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SubjectRe: [PATCH 2/4 v2] irqdomain: augment add_simple() to allocate descs
On 10/01/2012 02:35 AM, Linus Walleij wrote:
> From: Linus Walleij <linus.walleij@linaro.org>
>
> 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: Rob Herring <rob.herring@calxeda.com>
> 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>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Looks good.

Reviewed-by: Rob Herring <rob.herring@calxeda.com>

> ---
> ChangeLog v1->v2:
> - Switch descriptor allocation on IS_ENABLED(CONFIG_SPARSE_IRQ)
> so it won't attempt to allocate descriptors in the non-sparse
> case.
> - Use of_node_to_nid() to make sure we work on platforms with their
> own node concept.
> - Specify irq_alloc_descs(first_irq, first_irq ...) to emulate
> irq_alloc_desc_at().
> ---
> kernel/irq/irqdomain.c | 33 ++++++++++++++++++++++++++++-----
> 1 file changed, 28 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
> index 49a7772..4e69e24 100644
> --- a/kernel/irq/irqdomain.c
> +++ b/kernel/irq/irqdomain.c
> @@ -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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