lkml.org 
[lkml]   [2012]   [May]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH 6/8] irqdomain: Support identity mapped VIRQ allocation.
Date
On Sat, 19 May 2012 15:11:46 +0900, Paul Mundt <lethal@linux-sh.org> wrote:
> This adds a new irq_create_identity_mapping() routine to permit platforms
> to utilize 1:1 identity mapping between hardware and linux IRQs for
> domain population. The same semantics as irq_create_mapping() apply,
> though in this case we only support irqdesc allocation at a static
> location, rather than falling back on dynamic lookup.
>
> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
> ---
> include/linux/irqdomain.h | 2 ++
> kernel/irq/irqdomain.c | 41 +++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 43 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
> index 5abb533..e32d2e7 100644
> --- a/include/linux/irqdomain.h
> +++ b/include/linux/irqdomain.h
> @@ -149,6 +149,8 @@ extern unsigned int irq_create_mapping(struct irq_domain *host,
> extern void irq_dispose_mapping(unsigned int virq);
> extern unsigned int irq_find_mapping(struct irq_domain *host,
> irq_hw_number_t hwirq);
> +extern unsigned int irq_create_identity_mapping(struct irq_domain *host,
> + irq_hw_number_t hwirq);
> extern unsigned int irq_create_direct_mapping(struct irq_domain *host);
> extern void irq_radix_revmap_insert(struct irq_domain *host, unsigned int virq,
> irq_hw_number_t hwirq);
> diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
> index 5f0ca52..ac44781 100644
> --- a/kernel/irq/irqdomain.c
> +++ b/kernel/irq/irqdomain.c
> @@ -459,6 +459,47 @@ unsigned int irq_create_mapping(struct irq_domain *domain,
> }
> EXPORT_SYMBOL_GPL(irq_create_mapping);
>
> +/**
> + * irq_create_identity_mapping() - Allocate an identity mapped irq
> + * @domain: domain owning this hardware interrupt or NULL for default domain
> + * @hwirq: hardware irq number in that domain space
> + *
> + * This routine is used to allocate IRQs with a 1:1 identity mapping
> + * between the hardware and linux irq.
> + */
> +unsigned int irq_create_identity_mapping(struct irq_domain *domain,
> + irq_hw_number_t hwirq)

How about the following for an API (omitting error checking, and the
actual names are up for debate):

int irq_domain_associate_many(struct irq_domain *domain,
unsigned int irq_base,
irq_hw_number_t hwirq_base,
int count)
{
int i;
for (i = 0; i < count; i++)
irq_setup_virq(domain, irq_base + i, hwirq_base + i);
}
int irq_create_strict_mappings(struct irq_domain *domain,
unsigned int irq_base,
irq_hw_number_t hwirq_base,
int count)
{
/* Allows for non-identity, but still static mappings of a
* range of irq numbers */
irq_alloc_descs(irq_base, irq_base, irq_domain_nid(domain->of_node));
irq_domain_associate_many(domain, irq_base, hwirq, count);
...
}
/* in header */
static int irq_create_identity_mapping(struct irq_domain *domain,
irq_hw_number_t hwirq_base)
{
irq_create_strict_mappings(domain, hwirq_base, hwirq_base, 1);
}
That would give the ability to either associated for pre-allocated
irq_descs, or strict map for allocating a specific range of irqs.


> +{
> + int virq;
> +
> + pr_debug("irq: irq_create_identity_mapping(0x%p, 0x%lx)\n",
> + domain, hwirq);
> +
> + if (domain == NULL)
> + domain = irq_default_domain;

This is a new API, and I'm not a fan of the irq_default_domain usage
so I'd like just drop the above too lines. My opinion is that if your
calling into get a mapping, then the code really should know what
domain it is requesting from. If a default domain really is needed,
then there it should be explicit for the caller to find the default
domain and then pass that in to this function.

> + if (domain == NULL) {
> + WARN_ON(1);
> + return 0;
> + }
> +
> + virq = irq_alloc_desc_at(hwirq, irq_domain_nid(domain->of_node));
> + if (virq < 0) {
> + pr_debug("irq: -> virq allocation failed\n");
> + return 0;
> + }
> +
> + if (irq_setup_virq(domain, virq, hwirq)) {
> + if (domain->revmap_type != IRQ_DOMAIN_MAP_LEGACY)
> + irq_free_desc(virq);
> + return 0;
> + }
> +
> + pr_debug("irq: irq %lu identity mapped\n", hwirq);
> +
> + return virq;
> +}
> +EXPORT_SYMBOL_GPL(irq_create_identity_mapping);
> +
> unsigned int irq_create_of_mapping(struct device_node *controller,
> const u32 *intspec, unsigned int intsize)
> {
> --
> 1.7.9.rc0.28.g0e1cf
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/

--
Grant Likely, B.Sc, P.Eng.
Secret Lab Technologies, Ltd.


\
 
 \ /
  Last update: 2012-05-19 22:41    [from the cache]
©2003-2011 Jasper Spaans