irqdomain: Clean up irq_domain_push/pop_irq()

The irq_domain_push_irq() interface is used to add a new (outmost) level
to a hierarchical domain after IRQs have been allocated.

Possibly due to differing mental images of hierarchical domains, the
names used for the irq_data variables make these functions much harder
to understand than what they need to be.

Rename the struct irq_data pointer to the data embedded in the
descriptor as simply 'irq_data' and refer to the data allocated by this
interface as 'parent_irq_data' so that the names reflect how
hierarchical domains are implemented.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Hsin-Yi Wang <hsinyi@chromium.org>
Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230213104302.17307-12-johan+linaro@kernel.org

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 3a3213d730ee61895b0dbe222f3f4c66aa3ce721..6d480dc6ab53b5feb9501c6e9b0ff95ddb376a8c 100644 (file)
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -1598,8 +1598,8 @@ static void irq_domain_fix_revmap(struct irq_data *d)
  */
 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);
+       struct irq_data *irq_data = irq_get_irq_data(virq);
+       struct irq_data *parent_irq_data;
        struct irq_desc *desc;
        int rv = 0;
 
@@ -1624,45 +1624,44 @@ int irq_domain_push_irq(struct irq_domain *domain, int virq, void *arg)
        if (WARN_ON(!irq_domain_is_hierarchy(domain)))
                return -EINVAL;
 
-       if (!root_irq_data)
+       if (!irq_data)
                return -EINVAL;
 
-       if (domain->parent != root_irq_data->domain)
+       if (domain->parent != irq_data->domain)
                return -EINVAL;
 
-       child_irq_data = kzalloc_node(sizeof(*child_irq_data), GFP_KERNEL,
-                                     irq_data_get_node(root_irq_data));
-       if (!child_irq_data)
+       parent_irq_data = kzalloc_node(sizeof(*parent_irq_data), GFP_KERNEL,
+                                      irq_data_get_node(irq_data));
+       if (!parent_irq_data)
                return -ENOMEM;
 
        mutex_lock(&irq_domain_mutex);
 
        /* Copy the original irq_data. */
-       *child_irq_data = *root_irq_data;
+       *parent_irq_data = *irq_data;
 
        /*
-        * Overwrite the root_irq_data, which is embedded in struct
-        * irq_desc, with values for this domain.
+        * Overwrite the 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;
+       irq_data->parent_data = parent_irq_data;
+       irq_data->domain = domain;
+       irq_data->mask = 0;
+       irq_data->hwirq = 0;
+       irq_data->chip = NULL;
+       irq_data->chip_data = NULL;
 
        /* May (probably does) set hwirq, chip, etc. */
        rv = irq_domain_alloc_irqs_hierarchy(domain, virq, 1, arg);
        if (rv) {
                /* Restore the original irq_data. */
-               *root_irq_data = *child_irq_data;
-               kfree(child_irq_data);
+               *irq_data = *parent_irq_data;
+               kfree(parent_irq_data);
                goto error;
        }
 
-       irq_domain_fix_revmap(child_irq_data);
-       irq_domain_set_mapping(domain, root_irq_data->hwirq, root_irq_data);
-
+       irq_domain_fix_revmap(parent_irq_data);
+       irq_domain_set_mapping(domain, irq_data->hwirq, irq_data);
 error:
        mutex_unlock(&irq_domain_mutex);
 
@@ -1680,8 +1679,8 @@ EXPORT_SYMBOL_GPL(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 *irq_data = irq_get_irq_data(virq);
+       struct irq_data *parent_irq_data;
        struct irq_data *tmp_irq_data;
        struct irq_desc *desc;
 
@@ -1703,37 +1702,37 @@ int irq_domain_pop_irq(struct irq_domain *domain, int virq)
        if (domain == NULL)
                return -EINVAL;
 
-       if (!root_irq_data)
+       if (!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))
+       if (WARN_ON(irq_data != tmp_irq_data))
                return -EINVAL;
 
-       if (WARN_ON(root_irq_data->domain != domain))
+       if (WARN_ON(irq_data->domain != domain))
                return -EINVAL;
 
-       child_irq_data = root_irq_data->parent_data;
-       if (WARN_ON(!child_irq_data))
+       parent_irq_data = irq_data->parent_data;
+       if (WARN_ON(!parent_irq_data))
                return -EINVAL;
 
        mutex_lock(&irq_domain_mutex);
 
-       root_irq_data->parent_data = NULL;
+       irq_data->parent_data = NULL;
 
-       irq_domain_clear_mapping(domain, root_irq_data->hwirq);
+       irq_domain_clear_mapping(domain, irq_data->hwirq);
        irq_domain_free_irqs_hierarchy(domain, virq, 1);
 
        /* Restore the original irq_data. */
-       *root_irq_data = *child_irq_data;
+       *irq_data = *parent_irq_data;
 
-       irq_domain_fix_revmap(root_irq_data);
+       irq_domain_fix_revmap(irq_data);
 
        mutex_unlock(&irq_domain_mutex);
 
-       kfree(child_irq_data);
+       kfree(parent_irq_data);
 
        return 0;
 }