Re: [PATCH v3 10/27] genirq: Split __irq_reserve_irqs fromirq_alloc_descs

From: Alexander Gordeev
Date: Mon Jun 10 2013 - 09:51:09 EST


On Fri, Jun 07, 2013 at 03:30:56PM -0700, Yinghai Lu wrote:
> irq_alloc_descs and irq_reserve_irqs are almost the same.
> Separate code out to __irq_reserved_irqs, and other two reuse
> __irq_reserve_irqs.
>
> We will use __irq_reserve_irqs for coming ioapic hotplug support.
>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
> Cc: Alexander Gordeev <agordeev@xxxxxxxxxx>
> ---
> include/linux/irq.h | 1 +
> kernel/irq/irqdesc.c | 54 ++++++++++++++++++++++++++++++----------------------
> 2 files changed, 32 insertions(+), 23 deletions(-)
>
> diff --git a/include/linux/irq.h b/include/linux/irq.h
> index bc4e066..4e0fcbb 100644
> --- a/include/linux/irq.h
> +++ b/include/linux/irq.h
> @@ -600,6 +600,7 @@ int __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
>
> void irq_free_descs(unsigned int irq, unsigned int cnt);
> int irq_reserve_irqs(unsigned int from, unsigned int cnt);
> +int __irq_reserve_irqs(int irq, unsigned int from, unsigned int cnt);
>
> static inline void irq_free_desc(unsigned int irq)
> {
> diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
> index 192a302..3b9fb92 100644
> --- a/kernel/irq/irqdesc.c
> +++ b/kernel/irq/irqdesc.c
> @@ -340,18 +340,15 @@ void irq_free_descs(unsigned int from, unsigned int cnt)
> EXPORT_SYMBOL_GPL(irq_free_descs);
>
> /**
> - * irq_alloc_descs - allocate and initialize a range of irq descriptors
> - * @irq: Allocate for specific irq number if irq >= 0
> + * __irq_reserve_descs - reserve and initialize a range of irq descriptors
> + * @irq: Reserve for specific irq number if irq >= 0
> * @from: Start the search from this irq number
> - * @cnt: Number of consecutive irqs to allocate.
> - * @node: Preferred node on which the irq descriptor should be allocated
> - * @owner: Owning module (can be NULL)
> + * @cnt: Number of consecutive irqs to reserve.
> *
> * Returns the first irq number or error code
> */
> int __ref
> -__irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
> - struct module *owner)
> +__irq_reserve_irqs(int irq, unsigned int from, unsigned int cnt)
> {
> int start, ret;
>
> @@ -369,7 +366,7 @@ __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
> start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
> from, cnt, 0);
> ret = -EEXIST;
> - if (irq >=0 && start != irq)
> + if (irq >= 0 && start != irq)
> goto err;
>
> if (start + cnt > nr_irqs) {
> @@ -380,12 +377,36 @@ __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
>
> bitmap_set(allocated_irqs, start, cnt);
> mutex_unlock(&sparse_irq_lock);
> - return alloc_descs(start, cnt, node, owner);
> + return start;
>
> err:
> mutex_unlock(&sparse_irq_lock);
> return ret;
> }
> +
> +/**
> + * irq_alloc_descs - allocate and initialize a range of irq descriptors
> + * @irq: Allocate for specific irq number if irq >= 0
> + * @from: Start the search from this irq number
> + * @cnt: Number of consecutive irqs to allocate.
> + * @node: Preferred node on which the irq descriptor should be allocated
> + * @owner: Owning module (can be NULL)
> + *
> + * Returns the first irq number or error code
> + */
> +int __ref
> +__irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
> + struct module *owner)
> +{
> + int start;
> +
> + start = __irq_reserve_irqs(irq, from, cnt);
> +
> + if (start < 0)
> + return start;
> +
> + return alloc_descs(start, cnt, node, owner);

I think alloc_descs() fail path is needed before return.

> +}
> EXPORT_SYMBOL_GPL(__irq_alloc_descs);
>
> /**
> @@ -397,20 +418,7 @@ EXPORT_SYMBOL_GPL(__irq_alloc_descs);
> */
> int irq_reserve_irqs(unsigned int from, unsigned int cnt)
> {
> - unsigned int start;
> - int ret = 0;
> -
> - if (!cnt || (from + cnt) > nr_irqs)
> - return -EINVAL;
> -
> - mutex_lock(&sparse_irq_lock);
> - start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
> - if (start == from)
> - bitmap_set(allocated_irqs, start, cnt);
> - else
> - ret = -EEXIST;
> - mutex_unlock(&sparse_irq_lock);
> - return ret;
> + return __irq_reserve_irqs(from, from, cnt);
> }
>
> /**
> --
> 1.8.1.4
>

--
Regards,
Alexander Gordeev
agordeev@xxxxxxxxxx
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/