IA64 Linux 外部中断处理机制（转）

// 0x3000 Entry 12 (size 64 bundles) External Interrupt (4)
ENTRY(interrupt)
DBG_FAULT(12)
mov r31=pr  // prepare to save predicates
;;
SAVE_MIN_WITH_COVER // uses r31; defines r2 and r3
ssm psr.ic | PSR_DEFAULT_BITS
;;
adds r3=8,r2  // set up second base pointer for SAVE_REST
srlz.i   // ensure everybody knows psr.ic is back on
;;
SAVE_REST
;;
alloc r14=ar.pfs,0,0,2,0 // must be first in an insn group
mov out0=cr.ivr  // pass cr.ivr as first arg
add out1=16,sp  // pass pointer to pt_regs as second arg
;;
srlz.d   // make  sure we see the effect of cr.ivr
movl r14=ia64_leave_kernel
;;
mov rp=r14
br.call.sptk.many b6=ia64_handle_irq
END(interrupt)

saved_tpr = ia64_get_tpr();
ia64_srlz_d();
while (vector != IA64_SPURIOUS_INT_VECTOR) {
if (!IS_RESCHEDULE(vector)) {
ia64_set_tpr(vector);
ia64_srlz_d();
do_IRQ(local_vector_to_irq(vector), regs);
/*
* Disable interrupts and send EOI:
*/
local_irq_disable();
ia64_set_tpr(saved_tpr);
} else {
kstat.irqs[smp_processor_id()][IA64_IPI_RESCHEDULE]++;
}
ia64_eoi();
vector = ia64_get_ivr();
}
if (local_softirq_pending())
do_softirq();