diff options
| author | Bart Van Assche <bvanassche@acm.org> | 2024-10-15 12:09:52 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2024-10-16 21:56:59 +0200 |
| commit | 1ad2048bf7146efb83bc033147ca1611a7fe8494 (patch) | |
| tree | af3b86fae07871cfe8d621d777bf9cd23f942360 | |
| parent | f4dd946c775e85e4f9aa460cd3dba197c35e43f1 (diff) | |
| download | lwn-1ad2048bf7146efb83bc033147ca1611a7fe8494.tar.gz lwn-1ad2048bf7146efb83bc033147ca1611a7fe8494.zip | |
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
| -rw-r--r-- | include/linux/irqnr.h | 33 | ||||
| -rw-r--r-- | kernel/irq/irqdomain.c | 2 | ||||
| -rw-r--r-- | 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 7419b807b71b..a33088d27c54 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 e0bff21f30e0..ec6d8e72d980 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 9081ada81c3d..d226282c5b66 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; |