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irqdomain: augment add_simple() to allocate descs

Currently we rely on all IRQ chip instances to dynamically
allocate their IRQ descriptors unless they use the linear
IRQ domain. So for irqdomain_add_legacy() and
irqdomain_add_simple() the caller need to make sure that
descriptors are allocated.

Let's slightly augment the yet unused irqdomain_add_simple()
to also allocate descriptors as a means to simplify usage
and avoid code duplication throughout the kernel.

We warn if descriptors cannot be allocated, e.g. if a
platform has the bad habit of hogging descriptors at boot
time.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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1 parent c22df08 commit 2854d167cc545d0642277bf8b77f972a91146fc6 @linusw linusw committed Sep 27, 2012
Showing with 28 additions and 5 deletions.
  1. +28 −5 kernel/irq/irqdomain.c
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@@ -148,7 +148,8 @@ static unsigned int irq_domain_legacy_revmap(struct irq_domain *domain,
* @host_data: Controller private data pointer
*
* Allocates a legacy irq_domain if irq_base is positive or a linear
- * domain otherwise.
+ * domain otherwise. For the legacy domain, IRQ descriptors will also
+ * be allocated.
*
* This is intended to implement the expected behaviour for most
* interrupt controllers which is that a linear mapping should
@@ -162,11 +163,33 @@ struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
const struct irq_domain_ops *ops,
void *host_data)
{
- if (first_irq > 0)
- return irq_domain_add_legacy(of_node, size, first_irq, 0,
+ if (first_irq > 0) {
+ int irq_base;
+
+ if (IS_ENABLED(CONFIG_SPARSE_IRQ)) {
+ /*
+ * Set the descriptor allocator to search for a
+ * 1-to-1 mapping, such as irq_alloc_desc_at().
+ * Use of_node_to_nid() which is defined to
+ * numa_node_id() on platforms that have no custom
+ * implementation.
+ */
+ irq_base = irq_alloc_descs(first_irq, first_irq, size,
+ of_node_to_nid(of_node));
+ if (irq_base < 0) {
+ WARN(1, "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
+ first_irq);
+ irq_base = first_irq;
+ }
+ } else
+ irq_base = first_irq;
+
+ return irq_domain_add_legacy(of_node, size, irq_base, 0,
ops, host_data);
- else
- return irq_domain_add_linear(of_node, size, ops, host_data);
+ }
+
+ /* A linear domain is the default */
+ return irq_domain_add_linear(of_node, size, ops, host_data);
}
/**

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