[patch RFC 24/38] x86/xen: Consolidate XEN-MSI init

From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, Joerg Roedel <joro@8bytes.org>,
	iommu@lists.linux-foundation.org, linux-hyperv@vger.kernel.org,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Jon Derrick <jonathan.derrick@intel.com>,
	Lu Baolu <baolu.lu@linux.intel.com>, Wei Liu <wei.liu@kernel.org>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	Steve Wahl <steve.wahl@hpe.com>,
	Dimitri Sivanich <sivanich@hpe.com>, Russ Anderson <rja@hpe.com>,
	linux-pci@vger.kernel.org, Bjorn Helgaas <bhelgaas@google.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Jonathan Derrick <jonathan.derrick@intel.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	xen-devel@lists.xenproject.org, Juergen Gross <jgross@suse.com>,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	Stefano Stabellini <sstabellini@kernel.org>,
	Marc Zyngier <maz@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Megha Dey <megha.dey@intel.com>,
	Jason Gunthorpe <jgg@mellanox.com>,
	Dave Jiang <dave.jiang@intel.com>,
	Alex Williamson <alex.williamson@redhat.com>,
	Jacob Pan <jacob.jun.pan@intel.com>,
	Baolu Lu <baolu.lu@intel.com>, Kevin Tian <kevin.tian@intel.com>,
	Dan Williams <dan.j.williams@intel.com>
Subject: [patch RFC 24/38] x86/xen: Consolidate XEN-MSI init
Date: Fri, 21 Aug 2020 02:24:48 +0200	[thread overview]
Message-ID: <20200821002947.667887608@linutronix.de> (raw)
In-Reply-To: 20200821002424.119492231@linutronix.de

[-- Attachment #1: x86-xen--Consolidate-XEN-MSI-init.patch --]
[-- Type: text/plain, Size: 2993 bytes --]

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@linutronix.de>
---
 arch/x86/pci/xen.c |   51 ++++++++++++++++++++++++++++++++-------------------
 1 file changed, 32 insertions(+), 19 deletions(-)

--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -371,7 +371,10 @@ static void xen_initdom_restore_msi_irqs
 		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)
 {
@@ -403,7 +406,31 @@ static void xen_teardown_msi_irq(unsigne
 	WARN_ON_ONCE(1);
 }
 
-#endif
+static __init void xen_setup_pci_msi(void)
+{
+	if (xen_initial_domain()) {
+		x86_msi.setup_msi_irqs = xen_initdom_setup_msi_irqs;
+		x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs;
+		x86_msi.restore_msi_irqs = xen_initdom_restore_msi_irqs;
+		pci_msi_ignore_mask = 1;
+	} else if (xen_pv_domain()) {
+		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)
 {
@@ -420,12 +447,7 @@ 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;
 }
 
@@ -445,10 +467,7 @@ 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
 
@@ -481,13 +500,7 @@ 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_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;
 	/*

