arch/x86/kernel/irq.c

   1 /*
   2  * Common interrupt code for 32 and 64 bit
   3  */
   4 #include <linux/cpu.h>
   5 #include <linux/interrupt.h>
   6 #include <linux/kernel_stat.h>
   7 #include <linux/seq_file.h>
   8 #include <linux/smp.h>
   9 #include <linux/ftrace.h>
  10
  11 #include <asm/apic.h>
  12 #include <asm/io_apic.h>
  13 #include <asm/irq.h>
  14 #include <asm/idle.h>
  15 #include <asm/hw_irq.h>
  16
  17 atomic_t irq_err_count;
  18
  19 /* Function pointer for generic interrupt vector handling */
  20 void (*generic_interrupt_extension)(void) = NULL;
  21
  22 /*
  23  * 'what should we do if we get a hw irq event on an illegal vector'.
  24  * each architecture has to answer this themselves.
  25  */
  26 void ack_bad_irq(unsigned int irq)
  27 {
  28         if (printk_ratelimit())
  29                 pr_err("unexpected IRQ trap at vector %02x\n", irq);
  30
  31         /*
  32          * Currently unexpected vectors happen only on SMP and APIC.
  33          * We _must_ ack these because every local APIC has only N
  34          * irq slots per priority level, and a 'hanging, unacked' IRQ
  35          * holds up an irq slot - in excessive cases (when multiple
  36          * unexpected vectors occur) that might lock up the APIC
  37          * completely.
  38          * But only ack when the APIC is enabled -AK
  39          */
  40         ack_APIC_irq();
  41 }
  42
  43 #define irq_stats(x)            (&per_cpu(irq_stat, x))
  44 /*
  45  * /proc/interrupts printing:
  46  */
  47 static int show_other_interrupts(struct seq_file *p, int prec)
  48 {
  49         int j;
  50
  51         seq_printf(p, "%*s: ", prec, "NMI");
  52         for_each_online_cpu(j)
  53                 seq_printf(p, "%10u ", irq_stats(j)->__nmi_count);
  54         seq_printf(p, "  Non-maskable interrupts\n");
  55 #ifdef CONFIG_X86_LOCAL_APIC
  56         seq_printf(p, "%*s: ", prec, "LOC");
  57         for_each_online_cpu(j)
  58                 seq_printf(p, "%10u ", irq_stats(j)->apic_timer_irqs);
  59         seq_printf(p, "  Local timer interrupts\n");
  60
  61         seq_printf(p, "%*s: ", prec, "SPU");
  62         for_each_online_cpu(j)
  63                 seq_printf(p, "%10u ", irq_stats(j)->irq_spurious_count);
  64         seq_printf(p, "  Spurious interrupts\n");
  65         seq_printf(p, "%*s: ", prec, "CNT");
  66         for_each_online_cpu(j)
  67                 seq_printf(p, "%10u ", irq_stats(j)->apic_perf_irqs);
  68         seq_printf(p, "  Performance counter interrupts\n");
  69         seq_printf(p, "%*s: ", prec, "PND");
  70         for_each_online_cpu(j)
  71                 seq_printf(p, "%10u ", irq_stats(j)->apic_pending_irqs);
  72         seq_printf(p, "  Performance pending work\n");
  73 #endif
  74         if (generic_interrupt_extension) {
  75                 seq_printf(p, "%*s: ", prec, "PLT");
  76                 for_each_online_cpu(j)
  77                         seq_printf(p, "%10u ", irq_stats(j)->generic_irqs);
  78                 seq_printf(p, "  Platform interrupts\n");
  79         }
  80 #ifdef CONFIG_SMP
  81         seq_printf(p, "%*s: ", prec, "RES");
  82         for_each_online_cpu(j)
  83                 seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
  84         seq_printf(p, "  Rescheduling interrupts\n");
  85         seq_printf(p, "%*s: ", prec, "CAL");
  86         for_each_online_cpu(j)
  87                 seq_printf(p, "%10u ", irq_stats(j)->irq_call_count);
  88         seq_printf(p, "  Function call interrupts\n");
  89         seq_printf(p, "%*s: ", prec, "TLB");
  90         for_each_online_cpu(j)
  91                 seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
  92         seq_printf(p, "  TLB shootdowns\n");
  93 #endif
  94 #ifdef CONFIG_X86_MCE
  95         seq_printf(p, "%*s: ", prec, "TRM");
  96         for_each_online_cpu(j)
  97                 seq_printf(p, "%10u ", irq_stats(j)->irq_thermal_count);
  98         seq_printf(p, "  Thermal event interrupts\n");
  99 # ifdef CONFIG_X86_64
 100         seq_printf(p, "%*s: ", prec, "THR");
 101         for_each_online_cpu(j)
 102                 seq_printf(p, "%10u ", irq_stats(j)->irq_threshold_count);
 103         seq_printf(p, "  Threshold APIC interrupts\n");
 104 # endif
 105 #endif
 106         seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
 107 #if defined(CONFIG_X86_IO_APIC)
 108         seq_printf(p, "%*s: %10u\n", prec, "MIS", atomic_read(&irq_mis_count));
 109 #endif
 110         return 0;
 111 }
 112
 113 int show_interrupts(struct seq_file *p, void *v)
 114 {
 115         unsigned long flags, any_count = 0;
 116         int i = *(loff_t *) v, j, prec;
 117         struct irqaction *action;
 118         struct irq_desc *desc;
 119
 120         if (i > nr_irqs)
 121                 return 0;
 122
 123         for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
 124                 j *= 10;
 125
 126         if (i == nr_irqs)
 127                 return show_other_interrupts(p, prec);
 128
 129         /* print header */
 130         if (i == 0) {
 131                 seq_printf(p, "%*s", prec + 8, "");
 132                 for_each_online_cpu(j)
 133                         seq_printf(p, "CPU%-8d", j);
 134                 seq_putc(p, '\n');
 135         }
 136
 137         desc = irq_to_desc(i);
 138         if (!desc)
 139                 return 0;
 140
 141         spin_lock_irqsave(&desc->lock, flags);
 142         for_each_online_cpu(j)
 143                 any_count |= kstat_irqs_cpu(i, j);
 144         action = desc->action;
 145         if (!action && !any_count)
 146                 goto out;
 147
 148         seq_printf(p, "%*d: ", prec, i);
 149         for_each_online_cpu(j)
 150                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 151         seq_printf(p, " %8s", desc->chip->name);
 152         seq_printf(p, "-%-8s", desc->name);
 153
 154         if (action) {
 155                 seq_printf(p, "  %s", action->name);
 156                 while ((action = action->next) != NULL)
 157                         seq_printf(p, ", %s", action->name);
 158         }
 159
 160         seq_putc(p, '\n');
 161 out:
 162         spin_unlock_irqrestore(&desc->lock, flags);
 163         return 0;
 164 }
 165
 166 /*
 167  * /proc/stat helpers
 168  */
 169 u64 arch_irq_stat_cpu(unsigned int cpu)
 170 {
 171         u64 sum = irq_stats(cpu)->__nmi_count;
 172
 173 #ifdef CONFIG_X86_LOCAL_APIC
 174         sum += irq_stats(cpu)->apic_timer_irqs;
 175         sum += irq_stats(cpu)->irq_spurious_count;
 176         sum += irq_stats(cpu)->apic_perf_irqs;
 177         sum += irq_stats(cpu)->apic_pending_irqs;
 178 #endif
 179         if (generic_interrupt_extension)
 180                 sum += irq_stats(cpu)->generic_irqs;
 181 #ifdef CONFIG_SMP
 182         sum += irq_stats(cpu)->irq_resched_count;
 183         sum += irq_stats(cpu)->irq_call_count;
 184         sum += irq_stats(cpu)->irq_tlb_count;
 185 #endif
 186 #ifdef CONFIG_X86_MCE
 187         sum += irq_stats(cpu)->irq_thermal_count;
 188 # ifdef CONFIG_X86_64
 189         sum += irq_stats(cpu)->irq_threshold_count;
 190 # endif
 191 #endif
 192         return sum;
 193 }
 194
 195 u64 arch_irq_stat(void)
 196 {
 197         u64 sum = atomic_read(&irq_err_count);
 198
 199 #ifdef CONFIG_X86_IO_APIC
 200         sum += atomic_read(&irq_mis_count);
 201 #endif
 202         return sum;
 203 }
 204
 205
 206 /*
 207  * do_IRQ handles all normal device IRQ's (the special
 208  * SMP cross-CPU interrupts have their own specific
 209  * handlers).
 210  */
 211 unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
 212 {
 213         struct pt_regs *old_regs = set_irq_regs(regs);
 214
 215         /* high bit used in ret_from_ code  */
 216         unsigned vector = ~regs->orig_ax;
 217         unsigned irq;
 218
 219         exit_idle();
 220         irq_enter();
 221
 222         irq = __get_cpu_var(vector_irq)[vector];
 223
 224         if (!handle_irq(irq, regs)) {
 225                 ack_APIC_irq();
 226
 227                 if (printk_ratelimit())
 228                         pr_emerg("%s: %d.%d No irq handler for vector (irq %d)\n",
 229                                 __func__, smp_processor_id(), vector, irq);
 230         }
 231
 232         irq_exit();
 233
 234         set_irq_regs(old_regs);
 235         return 1;
 236 }
 237
 238 /*
 239  * Handler for GENERIC_INTERRUPT_VECTOR.
 240  */
 241 void smp_generic_interrupt(struct pt_regs *regs)
 242 {
 243         struct pt_regs *old_regs = set_irq_regs(regs);
 244
 245         ack_APIC_irq();
 246
 247         exit_idle();
 248
 249         irq_enter();
 250
 251         inc_irq_stat(generic_irqs);
 252
 253         if (generic_interrupt_extension)
 254                 generic_interrupt_extension();
 255
 256         irq_exit();
 257
 258         set_irq_regs(old_regs);
 259 }
 260
 261 EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);