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>

6 files changed, 12 insertions, 6 deletions

diff --git a/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c b/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c
index ca3a062ed1b9..11090ab4bf59 100644
--- a/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c
+++ b/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c
@@ -123,7 +123,8 @@ cpld_pic_cascade(unsigned int irq, struct irq_desc *desc)
 }
 
 static int
-cpld_pic_host_match(struct irq_domain *h, struct device_node *node)
+cpld_pic_host_match(struct irq_domain *h, struct device_node *node,
+		    enum irq_domain_bus_token bus_token)
 {
 	return cpld_pic_node == node;
 }
diff --git a/arch/powerpc/platforms/cell/interrupt.c b/arch/powerpc/platforms/cell/interrupt.c
index 3af8324c122e..a15f1efc295f 100644
--- a/arch/powerpc/platforms/cell/interrupt.c
+++ b/arch/powerpc/platforms/cell/interrupt.c
@@ -222,7 +222,8 @@ void iic_request_IPIs(void)
 #endif /* CONFIG_SMP */
 
 
-static int iic_host_match(struct irq_domain *h, struct device_node *node)
+static int iic_host_match(struct irq_domain *h, struct device_node *node,
+			  enum irq_domain_bus_token bus_token)
 {
 	return of_device_is_compatible(node,
 				    "IBM,CBEA-Internal-Interrupt-Controller");
diff --git a/arch/powerpc/platforms/embedded6xx/flipper-pic.c b/arch/powerpc/platforms/embedded6xx/flipper-pic.c
index 4cde8e7da4b8..b7866e01483d 100644
--- a/arch/powerpc/platforms/embedded6xx/flipper-pic.c
+++ b/arch/powerpc/platforms/embedded6xx/flipper-pic.c
@@ -108,7 +108,8 @@ static int flipper_pic_map(struct irq_domain *h, unsigned int virq,
 	return 0;
 }
 
-static int flipper_pic_match(struct irq_domain *h, struct device_node *np)
+static int flipper_pic_match(struct irq_domain *h, struct device_node *np,
+			     enum irq_domain_bus_token bus_token)
 {
 	return 1;
 }
diff --git a/arch/powerpc/platforms/powermac/pic.c b/arch/powerpc/platforms/powermac/pic.c
index 59cfc9d63c2d..6f4f8b060def 100644
--- a/arch/powerpc/platforms/powermac/pic.c
+++ b/arch/powerpc/platforms/powermac/pic.c
@@ -268,7 +268,8 @@ static struct irqaction gatwick_cascade_action = {
 	.name		= "cascade",
 };
 
-static int pmac_pic_host_match(struct irq_domain *h, struct device_node *node)
+static int pmac_pic_host_match(struct irq_domain *h, struct device_node *node,
+			       enum irq_domain_bus_token bus_token)
 {
 	/* We match all, we don't always have a node anyway */
 	return 1;
diff --git a/arch/powerpc/platforms/powernv/opal-irqchip.c b/arch/powerpc/platforms/powernv/opal-irqchip.c
index e2e7d75f52f3..2c91ee7800b9 100644
--- a/arch/powerpc/platforms/powernv/opal-irqchip.c
+++ b/arch/powerpc/platforms/powernv/opal-irqchip.c
@@ -134,7 +134,8 @@ static void opal_handle_irq_work(struct irq_work *work)
 	opal_handle_events(be64_to_cpu(last_outstanding_events));
 }
 
-static int opal_event_match(struct irq_domain *h, struct device_node *node)
+static int opal_event_match(struct irq_domain *h, struct device_node *node,
+			    enum irq_domain_bus_token bus_token)
 {
 	return h->of_node == node;
 }
diff --git a/arch/powerpc/platforms/ps3/interrupt.c b/arch/powerpc/platforms/ps3/interrupt.c
index a6c42f34303a..638c4060938e 100644
--- a/arch/powerpc/platforms/ps3/interrupt.c
+++ b/arch/powerpc/platforms/ps3/interrupt.c
@@ -678,7 +678,8 @@ static int ps3_host_map(struct irq_domain *h, unsigned int virq,
 	return 0;
 }
 
-static int ps3_host_match(struct irq_domain *h, struct device_node *np)
+static int ps3_host_match(struct irq_domain *h, struct device_node *np,
+			  enum irq_domain_bus_token bus_token)
 {
 	/* Match all */
 	return 1;