genirq: Allow fwnode to carry name information only

In order to provide proper debug interface it's required to have domain
names available when the domain is added. Non fwnode based architectures
like x86 have no way to do so.

It's not possible to use domain ops or host data for this as domain ops
might be the same for several instances, but the names have to be unique.

Extend the irqchip fwnode to allow transporting the domain name. If no node
is supplied, create a 'unknown-N' placeholder.

Warn if an invalid node is supplied and treat it like no node. This happens
e.g. with i2 devices on x86 which hand in an ACPI type node which has no
interface for retrieving the name.

[ Folded a fix from Marc to make DT name parsing work ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235443.588784933@linutronix.de

1 files changed, 30 insertions, 1 deletions

diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 9f3616085423..9cf32a2fbe69 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -189,6 +189,9 @@ enum {
 	/* Irq domain implements MSI remapping */
 	IRQ_DOMAIN_FLAG_MSI_REMAP	= (1 << 5),
 
+	/* Irq domain name was allocated in __irq_domain_add() */
+	IRQ_DOMAIN_NAME_ALLOCATED	= (1 << 6),
+
 	/*
 	 * Flags starting from IRQ_DOMAIN_FLAG_NONCORE are reserved
 	 * for implementation specific purposes and ignored by the
@@ -203,7 +206,33 @@ static inline struct device_node *irq_domain_get_of_node(struct irq_domain *d)
 }
 
 #ifdef CONFIG_IRQ_DOMAIN
-struct fwnode_handle *irq_domain_alloc_fwnode(void *data);
+struct fwnode_handle *__irq_domain_alloc_fwnode(unsigned int type, int id,
+						const char *name, void *data);
+
+enum {
+	IRQCHIP_FWNODE_REAL,
+	IRQCHIP_FWNODE_NAMED,
+	IRQCHIP_FWNODE_NAMED_ID,
+};
+
+static inline
+struct fwnode_handle *irq_domain_alloc_named_fwnode(const char *name)
+{
+	return __irq_domain_alloc_fwnode(IRQCHIP_FWNODE_NAMED, 0, name, NULL);
+}
+
+static inline
+struct fwnode_handle *irq_domain_alloc_named_id_fwnode(const char *name, int id)
+{
+	return __irq_domain_alloc_fwnode(IRQCHIP_FWNODE_NAMED_ID, id, name,
+					 NULL);
+}
+
+static inline struct fwnode_handle *irq_domain_alloc_fwnode(void *data)
+{
+	return __irq_domain_alloc_fwnode(IRQCHIP_FWNODE_REAL, 0, NULL, data);
+}
+
 void irq_domain_free_fwnode(struct fwnode_handle *fwnode);
 struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, int size,
 				    irq_hw_number_t hwirq_max, int direct_max,