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