[PATCH 24/37] powerpc: return early if irq_host lookup type is wrong

[Grant Likely]

On Wed, May 11, 2011 at 7:29 AM, Milton Miller <miltonm at bga.com> wrote:
> If for some reason the code incrorectly calls the wrong function to
> manage the revmap, not only should we warn, we should take action.
> However, in the paths we expect to be taken every delivered interrupt
> change to WARN_ON_ONCE.  Use the if (WARN_ON(x)) format to get the
> unlikely for free.
>
> Signed-off-by: Milton Miller <miltonm at bga.com>

Looks right.

Reviewed-by: Grant Likely <grant.likely at secretlab.ca>

> ---
>  arch/powerpc/kernel/irq.c |   12 +++++++-----
>  1 files changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
> index f42e869..4a5aa8c 100644
> --- a/arch/powerpc/kernel/irq.c
> +++ b/arch/powerpc/kernel/irq.c
> @@ -814,8 +814,7 @@ void irq_dispose_mapping(unsigned int virq)
>                return;
>
>        host = irq_map[virq].host;
> -       WARN_ON (host == NULL);
> -       if (host == NULL)
> +       if (WARN_ON(host == NULL))
>                return;
>
>        /* Never unmap legacy interrupts */
> @@ -898,7 +897,8 @@ unsigned int irq_radix_revmap_lookup(struct irq_host *host,
>        struct irq_map_entry *ptr;
>        unsigned int virq;
>
> -       WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
> +       if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_TREE))
> +               return irq_find_mapping(host, hwirq);
>
>        /*
>         * No rcu_read_lock(ing) needed, the ptr returned can't go under us
> @@ -922,7 +922,8 @@ unsigned int irq_radix_revmap_lookup(struct irq_host *host,
>  void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
>                             irq_hw_number_t hwirq)
>  {
> -       WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
> +       if (WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE))
> +               return;
>
>        if (virq != NO_IRQ) {
>                mutex_lock(&revmap_trees_mutex);
> @@ -937,7 +938,8 @@ unsigned int irq_linear_revmap(struct irq_host *host,
>  {
>        unsigned int *revmap;
>
> -       WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
> +       if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_LINEAR))
> +               return irq_find_mapping(host, hwirq);
>
>        /* Check revmap bounds */
>        if (unlikely(hwirq >= host->revmap_data.linear.size))
> --
> 1.7.0.4
>
>



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