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         seq_printf(p, "PND: ");
  71         for_each_online_cpu(j)
  72                 seq_printf(p, "%10u ", irq_stats(j)->apic_pending_irqs);
  73         seq_printf(p, "  Performance pending work\n");
  74 #endif
  75         if (generic_interrupt_extension) {
  76                 seq_printf(p, "PLT: ");
  77                 for_each_online_cpu(j)
  78                         seq_printf(p, "%10u ", irq_stats(j)->generic_irqs);
  79                 seq_printf(p, "  Platform interrupts\n");
  80         }
  81 #ifdef CONFIG_SMP
  82         seq_printf(p, "%*s: ", prec, "RES");
  83         for_each_online_cpu(j)
  84                 seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
  85         seq_printf(p, "  Rescheduling interrupts\n");
  86         seq_printf(p, "%*s: ", prec, "CAL");
  87         for_each_online_cpu(j)
  88                 seq_printf(p, "%10u ", irq_stats(j)->irq_call_count);
  89         seq_printf(p, "  Function call interrupts\n");
  90         seq_printf(p, "%*s: ", prec, "TLB");
  91         for_each_online_cpu(j)
  92                 seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
  93         seq_printf(p, "  TLB shootdowns\n");
  94 #endif
  95 #ifdef CONFIG_X86_MCE
  96         seq_printf(p, "%*s: ", prec, "TRM");
  97         for_each_online_cpu(j)
  98                 seq_printf(p, "%10u ", irq_stats(j)->irq_thermal_count);
  99         seq_printf(p, "  Thermal event interrupts\n");
 100 # ifdef CONFIG_X86_64
 101         seq_printf(p, "%*s: ", prec, "THR");
 102         for_each_online_cpu(j)
 103                 seq_printf(p, "%10u ", irq_stats(j)->irq_threshold_count);
 104         seq_printf(p, "  Threshold APIC interrupts\n");
 105 # endif
 106 #endif
 107         seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
 108 #if defined(CONFIG_X86_IO_APIC)
 109         seq_printf(p, "%*s: %10u\n", prec, "MIS", atomic_read(&irq_mis_count));
 110 #endif
 111         return 0;
 112 }
 113
 114 int show_interrupts(struct seq_file *p, void *v)
 115 {
 116         unsigned long flags, any_count = 0;
 117         int i = *(loff_t *) v, j, prec;
 118         struct irqaction *action;
 119         struct irq_desc *desc;
 120
 121         if (i > nr_irqs)
 122                 return 0;
 123
 124         for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
 125                 j *= 10;
 126
 127         if (i == nr_irqs)
 128                 return show_other_interrupts(p, prec);
 129
 130         /* print header */
 131         if (i == 0) {
 132                 seq_printf(p, "%*s", prec + 8, "");
 133                 for_each_online_cpu(j)
 134                         seq_printf(p, "CPU%-8d", j);
 135                 seq_putc(p, '\n');
 136         }
 137
 138         desc = irq_to_desc(i);
 139         if (!desc)
 140                 return 0;
 141
 142         spin_lock_irqsave(&desc->lock, flags);
 143         for_each_online_cpu(j)
 144                 any_count |= kstat_irqs_cpu(i, j);
 145         action = desc->action;
 146         if (!action && !any_count)
 147                 goto out;
 148
 149         seq_printf(p, "%*d: ", prec, i);
 150         for_each_online_cpu(j)
 151                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 152         seq_printf(p, " %8s", desc->chip->name);
 153         seq_printf(p, "-%-8s", desc->name);
 154
 155         if (action) {
 156                 seq_printf(p, "  %s", action->name);
 157                 while ((action = action->next) != NULL)
 158                         seq_printf(p, ", %s", action->name);
 159         }
 160
 161         seq_putc(p, '\n');
 162 out:
 163         spin_unlock_irqrestore(&desc->lock, flags);
 164         return 0;
 165 }
 166
 167 /*
 168  * /proc/stat helpers
 169  */
 170 u64 arch_irq_stat_cpu(unsigned int cpu)
 171 {
 172         u64 sum = irq_stats(cpu)->__nmi_count;
 173
 174 #ifdef CONFIG_X86_LOCAL_APIC
 175         sum += irq_stats(cpu)->apic_timer_irqs;
 176         sum += irq_stats(cpu)->irq_spurious_count;
 177         sum += irq_stats(cpu)->apic_perf_irqs;
 178         sum += irq_stats(cpu)->apic_pending_irqs;
 179 #endif
 180         if (generic_interrupt_extension)
 181                 sum += irq_stats(cpu)->generic_irqs;
 182 #ifdef CONFIG_SMP
 183         sum += irq_stats(cpu)->irq_resched_count;
 184         sum += irq_stats(cpu)->irq_call_count;
 185         sum += irq_stats(cpu)->irq_tlb_count;
 186 #endif
 187 #ifdef CONFIG_X86_MCE
 188         sum += irq_stats(cpu)->irq_thermal_count;
 189 # ifdef CONFIG_X86_64
 190         sum += irq_stats(cpu)->irq_threshold_count;
 191 #endif
 192 #endif
 193         return sum;
 194 }
 195
 196 u64 arch_irq_stat(void)
 197 {
 198         u64 sum = atomic_read(&irq_err_count);
 199
 200 #ifdef CONFIG_X86_IO_APIC
 201         sum += atomic_read(&irq_mis_count);
 202 #endif
 203         return sum;
 204 }
 205
 206
 207 /*
 208  * do_IRQ handles all normal device IRQ's (the special
 209  * SMP cross-CPU interrupts have their own specific
 210  * handlers).
 211  */
 212 unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
 213 {
 214         struct pt_regs *old_regs = set_irq_regs(regs);
 215
 216         /* high bit used in ret_from_ code  */
 217         unsigned vector = ~regs->orig_ax;
 218         unsigned irq;
 219
 220         exit_idle();
 221         irq_enter();
 222
 223         irq = __get_cpu_var(vector_irq)[vector];
 224
 225         if (!handle_irq(irq, regs)) {
 226 #ifdef CONFIG_X86_64
 227                 if (!disable_apic)
 228                         ack_APIC_irq();
 229 #endif
 230
 231                 if (printk_ratelimit())
 232                         printk(KERN_EMERG "%s: %d.%d No irq handler for vector (irq %d)\n",
 233                                __func__, smp_processor_id(), vector, irq);
 234         }
 235
 236         irq_exit();
 237
 238         set_irq_regs(old_regs);
 239         return 1;
 240 }
 241
 242 /*
 243  * Handler for GENERIC_INTERRUPT_VECTOR.
 244  */
 245 void smp_generic_interrupt(struct pt_regs *regs)
 246 {
 247         struct pt_regs *old_regs = set_irq_regs(regs);
 248
 249         ack_APIC_irq();
 250
 251         exit_idle();
 252
 253         irq_enter();
 254
 255         inc_irq_stat(generic_irqs);
 256
 257         if (generic_interrupt_extension)
 258                 generic_interrupt_extension();
 259
 260         irq_exit();
 261
 262         set_irq_regs(old_regs);
 263 }
 264
 265 EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);