irqdomain: Introduce a firmware-specific IRQ specifier structure

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@arm.com>
Reviewed-and-tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Tomasz Nowicki <tomasz.nowicki@linaro.org>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Graeme Gregory <graeme@xora.org.uk>
Cc: Jake Oshins <jakeo@microsoft.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Link: http://lkml.kernel.org/r/1444737105-31573-5-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 607c185..533c974 100644 (file)
--- 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 023ab6d..86dfd40 100644 (file)
--- 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 {