Re: [PATCH hyperv-next v6 11/11] PCI: hv: Get vPCI MSI IRQ domain from DeviceTree

Rafael J. Wysocki
2025-03-26T14:57:00Z

On Sat, Mar 15, 2025 at 1:19 AM Roman Kisel <romank@linux.microsoft.com> wrote:
>
> The hyperv-pci driver uses ACPI for MSI IRQ domain configuration on
> arm64. It won't be able to do that in the VTL mode where only DeviceTree
> can be used.
>
> Update the hyperv-pci driver to get vPCI MSI IRQ domain in the DeviceTree
> case, too.
>
> Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
> ---
> drivers/pci/controller/pci-hyperv.c | 73 ++++++++++++++++++++++++++---
> 1 file changed, 67 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> index 6084b38bdda1..cbff19e8a07c 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -50,6 +50,7 @@
> #include <linux/irqdomain.h>
> #include <linux/acpi.h>
> #include <linux/sizes.h>
> +#include <linux/of_irq.h>
> #include <asm/mshyperv.h>
>
> /*
> @@ -817,9 +818,17 @@ static int hv_pci_vec_irq_gic_domain_alloc(struct irq_domain *domain,
> int ret;
>
> fwspec.fwnode = domain->parent->fwnode;
> - fwspec.param_count = 2;
> - fwspec.param[0] = hwirq;
> - fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
> + if (is_of_node(fwspec.fwnode)) {
> + /* SPI lines for OF translations start at offset 32 */
> + fwspec.param_count = 3;
> + fwspec.param[0] = 0;
> + fwspec.param[1] = hwirq - 32;
> + fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
> + } else {
> + fwspec.param_count = 2;
> + fwspec.param[0] = hwirq;
> + fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
> + }
>
> ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
> if (ret)
> @@ -887,10 +896,47 @@ static const struct irq_domain_ops hv_pci_domain_ops = {
> .activate = hv_pci_vec_irq_domain_activate,
> };
>
> +#ifdef CONFIG_OF
> +
> +static struct irq_domain *hv_pci_of_irq_domain_parent(void)
> +{
> + struct device_node *parent;
> + struct irq_domain *domain;
> +
> + parent = of_irq_find_parent(hv_get_vmbus_root_device()->of_node);
> + if (!parent)
> + return NULL;
> + domain = irq_find_host(parent);
> + of_node_put(parent);
> +
> + return domain;
> +}
> +
> +#endif
> +
> +#ifdef CONFIG_ACPI
> +
> +static struct irq_domain *hv_pci_acpi_irq_domain_parent(void)
> +{
> + struct irq_domain *domain;
> + acpi_gsi_domain_disp_fn gsi_domain_disp_fn;
> +
> + if (acpi_irq_model != ACPI_IRQ_MODEL_GIC)
> + return NULL;
> + gsi_domain_disp_fn = acpi_get_gsi_dispatcher();
> + if (!gsi_domain_disp_fn)
> + return NULL;
> + return irq_find_matching_fwnode(gsi_domain_disp_fn(0),
> + DOMAIN_BUS_ANY);
> +}
> +
> +#endif
> +
> static int hv_pci_irqchip_init(void)
> {
> static struct hv_pci_chip_data *chip_data;
> struct fwnode_handle *fn = NULL;
> + struct irq_domain *irq_domain_parent = NULL;
> int ret = -ENOMEM;
>
> chip_data = kzalloc(sizeof(*chip_data), GFP_KERNEL);
> @@ -907,9 +953,24 @@ static int hv_pci_irqchip_init(void)
> * way to ensure that all the corresponding devices are also gone and
> * no interrupts will be generated.
> */
> - hv_msi_gic_irq_domain = acpi_irq_create_hierarchy(0, HV_PCI_MSI_SPI_NR,
> - fn, &hv_pci_domain_ops,
> - chip_data);
> +#ifdef CONFIG_ACPI
> + if (!acpi_disabled)
> + irq_domain_parent = hv_pci_acpi_irq_domain_parent();
> +#endif
> +#if defined(CONFIG_OF)

Why don't you do

#ifdef CONFIG_OF

here for consistency?

> + if (!irq_domain_parent)
> + irq_domain_parent = hv_pci_of_irq_domain_parent();
> +#endif
> + if (!irq_domain_parent) {
> + WARN_ONCE(1, "Invalid firmware configuration for VMBus interrupts\n");
> + ret = -EINVAL;
> + goto free_chip;
> + }
> +
> + hv_msi_gic_irq_domain = irq_domain_create_hierarchy(
> + irq_domain_parent, 0, HV_PCI_MSI_SPI_NR,
> + fn, &hv_pci_domain_ops,
> + chip_data);
>
> if (!hv_msi_gic_irq_domain) {
> pr_err("Failed to create Hyper-V arm64 vPCI MSI IRQ domain\n");
> --