The following commit has been merged into the irq/core branch of tip:
Commit-ID: 1ad2048bf7146efb83bc033147ca1611a7fe8494
Gitweb: https://git.kernel.org/tip/1ad2048bf7146efb83bc033147ca1611a7fe8494
Author: Bart Van Assche <bvanassche@acm.org>
AuthorDate: Tue, 15 Oct 2024 12:09:52 -07:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Wed, 16 Oct 2024 21:56:59 +02:00
genirq: Switch to irq_get_nr_irqs()
Use the irq_get_nr_irqs() function instead of the global variable
'nr_irqs'. Cache the result of this function in a local variable in
order not to rely on CSE (common subexpression elimination). Prepare
for changing 'nr_irqs' from an exported global variable into a variable
with file scope.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241015190953.1266194-22-bvanassche@acm.org
---
include/linux/irqnr.h | 33 +++++++++++++++++++--------------
kernel/irq/irqdomain.c | 2 +-
kernel/irq/proc.c | 3 ++-
3 files changed, 22 insertions(+), 16 deletions(-)
diff --git a/include/linux/irqnr.h b/include/linux/irqnr.h
index 7419b80..a33088d 100644
--- a/include/linux/irqnr.h
+++ b/include/linux/irqnr.h
@@ -11,26 +11,31 @@ unsigned int irq_set_nr_irqs(unsigned int nr);
extern struct irq_desc *irq_to_desc(unsigned int irq);
unsigned int irq_get_next_irq(unsigned int offset);
-# define for_each_irq_desc(irq, desc) \
- for (irq = 0, desc = irq_to_desc(irq); irq < nr_irqs; \
- irq++, desc = irq_to_desc(irq)) \
- if (!desc) \
- ; \
- else
-
+#define for_each_irq_desc(irq, desc) \
+ for (unsigned int __nr_irqs__ = irq_get_nr_irqs(); __nr_irqs__; \
+ __nr_irqs__ = 0) \
+ for (irq = 0, desc = irq_to_desc(irq); irq < __nr_irqs__; \
+ irq++, desc = irq_to_desc(irq)) \
+ if (!desc) \
+ ; \
+ else
# define for_each_irq_desc_reverse(irq, desc) \
- for (irq = nr_irqs - 1, desc = irq_to_desc(irq); irq >= 0; \
- irq--, desc = irq_to_desc(irq)) \
+ for (irq = irq_get_nr_irqs() - 1, desc = irq_to_desc(irq); \
+ irq >= 0; irq--, desc = irq_to_desc(irq)) \
if (!desc) \
; \
else
-# define for_each_active_irq(irq) \
- for (irq = irq_get_next_irq(0); irq < nr_irqs; \
- irq = irq_get_next_irq(irq + 1))
+#define for_each_active_irq(irq) \
+ for (unsigned int __nr_irqs__ = irq_get_nr_irqs(); __nr_irqs__; \
+ __nr_irqs__ = 0) \
+ for (irq = irq_get_next_irq(0); irq < __nr_irqs__; \
+ irq = irq_get_next_irq(irq + 1))
-#define for_each_irq_nr(irq) \
- for (irq = 0; irq < nr_irqs; irq++)
+#define for_each_irq_nr(irq) \
+ for (unsigned int __nr_irqs__ = irq_get_nr_irqs(); __nr_irqs__; \
+ __nr_irqs__ = 0) \
+ for (irq = 0; irq < __nr_irqs__; irq++)
#endif
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index e0bff21..ec6d8e7 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -1225,7 +1225,7 @@ int irq_domain_alloc_descs(int virq, unsigned int cnt, irq_hw_number_t hwirq,
virq = __irq_alloc_descs(virq, virq, cnt, node, THIS_MODULE,
affinity);
} else {
- hint = hwirq % nr_irqs;
+ hint = hwirq % irq_get_nr_irqs();
if (hint == 0)
hint++;
virq = __irq_alloc_descs(-1, hint, cnt, node, THIS_MODULE,
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 9081ada..d226282 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -457,11 +457,12 @@ int __weak arch_show_interrupts(struct seq_file *p, int prec)
}
#ifndef ACTUAL_NR_IRQS
-# define ACTUAL_NR_IRQS nr_irqs
+# define ACTUAL_NR_IRQS irq_get_nr_irqs()
#endif
int show_interrupts(struct seq_file *p, void *v)
{
+ const unsigned int nr_irqs = irq_get_nr_irqs();
static int prec;
int i = *(loff_t *) v, j;