e360adbe29
Provide a mechanism that allows running code in IRQ context. It is most useful for NMI code that needs to interact with the rest of the system -- like wakeup a task to drain buffers. Perf currently has such a mechanism, so extract that and provide it as a generic feature, independent of perf so that others may also benefit. The IRQ context callback is generated through self-IPIs where possible, or on architectures like powerpc the decrementer (the built-in timer facility) is set to generate an interrupt immediately. Architectures that don't have anything like this get to do with a callback from the timer tick. These architectures can call irq_work_run() at the tail of any IRQ handlers that might enqueue such work (like the perf IRQ handler) to avoid undue latencies in processing the work. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Kyle McMartin <kyle@mcmartin.ca> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [ various fixes ] Signed-off-by: Huang Ying <ying.huang@intel.com> LKML-Reference: <1287036094.7768.291.camel@yhuang-dev> Signed-off-by: Ingo Molnar <mingo@elte.hu>
31 lines
538 B
C
31 lines
538 B
C
/*
|
|
* x86 specific code for irq_work
|
|
*
|
|
* Copyright (C) 2010 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/irq_work.h>
|
|
#include <linux/hardirq.h>
|
|
#include <asm/apic.h>
|
|
|
|
void smp_irq_work_interrupt(struct pt_regs *regs)
|
|
{
|
|
irq_enter();
|
|
ack_APIC_irq();
|
|
inc_irq_stat(apic_irq_work_irqs);
|
|
irq_work_run();
|
|
irq_exit();
|
|
}
|
|
|
|
void arch_irq_work_raise(void)
|
|
{
|
|
#ifdef CONFIG_X86_LOCAL_APIC
|
|
if (!cpu_has_apic)
|
|
return;
|
|
|
|
apic->send_IPI_self(IRQ_WORK_VECTOR);
|
|
apic_wait_icr_idle();
|
|
#endif
|
|
}
|