Merge branch irq/irqdomain-locking into irq/irqchip-next

* irq/irqdomain-locking:
  : .
  : irqdomain locking overhaul courtesy of Johan Hovold.
  :
  : From the cover letter:
  :
  : "Parallel probing (e.g. due to asynchronous probing) of devices that
  : share interrupts can currently result in two mappings for the same
  : hardware interrupt to be created.
  :
  : This series fixes this mapping race and reworks the irqdomain locking so
  : that in the end the global irq_domain_mutex is only used for managing
  : the likewise global irq_domain_list, while domain operations (e.g. IRQ
  : allocations) use per-domain (hierarchy) locking."
  : .
  irqdomain: Switch to per-domain locking
  irqchip/mvebu-odmi: Use irq_domain_create_hierarchy()
  irqchip/loongson-pch-msi: Use irq_domain_create_hierarchy()
  irqchip/gic-v3-mbi: Use irq_domain_create_hierarchy()
  irqchip/gic-v3-its: Use irq_domain_create_hierarchy()
  irqchip/gic-v2m: Use irq_domain_create_hierarchy()
  irqchip/alpine-msi: Use irq_domain_add_hierarchy()
  x86/uv: Use irq_domain_create_hierarchy()
  x86/ioapic: Use irq_domain_create_hierarchy()
  irqdomain: Clean up irq_domain_push/pop_irq()
  irqdomain: Drop leftover brackets
  irqdomain: Drop dead domain-name assignment
  irqdomain: Drop revmap mutex
  irqdomain: Fix domain registration race
  irqdomain: Fix mapping-creation race
  irqdomain: Refactor __irq_domain_alloc_irqs()
  irqdomain: Look for existing mapping only once
  irqdomain: Drop bogus fwspec-mapping error handling
  irqdomain: Fix disassociation race
  irqdomain: Fix association race

Signed-off-by: Marc Zyngier <maz@kernel.org>

Author: Marc Zyngier

arch/x86/kernel/apic/io_apic.c

@@ -2364,18 +2364,15 @@ static int mp_irqdomain_create(int ioapic)
 		return -ENODEV;
 	}
 
-	ip->irqdomain = irq_domain_create_linear(fn, hwirqs, cfg->ops,
-						 (void *)(long)ioapic);
-
+	ip->irqdomain = irq_domain_create_hierarchy(parent, 0, hwirqs, fn, cfg->ops,
+						    (void *)(long)ioapic);
 	if (!ip->irqdomain) {
 		/* Release fw handle if it was allocated above */
 		if (!cfg->dev)
 			irq_domain_free_fwnode(fn);
 		return -ENOMEM;
 	}
 
-	ip->irqdomain->parent = parent;
-
 	if (cfg->type == IOAPIC_DOMAIN_LEGACY ||
 	    cfg->type == IOAPIC_DOMAIN_STRICT)
 		ioapic_dynirq_base = max(ioapic_dynirq_base,

arch/x86/platform/uv/uv_irq.c

@@ -166,10 +166,9 @@ static struct irq_domain *uv_get_irq_domain(void)
 	if (!fn)
 		goto out;
 
-	uv_domain = irq_domain_create_tree(fn, &uv_domain_ops, NULL);
-	if (uv_domain)
-		uv_domain->parent = x86_vector_domain;
-	else
+	uv_domain = irq_domain_create_hierarchy(x86_vector_domain, 0, 0, fn,
+						&uv_domain_ops, NULL);
+	if (!uv_domain)
 		irq_domain_free_fwnode(fn);
 out:
 	mutex_unlock(&uv_lock);

drivers/irqchip/irq-alpine-msi.c

@@ -205,16 +205,14 @@ static int alpine_msix_init_domains(struct alpine_msix_data *priv,
 		return -ENXIO;
 	}
 
-	middle_domain = irq_domain_add_tree(NULL,
-					    &alpine_msix_middle_domain_ops,
-					    priv);
+	middle_domain = irq_domain_add_hierarchy(gic_domain, 0, 0, NULL,
+						 &alpine_msix_middle_domain_ops,
+						 priv);
 	if (!middle_domain) {
 		pr_err("Failed to create the MSIX middle domain\n");
 		return -ENOMEM;
 	}
 
-	middle_domain->parent = gic_domain;
-
 	msi_domain = pci_msi_create_irq_domain(of_node_to_fwnode(node),
 					       &alpine_msix_domain_info,
 					       middle_domain);

drivers/irqchip/irq-gic-v2m.c

@@ -287,15 +287,14 @@ static __init int gicv2m_allocate_domains(struct irq_domain *parent)
 	if (!v2m)
 		return 0;
 
-	inner_domain = irq_domain_create_tree(v2m->fwnode,
-					      &gicv2m_domain_ops, v2m);
+	inner_domain = irq_domain_create_hierarchy(parent, 0, 0, v2m->fwnode,
+						   &gicv2m_domain_ops, v2m);
 	if (!inner_domain) {
 		pr_err("Failed to create GICv2m domain\n");
 		return -ENOMEM;
 	}
 
 	irq_domain_update_bus_token(inner_domain, DOMAIN_BUS_NEXUS);
-	inner_domain->parent = parent;
 	pci_domain = pci_msi_create_irq_domain(v2m->fwnode,
 					       &gicv2m_msi_domain_info,
 					       inner_domain);

drivers/irqchip/irq-gic-v3-its.c

@@ -4909,18 +4909,19 @@ static int its_init_domain(struct fwnode_handle *handle, struct its_node *its)
 	if (!info)
 		return -ENOMEM;
 
-	inner_domain = irq_domain_create_tree(handle, &its_domain_ops, its);
+	info->ops = &its_msi_domain_ops;
+	info->data = its;
+
+	inner_domain = irq_domain_create_hierarchy(its_parent,
+						   its->msi_domain_flags, 0,
+						   handle, &its_domain_ops,
+						   info);
 	if (!inner_domain) {
 		kfree(info);
 		return -ENOMEM;
 	}
 
-	inner_domain->parent = its_parent;
 	irq_domain_update_bus_token(inner_domain, DOMAIN_BUS_NEXUS);
-	inner_domain->flags |= its->msi_domain_flags;
-	info->ops = &its_msi_domain_ops;
-	info->data = its;
-	inner_domain->host_data = info;
 
 	return 0;
 }

drivers/irqchip/irq-gic-v3-mbi.c

@@ -233,13 +233,12 @@ static int mbi_allocate_domains(struct irq_domain *parent)
 	struct irq_domain *nexus_domain, *pci_domain, *plat_domain;
 	int err;
 
-	nexus_domain = irq_domain_create_tree(parent->fwnode,
-					      &mbi_domain_ops, NULL);
+	nexus_domain = irq_domain_create_hierarchy(parent, 0, 0, parent->fwnode,
+						   &mbi_domain_ops, NULL);
 	if (!nexus_domain)
 		return -ENOMEM;
 
 	irq_domain_update_bus_token(nexus_domain, DOMAIN_BUS_NEXUS);
-	nexus_domain->parent = parent;
 
 	err = mbi_allocate_pci_domain(nexus_domain, &pci_domain);
 

drivers/irqchip/irq-loongson-pch-msi.c

@@ -163,16 +163,15 @@ static int pch_msi_init_domains(struct pch_msi_data *priv,
 {
 	struct irq_domain *middle_domain, *msi_domain;
 
-	middle_domain = irq_domain_create_linear(domain_handle,
-						priv->num_irqs,
-						&pch_msi_middle_domain_ops,
-						priv);
+	middle_domain = irq_domain_create_hierarchy(parent, 0, priv->num_irqs,
+						    domain_handle,
+						    &pch_msi_middle_domain_ops,
+						    priv);
 	if (!middle_domain) {
 		pr_err("Failed to create the MSI middle domain\n");
 		return -ENOMEM;
 	}
 
-	middle_domain->parent = parent;
 	irq_domain_update_bus_token(middle_domain, DOMAIN_BUS_NEXUS);
 
 	msi_domain = pci_msi_create_irq_domain(domain_handle,

drivers/irqchip/irq-mvebu-odmi.c

@@ -161,7 +161,7 @@ static struct msi_domain_info odmi_msi_domain_info = {
 static int __init mvebu_odmi_init(struct device_node *node,
 				  struct device_node *parent)
 {
-	struct irq_domain *inner_domain, *plat_domain;
+	struct irq_domain *parent_domain, *inner_domain, *plat_domain;
 	int ret, i;
 
 	if (of_property_read_u32(node, "marvell,odmi-frames", &odmis_count))
@@ -197,16 +197,17 @@ static int __init mvebu_odmi_init(struct device_node *node,
 		}
 	}
 
-	inner_domain = irq_domain_create_linear(of_node_to_fwnode(node),
-						odmis_count * NODMIS_PER_FRAME,
-						&odmi_domain_ops, NULL);
+	parent_domain = irq_find_host(parent);
+
+	inner_domain = irq_domain_create_hierarchy(parent_domain, 0,
+						   odmis_count * NODMIS_PER_FRAME,
+						   of_node_to_fwnode(node),
+						   &odmi_domain_ops, NULL);
 	if (!inner_domain) {
 		ret = -ENOMEM;
 		goto err_unmap;
 	}
 
-	inner_domain->parent = irq_find_host(parent);
-
 	plat_domain = platform_msi_create_irq_domain(of_node_to_fwnode(node),
 						     &odmi_msi_domain_info,
 						     inner_domain);

include/linux/irqdomain.h

@@ -125,6 +125,8 @@ struct irq_domain_chip_generic;
  *		core code.
  * @flags:	Per irq_domain flags
  * @mapcount:	The number of mapped interrupts
+ * @mutex:	Domain lock, hierarchical domains use root domain's lock
+ * @root:	Pointer to root domain, or containing structure if non-hierarchical
  *
  * Optional elements:
  * @fwnode:	Pointer to firmware node associated with the irq_domain. Pretty easy
@@ -143,7 +145,6 @@ struct irq_domain_chip_generic;
  * Revmap data, used internally by the irq domain code:
  * @revmap_size:	Size of the linear map table @revmap[]
  * @revmap_tree:	Radix map tree for hwirqs that don't fit in the linear map
- * @revmap_mutex:	Lock for the revmap
  * @revmap:		Linear table of irq_data pointers
  */
 struct irq_domain {
@@ -153,6 +154,8 @@ struct irq_domain {
 	void				*host_data;
 	unsigned int			flags;
 	unsigned int			mapcount;
+	struct mutex			mutex;
+	struct irq_domain		*root;
 
 	/* Optional data */
 	struct fwnode_handle		*fwnode;
@@ -171,7 +174,6 @@ struct irq_domain {
 	irq_hw_number_t			hwirq_max;
 	unsigned int			revmap_size;
 	struct radix_tree_root		revmap_tree;
-	struct mutex			revmap_mutex;
 	struct irq_data __rcu		*revmap[];
 };