arch/x86/kernel/irq_64.c

   1 /*
   2  *      Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
   3  *
   4  * This file contains the lowest level x86_64-specific interrupt
   5  * entry and irq statistics code. All the remaining irq logic is
   6  * done by the generic kernel/irq/ code and in the
   7  * x86_64-specific irq controller code. (e.g. i8259.c and
   8  * io_apic.c.)
   9  */
  10
  11 #include <linux/kernel_stat.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/seq_file.h>
  14 #include <linux/module.h>
  15 #include <linux/delay.h>
  16 #include <asm/uaccess.h>
  17 #include <asm/io_apic.h>
  18 #include <asm/idle.h>
  19 #include <asm/smp.h>
  20
  21 atomic_t irq_err_count;
  22
  23 #ifdef CONFIG_DEBUG_STACKOVERFLOW
  24 /*
  25  * Probabilistic stack overflow check:
  26  *
  27  * Only check the stack in process context, because everything else
  28  * runs on the big interrupt stacks. Checking reliably is too expensive,
  29  * so we just check from interrupts.
  30  */
  31 static inline void stack_overflow_check(struct pt_regs *regs)
  32 {
  33         u64 curbase = (u64)task_stack_page(current);
  34         static unsigned long warned = -60*HZ;
  35
  36         if (regs->rsp >= curbase && regs->rsp <= curbase + THREAD_SIZE &&
  37             regs->rsp <  curbase + sizeof(struct thread_info) + 128 &&
  38             time_after(jiffies, warned + 60*HZ)) {
  39                 printk("do_IRQ: %s near stack overflow (cur:%Lx,rsp:%lx)\n",
  40                        current->comm, curbase, regs->rsp);
  41                 show_stack(NULL,NULL);
  42                 warned = jiffies;
  43         }
  44 }
  45 #endif
  46
  47 /*
  48  * Generic, controller-independent functions:
  49  */
  50
  51 int show_interrupts(struct seq_file *p, void *v)
  52 {
  53         int i = *(loff_t *) v, j;
  54         struct irqaction * action;
  55         unsigned long flags;
  56
  57         if (i == 0) {
  58                 seq_printf(p, "           ");
  59                 for_each_online_cpu(j)
  60                         seq_printf(p, "CPU%-8d",j);
  61                 seq_putc(p, '\n');
  62         }
  63
  64         if (i < NR_IRQS) {
  65                 unsigned any_count = 0;
  66
  67                 spin_lock_irqsave(&irq_desc[i].lock, flags);
  68 #ifndef CONFIG_SMP
  69                 any_count = kstat_irqs(i);
  70 #else
  71                 for_each_online_cpu(j)
  72                         any_count |= kstat_cpu(j).irqs[i];
  73 #endif
  74                 action = irq_desc[i].action;
  75                 if (!action && !any_count)
  76                         goto skip;
  77                 seq_printf(p, "%3d: ",i);
  78 #ifndef CONFIG_SMP
  79                 seq_printf(p, "%10u ", kstat_irqs(i));
  80 #else
  81                 for_each_online_cpu(j)
  82                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
  83 #endif
  84                 seq_printf(p, " %8s", irq_desc[i].chip->name);
  85                 seq_printf(p, "-%-8s", irq_desc[i].name);
  86
  87                 if (action) {
  88                         seq_printf(p, "  %s", action->name);
  89                         while ((action = action->next) != NULL)
  90                                 seq_printf(p, ", %s", action->name);
  91                 }
  92                 seq_putc(p, '\n');
  93 skip:
  94                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
  95         } else if (i == NR_IRQS) {
  96                 seq_printf(p, "NMI: ");
  97                 for_each_online_cpu(j)
  98                         seq_printf(p, "%10u ", cpu_pda(j)->__nmi_count);
  99                 seq_printf(p, "  Non-maskable interrupts\n");
 100                 seq_printf(p, "LOC: ");
 101                 for_each_online_cpu(j)
 102                         seq_printf(p, "%10u ", cpu_pda(j)->apic_timer_irqs);
 103                 seq_printf(p, "  Local timer interrupts\n");
 104 #ifdef CONFIG_SMP
 105                 seq_printf(p, "RES: ");
 106                 for_each_online_cpu(j)
 107                         seq_printf(p, "%10u ", cpu_pda(j)->irq_resched_count);
 108                 seq_printf(p, "  Rescheduling interrupts\n");
 109                 seq_printf(p, "CAL: ");
 110                 for_each_online_cpu(j)
 111                         seq_printf(p, "%10u ", cpu_pda(j)->irq_call_count);
 112                 seq_printf(p, "  function call interrupts\n");
 113                 seq_printf(p, "TLB: ");
 114                 for_each_online_cpu(j)
 115                         seq_printf(p, "%10u ", cpu_pda(j)->irq_tlb_count);
 116                 seq_printf(p, "  TLB shootdowns\n");
 117 #endif
 118                 seq_printf(p, "TRM: ");
 119                 for_each_online_cpu(j)
 120                         seq_printf(p, "%10u ", cpu_pda(j)->irq_thermal_count);
 121                 seq_printf(p, "  Thermal event interrupts\n");
 122                 seq_printf(p, "THR: ");
 123                 for_each_online_cpu(j)
 124                         seq_printf(p, "%10u ", cpu_pda(j)->irq_threshold_count);
 125                 seq_printf(p, "  Threshold APIC interrupts\n");
 126                 seq_printf(p, "SPU: ");
 127                 for_each_online_cpu(j)
 128                         seq_printf(p, "%10u ", cpu_pda(j)->irq_spurious_count);
 129                 seq_printf(p, "  Spurious interrupts\n");
 130                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
 131         }
 132         return 0;
 133 }
 134
 135 /*
 136  * do_IRQ handles all normal device IRQ's (the special
 137  * SMP cross-CPU interrupts have their own specific
 138  * handlers).
 139  */
 140 asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
 141 {
 142         struct pt_regs *old_regs = set_irq_regs(regs);
 143
 144         /* high bit used in ret_from_ code  */
 145         unsigned vector = ~regs->orig_rax;
 146         unsigned irq;
 147
 148         exit_idle();
 149         irq_enter();
 150         irq = __get_cpu_var(vector_irq)[vector];
 151
 152 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 153         stack_overflow_check(regs);
 154 #endif
 155
 156         if (likely(irq < NR_IRQS))
 157                 generic_handle_irq(irq);
 158         else {
 159                 if (!disable_apic)
 160                         ack_APIC_irq();
 161
 162                 if (printk_ratelimit())
 163                         printk(KERN_EMERG "%s: %d.%d No irq handler for vector\n",
 164                                 __func__, smp_processor_id(), vector);
 165         }
 166
 167         irq_exit();
 168
 169         set_irq_regs(old_regs);
 170         return 1;
 171 }
 172
 173 #ifdef CONFIG_HOTPLUG_CPU
 174 void fixup_irqs(cpumask_t map)
 175 {
 176         unsigned int irq;
 177         static int warned;
 178
 179         for (irq = 0; irq < NR_IRQS; irq++) {
 180                 cpumask_t mask;
 181                 int break_affinity = 0;
 182                 int set_affinity = 1;
 183
 184                 if (irq == 2)
 185                         continue;
 186
 187                 /* interrupt's are disabled at this point */
 188                 spin_lock(&irq_desc[irq].lock);
 189
 190                 if (!irq_has_action(irq) ||
 191                     cpus_equal(irq_desc[irq].affinity, map)) {
 192                         spin_unlock(&irq_desc[irq].lock);
 193                         continue;
 194                 }
 195
 196                 cpus_and(mask, irq_desc[irq].affinity, map);
 197                 if (cpus_empty(mask)) {
 198                         break_affinity = 1;
 199                         mask = map;
 200                 }
 201
 202                 if (irq_desc[irq].chip->mask)
 203                         irq_desc[irq].chip->mask(irq);
 204
 205                 if (irq_desc[irq].chip->set_affinity)
 206                         irq_desc[irq].chip->set_affinity(irq, mask);
 207                 else if (!(warned++))
 208                         set_affinity = 0;
 209
 210                 if (irq_desc[irq].chip->unmask)
 211                         irq_desc[irq].chip->unmask(irq);
 212
 213                 spin_unlock(&irq_desc[irq].lock);
 214
 215                 if (break_affinity && set_affinity)
 216                         printk("Broke affinity for irq %i\n", irq);
 217                 else if (!set_affinity)
 218                         printk("Cannot set affinity for irq %i\n", irq);
 219         }
 220
 221         /* That doesn't seem sufficient.  Give it 1ms. */
 222         local_irq_enable();
 223         mdelay(1);
 224         local_irq_disable();
 225 }
 226 #endif
 227
 228 extern void call_softirq(void);
 229
 230 asmlinkage void do_softirq(void)
 231 {
 232         __u32 pending;
 233         unsigned long flags;
 234
 235         if (in_interrupt())
 236                 return;
 237
 238         local_irq_save(flags);
 239         pending = local_softirq_pending();
 240         /* Switch to interrupt stack */
 241         if (pending) {
 242                 call_softirq();
 243                 WARN_ON_ONCE(softirq_count());
 244         }
 245         local_irq_restore(flags);
 246 }