genirq: Use hlist for managing resend handlers
The current implementation utilizes a bitmap for managing interrupt resend handlers, which is allocated based on the SPARSE_IRQ/NR_IRQS macros. However, this method may not efficiently utilize memory during runtime, particularly when IRQ_BITMAP_BITS is large. Address this issue by using an hlist to manage interrupt resend handlers instead of relying on a static bitmap memory allocation. Additionally, a new function, clear_irq_resend(), is introduced and called from irq_shutdown to ensure a graceful teardown of the interrupt. Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230519134902.1495562-2-sdonthineni@nvidia.com