diff --git a/include/linux/irq.h b/include/linux/irq.h index cefacf928b33..096b74d5d0d7 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -400,6 +400,7 @@ static inline struct irq_2_iommu *irq_data_get_iommu(struct irq_data *d) int irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node); void irq_free_descs(unsigned int irq, unsigned int cnt); +int irq_reserve_irqs(unsigned int from, unsigned int cnt); static inline int irq_alloc_desc(int node) { diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 2e7e94ef64da..35d9052901b9 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -463,6 +463,32 @@ err: return ret; } +/** + * irq_reserve_irqs - mark irqs allocated + * @from: mark from irq number + * @cnt: number of irqs to mark + * + * Returns 0 on success or an appropriate error code + */ +int irq_reserve_irqs(unsigned int from, unsigned int cnt) +{ + unsigned long flags; + unsigned int start; + int ret = 0; + + if (!cnt || (from + cnt) > nr_irqs) + return -EINVAL; + + raw_spin_lock_irqsave(&sparse_irq_lock, flags); + start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0); + if (start == from) + bitmap_set(allocated_irqs, start, cnt); + else + ret = -EEXIST; + raw_spin_unlock_irqrestore(&sparse_irq_lock, flags); + return ret; +} + /** * irq_get_next_irq - get next allocated irq number * @offset: where to start the search