genirq/irqdomain: Allow irq domain aliasing
It is not uncommon (at least with the ARM stuff) to have a piece
of hardware that implements different flavours of "interrupts".
A typical example of this is the GICv3 ITS, which implements
standard PCI/MSI support, but also some form of "generic MSI".
So far, the PCI/MSI domain is registered using the ITS device_node,
so that irq_find_host can return it. On the contrary, the raw MSI
domain is not registered with an device_node, making it impossible
to be looked up by another subsystem (obviously, using the same
device_node twice would only result in confusion, as it is not
defined which one irq_find_host would return).
A solution to this is to "type" domains that may be aliasing, and
to be able to lookup an device_node that matches a given type.
For this, we introduce irq_find_matching_host() as a superset
of irq_find_host:
struct irq_domain *irq_find_matching_host(struct device_node *node,
enum irq_domain_bus_token bus_token);
where bus_token is the "type" we want to match the domain against
(so far, only DOMAIN_BUS_ANY is defined). This result in some
moderately invasive changes on the PPC side (which is the only
user of the .match method).
This has otherwise no functionnal change.
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Yijing Wang <wangyijing@huawei.com>
Cc: Ma Jun <majun258@huawei.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Duc Dang <dhdang@apm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/1438091186-10244-2-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 744ac0e..91a83ad 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -45,6 +45,17 @@
/* Number of irqs reserved for a legacy isa controller */
#define NUM_ISA_INTERRUPTS 16
+/*
+ * Should several domains have the same device node, but serve
+ * different purposes (for example one domain is for PCI/MSI, and the
+ * other for wired IRQs), they can be distinguished using a
+ * bus-specific token. Most domains are expected to only carry
+ * DOMAIN_BUS_ANY.
+ */
+enum irq_domain_bus_token {
+ DOMAIN_BUS_ANY = 0,
+};
+
/**
* struct irq_domain_ops - Methods for irq_domain objects
* @match: Match an interrupt controller device node to a host, returns
@@ -61,7 +72,8 @@
* to setup the irq_desc when returning from map().
*/
struct irq_domain_ops {
- int (*match)(struct irq_domain *d, struct device_node *node);
+ int (*match)(struct irq_domain *d, struct device_node *node,
+ enum irq_domain_bus_token bus_token);
int (*map)(struct irq_domain *d, unsigned int virq, irq_hw_number_t hw);
void (*unmap)(struct irq_domain *d, unsigned int virq);
int (*xlate)(struct irq_domain *d, struct device_node *node,
@@ -116,6 +128,7 @@
/* Optional data */
struct device_node *of_node;
+ enum irq_domain_bus_token bus_token;
struct irq_domain_chip_generic *gc;
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
struct irq_domain *parent;
@@ -161,9 +174,15 @@
irq_hw_number_t first_hwirq,
const struct irq_domain_ops *ops,
void *host_data);
-extern struct irq_domain *irq_find_host(struct device_node *node);
+extern struct irq_domain *irq_find_matching_host(struct device_node *node,
+ enum irq_domain_bus_token bus_token);
extern void irq_set_default_host(struct irq_domain *host);
+static inline struct irq_domain *irq_find_host(struct device_node *node)
+{
+ return irq_find_matching_host(node, DOMAIN_BUS_ANY);
+}
+
/**
* irq_domain_add_linear() - Allocate and register a linear revmap irq_domain.
* @of_node: pointer to interrupt controller's device tree node.