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authorShanker Donthineni <sdonthineni@nvidia.com>2023-05-19 08:49:01 -0500
committerThomas Gleixner <tglx@linutronix.de>2023-05-24 11:39:44 +0200
commit5e630aa8d9fcd4c0cb6d5d09422009533aba979a (patch)
tree15626c452949bd440e5f4dbf4ed44b1f9f52665a /kernel/irq
parentbc06a9e0874239cb6d4eebcb0ecd1a91ad9272db (diff)
downloadlwn-5e630aa8d9fcd4c0cb6d5d09422009533aba979a.tar.gz
lwn-5e630aa8d9fcd4c0cb6d5d09422009533aba979a.zip
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: Shanker Donthineni <sdonthineni@nvidia.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230519134902.1495562-3-sdonthineni@nvidia.com
Diffstat (limited to 'kernel/irq')
-rw-r--r--kernel/irq/internals.h4
-rw-r--r--kernel/irq/irqdesc.c30
2 files changed, 22 insertions, 12 deletions
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 51fc8c497c22..f3f2090dd2de 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -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
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index b401b89b226a..e0d9dd9b36f9 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -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 @@ err:
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 *