diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2010-10-12 12:31:46 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2010-10-12 16:39:07 +0200 |
| commit | 06f6c3399e9f9ff6eafc200e80f9226c3cee0eaf (patch) | |
| tree | f4d8fc67194b1a50bfe501634088b3776ca6bbd4 | |
| parent | a98d24b71b6e229965f18dc00d28dc71cb8fe324 (diff) | |
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 <tglx@linutronix.de>
| -rw-r--r-- | include/linux/irq.h | 1 | ||||
| -rw-r--r-- | kernel/irq/irqdesc.c | 26 |
2 files changed, 27 insertions, 0 deletions
diff --git a/include/linux/irq.h b/include/linux/irq.h index cefacf928b3..096b74d5d0d 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 2e7e94ef64d..35d9052901b 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -464,6 +464,32 @@ err: } /** + * 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 * |