[PATCH v2 10/19] irqdomain: Introduce irq_domain_alloc() and irq_domain_publish()

Herve Codina
2024-05-27T16:15:17Z

The irq_domain_add_*() family functions create an irq_domain and also
publish this newly created to domain. Once an irq_domain is published,
consumers can request IRQ in order to use them.

Some interrupt controller drivers have to perform some more operations
with the created irq_domain in order to have it ready to be used.
For instance:
- Allocate generic irq chips with irq_alloc_domain_generic_chips()
- Retrieve the generic irq chips with irq_get_domain_generic_chip()
- Initialize retrieved chips: set register base address and offsets,
set several hooks such as irq_mask, irq_unmask, ...

To avoid a window where the domain is published but not yet ready to be
used, introduce irq_domain_alloc_*() family functions to create the
irq_domain and irq_domain_publish() to publish the irq_domain.
With this new functions, any additional initialisation can then be done
between the call creating the irq_domain and the call publishing it.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
include/linux/irqdomain.h | 16 +++++++
kernel/irq/irqdomain.c | 91 ++++++++++++++++++++++++++++-----------
2 files changed, 82 insertions(+), 25 deletions(-)

diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 21ecf582a0fe..86203e7e6659 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -257,6 +257,22 @@ static inline struct fwnode_handle *irq_domain_alloc_fwnode(phys_addr_t *pa)
}

void irq_domain_free_fwnode(struct fwnode_handle *fwnode);
+struct irq_domain *irq_domain_alloc(struct fwnode_handle *fwnode, unsigned int size,
+ irq_hw_number_t hwirq_max, int direct_max,
+ const struct irq_domain_ops *ops,
+ void *host_data);
+
+static inline struct irq_domain *irq_domain_alloc_linear(struct fwnode_handle *fwnode,
+ unsigned int size,
+ const struct irq_domain_ops *ops,
+ void *host_data)
+{
+ return irq_domain_alloc(fwnode, size, size, 0, ops, host_data);
+}
+
+void irq_domain_free(struct irq_domain *domain);
+void irq_domain_publish(struct irq_domain *domain);
+void irq_domain_unpublish(struct irq_domain *domain);
struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, unsigned int size,
irq_hw_number_t hwirq_max, int direct_max,
const struct irq_domain_ops *ops,
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 86f8b91b0d3a..06c3e1b03a1d 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -231,7 +231,38 @@ static struct irq_domain *__irq_domain_create(struct fwnode_handle *fwnode,
return domain;
}

-static void __irq_domain_publish(struct irq_domain *domain)
+struct irq_domain *irq_domain_alloc(struct fwnode_handle *fwnode, unsigned int size,
+ irq_hw_number_t hwirq_max, int direct_max,
+ const struct irq_domain_ops *ops,
+ void *host_data)
+{
+ return __irq_domain_create(fwnode, size, hwirq_max, direct_max, ops,
+ host_data);
+}
+EXPORT_SYMBOL_GPL(irq_domain_alloc);
+
+/**
+ * irq_domain_free() - Free an irq domain.
+ * @domain: domain to free
+ *
+ * This routine is used to free an irq domain. The caller must ensure
+ * that the domain is not published.
+ */
+void irq_domain_free(struct irq_domain *domain)
+{
+ fwnode_dev_initialized(domain->fwnode, false);
+ fwnode_handle_put(domain->fwnode);
+ if (domain->flags & IRQ_DOMAIN_NAME_ALLOCATED)
+ kfree(domain->name);
+ kfree(domain);
+}
+EXPORT_SYMBOL_GPL(irq_domain_free);
+
+/**
+ * irq_domain_publish() - Publish an irq domain.
+ * @domain: domain to publish
+ */
+void irq_domain_publish(struct irq_domain *domain)
{
mutex_lock(&irq_domain_mutex);
debugfs_add_domain_dir(domain);
@@ -240,6 +271,36 @@ static void __irq_domain_publish(struct irq_domain *domain)

pr_debug("Added domain %s\n", domain->name);
}
+EXPORT_SYMBOL_GPL(irq_domain_publish);
+
+/**
+ * irq_domain_unpublish() - Unpublish an irq domain.
+ * @domain: domain to unpublish
+ *
+ * This routine is used to unpublish an irq domain. The caller must ensure
+ * that all mappings within the domain have been disposed of prior to
+ * use, depending on the revmap type.
+ */
+void irq_domain_unpublish(struct irq_domain *domain)
+{
+ mutex_lock(&irq_domain_mutex);
+ debugfs_remove_domain_dir(domain);
+
+ WARN_ON(!radix_tree_empty(&domain->revmap_tree));
+
+ list_del(&domain->link);
+
+ /*
+ * If the going away domain is the default one, reset it.
+ */
+ if (unlikely(irq_default_domain == domain))
+ irq_set_default_host(NULL);
+
+ mutex_unlock(&irq_domain_mutex);
+
+ pr_debug("Removed domain %s\n", domain->name);
+}
+EXPORT_SYMBOL_GPL(irq_domain_unpublish);

/**
* __irq_domain_add() - Allocate a new irq_domain data structure
@@ -264,7 +325,7 @@ struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, unsigned int s
domain = __irq_domain_create(fwnode, size, hwirq_max, direct_max,
ops, host_data);
if (domain)
- __irq_domain_publish(domain);
+ irq_domain_publish(domain);

return domain;
}
@@ -280,28 +341,8 @@ EXPORT_SYMBOL_GPL(__irq_domain_add);
*/
void irq_domain_remove(struct irq_domain *domain)
{
- mutex_lock(&irq_domain_mutex);
- debugfs_remove_domain_dir(domain);
-
- WARN_ON(!radix_tree_empty(&domain->revmap_tree));
-
- list_del(&domain->link);
-
- /*
- * If the going away domain is the default one, reset it.
- */
- if (unlikely(irq_default_domain == domain))
- irq_set_default_host(NULL);
-
- mutex_unlock(&irq_domain_mutex);
-
- pr_debug("Removed domain %s\n", domain->name);
-
- fwnode_dev_initialized(domain->fwnode, false);
- fwnode_handle_put(domain->fwnode);
- if (domain->flags & IRQ_DOMAIN_NAME_ALLOCATED)
- kfree(domain->name);
- kfree(domain);
+ irq_domain_unpublish(domain);
+ irq_domain_free(domain);
}
EXPORT_SYMBOL_GPL(irq_domain_remove);

@@ -1184,7 +1225,7 @@ struct irq_domain *irq_domain_create_hierarchy(struct irq_domain *parent,
domain->parent = parent;
domain->flags |= flags;

- __irq_domain_publish(domain);
+ irq_domain_publish(domain);
}

return domain;
--
2.45.0