On 2024/11/13 23:31, Thomas Gleixner wrote:
On Wed, Nov 13 2024 at 14:43, Chen Wang wrote:
On 2024/11/13 14:14, Thomas Gleixner wrote:
+
+ middle_domain = irq_domain_create_hierarchy(plic_domain, 0, priv->num_irqs,
+ fwnode,
+ &pch_msi_middle_domain_ops,
+ priv);
So now you have created a domain. How is that supposed to be used by the
PCI layer?
Here I create the domain and attached it to the fwnode. In PCI driver,
it can set this msi controller as its ""interrupt-parent" and find the
domain attached as below:
static int pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
parent_node = of_irq_find_parent(dev->of_node);
parent_domain = irq_find_host(parent_node);
...
}
I assume you then want to create a global PCI/MSI domain via
pci_msi_create_irq_domain(), right?
Yes, I am writing another pcie driver, which will call
pci_msi_create_irq_domain() to create a child domain of this middle_domain.
That's not the preferred way to do that. Any new implementation should
use the MSI parent model, where each PCI device creates it's own per
device MSI domain with the MSI interrupt controller as parent
domain.
There is a library with helper functions, irq-msi-lib.[ch]. See
gicv2m_allocate_domains() or pch_msi_init_domains() for reference.
Thanks, I will check this out.
Regards,
Chen
Thanks
tglx
