[PATCH v5 1/6] irqdomain: Introduce irq_domain_create_simple() API

Andy Shevchenko
2021-03-08T19:46:29Z

Linus Walleij pointed out that ird_domain_add_simple() gained
additional functionality and can't be anymore replaced with
a simple conditional. In preparation to upgrade GPIO library
to use fwnode, introduce irq_domain_create_simple() API which is
functional equivalent to the existing irq_domain_add_simple(),
but takes a pointer to the struct fwnode_handle as a parameter.

While at it, amend documentation to mention irq_domain_create_*()
functions where it makes sense.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
---
Documentation/core-api/irq/irq-domain.rst | 22 ++++++++++++----------
include/linux/irqdomain.h | 19 ++++++++++++++-----
kernel/irq/irqdomain.c | 20 ++++++++++----------
3 files changed, 36 insertions(+), 25 deletions(-)

diff --git a/Documentation/core-api/irq/irq-domain.rst b/Documentation/core-api/irq/irq-domain.rst
index a77c24c27f7b..8214e215a8bf 100644
--- a/Documentation/core-api/irq/irq-domain.rst
+++ b/Documentation/core-api/irq/irq-domain.rst
@@ -42,10 +42,10 @@ irq_domain usage
================

An interrupt controller driver creates and registers an irq_domain by
-calling one of the irq_domain_add_*() functions (each mapping method
-has a different allocator function, more on that later). The function
-will return a pointer to the irq_domain on success. The caller must
-provide the allocator function with an irq_domain_ops structure.
+calling one of the irq_domain_add_*() or irq_domain_create_*() functions
+(each mapping method has a different allocator function, more on that later).
+The function will return a pointer to the irq_domain on success. The caller
+must provide the allocator function with an irq_domain_ops structure.

In most cases, the irq_domain will begin empty without any mappings
between hwirq and IRQ numbers. Mappings are added to the irq_domain
@@ -147,6 +147,7 @@ Legacy
irq_domain_add_simple()
irq_domain_add_legacy()
irq_domain_add_legacy_isa()
+ irq_domain_create_simple()
irq_domain_create_legacy()

The Legacy mapping is a special case for drivers that already have a
@@ -169,13 +170,13 @@ supported. For example, ISA controllers would use the legacy map for
mapping Linux IRQs 0-15 so that existing ISA drivers get the correct IRQ
numbers.

-Most users of legacy mappings should use irq_domain_add_simple() which
-will use a legacy domain only if an IRQ range is supplied by the
-system and will otherwise use a linear domain mapping. The semantics
-of this call are such that if an IRQ range is specified then
+Most users of legacy mappings should use irq_domain_add_simple() or
+irq_domain_create_simple() which will use a legacy domain only if an IRQ range
+is supplied by the system and will otherwise use a linear domain mapping.
+The semantics of this call are such that if an IRQ range is specified then
descriptors will be allocated on-the-fly for it, and if no range is
-specified it will fall through to irq_domain_add_linear() which means
-*no* irq descriptors will be allocated.
+specified it will fall through to irq_domain_add_linear() or
+irq_domain_create_linear() which means *no* irq descriptors will be allocated.

A typical use case for simple domains is where an irqchip provider
is supporting both dynamic and static IRQ assignments.
@@ -186,6 +187,7 @@ that the driver using the simple domain call irq_create_mapping()
before any irq_find_mapping() since the latter will actually work
for the static IRQ assignment case.

+irq_domain_add_simple() and irq_domain_create_simple() as well as
irq_domain_add_legacy() and irq_domain_create_legacy() are functionally
equivalent, except for the first argument is different - the former
accepts an Open Firmware specific 'struct device_node', while the latter
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 42d196805f58..6e78f5909723 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -260,11 +260,11 @@ struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, int size,
irq_hw_number_t hwirq_max, int direct_max,
const struct irq_domain_ops *ops,
void *host_data);
-struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
- unsigned int size,
- unsigned int first_irq,
- const struct irq_domain_ops *ops,
- void *host_data);
+struct irq_domain *irq_domain_create_simple(struct fwnode_handle *fwnode,
+ unsigned int size,
+ unsigned int first_irq,
+ const struct irq_domain_ops *ops,
+ void *host_data);
struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
unsigned int size,
unsigned int first_irq,
@@ -329,6 +329,15 @@ static inline struct irq_domain *irq_find_host(struct device_node *node)
return d;
}

+static inline struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
+ unsigned int size,
+ unsigned int first_irq,
+ const struct irq_domain_ops *ops,
+ void *host_data)
+{
+ return irq_domain_create_simple(of_node_to_fwnode(of_node), size, first_irq, ops, host_data);
+}
+
/**
* irq_domain_add_linear() - Allocate and register a linear revmap irq_domain.
* @of_node: pointer to interrupt controller's device tree node.
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 288151393a06..a7f4028971e4 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -295,8 +295,8 @@ void irq_domain_update_bus_token(struct irq_domain *domain,
EXPORT_SYMBOL_GPL(irq_domain_update_bus_token);

/**
- * irq_domain_add_simple() - Register an irq_domain and optionally map a range of irqs
- * @of_node: pointer to interrupt controller's device tree node.
+ * irq_domain_create_simple() - Register an irq_domain and optionally map a range of irqs
+ * @fwnode: firmware node for the interrupt controller
* @size: total number of irqs in mapping
* @first_irq: first number of irq block assigned to the domain,
* pass zero to assign irqs on-the-fly. If first_irq is non-zero, then
@@ -312,15 +312,15 @@ EXPORT_SYMBOL_GPL(irq_domain_update_bus_token);
* irqs get mapped dynamically on the fly. However, if the controller requires
* static virq assignments (non-DT boot) then it will set that up correctly.
*/
-struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
- unsigned int size,
- unsigned int first_irq,
- const struct irq_domain_ops *ops,
- void *host_data)
+struct irq_domain *irq_domain_create_simple(struct fwnode_handle *fwnode,
+ unsigned int size,
+ unsigned int first_irq,
+ const struct irq_domain_ops *ops,
+ void *host_data)
{
struct irq_domain *domain;

- domain = __irq_domain_add(of_node_to_fwnode(of_node), size, size, 0, ops, host_data);
+ domain = __irq_domain_add(fwnode, size, size, 0, ops, host_data);
if (!domain)
return NULL;

@@ -328,7 +328,7 @@ struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
if (IS_ENABLED(CONFIG_SPARSE_IRQ)) {
/* attempt to allocated irq_descs */
int rc = irq_alloc_descs(first_irq, first_irq, size,
- of_node_to_nid(of_node));
+ of_node_to_nid(to_of_node(fwnode)));
if (rc < 0)
pr_info("Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
first_irq);
@@ -338,7 +338,7 @@ struct irq_domain *irq_domain_add_simple(struct device_node *of_node,

return domain;
}
-EXPORT_SYMBOL_GPL(irq_domain_add_simple);
+EXPORT_SYMBOL_GPL(irq_domain_create_simple);

/**
* irq_domain_add_legacy() - Allocate and register a legacy revmap irq_domain.
--
2.30.1