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>
This commit is contained in:
Marc Zyngier
2015-07-28 14:46:08 +01:00
committed by Thomas Gleixner
parent 8505a81bb0
commit ad3aedfbb0
14 changed files with 58 additions and 19 deletions

View File

@@ -187,10 +187,12 @@ struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
EXPORT_SYMBOL_GPL(irq_domain_add_legacy);
/**
* irq_find_host() - Locates a domain for a given device node
* irq_find_matching_host() - Locates a domain for a given device node
* @node: device-tree node of the interrupt controller
* @bus_token: domain-specific data
*/
struct irq_domain *irq_find_host(struct device_node *node)
struct irq_domain *irq_find_matching_host(struct device_node *node,
enum irq_domain_bus_token bus_token)
{
struct irq_domain *h, *found = NULL;
int rc;
@@ -199,13 +201,19 @@ struct irq_domain *irq_find_host(struct device_node *node)
* it might potentially be set to match all interrupts in
* the absence of a device node. This isn't a problem so far
* yet though...
*
* bus_token == DOMAIN_BUS_ANY matches any domain, any other
* values must generate an exact match for the domain to be
* selected.
*/
mutex_lock(&irq_domain_mutex);
list_for_each_entry(h, &irq_domain_list, link) {
if (h->ops->match)
rc = h->ops->match(h, node);
rc = h->ops->match(h, node, bus_token);
else
rc = (h->of_node != NULL) && (h->of_node == node);
rc = ((h->of_node != NULL) && (h->of_node == node) &&
((bus_token == DOMAIN_BUS_ANY) ||
(h->bus_token == bus_token)));
if (rc) {
found = h;
@@ -215,7 +223,7 @@ struct irq_domain *irq_find_host(struct device_node *node)
mutex_unlock(&irq_domain_mutex);
return found;
}
EXPORT_SYMBOL_GPL(irq_find_host);
EXPORT_SYMBOL_GPL(irq_find_matching_host);
/**
* irq_set_default_host() - Set a "default" irq domain