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author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2010-10-14 14:01:34 +0800 |
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committer | Ingo Molnar <mingo@elte.hu> | 2010-10-18 19:58:50 +0200 |
commit | e360adbe29241a0194e10e20595360dd7b98a2b3 (patch) | |
tree | ef5fa5f50a895096bfb25bc11b25949603158238 /arch/x86/kernel/irq_work.c | |
parent | 8e5fc1a7320baf6076391607515dceb61319b36a (diff) | |
download | kernel_goldelico_gta04-e360adbe29241a0194e10e20595360dd7b98a2b3.zip kernel_goldelico_gta04-e360adbe29241a0194e10e20595360dd7b98a2b3.tar.gz kernel_goldelico_gta04-e360adbe29241a0194e10e20595360dd7b98a2b3.tar.bz2 |
irq_work: Add generic hardirq context callbacks
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>
Diffstat (limited to 'arch/x86/kernel/irq_work.c')
-rw-r--r-- | arch/x86/kernel/irq_work.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/x86/kernel/irq_work.c b/arch/x86/kernel/irq_work.c new file mode 100644 index 0000000..ca8f703 --- /dev/null +++ b/arch/x86/kernel/irq_work.c @@ -0,0 +1,30 @@ +/* + * 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 +} |