This commit refactors the alloc/free irq num, two functions are defined:
- uint32_t alloc_irq_num(uint32_t irq)
- if irq is valid, mark the irq_desc as used; if it's IRQ_INVALID,
alloc a free irq, or else do nothing;
- return: irq num on success, or IRQ_INVALID on failure.
- void free_irq_num(uint32_t irq)
- free the irq num allocated via alloc_irq_num();
And a global spinlock to protect it from concurrent allocation/free.
Signed-off-by: Yan, Like <like.yan@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>