Re: [patch 14/47] genirq: Implement a sane sparse_irq allocator

From: Yinghai Lu
Date: Fri Oct 01 2010 - 01:32:02 EST


On 09/30/2010 04:15 PM, Thomas Gleixner wrote:
......
> ---
> include/linux/irq.h | 25 +++++
> kernel/irq/irqdesc.c | 226 +++++++++++++++++++++++++++++++++++++++++++++++++--
> 2 files changed, 243 insertions(+), 8 deletions(-)
>
> Index: linux-2.6-tip/include/linux/irq.h
> ===================================================================
> --- linux-2.6-tip.orig/include/linux/irq.h
> +++ linux-2.6-tip/include/linux/irq.h
> @@ -276,6 +276,31 @@ static inline struct irq_desc *move_irq_
>
> extern struct irq_desc *irq_to_desc_alloc_node(unsigned int irq, int node);
>
> +int irq_alloc_descs(unsigned int irq, unsigned int from, unsigned int cnt, int node);
> +
> +static inline int irq_alloc_desc(int node)
> +{
> + return irq_alloc_descs(0, 0, 1, node);
> +}
> +
> +static inline int
> +irq_alloc_desc_at(unsigned int at, int node)
> +{
> + return irq_alloc_descs(at, 0, 1, node);

need to change to

return irq_alloc_descs(at, at, 1, node);

> +}
> +
...

> Index: linux-2.6-tip/kernel/irq/irqdesc.c
> ===================================================================
> --- linux-2.6-tip.orig/kernel/irq/irqdesc.c
> +++ linux-2.6-tip/kernel/irq/irqdesc.c
...

> +/**
> + * 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
> + *
> + * Returns the first irq number or error code
> + */
> +int __ref
> +irq_alloc_descs(unsigned int irq, unsigned int from, unsigned int cnt, int node)
> +{
> + unsigned long flags;
> + int start, ret;
> +
> + if (!cnt)
> + return -EINVAL;
> +
> + raw_spin_lock_irqsave(&sparse_irq_lock, flags);
> +
or add
if (irq)
from = irq;
here.

> + start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
> + ret = -EEXIST;
> + if (irq && start != irq)
> + goto err;
> +
> + ret = -ENOMEM;
> + if (start >= nr_irqs)
> + goto err;
> +
> + bitmap_set(allocated_irqs, start, cnt);
> + raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
> + return alloc_descs(start, cnt, node);
> +
> +err:
> + raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
> + return ret;
> +}

Yinghai
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