From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Daney Subject: [PATCH v5 3/6] irqdomain: Add irq_domain_{push,pop}_irq() functions. Date: Tue, 28 Feb 2017 17:48:49 -0800 Message-ID: <1488332932-2691-4-git-send-email-david.daney@cavium.com> References: <1488332932-2691-1-git-send-email-david.daney@cavium.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1488332932-2691-1-git-send-email-david.daney@cavium.com> Sender: linux-kernel-owner@vger.kernel.org To: Linus Walleij , Alexandre Courbot , Rob Herring , Mark Rutland , Marc Zyngier , Thomas Gleixner , linux-gpio@vger.kernel.org, devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org, David Daney List-Id: linux-gpio@vger.kernel.org For an already existing irqdomain hierarchy, as might be obtained via a call to pci_enable_msix(), a PCI driver wishing to add an additional irqdomain to the hierarchy needs to be able to insert the irqdomain to that already initialized hierarchy. Calling irq_domain_create_hierarchy() allows the new irqdomain to be created, but no existing code allows for initializing the associated irq_data. Add a couple of helper functions (irq_domain_push_irq() irq_domain_pop_irq()) to initialize the irq_data for the new irqdomain. Signed-off-by: David Daney --- include/linux/irqdomain.h | 3 + kernel/irq/irqdomain.c | 137 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 140 insertions(+) diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h index 188eced..a7a16b7 100644 --- a/include/linux/irqdomain.h +++ b/include/linux/irqdomain.h @@ -425,6 +425,9 @@ extern void irq_domain_free_irqs_common(struct irq_domain *domain, extern void irq_domain_free_irqs_top(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs); +extern int irq_domain_push_irq(struct irq_domain *domain, int virq, void *arg); +extern int irq_domain_pop_irq(struct irq_domain *domain, int virq); + extern int irq_domain_alloc_irqs_parent(struct irq_domain *domain, unsigned int irq_base, unsigned int nr_irqs, void *arg); diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index 31805f2..d5d1c01 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -1304,6 +1304,143 @@ int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base, return ret; } +/* The irq_data was moved, fix the revmap to refer to the new location */ +static void irq_domain_fix_revmap(struct irq_data *d) +{ + void **slot; + + if (d->hwirq < d->domain->revmap_size) + return; /* Not using radix tree. */ + + /* Fix up the revmap. */ + mutex_lock(&revmap_trees_mutex); + slot = radix_tree_lookup_slot(&d->domain->revmap_tree, d->hwirq); + if (slot) + radix_tree_replace_slot(&d->domain->revmap_tree, slot, d); + mutex_unlock(&revmap_trees_mutex); +} + +/** + * irq_domain_push_irq() - Push a domain in to the top of a hierarchy. + * @domain: Domain to push. + * @virq: Irq to push the domain in to. + * @arg: Passed to the irq_domain_ops alloc() function. + * + * For an already existing irqdomain hierarchy, as might be obtained + * via a call to pci_enable_msix(), add an additional domain to the + * head of the processing chain. + */ +int irq_domain_push_irq(struct irq_domain *domain, int virq, void *arg) +{ + struct irq_data *child_irq_data; + struct irq_data *root_irq_data = irq_get_irq_data(virq); + + if (domain == NULL) + return -EINVAL; + + if (WARN_ON(!domain->ops->alloc)) + return -EINVAL; + + if (!root_irq_data) + return -EINVAL; + + child_irq_data = kzalloc_node(sizeof(*child_irq_data), GFP_KERNEL, + irq_data_get_node(root_irq_data)); + if (!child_irq_data) + return -ENOMEM; + + mutex_lock(&irq_domain_mutex); + + /* Copy the original irq_data. */ + *child_irq_data = *root_irq_data; + + irq_domain_fix_revmap(child_irq_data); + + /* + * Overwrite the root_irq_data, which is embedded in struct + * irq_desc, with values for this domain. + */ + root_irq_data->parent_data = child_irq_data; + root_irq_data->domain = domain; + root_irq_data->mask = 0; + root_irq_data->hwirq = 0; + root_irq_data->chip = NULL; + root_irq_data->chip_data = NULL; + domain->ops->alloc(domain, virq, 1, arg); + + if (root_irq_data->hwirq < domain->revmap_size) { + domain->linear_revmap[root_irq_data->hwirq] = virq; + } else { + mutex_lock(&revmap_trees_mutex); + radix_tree_insert(&domain->revmap_tree, + root_irq_data->hwirq, root_irq_data); + mutex_unlock(&revmap_trees_mutex); + } + + mutex_unlock(&irq_domain_mutex); + + return 0; +} +EXPORT_SYMBOL_GPL(irq_domain_push_irq); + +/** + * irq_domain_pop_irq() - Remove a domain from the top of a hierarchy. + * @domain: Domain to remove. + * @virq: Irq to remove the domain from. + * + * Undo the effects of a call to irq_domain_push_irq(). + */ +int irq_domain_pop_irq(struct irq_domain *domain, int virq) +{ + struct irq_data *root_irq_data = irq_get_irq_data(virq); + struct irq_data *child_irq_data; + struct irq_data *tmp_irq_data; + + if (domain == NULL) + return -EINVAL; + + if (!root_irq_data) + return -EINVAL; + + tmp_irq_data = irq_domain_get_irq_data(domain, virq); + + /* We can only "pop" if this domain is at the top of the list */ + if (WARN_ON(root_irq_data != tmp_irq_data)) + return -EINVAL; + + if (WARN_ON(root_irq_data->domain != domain)) + return -EINVAL; + + child_irq_data = root_irq_data->parent_data; + if (WARN_ON(!child_irq_data)) + return -EINVAL; + + mutex_lock(&irq_domain_mutex); + + root_irq_data->parent_data = NULL; + + if (root_irq_data->hwirq >= domain->revmap_size) { + mutex_lock(&revmap_trees_mutex); + radix_tree_delete(&domain->revmap_tree, root_irq_data->hwirq); + mutex_unlock(&revmap_trees_mutex); + } + + if (domain->ops->free) + domain->ops->free(domain, virq, 1); + + /* Restore the original irq_data. */ + *root_irq_data = *child_irq_data; + + irq_domain_fix_revmap(root_irq_data); + + mutex_unlock(&irq_domain_mutex); + + kfree(child_irq_data); + + return 0; +} +EXPORT_SYMBOL_GPL(irq_domain_pop_irq); + /** * irq_domain_free_irqs - Free IRQ number and associated data structures * @virq: base IRQ number -- 1.8.3.1