release_fn)(struct pci_host_bridge *);
> + void (*init_platform_service_irqs)(struct pci_dev *dev, int *irqs,
> + int plat_mask);
> void *release_data;
> unsigned int ignore_reset_delay:1; /* For entire hierarchy */
> unsigned int no_ext_tags:1; /* No Extended Tags */
> --
> 2.34.1
>
