On Mon, Aug 30, 2021 at 10:08:10AM +0200, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
>
> Avoid registering service IRQs if there is no service that offers them
> or no driver to register a handler against them. This saves IRQ vectors
> when they are limited (e.g. on x86) and also avoids that spurious events
> could hit a missing handler. Such spurious events need to be generated
> by the Jailhouse hypervisor for active MSI vectors when enabling or
> disabling itself.
>
> Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
Applied to pci/portdrv for v5.16, thanks!
> ---
>
> Changes in v2:
> - move initialization of irqs to address test bot finding
>
> drivers/pci/pcie/portdrv_core.c | 47 +++++++++++++++++++++------------
> 1 file changed, 30 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
> index e1fed6649c41..0e2556269429 100644
> --- a/drivers/pci/pcie/portdrv_core.c
> +++ b/drivers/pci/pcie/portdrv_core.c
> @@ -166,9 +166,6 @@ static int pcie_init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
> {
> int ret, i;
>
> - for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
> - irqs[i] = -1;
> -
> /*
> * If we support PME but can't use MSI/MSI-X for it, we have to
> * fall back to INTx or other interrupts, e.g., a system shared
> @@ -312,8 +309,10 @@ static int pcie_device_init(struct pci_dev *pdev, int service, int irq)
> */
> int pcie_port_device_register(struct pci_dev *dev)
> {
> - int status, capabilities, i, nr_service;
> - int irqs[PCIE_PORT_DEVICE_MAXSERVICES];
> + int status, capabilities, irq_services, i, nr_service;
> + int irqs[PCIE_PORT_DEVICE_MAXSERVICES] = {
> + [0 ... PCIE_PORT_DEVICE_MAXSERVICES-1] = -1
> + };
>
> /* Enable PCI Express port device */
> status = pci_enable_device(dev);
> @@ -326,18 +325,32 @@ int pcie_port_device_register(struct pci_dev *dev)
> return 0;
>
> pci_set_master(dev);
> - /*
> - * Initialize service irqs. Don't use service devices that
> - * require interrupts if there is no way to generate them.
> - * However, some drivers may have a polling mode (e.g. pciehp_poll_mode)
> - * that can be used in the absence of irqs. Allow them to determine
> - * if that is to be used.
> - */
> - status = pcie_init_service_irqs(dev, irqs, capabilities);
> - if (status) {
> - capabilities &= PCIE_PORT_SERVICE_HP;
> - if (!capabilities)
> - goto error_disable;
> +
> + irq_services = 0;
> + if (IS_ENABLED(CONFIG_PCIE_PME))
> + irq_services |= PCIE_PORT_SERVICE_PME;
> + if (IS_ENABLED(CONFIG_PCIEAER))
> + irq_services |= PCIE_PORT_SERVICE_AER;
> + if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
> + irq_services |= PCIE_PORT_SERVICE_HP;
> + if (IS_ENABLED(CONFIG_PCIE_DPC))
> + irq_services |= PCIE_PORT_SERVICE_DPC;
> + irq_services &= capabilities;
> +
> + if (irq_services) {
> + /*
> + * Initialize service irqs. Don't use service devices that
> + * require interrupts if there is no way to generate them.
> + * However, some drivers may have a polling mode (e.g.
> + * pciehp_poll_mode) that can be used in the absence of irqs.
> + * Allow them to determine if that is to be used.
> + */
> + status = pcie_init_service_irqs(dev, irqs, irq_services);
> + if (status) {
> + irq_services &= PCIE_PORT_SERVICE_HP;
> + if (!irq_services)
> + goto error_disable;
> + }
> }
>
> /* Allocate child services if any */
> --
> 2.31.1
