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/******************************************************************************
* common/softirq.c
*
* Softirqs in Xen are only executed in an outermost activation (e.g., never
* within an interrupt activation). This simplifies some things and generally
* seems a good thing.
*
* Copyright (c) 2003, K A Fraser
* Copyright (c) 1992, Linus Torvalds
*/
#include <xen/config.h>
#include <xen/init.h>
#include <xen/mm.h>
#include <xen/preempt.h>
#include <xen/sched.h>
#include <xen/rcupdate.h>
#include <xen/softirq.h>
#ifndef __ARCH_IRQ_STAT
irq_cpustat_t irq_stat[NR_CPUS];
#endif
static softirq_handler softirq_handlers[NR_SOFTIRQS];
static void __do_softirq(unsigned long ignore_mask)
{
unsigned int i, cpu;
unsigned long pending;
for ( ; ; )
{
/*
* Initialise @cpu on every iteration: SCHEDULE_SOFTIRQ may move
* us to another processor.
*/
cpu = smp_processor_id();
if ( rcu_pending(cpu) )
rcu_check_callbacks(cpu);
if ( ((pending = (softirq_pending(cpu) & ~ignore_mask)) == 0)
|| cpu_is_offline(cpu) )
break;
i = find_first_set_bit(pending);
clear_bit(i, &softirq_pending(cpu));
(*softirq_handlers[i])();
}
}
void process_pending_softirqs(void)
{
ASSERT(!in_irq() && local_irq_is_enabled());
/* Do not enter scheduler as it can preempt the calling context. */
__do_softirq(1ul<<SCHEDULE_SOFTIRQ);
}
asmlinkage void do_softirq(void)
{
ASSERT_NOT_IN_ATOMIC();
__do_softirq(0);
}
void open_softirq(int nr, softirq_handler handler)
{
ASSERT(nr < NR_SOFTIRQS);
softirq_handlers[nr] = handler;
}
void cpumask_raise_softirq(const cpumask_t *mask, unsigned int nr)
{
int cpu;
cpumask_t send_mask;
cpumask_clear(&send_mask);
for_each_cpu(cpu, mask)
if ( !test_and_set_bit(nr, &softirq_pending(cpu)) )
cpumask_set_cpu(cpu, &send_mask);
smp_send_event_check_mask(&send_mask);
}
void cpu_raise_softirq(unsigned int cpu, unsigned int nr)
{
if ( !test_and_set_bit(nr, &softirq_pending(cpu))
&& (cpu != smp_processor_id()) )
smp_send_event_check_cpu(cpu);
}
void raise_softirq(unsigned int nr)
{
set_bit(nr, &softirq_pending(smp_processor_id()));
}
void __init softirq_init(void)
{
}
/*
* Local variables:
* mode: C
* c-file-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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