kernel/irq/irqdesc.c

Source file repositories/reference/linux-study-clean/kernel/irq/irqdesc.c

File Facts

System
Linux kernel
Corpus path
kernel/irq/irqdesc.c
Extension
.c
Size
27967 bytes
Lines
1092
Domain
Core OS
Bucket
Scheduler, Processes, Timers, Sync, And Syscalls
Inferred role
Core OS: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

static inline void free_masks(struct irq_desc *desc) { }
#endif

static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
			      const struct cpumask *affinity, struct module *owner)
{
	desc->irq_common_data.handler_data = NULL;
	desc->irq_common_data.msi_desc = NULL;

	desc->irq_data.common = &desc->irq_common_data;
	desc->irq_data.irq = irq;
	desc->irq_data.chip = &no_irq_chip;
	desc->irq_data.chip_data = NULL;
	irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
	irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
	desc->handle_irq = handle_bad_irq;
	desc->depth = 1;
	desc->irq_count = 0;
	desc->irqs_unhandled = 0;
	desc->tot_count = 0;
	desc->name = NULL;
	desc->owner = owner;
	rcuref_init(&desc->refcnt, 1);
	desc_smp_init(desc, node, affinity);
}

unsigned int total_nr_irqs __read_mostly = NR_IRQS;

/**
 * irq_get_nr_irqs() - Number of interrupts supported by the system.
 */
unsigned int irq_get_nr_irqs(void)
{
	return total_nr_irqs;
}
EXPORT_SYMBOL_GPL(irq_get_nr_irqs);

/**
 * irq_set_nr_irqs() - Set the number of interrupts supported by the system.
 * @nr: New number of interrupts.
 *
 * Return: @nr.
 */
unsigned int __init irq_set_nr_irqs(unsigned int nr)
{
	total_nr_irqs = nr;
	irq_proc_calc_prec();
	return nr;
}

static DEFINE_MUTEX(sparse_irq_lock);
static struct maple_tree sparse_irqs = MTREE_INIT_EXT(sparse_irqs,
					MT_FLAGS_ALLOC_RANGE |
					MT_FLAGS_LOCK_EXTERN |
					MT_FLAGS_USE_RCU,
					sparse_irq_lock);

static int irq_find_free_area(unsigned int from, unsigned int cnt)
{
	MA_STATE(mas, &sparse_irqs, 0, 0);

	if (mas_empty_area(&mas, from, MAX_SPARSE_IRQS, cnt))
		return -ENOSPC;
	return mas.index;
}

struct irq_desc *irq_find_desc_at_or_after(unsigned int offset)
{
	unsigned long index = offset;

	lockdep_assert_in_rcu_read_lock();
	return mt_find(&sparse_irqs, &index, total_nr_irqs);
}

static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
{
	MA_STATE(mas, &sparse_irqs, irq, irq);
	WARN_ON(mas_store_gfp(&mas, desc, GFP_KERNEL) != 0);
}

static void delete_irq_desc(unsigned int irq)
{
	MA_STATE(mas, &sparse_irqs, irq, irq);
	mas_erase(&mas);
}

#ifdef CONFIG_SPARSE_IRQ
static const struct kobj_type irq_kobj_type;
#endif

Annotation

Implementation Notes