• eric miao's avatar
    ARM: 6532/1: Allow machine to specify it's own IRQ handlers at run-time · 52108641
    eric miao authored
    Normally different ARM platform has different way to decode the IRQ
    hardware status and demultiplex to the corresponding IRQ handler.
    This is highly optimized by macro irq_handler in entry-armv.S, and
    each machine defines their own macro to decode the IRQ number.
    However, this prevents multiple machine classes to be built into a
    single kernel.
    
    By allowing each machine to specify thier own handler, and making
    function pointer 'handle_arch_irq' to point to it at run time, this
    can be solved. And introduce CONFIG_MULTI_IRQ_HANDLER to allow both
    solutions to work.
    
    Comparing with the highly optimized macro of irq_handler, the new
    function must be written with care not to lose too much performance.
    And the IPI stuff on SMP is expected to move to the provided arch
    IRQ handler as well.
    
    The assembly code to invoke handle_arch_irq is optimized by Russell
    King.
    Signed-off-by: default avatarEric Miao <eric.miao@canonical.com>
    Acked-by: default avatarNicolas Pitre <nicolas.pitre@linaro.org>
    Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
    52108641
irq.h 905 Bytes