irq_domain: Move irq_domain code from powerpc to kernel/irq

This patch only moves the code.  It doesn't make any changes, and the
code is still only compiled for powerpc.  Follow-on patches will generalize
the code for other architectures.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>

arch/powerpc/Kconfig

@@ -135,6 +135,7 @@ config PPC
 	select HAVE_GENERIC_HARDIRQS
 	select HAVE_SPARSE_IRQ
 	select IRQ_PER_CPU
+	select IRQ_DOMAIN
 	select GENERIC_IRQ_SHOW
 	select GENERIC_IRQ_SHOW_LEVEL
 	select IRQ_FORCED_THREADING

arch/powerpc/include/asm/irq.h

@@ -42,154 +42,10 @@ extern atomic_t ppc_n_lost_interrupts;
 /* Same thing, used by the generic IRQ code */
 #define NR_IRQS_LEGACY		NUM_ISA_INTERRUPTS
 
-/*
- * The host code and data structures are fairly agnostic to the fact that
- * we use an open firmware device-tree. We do have references to struct
- * device_node in two places: in irq_find_host() to find the host matching
- * a given interrupt controller node, and of course as an argument to its
- * counterpart host->ops->match() callback. However, those are treated as
- * generic pointers by the core and the fact that it's actually a device-node
- * pointer is purely a convention between callers and implementation. This
- * code could thus be used on other architectures by replacing those two
- * by some sort of arch-specific void * "token" used to identify interrupt
- * controllers.
- */
-
 struct irq_data;
 extern irq_hw_number_t irqd_to_hwirq(struct irq_data *d);
 extern irq_hw_number_t virq_to_hw(unsigned int virq);
 
-/**
- * irq_alloc_host - Allocate a new irq_domain data structure
- * @of_node: optional device-tree node of the interrupt controller
- * @revmap_type: type of reverse mapping to use
- * @revmap_arg: for IRQ_DOMAIN_MAP_LINEAR linear only: size of the map
- * @ops: map/unmap host callbacks
- * @inval_irq: provide a hw number in that host space that is always invalid
- *
- * Allocates and initialize and irq_domain structure. Note that in the case of
- * IRQ_DOMAIN_MAP_LEGACY, the map() callback will be called before this returns
- * for all legacy interrupts except 0 (which is always the invalid irq for
- * a legacy controller). For a IRQ_DOMAIN_MAP_LINEAR, the map is allocated by
- * this call as well. For a IRQ_DOMAIN_MAP_TREE, the radix tree will be allocated
- * later during boot automatically (the reverse mapping will use the slow path
- * until that happens).
- */
-extern struct irq_domain *irq_alloc_host(struct device_node *of_node,
-				       unsigned int revmap_type,
-				       unsigned int revmap_arg,
-				       struct irq_domain_ops *ops,
-				       irq_hw_number_t inval_irq);
-
-
-/**
- * irq_find_host - Locates a host for a given device node
- * @node: device-tree node of the interrupt controller
- */
-extern struct irq_domain *irq_find_host(struct device_node *node);
-
-
-/**
- * irq_set_default_host - Set a "default" host
- * @host: default host pointer
- *
- * For convenience, it's possible to set a "default" host that will be used
- * whenever NULL is passed to irq_create_mapping(). It makes life easier for
- * platforms that want to manipulate a few hard coded interrupt numbers that
- * aren't properly represented in the device-tree.
- */
-extern void irq_set_default_host(struct irq_domain *host);
-
-
-/**
- * irq_set_virq_count - Set the maximum number of virt irqs
- * @count: number of linux virtual irqs, capped with NR_IRQS
- *
- * This is mainly for use by platforms like iSeries who want to program
- * the virtual irq number in the controller to avoid the reverse mapping
- */
-extern void irq_set_virq_count(unsigned int count);
-
-
-/**
- * irq_create_mapping - Map a hardware interrupt into linux virq space
- * @host: host owning this hardware interrupt or NULL for default host
- * @hwirq: hardware irq number in that host space
- *
- * Only one mapping per hardware interrupt is permitted. Returns a linux
- * virq number.
- * If the sense/trigger is to be specified, set_irq_type() should be called
- * on the number returned from that call.
- */
-extern unsigned int irq_create_mapping(struct irq_domain *host,
-				       irq_hw_number_t hwirq);
-
-
-/**
- * irq_dispose_mapping - Unmap an interrupt
- * @virq: linux virq number of the interrupt to unmap
- */
-extern void irq_dispose_mapping(unsigned int virq);
-
-/**
- * irq_find_mapping - Find a linux virq from an hw irq number.
- * @host: host owning this hardware interrupt
- * @hwirq: hardware irq number in that host space
- *
- * This is a slow path, for use by generic code. It's expected that an
- * irq controller implementation directly calls the appropriate low level
- * mapping function.
- */
-extern unsigned int irq_find_mapping(struct irq_domain *host,
-				     irq_hw_number_t hwirq);
-
-/**
- * irq_create_direct_mapping - Allocate a virq for direct mapping
- * @host: host to allocate the virq for or NULL for default host
- *
- * This routine is used for irq controllers which can choose the hardware
- * interrupt numbers they generate. In such a case it's simplest to use
- * the linux virq as the hardware interrupt number.
- */
-extern unsigned int irq_create_direct_mapping(struct irq_domain *host);
-
-/**
- * irq_radix_revmap_insert - Insert a hw irq to linux virq number mapping.
- * @host: host owning this hardware interrupt
- * @virq: linux irq number
- * @hwirq: hardware irq number in that host space
- *
- * This is for use by irq controllers that use a radix tree reverse
- * mapping for fast lookup.
- */
-extern void irq_radix_revmap_insert(struct irq_domain *host, unsigned int virq,
-				    irq_hw_number_t hwirq);
-
-/**
- * irq_radix_revmap_lookup - Find a linux virq from a hw irq number.
- * @host: host owning this hardware interrupt
- * @hwirq: hardware irq number in that host space
- *
- * This is a fast path, for use by irq controller code that uses radix tree
- * revmaps
- */
-extern unsigned int irq_radix_revmap_lookup(struct irq_domain *host,
-					    irq_hw_number_t hwirq);
-
-/**
- * irq_linear_revmap - Find a linux virq from a hw irq number.
- * @host: host owning this hardware interrupt
- * @hwirq: hardware irq number in that host space
- *
- * This is a fast path, for use by irq controller code that uses linear
- * revmaps. It does fallback to the slow path if the revmap doesn't exist
- * yet and will create the revmap entry with appropriate locking
- */
-
-extern unsigned int irq_linear_revmap(struct irq_domain *host,
-				      irq_hw_number_t hwirq);
-
-
 /**
  * irq_early_init - Init irq remapping subsystem
  */

include/linux/irqdomain.h

@@ -16,6 +16,17 @@
  * (though a domain can cover more than one PIC if they have a flat number
  * model). It's the domain callbacks that are responsible for setting the
  * irq_chip on a given irq_desc after it's been mapped.
+ *
+ * The host code and data structures are agnostic to whether or not
+ * we use an open firmware device-tree. We do have references to struct
+ * device_node in two places: in irq_find_host() to find the host matching
+ * a given interrupt controller node, and of course as an argument to its
+ * counterpart domain->ops->match() callback. However, those are treated as
+ * generic pointers by the core and the fact that it's actually a device-node
+ * pointer is purely a convention between callers and implementation. This
+ * code could thus be used on other architectures by replacing those two
+ * by some sort of arch-specific void * "token" used to identify interrupt
+ * controllers.
  */
 
 #ifndef _LINUX_IRQDOMAIN_H
@@ -108,6 +119,32 @@ struct irq_domain {
 };
 
 #ifdef CONFIG_IRQ_DOMAIN
+#ifdef CONFIG_PPC
+extern struct irq_domain *irq_alloc_host(struct device_node *of_node,
+				       unsigned int revmap_type,
+				       unsigned int revmap_arg,
+				       struct irq_domain_ops *ops,
+				       irq_hw_number_t inval_irq);
+extern struct irq_domain *irq_find_host(struct device_node *node);
+extern void irq_set_default_host(struct irq_domain *host);
+extern void irq_set_virq_count(unsigned int count);
+
+
+extern unsigned int irq_create_mapping(struct irq_domain *host,
+				       irq_hw_number_t hwirq);
+extern void irq_dispose_mapping(unsigned int virq);
+extern unsigned int irq_find_mapping(struct irq_domain *host,
+				     irq_hw_number_t hwirq);
+extern unsigned int irq_create_direct_mapping(struct irq_domain *host);
+extern void irq_radix_revmap_insert(struct irq_domain *host, unsigned int virq,
+				    irq_hw_number_t hwirq);
+extern unsigned int irq_radix_revmap_lookup(struct irq_domain *host,
+					    irq_hw_number_t hwirq);
+extern unsigned int irq_linear_revmap(struct irq_domain *host,
+				      irq_hw_number_t hwirq);
+
+#else /* CONFIG_PPC */
+
 /**
  * irq_domain_to_irq() - Translate from a hardware irq to a linux irq number
  *
@@ -137,15 +174,16 @@ extern void irq_domain_add(struct irq_domain *domain);
 extern void irq_domain_del(struct irq_domain *domain);
 
 extern struct irq_domain_ops irq_domain_simple_ops;
-#endif /* CONFIG_IRQ_DOMAIN */
 
-#if defined(CONFIG_IRQ_DOMAIN) && defined(CONFIG_OF_IRQ)
+#if defined(CONFIG_OF_IRQ)
 extern void irq_domain_add_simple(struct device_node *controller, int irq_base);
 extern void irq_domain_generate_simple(const struct of_device_id *match,
 					u64 phys_base, unsigned int irq_start);
-#else /* CONFIG_IRQ_DOMAIN && CONFIG_OF_IRQ */
+#else /* CONFIG_OF_IRQ */
 static inline void irq_domain_generate_simple(const struct of_device_id *match,
 					u64 phys_base, unsigned int irq_start) { }
-#endif /* CONFIG_IRQ_DOMAIN && CONFIG_OF_IRQ */
+#endif /* !CONFIG_OF_IRQ */
+#endif /* !CONFIG_PPC */
+#endif /* CONFIG_IRQ_DOMAIN */
 
 #endif /* _LINUX_IRQDOMAIN_H */