• Mark Rutland's avatar
    arm64: unwind: avoid percpu indirection for irq stack · 09668372
    Mark Rutland authored
    Our IRQ_STACK_PTR() and on_irq_stack() helpers both take a cpu argument,
    used to generate a percpu address. In all cases, they are passed
    {raw_,}smp_processor_id(), so this parameter is redundant.
    
    Since {raw_,}smp_processor_id() use a percpu variable internally, this
    approach means we generate a percpu offset to find the current cpu, then
    use this to index an array of percpu offsets, which we then use to find
    the current CPU's IRQ stack pointer. Thus, most of the work is
    redundant.
    
    Instead, we can consistently use raw_cpu_ptr() to generate the CPU's
    irq_stack pointer by simply adding the percpu offset to the irq_stack
    address, which is simpler in both respects.
    Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
    Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
    Cc: Catalin Marinas <catalin.marinas@arm.com>
    Cc: James Morse <james.morse@arm.com>
    Cc: Will Deacon <will.deacon@arm.com>
    09668372
irq.h 1.52 KB