From 06f6c3399e9f9ff6eafc200e80f9226c3cee0eaf Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 12 Oct 2010 12:31:46 +0200 Subject: genirq: Implement irq reservation Mark a range of interrupts as allocated. In the SPARSE_IRQ=n case we need this to update the bitmap for the legacy irqs so the enumerator via irq_get_next_irq() works. Signed-off-by: Thomas Gleixner --- kernel/irq/irqdesc.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'kernel/irq') diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 2e7e94ef64d..35d9052901b 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 -- cgit v1.2.3