[tip: x86/irq] x86/xen: Consolidate XEN-MSI init

[tip-bot2 for Thomas Gleixner]

The following commit has been merged into the x86/irq branch of tip:

Commit-ID:     70b59379efc3c818f48b8037e574654fb29f907c
Gitweb:        https://git.kernel.org/tip/70b59379efc3c818f48b8037e574654fb29f907c
Author:        Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate:    Wed, 26 Aug 2020 13:16:56 +02:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Wed, 16 Sep 2020 16:52:36 +02:00

x86/xen: Consolidate XEN-MSI init

X86 cannot store the irq domain pointer in struct device without breaking
XEN because the irq domain pointer takes precedence over arch_*_msi_irqs()
fallbacks.

To achieve this XEN MSI interrupt management needs to be wrapped into an
irq domain.

Move the x86_msi ops setup into a single function to prepare for this.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
Link: https://lore.kernel.org/r/20200826112333.420224092@xxxxxxxxxxxxx
---
 arch/x86/pci/xen.c | 51 ++++++++++++++++++++++++++++-----------------
 1 file changed, 32 insertions(+), 19 deletions(-)

diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 6a2debe..3a5611b 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -372,7 +372,10 @@ static void xen_initdom_restore_msi_irqs(struct pci_dev *dev)
 		WARN(ret && ret != -ENOSYS, "restore_msi -> %d\n", ret);
 	}
 }
-#endif
+#else /* CONFIG_XEN_DOM0 */
+#define xen_initdom_setup_msi_irqs	NULL
+#define xen_initdom_restore_msi_irqs	NULL
+#endif /* !CONFIG_XEN_DOM0 */
 
 static void xen_teardown_msi_irqs(struct pci_dev *dev)
 {
@@ -404,7 +407,31 @@ static void xen_teardown_msi_irq(unsigned int irq)
 	WARN_ON_ONCE(1);
 }
 
-#endif
+static __init void xen_setup_pci_msi(void)
+{
+	if (xen_pv_domain()) {
+		if (xen_initial_domain()) {
+			x86_msi.setup_msi_irqs = xen_initdom_setup_msi_irqs;
+			x86_msi.restore_msi_irqs = xen_initdom_restore_msi_irqs;
+		} else {
+			x86_msi.setup_msi_irqs = xen_setup_msi_irqs;
+		}
+		x86_msi.teardown_msi_irqs = xen_pv_teardown_msi_irqs;
+		pci_msi_ignore_mask = 1;
+	} else if (xen_hvm_domain()) {
+		x86_msi.setup_msi_irqs = xen_hvm_setup_msi_irqs;
+		x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs;
+	} else {
+		WARN_ON_ONCE(1);
+		return;
+	}
+
+	x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
+}
+
+#else /* CONFIG_PCI_MSI */
+static inline void xen_setup_pci_msi(void) { }
+#endif /* CONFIG_PCI_MSI */
 
 int __init pci_xen_init(void)
 {
@@ -421,12 +448,7 @@ int __init pci_xen_init(void)
 	/* Keep ACPI out of the picture */
 	acpi_noirq_set();
 
-#ifdef CONFIG_PCI_MSI
-	x86_msi.setup_msi_irqs = xen_setup_msi_irqs;
-	x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
-	x86_msi.teardown_msi_irqs = xen_pv_teardown_msi_irqs;
-	pci_msi_ignore_mask = 1;
-#endif
+	xen_setup_pci_msi();
 	return 0;
 }
 
@@ -446,10 +468,7 @@ static void __init xen_hvm_msi_init(void)
 		    ((eax & XEN_HVM_CPUID_APIC_ACCESS_VIRT) && boot_cpu_has(X86_FEATURE_APIC)))
 			return;
 	}
-
-	x86_msi.setup_msi_irqs = xen_hvm_setup_msi_irqs;
-	x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs;
-	x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
+	xen_setup_pci_msi();
 }
 #endif
 
@@ -482,13 +501,7 @@ int __init pci_xen_initial_domain(void)
 {
 	int irq;
 
-#ifdef CONFIG_PCI_MSI
-	x86_msi.setup_msi_irqs = xen_initdom_setup_msi_irqs;
-	x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
-	x86_msi.teardown_msi_irqs = xen_teardown_pv_msi_irqs;
-	x86_msi.restore_msi_irqs = xen_initdom_restore_msi_irqs;
-	pci_msi_ignore_mask = 1;
-#endif
+	xen_setup_pci_msi();
 	__acpi_register_gsi = acpi_register_gsi_xen;
 	__acpi_unregister_gsi = NULL;
 	/*