Commit 5e630aa8 authored by Shanker Donthineni's avatar Shanker Donthineni Committed by Thomas Gleixner
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genirq: Encapsulate sparse bitmap handling 



Move the open coded sparse bitmap handling into helper functions as
a preparatory step for converting the sparse interrupt management
to a maple tree.

No functional change.

Signed-off-by: default avatarShanker Donthineni <sdonthineni@nvidia.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230519134902.1495562-3-sdonthineni@nvidia.com
parent bc06a9e0

kernel/irq/internals.h

+2 −2
Original line number Diff line number Diff line
@@ -12,9 +12,9 @@ 
#include <linux/sched/clock.h>



#ifdef CONFIG_SPARSE_IRQ

# define IRQ_BITMAP_BITS	(NR_IRQS + 8196)

# define MAX_SPARSE_IRQS	(NR_IRQS + 8196)

#else

# define IRQ_BITMAP_BITS	NR_IRQS

# define MAX_SPARSE_IRQS	NR_IRQS

#endif



#define istate core_internal_state__do_not_mess_with_it

kernel/irq/irqdesc.c

+20 −10
Original line number Diff line number Diff line
@@ -131,7 +131,18 @@ int nr_irqs = NR_IRQS; 
EXPORT_SYMBOL_GPL(nr_irqs);



static DEFINE_MUTEX(sparse_irq_lock);

static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);

static DECLARE_BITMAP(allocated_irqs, MAX_SPARSE_IRQS);



static int irq_find_free_area(unsigned int from, unsigned int cnt)

{

	return bitmap_find_next_zero_area(allocated_irqs, MAX_SPARSE_IRQS,

					  from, cnt, 0);

}



static unsigned int irq_find_at_or_after(unsigned int offset)

{

	return find_next_bit(allocated_irqs, nr_irqs, offset);

}



#ifdef CONFIG_SPARSE_IRQ
@@ -517,7 +528,7 @@ static int alloc_descs(unsigned int start, unsigned int cnt, int node, 


static int irq_expand_nr_irqs(unsigned int nr)

{

	if (nr > IRQ_BITMAP_BITS)

	if (nr > MAX_SPARSE_IRQS)

		return -ENOMEM;

	nr_irqs = nr;

	return 0;
@@ -535,11 +546,11 @@ int __init early_irq_init(void) 
	printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",

	       NR_IRQS, nr_irqs, initcnt);



	if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))

		nr_irqs = IRQ_BITMAP_BITS;

	if (WARN_ON(nr_irqs > MAX_SPARSE_IRQS))

		nr_irqs = MAX_SPARSE_IRQS;



	if (WARN_ON(initcnt > IRQ_BITMAP_BITS))

		initcnt = IRQ_BITMAP_BITS;

	if (WARN_ON(initcnt > MAX_SPARSE_IRQS))

		initcnt = MAX_SPARSE_IRQS;



	if (initcnt > nr_irqs)

		nr_irqs = initcnt;
@@ -812,8 +823,7 @@ __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node, 


	mutex_lock(&sparse_irq_lock);



	start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,

					   from, cnt, 0);

	start = irq_find_free_area(from, cnt);

	ret = -EEXIST;

	if (irq >=0 && start != irq)

		goto unlock;
@@ -834,11 +844,11 @@ EXPORT_SYMBOL_GPL(__irq_alloc_descs); 
 * irq_get_next_irq - get next allocated irq number

 * @offset:	where to start the search

 *

 * Returns next irq number after offset or nr_irqs if none is found.

 * Returns next irq number at or after offset or nr_irqs if none is found.

 */

unsigned int irq_get_next_irq(unsigned int offset)

{

	return find_next_bit(allocated_irqs, nr_irqs, offset);

	return irq_find_at_or_after(offset);

}



struct irq_desc *