| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <1337428920-7674-1-git-send-email-broonie@opensource.wolfsonmicro.com>
Date: Sat, 19 May 2012 13:02:00 +0100
From: Mark Brown <broonie@...nsource.wolfsonmicro.com>
To: Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Grant Likely <grant.likely@...retlab.ca>,
Thomas Gleixner <tglx@...utronix.de>
Cc: linux-kernel@...r.kernel.org,
Mark Brown <broonie@...nsource.wolfsonmicro.com>
Subject: [PATCH] irq_domain: Standardise legacy/linear domain selection
A large proportion of interrupt controllers that support legacy mappings
do so because non-DT systems need to use fixed IRQ numbers when registering
devices via buses but can otherwise use a linear mapping. The interrupt
controller itself typically is not affected by the mapping used and best
practice is to use a linear mapping where possible so drivers frequently
select at runtime depending on if a legacy range has been allocated to
them.
Standardise this behaviour by providing irq_domain_register_simple() which
will allocate a linear mapping unless a positive first_irq is provided in
which case it will fall back to a legacy mapping. This helps make best
practice for irq_domain adoption clearer.
Signed-off-by: Mark Brown <broonie@...nsource.wolfsonmicro.com>
---
Documentation/IRQ-domain.txt | 5 +++++
include/linux/irqdomain.h | 5 +++++
kernel/irq/irqdomain.c | 30 ++++++++++++++++++++++++++++++
3 files changed, 40 insertions(+)
diff --git a/Documentation/IRQ-domain.txt b/Documentation/IRQ-domain.txt
index 27dcaab..1401cec 100644
--- a/Documentation/IRQ-domain.txt
+++ b/Documentation/IRQ-domain.txt
@@ -93,6 +93,7 @@ Linux IRQ number into the hardware.
Most drivers cannot use this mapping.
==== Legacy ====
+irq_domain_add_simple()
irq_domain_add_legacy()
irq_domain_add_legacy_isa()
@@ -115,3 +116,7 @@ The legacy map should only be used if fixed IRQ mappings must be
supported. For example, ISA controllers would use the legacy map for
mapping Linux IRQs 0-15 so that existing ISA drivers get the correct IRQ
numbers.
+
+Most users of legacy mappings should use irq_domain_add_simple() which
+will use a legacy domain only if an IRQ range is supplied by the
+system and will otherwise use a linear domain mapping.
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index c65740d..fcf4142 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -112,6 +112,11 @@ struct irq_domain {
};
#ifdef CONFIG_IRQ_DOMAIN
+struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
+ unsigned int size,
+ unsigned int first_irq,
+ const struct irq_domain_ops *ops,
+ void *host_data);
struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
unsigned int size,
unsigned int first_irq,
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index d0e50eb..86ae10f 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -77,6 +77,36 @@ static unsigned int irq_domain_legacy_revmap(struct irq_domain *domain,
}
/**
+ * irq_domain_add_simple() - Allocate and register a simple irq_domain.
+ * @of_node: pointer to interrupt controller's device tree node.
+ * @size: total number of irqs in mapping
+ * @first_irq: first number of irq block assigned to the domain
+ * @ops: map/unmap domain callbacks
+ * @host_data: Controller private data pointer
+ *
+ * Allocates a legacy irq_domain if irq_base is positive or a linear
+ * domain otherwise.
+ *
+ * This is intended to implement the expected behaviour for most
+ * interrupt controllers which is that a linear mapping should
+ * normally be used unless the system requires a legacy mapping in
+ * order to support supplying interrupt numbers during non-DT
+ * registration of devices.
+ */
+struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
+ unsigned int size,
+ unsigned int first_irq,
+ const struct irq_domain_ops *ops,
+ void *host_data)
+{
+ if (first_irq > 0)
+ return irq_domain_add_legacy(of_node, size, first_irq, 0,
+ ops, host_data);
+ else
+ return irq_domain_add_linear(of_node, size, ops, host_data);
+}
+
+/**
* irq_domain_add_legacy() - Allocate and register a legacy revmap irq_domain.
* @of_node: pointer to interrupt controller's device tree node.
* @size: total number of irqs in legacy mapping
--
1.7.10
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists