Commit b5eb78f7 authored by Yinghai Lu's avatar Yinghai Lu Committed by H. Peter Anvin
Browse files

sparseirq: Use radix_tree instead of ptrs array 



Use radix_tree irq_desc_tree instead of irq_desc_ptrs.

-v2: according to Eric and cyrill to use radix_tree_lookup_slot and
     radix_tree_replace_slot

Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
LKML-Reference: <1265793639-15071-32-git-send-email-yinghai@kernel.org>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 99558f0b

kernel/irq/handle.c

+25 −24
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/kernel_stat.h>

#include <linux/rculist.h>

#include <linux/hash.h>

#include <linux/radix-tree.h>

#include <trace/events/irq.h>



#include "internals.h"
@@ -127,7 +128,26 @@ static void init_one_irq_desc(int irq, struct irq_desc *desc, int node) 
 */

DEFINE_RAW_SPINLOCK(sparse_irq_lock);



static struct irq_desc **irq_desc_ptrs __read_mostly;

static RADIX_TREE(irq_desc_tree, GFP_ATOMIC);



static void set_irq_desc(unsigned int irq, struct irq_desc *desc)

{

	radix_tree_insert(&irq_desc_tree, irq, desc);

}



struct irq_desc *irq_to_desc(unsigned int irq)

{

	return radix_tree_lookup(&irq_desc_tree, irq);

}



void replace_irq_desc(unsigned int irq, struct irq_desc *desc)

{

	void **ptr;



	ptr = radix_tree_lookup_slot(&irq_desc_tree, irq);

	if (ptr)

		radix_tree_replace_slot(ptr, desc);

}



static struct irq_desc irq_desc_legacy[NR_IRQS_LEGACY] __cacheline_aligned_in_smp = {

	[0 ... NR_IRQS_LEGACY-1] = {
@@ -159,9 +179,6 @@ int __init early_irq_init(void) 
	legacy_count = ARRAY_SIZE(irq_desc_legacy);

	node = first_online_node;



	/* allocate irq_desc_ptrs array based on nr_irqs */

	irq_desc_ptrs = kcalloc(nr_irqs, sizeof(void *), GFP_NOWAIT);



	/* allocate based on nr_cpu_ids */

	kstat_irqs_legacy = kzalloc_node(NR_IRQS_LEGACY * nr_cpu_ids *

					  sizeof(int), GFP_NOWAIT, node);
@@ -175,28 +192,12 @@ int __init early_irq_init(void) 
		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);

		alloc_desc_masks(&desc[i], node, true);

		init_desc_masks(&desc[i]);

		irq_desc_ptrs[i] = desc + i;

		set_irq_desc(i, &desc[i]);

	}



	for (i = legacy_count; i < nr_irqs; i++)

		irq_desc_ptrs[i] = NULL;



	return arch_early_irq_init();

}



struct irq_desc *irq_to_desc(unsigned int irq)

{

	if (irq_desc_ptrs && irq < nr_irqs)

		return irq_desc_ptrs[irq];



	return NULL;

}



void replace_irq_desc(unsigned int irq, struct irq_desc *desc)

{

	irq_desc_ptrs[irq] = desc;

}



struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)

{

	struct irq_desc *desc;
@@ -208,14 +209,14 @@ struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node) 
		return NULL;

	}



	desc = irq_desc_ptrs[irq];

	desc = irq_to_desc(irq);

	if (desc)

		return desc;



	raw_spin_lock_irqsave(&sparse_irq_lock, flags);



	/* We have to check it to avoid races with another CPU */

	desc = irq_desc_ptrs[irq];

	desc = irq_to_desc(irq);

	if (desc)

		goto out_unlock;
@@ -228,7 +229,7 @@ struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node) 
	}

	init_one_irq_desc(irq, desc, node);



	irq_desc_ptrs[irq] = desc;

	set_irq_desc(irq, desc);



out_unlock:

	raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);

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