x86/xen: Wrap XEN MSI management into irqdomain (2e4386eb) · Commits · 戴 / test

arch/x86/pci/xen.c

+63 −0

Original line number	Diff line number	Diff line
		@@ -407,6 +407,63 @@ static void xen_teardown_msi_irq(unsigned int irq)
		WARN_ON_ONCE(1);
		}

		static int xen_msi_domain_alloc_irqs(struct irq_domain *domain,
		struct device *dev, int nvec)
		{
		int type;

		if (WARN_ON_ONCE(!dev_is_pci(dev)))
		return -EINVAL;

		if (first_msi_entry(dev)->msi_attrib.is_msix)
		type = PCI_CAP_ID_MSIX;
		else
		type = PCI_CAP_ID_MSI;

		return x86_msi.setup_msi_irqs(to_pci_dev(dev), nvec, type);
		}

		static void xen_msi_domain_free_irqs(struct irq_domain *domain,
		struct device *dev)
		{
		if (WARN_ON_ONCE(!dev_is_pci(dev)))
		return;

		x86_msi.teardown_msi_irqs(to_pci_dev(dev));
		}

		static struct msi_domain_ops xen_pci_msi_domain_ops = {
		.domain_alloc_irqs = xen_msi_domain_alloc_irqs,
		.domain_free_irqs = xen_msi_domain_free_irqs,
		};

		static struct msi_domain_info xen_pci_msi_domain_info = {
		.ops = &xen_pci_msi_domain_ops,
		};

		/*
		* This irq domain is a blatant violation of the irq domain design, but
		* distangling XEN into real irq domains is not a job for mere mortals with
		* limited XENology. But it's the least dangerous way for a mere mortal to
		* get rid of the arch_*_msi_irqs() hackery in order to store the irq
		* domain pointer in struct device. This irq domain wrappery allows to do
		* that without breaking XEN terminally.
		*/
		static __init struct irq_domain *xen_create_pci_msi_domain(void)
		{
		struct irq_domain *d = NULL;
		struct fwnode_handle *fn;

		fn = irq_domain_alloc_named_fwnode("XEN-MSI");
		if (fn)
		d = msi_create_irq_domain(fn, &xen_pci_msi_domain_info, NULL);

		/* FIXME: No idea how to survive if this fails */
		BUG_ON(!d);

		return d;
		}

		static __init void xen_setup_pci_msi(void)
		{
		if (xen_pv_domain()) {
		@@ -427,6 +484,12 @@ static __init void xen_setup_pci_msi(void)
		}

		x86_msi.teardown_msi_irq = xen_teardown_msi_irq;

		/*
		* Override the PCI/MSI irq domain init function. No point
		* in allocating the native domain and never use it.
		*/
		x86_init.irqs.create_pci_msi_domain = xen_create_pci_msi_domain;
		}

		#else /* CONFIG_PCI_MSI */

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