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