[PATCH 04/16] irqdomain: Introduce a firmware-specific IRQ specifier structure

From: Marc Zyngier
Date: Tue Oct 06 2015 - 13:41:27 EST


So far the closest thing to a generic IRQ specifier structure is
of_phandle_args, which happens to be pretty OF specific (the of_node
pointer in there is quite annoying).

Let's introduce 'struct irq_fwspec' that can be used in place of
of_phandle_args for OF, but also for other firmware implementations
(that'd be ACPI). This is used together with a new 'translate' method
that is the pendent of 'xlate'.

We convert irq_create_of_mapping to use this new structure (with a
small hack that will be removed later).

Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
include/linux/irqdomain.h | 20 ++++++++++++++++
kernel/irq/irqdomain.c | 59 ++++++++++++++++++++++++++++++++++++++---------
2 files changed, 68 insertions(+), 11 deletions(-)

diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 607c185..533c974 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -46,6 +46,24 @@ struct irq_data;
/* Number of irqs reserved for a legacy isa controller */
#define NUM_ISA_INTERRUPTS 16

+#define IRQ_DOMAIN_IRQ_SPEC_PARAMS 16
+
+/**
+ * struct irq_fwspec - generic IRQ specifier structure
+ *
+ * @fwnode: Pointer to a firmware-specific descriptor
+ * @param_count: Number of device-specific parameters
+ * @param: Device-specific parameters
+ *
+ * This structure, directly modeled after of_phandle_args, is used to
+ * pass a device-specific description of an interrupt.
+ */
+struct irq_fwspec {
+ struct fwnode_handle *fwnode;
+ int param_count;
+ u32 param[IRQ_DOMAIN_IRQ_SPEC_PARAMS];
+};
+
/*
* Should several domains have the same device node, but serve
* different purposes (for example one domain is for PCI/MSI, and the
@@ -92,6 +110,8 @@ struct irq_domain_ops {
unsigned int nr_irqs);
void (*activate)(struct irq_domain *d, struct irq_data *irq_data);
void (*deactivate)(struct irq_domain *d, struct irq_data *irq_data);
+ int (*translate)(struct irq_domain *d, struct irq_fwspec *fwspec,
+ unsigned long *out_hwirq, unsigned int *out_type);
#endif
};

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 10b6105..3f07055 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -484,30 +484,67 @@ int irq_create_strict_mappings(struct irq_domain *domain, unsigned int irq_base,
}
EXPORT_SYMBOL_GPL(irq_create_strict_mappings);

+static int irq_domain_translate(struct irq_domain *d,
+ struct irq_fwspec *fwspec,
+ irq_hw_number_t *hwirq, unsigned int *type)
+{
+#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
+ if (d->ops->translate)
+ return d->ops->translate(d, fwspec, hwirq, type);
+#endif
+ if (d->ops->xlate)
+ return d->ops->xlate(d, to_of_node(fwspec->fwnode),
+ fwspec->param, fwspec->param_count,
+ hwirq, type);
+
+ /* If domain has no translation, then we assume interrupt line */
+ *hwirq = fwspec->param[0];
+ return 0;
+}
+
+static void of_phandle_args_to_fwspec(struct of_phandle_args *irq_data,
+ struct irq_fwspec *fwspec)
+{
+ int i;
+
+ fwspec->fwnode = irq_data->np ? &irq_data->np->fwnode : NULL;
+ fwspec->param_count = irq_data->args_count;
+
+ for (i = 0; i < irq_data->args_count; i++)
+ fwspec->param[i] = irq_data->args[i];
+}
+
unsigned int irq_create_of_mapping(struct of_phandle_args *irq_data)
{
+ struct irq_fwspec fwspec;
struct irq_domain *domain;
irq_hw_number_t hwirq;
unsigned int type = IRQ_TYPE_NONE;
int virq;

- domain = irq_data->np ? irq_find_host(irq_data->np) : irq_default_domain;
+ of_phandle_args_to_fwspec(irq_data, &fwspec);
+
+ if (fwspec.fwnode)
+ domain = irq_find_matching_fwnode(fwspec.fwnode, DOMAIN_BUS_ANY);
+ else
+ domain = irq_default_domain;
+
if (!domain) {
pr_warn("no irq domain found for %s !\n",
- of_node_full_name(irq_data->np));
+ of_node_full_name(to_of_node(fwspec.fwnode)));
return 0;
}

- /* If domain has no translation, then we assume interrupt line */
- if (domain->ops->xlate == NULL)
- hwirq = irq_data->args[0];
- else {
- if (domain->ops->xlate(domain, irq_data->np, irq_data->args,
- irq_data->args_count, &hwirq, &type))
- return 0;
- }
+ if (irq_domain_translate(domain, &fwspec, &hwirq, &type))
+ return 0;

if (irq_domain_is_hierarchy(domain)) {
+ /* Temporary hack */
+ void *desc = &fwspec;
+#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
+ if (!domain->ops->translate)
+ desc = irq_data;
+#endif
/*
* If we've already configured this interrupt,
* don't do it again, or hell will break loose.
@@ -516,7 +553,7 @@ unsigned int irq_create_of_mapping(struct of_phandle_args *irq_data)
if (virq)
return virq;

- virq = irq_domain_alloc_irqs(domain, 1, NUMA_NO_NODE, irq_data);
+ virq = irq_domain_alloc_irqs(domain, 1, NUMA_NO_NODE, desc);
if (virq <= 0)
return 0;
} else {
--
2.1.4

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