forked from Minki/linux
84e21493a3
In the presence of interrupt-remapping, irqs will be migrated in the process context and we don't do (and there is no need to) irq_chip mask/unmask while migrating the interrupt. Similarly fix the fixup_irqs() that get called during cpu offline and avoid calling irq_chip mask/unmask for irqs that are ok to be migrated in the process context. While we didn't observe any race condition with the existing code, this change takes complete advantage of interrupt-remapping in the newer generation platforms and avoids any potential HW lockup's (that often worry Eric :) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Cc: garyhade@us.ibm.com LKML-Reference: <20091026230001.661423939@sbs-t61.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
338 lines
8.1 KiB
C
338 lines
8.1 KiB
C
/*
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* Common interrupt code for 32 and 64 bit
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*/
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#include <linux/cpu.h>
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#include <linux/interrupt.h>
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#include <linux/kernel_stat.h>
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#include <linux/seq_file.h>
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#include <linux/smp.h>
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#include <linux/ftrace.h>
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#include <asm/apic.h>
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#include <asm/io_apic.h>
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#include <asm/irq.h>
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#include <asm/idle.h>
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#include <asm/mce.h>
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#include <asm/hw_irq.h>
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atomic_t irq_err_count;
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/* Function pointer for generic interrupt vector handling */
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void (*generic_interrupt_extension)(void) = NULL;
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/*
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* 'what should we do if we get a hw irq event on an illegal vector'.
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* each architecture has to answer this themselves.
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*/
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void ack_bad_irq(unsigned int irq)
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{
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if (printk_ratelimit())
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pr_err("unexpected IRQ trap at vector %02x\n", irq);
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/*
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* Currently unexpected vectors happen only on SMP and APIC.
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* We _must_ ack these because every local APIC has only N
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* irq slots per priority level, and a 'hanging, unacked' IRQ
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* holds up an irq slot - in excessive cases (when multiple
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* unexpected vectors occur) that might lock up the APIC
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* completely.
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* But only ack when the APIC is enabled -AK
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*/
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ack_APIC_irq();
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}
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#define irq_stats(x) (&per_cpu(irq_stat, x))
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/*
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* /proc/interrupts printing:
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*/
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static int show_other_interrupts(struct seq_file *p, int prec)
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{
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int j;
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seq_printf(p, "%*s: ", prec, "NMI");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", irq_stats(j)->__nmi_count);
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seq_printf(p, " Non-maskable interrupts\n");
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#ifdef CONFIG_X86_LOCAL_APIC
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seq_printf(p, "%*s: ", prec, "LOC");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", irq_stats(j)->apic_timer_irqs);
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seq_printf(p, " Local timer interrupts\n");
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seq_printf(p, "%*s: ", prec, "SPU");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", irq_stats(j)->irq_spurious_count);
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seq_printf(p, " Spurious interrupts\n");
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seq_printf(p, "%*s: ", prec, "CNT");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", irq_stats(j)->apic_perf_irqs);
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seq_printf(p, " Performance counter interrupts\n");
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seq_printf(p, "%*s: ", prec, "PND");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", irq_stats(j)->apic_pending_irqs);
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seq_printf(p, " Performance pending work\n");
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#endif
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if (generic_interrupt_extension) {
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seq_printf(p, "%*s: ", prec, "PLT");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", irq_stats(j)->generic_irqs);
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seq_printf(p, " Platform interrupts\n");
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}
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#ifdef CONFIG_SMP
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seq_printf(p, "%*s: ", prec, "RES");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
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seq_printf(p, " Rescheduling interrupts\n");
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seq_printf(p, "%*s: ", prec, "CAL");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", irq_stats(j)->irq_call_count);
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seq_printf(p, " Function call interrupts\n");
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seq_printf(p, "%*s: ", prec, "TLB");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
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seq_printf(p, " TLB shootdowns\n");
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#endif
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#ifdef CONFIG_X86_MCE
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seq_printf(p, "%*s: ", prec, "TRM");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", irq_stats(j)->irq_thermal_count);
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seq_printf(p, " Thermal event interrupts\n");
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# ifdef CONFIG_X86_MCE_THRESHOLD
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seq_printf(p, "%*s: ", prec, "THR");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", irq_stats(j)->irq_threshold_count);
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seq_printf(p, " Threshold APIC interrupts\n");
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# endif
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#endif
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#ifdef CONFIG_X86_MCE
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seq_printf(p, "%*s: ", prec, "MCE");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", per_cpu(mce_exception_count, j));
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seq_printf(p, " Machine check exceptions\n");
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seq_printf(p, "%*s: ", prec, "MCP");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", per_cpu(mce_poll_count, j));
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seq_printf(p, " Machine check polls\n");
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#endif
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seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
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#if defined(CONFIG_X86_IO_APIC)
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seq_printf(p, "%*s: %10u\n", prec, "MIS", atomic_read(&irq_mis_count));
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#endif
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return 0;
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}
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int show_interrupts(struct seq_file *p, void *v)
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{
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unsigned long flags, any_count = 0;
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int i = *(loff_t *) v, j, prec;
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struct irqaction *action;
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struct irq_desc *desc;
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if (i > nr_irqs)
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return 0;
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for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
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j *= 10;
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if (i == nr_irqs)
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return show_other_interrupts(p, prec);
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/* print header */
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if (i == 0) {
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seq_printf(p, "%*s", prec + 8, "");
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for_each_online_cpu(j)
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seq_printf(p, "CPU%-8d", j);
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seq_putc(p, '\n');
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}
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desc = irq_to_desc(i);
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if (!desc)
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return 0;
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spin_lock_irqsave(&desc->lock, flags);
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for_each_online_cpu(j)
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any_count |= kstat_irqs_cpu(i, j);
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action = desc->action;
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if (!action && !any_count)
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goto out;
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seq_printf(p, "%*d: ", prec, i);
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
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seq_printf(p, " %8s", desc->chip->name);
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seq_printf(p, "-%-8s", desc->name);
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if (action) {
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seq_printf(p, " %s", action->name);
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while ((action = action->next) != NULL)
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seq_printf(p, ", %s", action->name);
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}
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seq_putc(p, '\n');
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out:
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spin_unlock_irqrestore(&desc->lock, flags);
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return 0;
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}
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/*
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* /proc/stat helpers
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*/
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u64 arch_irq_stat_cpu(unsigned int cpu)
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{
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u64 sum = irq_stats(cpu)->__nmi_count;
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#ifdef CONFIG_X86_LOCAL_APIC
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sum += irq_stats(cpu)->apic_timer_irqs;
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sum += irq_stats(cpu)->irq_spurious_count;
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sum += irq_stats(cpu)->apic_perf_irqs;
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sum += irq_stats(cpu)->apic_pending_irqs;
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#endif
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if (generic_interrupt_extension)
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sum += irq_stats(cpu)->generic_irqs;
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#ifdef CONFIG_SMP
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sum += irq_stats(cpu)->irq_resched_count;
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sum += irq_stats(cpu)->irq_call_count;
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sum += irq_stats(cpu)->irq_tlb_count;
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#endif
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#ifdef CONFIG_X86_MCE
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sum += irq_stats(cpu)->irq_thermal_count;
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# ifdef CONFIG_X86_MCE_THRESHOLD
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sum += irq_stats(cpu)->irq_threshold_count;
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# endif
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#endif
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#ifdef CONFIG_X86_MCE
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sum += per_cpu(mce_exception_count, cpu);
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sum += per_cpu(mce_poll_count, cpu);
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#endif
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return sum;
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}
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u64 arch_irq_stat(void)
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{
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u64 sum = atomic_read(&irq_err_count);
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#ifdef CONFIG_X86_IO_APIC
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sum += atomic_read(&irq_mis_count);
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#endif
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return sum;
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}
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/*
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* do_IRQ handles all normal device IRQ's (the special
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* SMP cross-CPU interrupts have their own specific
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* handlers).
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*/
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unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
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{
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struct pt_regs *old_regs = set_irq_regs(regs);
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/* high bit used in ret_from_ code */
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unsigned vector = ~regs->orig_ax;
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unsigned irq;
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exit_idle();
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irq_enter();
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irq = __get_cpu_var(vector_irq)[vector];
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if (!handle_irq(irq, regs)) {
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ack_APIC_irq();
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if (printk_ratelimit())
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pr_emerg("%s: %d.%d No irq handler for vector (irq %d)\n",
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__func__, smp_processor_id(), vector, irq);
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}
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run_local_timers();
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irq_exit();
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set_irq_regs(old_regs);
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return 1;
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}
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/*
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* Handler for GENERIC_INTERRUPT_VECTOR.
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*/
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void smp_generic_interrupt(struct pt_regs *regs)
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{
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struct pt_regs *old_regs = set_irq_regs(regs);
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ack_APIC_irq();
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exit_idle();
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irq_enter();
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inc_irq_stat(generic_irqs);
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if (generic_interrupt_extension)
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generic_interrupt_extension();
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run_local_timers();
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irq_exit();
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set_irq_regs(old_regs);
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}
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EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);
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#ifdef CONFIG_HOTPLUG_CPU
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/* A cpu has been removed from cpu_online_mask. Reset irq affinities. */
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void fixup_irqs(void)
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{
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unsigned int irq;
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static int warned;
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struct irq_desc *desc;
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for_each_irq_desc(irq, desc) {
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int break_affinity = 0;
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int set_affinity = 1;
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const struct cpumask *affinity;
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if (!desc)
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continue;
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if (irq == 2)
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continue;
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/* interrupt's are disabled at this point */
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spin_lock(&desc->lock);
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affinity = desc->affinity;
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if (!irq_has_action(irq) ||
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cpumask_equal(affinity, cpu_online_mask)) {
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spin_unlock(&desc->lock);
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continue;
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}
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if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
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break_affinity = 1;
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affinity = cpu_all_mask;
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}
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if (!(desc->status & IRQ_MOVE_PCNTXT) && desc->chip->mask)
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desc->chip->mask(irq);
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if (desc->chip->set_affinity)
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desc->chip->set_affinity(irq, affinity);
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else if (!(warned++))
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set_affinity = 0;
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if (!(desc->status & IRQ_MOVE_PCNTXT) && desc->chip->unmask)
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desc->chip->unmask(irq);
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spin_unlock(&desc->lock);
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if (break_affinity && set_affinity)
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printk("Broke affinity for irq %i\n", irq);
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else if (!set_affinity)
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printk("Cannot set affinity for irq %i\n", irq);
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}
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/* That doesn't seem sufficient. Give it 1ms. */
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local_irq_enable();
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mdelay(1);
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local_irq_disable();
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}
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#endif
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