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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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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
/*
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* x86 specific code for irq_work
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*
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* Copyright (C) 2010 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
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*/
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#include <linux/kernel.h>
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#include <linux/irq_work.h>
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#include <linux/hardirq.h>
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#include <asm/apic.h>
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void smp_irq_work_interrupt(struct pt_regs *regs)
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{
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irq_enter();
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ack_APIC_irq();
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inc_irq_stat(apic_irq_work_irqs);
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irq_work_run();
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irq_exit();
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}
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void arch_irq_work_raise(void)
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{
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#ifdef CONFIG_X86_LOCAL_APIC
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if (!cpu_has_apic)
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return;
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apic->send_IPI_self(IRQ_WORK_VECTOR);
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apic_wait_icr_idle();
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#endif
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}
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