Commit 1ad2048b authored by Bart Van Assche's avatar Bart Van Assche Committed by Thomas Gleixner
Browse files

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: default avatarBart Van Assche <bvanassche@acm.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241015190953.1266194-22-bvanassche@acm.org
parent f4dd946c

include/linux/irqnr.h

+19 −14
Original line number Diff line number Diff line
@@ -12,25 +12,30 @@ 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;		\

	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;	\

	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++)

	for (unsigned int __nr_irqs__ = irq_get_nr_irqs(); __nr_irqs__; \

	     __nr_irqs__ = 0)                                           \

		for (irq = 0; irq < __nr_irqs__; irq++)



#endif

kernel/irq/irqdomain.c

+1 −1
Original line number Diff line number Diff line
@@ -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,

kernel/irq/proc.c

+2 −1
Original line number Diff line number Diff line
@@ -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;