2 files changed, 67 insertions, 3 deletions

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 36b0c2e55929..4befe09053c1 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -28,6 +28,40 @@ int pci_msi_ignore_mask;
 
 #define msix_table_size(flags)  ((flags & PCI_MSIX_FLAGS_QSIZE) + 1)
 
+#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
+static struct irq_domain *pci_msi_default_domain;
+static DEFINE_MUTEX(pci_msi_domain_lock);
+
+struct irq_domain * __weak arch_get_pci_msi_domain(struct pci_dev *dev)
+{
+        return pci_msi_default_domain;
+}
+
+static int pci_msi_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+        struct irq_domain *domain;
+
+        domain = arch_get_pci_msi_domain(dev);
+        if (domain)
+                return pci_msi_domain_alloc_irqs(domain, dev, nvec, type);
+
+        return arch_setup_msi_irqs(dev, nvec, type);
+}
+
+static void pci_msi_teardown_msi_irqs(struct pci_dev *dev)
+{
+        struct irq_domain *domain;
+
+        domain = arch_get_pci_msi_domain(dev);
+        if (domain)
+                pci_msi_domain_free_irqs(domain, dev);
+        else
+                arch_teardown_msi_irqs(dev);
+}
+#else
+#define pci_msi_setup_msi_irqs          arch_setup_msi_irqs
+#define pci_msi_teardown_msi_irqs       arch_teardown_msi_irqs
+#endif
 
 /* Arch hooks */
 
@@ -348,7 +382,7 @@ static void free_msi_irqs(struct pci_dev *dev)
                         for (i = 0; i < entry->nvec_used; i++)
                                 BUG_ON(irq_has_action(entry->irq + i));
 
-        arch_teardown_msi_irqs(dev);
+        pci_msi_teardown_msi_irqs(dev);
 
         list_for_each_entry_safe(entry, tmp, &dev->msi_list, list) {
                 if (entry->msi_attrib.is_msix) {
@@ -600,7 +634,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec)
         list_add_tail(&entry->list, &dev->msi_list);
 
         /* Configure MSI capability structure */
-        ret = arch_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI);
+        ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI);
         if (ret) {
                 msi_mask_irq(entry, mask, ~mask);
                 free_msi_irqs(dev);
@@ -715,7 +749,7 @@ static int msix_capability_init(struct pci_dev *dev,
         if (ret)
                 return ret;
 
-        ret = arch_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX);
+        ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX);
         if (ret)
                 goto out_avail;
 
@@ -1258,4 +1292,31 @@ void pci_msi_domain_free_irqs(struct irq_domain *domain, struct pci_dev *dev)
 {
         msi_domain_free_irqs(domain, &dev->dev);
 }
+
+/**
+ * pci_msi_create_default_irq_domain - Create a default MSI interrupt domain
+ * @node:       Optional device-tree node of the interrupt controller
+ * @info:       MSI domain info
+ * @parent:     Parent irq domain
+ *
+ * Returns: A domain pointer or NULL in case of failure. If successful
+ * the default PCI/MSI irqdomain pointer is updated.
+ */
+struct irq_domain *pci_msi_create_default_irq_domain(struct device_node *node,
+                struct msi_domain_info *info, struct irq_domain *parent)
+{
+        struct irq_domain *domain;
+
+        mutex_lock(&pci_msi_domain_lock);
+        if (pci_msi_default_domain) {
+                pr_err("PCI: default irq domain for PCI MSI has already been created.\n");
+                domain = NULL;
+        } else {
+                domain = pci_msi_create_irq_domain(node, info, parent);
+                pci_msi_default_domain = domain;
+        }
+        mutex_unlock(&pci_msi_domain_lock);
+
+        return domain;
+}
 #endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */
diff --git a/include/linux/msi.h b/include/linux/msi.h
index 1628788aee25..692f217ae813 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -228,6 +228,9 @@ struct irq_domain *pci_msi_create_irq_domain(struct device_node *node,
 int pci_msi_domain_alloc_irqs(struct irq_domain *domain, struct pci_dev *dev,
                               int nvec, int type);
 void pci_msi_domain_free_irqs(struct irq_domain *domain, struct pci_dev *dev);
+struct irq_domain *pci_msi_create_default_irq_domain(struct device_node *node,
+                 struct msi_domain_info *info, struct irq_domain *parent);
+
 irq_hw_number_t pci_msi_domain_calc_hwirq(struct pci_dev *dev,
                                           struct msi_desc *desc);
 int pci_msi_domain_check_cap(struct irq_domain *domain,