[PATCH 23/37] powerpc: radix trees are available before init_IRQ

[Grant Likely]

On Wed, May 11, 2011 at 7:29 AM, Milton Miller <miltonm at bga.com> wrote:
> Since the generic irq code uses a radix tree for sparse interrupts,
> the initcall ordering has been changed to initialize radix trees before
> irqs.   We no longer need to defer creating revmap radix trees to the
> arch_initcall irq_late_init.
>
> Also, the kmem caches are allocated so we don't need to use
> zalloc_maybe_bootmem.
>
> Signed-off-by: Milton Miller <miltonm at bga.com>

w00t.  Looks right to me.

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

> ---
>  arch/powerpc/kernel/irq.c |   78 ++------------------------------------------
>  1 files changed, 4 insertions(+), 74 deletions(-)
>
> diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
> index 826552c..f42e869 100644
> --- a/arch/powerpc/kernel/irq.c
> +++ b/arch/powerpc/kernel/irq.c
> @@ -493,7 +493,6 @@ struct irq_map_entry {
>
>  static LIST_HEAD(irq_hosts);
>  static DEFINE_RAW_SPINLOCK(irq_big_lock);
> -static unsigned int revmap_trees_allocated;
>  static DEFINE_MUTEX(revmap_trees_mutex);
>  static struct irq_map_entry irq_map[NR_IRQS];
>  static unsigned int irq_virq_count = NR_IRQS;
> @@ -537,7 +536,7 @@ struct irq_host *irq_alloc_host(struct device_node *of_node,
>        /* Allocate structure and revmap table if using linear mapping */
>        if (revmap_type == IRQ_HOST_MAP_LINEAR)
>                size += revmap_arg * sizeof(unsigned int);
> -       host = zalloc_maybe_bootmem(size, GFP_KERNEL);
> +       host = kzalloc(size, GFP_KERNEL);
>        if (host == NULL)
>                return NULL;
>
> @@ -605,6 +604,9 @@ struct irq_host *irq_alloc_host(struct device_node *of_node,
>                smp_wmb();
>                host->revmap_data.linear.revmap = rmap;
>                break;
> +       case IRQ_HOST_MAP_TREE:
> +               INIT_RADIX_TREE(&host->revmap_data.tree, GFP_KERNEL);
> +               break;
>        default:
>                break;
>        }
> @@ -839,13 +841,6 @@ void irq_dispose_mapping(unsigned int virq)
>                        host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
>                break;
>        case IRQ_HOST_MAP_TREE:
> -               /*
> -                * Check if radix tree allocated yet, if not then nothing to
> -                * remove.
> -                */
> -               smp_rmb();
> -               if (revmap_trees_allocated < 1)
> -                       break;
>                mutex_lock(&revmap_trees_mutex);
>                radix_tree_delete(&host->revmap_data.tree, hwirq);
>                mutex_unlock(&revmap_trees_mutex);
> @@ -906,14 +901,6 @@ unsigned int irq_radix_revmap_lookup(struct irq_host *host,
>        WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
>
>        /*
> -        * Check if the radix tree exists and has bee initialized.
> -        * If not, we fallback to slow mode
> -        */
> -       if (revmap_trees_allocated < 2)
> -               return irq_find_mapping(host, hwirq);
> -
> -       /* Now try to resolve */
> -       /*
>         * No rcu_read_lock(ing) needed, the ptr returned can't go under us
>         * as it's referencing an entry in the static irq_map table.
>         */
> @@ -935,18 +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);
>
> -       /*
> -        * Check if the radix tree exists yet.
> -        * If not, then the irq will be inserted into the tree when it gets
> -        * initialized.
> -        */
> -       smp_rmb();
> -       if (revmap_trees_allocated < 1)
> -               return;
> -
>        if (virq != NO_IRQ) {
>                mutex_lock(&revmap_trees_mutex);
>                radix_tree_insert(&host->revmap_data.tree, hwirq,
> @@ -1054,53 +1031,6 @@ int arch_early_irq_init(void)
>        return 0;
>  }
>
> -/* We need to create the radix trees late */
> -static int irq_late_init(void)
> -{
> -       struct irq_host *h;
> -       unsigned int i;
> -
> -       /*
> -        * No mutual exclusion with respect to accessors of the tree is needed
> -        * here as the synchronization is done via the state variable
> -        * revmap_trees_allocated.
> -        */
> -       list_for_each_entry(h, &irq_hosts, link) {
> -               if (h->revmap_type == IRQ_HOST_MAP_TREE)
> -                       INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
> -       }
> -
> -       /*
> -        * Make sure the radix trees inits are visible before setting
> -        * the flag
> -        */
> -       smp_wmb();
> -       revmap_trees_allocated = 1;
> -
> -       /*
> -        * Insert the reverse mapping for those interrupts already present
> -        * in irq_map[].
> -        */
> -       mutex_lock(&revmap_trees_mutex);
> -       for (i = 0; i < irq_virq_count; i++) {
> -               if (irq_map[i].host &&
> -                   (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
> -                       radix_tree_insert(&irq_map[i].host->revmap_data.tree,
> -                                         irq_map[i].hwirq, &irq_map[i]);
> -       }
> -       mutex_unlock(&revmap_trees_mutex);
> -
> -       /*
> -        * Make sure the radix trees insertions are visible before setting
> -        * the flag
> -        */
> -       smp_wmb();
> -       revmap_trees_allocated = 2;
> -
> -       return 0;
> -}
> -arch_initcall(irq_late_init);
> -
>  #ifdef CONFIG_VIRQ_DEBUG
>  static int virq_debug_show(struct seq_file *m, void *private)
>  {
> --
> 1.7.0.4
>
>



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