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 /*
  24  * 'what should we do if we get a hw irq event on an illegal vector'.
  25  * each architecture has to answer this themselves.
  26  */
  27 void ack_bad_irq(unsigned int irq)
  28 {
  29         printk(KERN_WARNING "unexpected IRQ trap at vector %02x\n", irq);
  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 don't ack when the APIC is disabled. -AK
  38          */
  39         if (!disable_apic)
  40                 ack_APIC_irq();
  41 }
  42
  43 #ifdef CONFIG_DEBUG_STACKOVERFLOW
  44 /*
  45  * Probabilistic stack overflow check:
  46  *
  47  * Only check the stack in process context, because everything else
  48  * runs on the big interrupt stacks. Checking reliably is too expensive,
  49  * so we just check from interrupts.
  50  */
  51 static inline void stack_overflow_check(struct pt_regs *regs)
  52 {
  53         u64 curbase = (u64)task_stack_page(current);
  54         static unsigned long warned = -60*HZ;
  55
  56         if (regs->sp >= curbase && regs->sp <= curbase + THREAD_SIZE &&
  57             regs->sp <  curbase + sizeof(struct thread_info) + 128 &&
  58             time_after(jiffies, warned + 60*HZ)) {
  59                 printk("do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n",
  60                        current->comm, curbase, regs->sp);
  61                 show_stack(NULL,NULL);
  62                 warned = jiffies;
  63         }
  64 }
  65 #endif
  66
  67 /*
  68  * Generic, controller-independent functions:
  69  */
  70
  71 int show_interrupts(struct seq_file *p, void *v)
  72 {
  73         int i = *(loff_t *) v, j;
  74         struct irqaction * action;
  75         unsigned long flags;
  76
  77         if (i == 0) {
  78                 seq_printf(p, "           ");
  79                 for_each_online_cpu(j)
  80                         seq_printf(p, "CPU%-8d",j);
  81                 seq_putc(p, '\n');
  82         }
  83
  84         if (i < NR_IRQS) {
  85                 unsigned any_count = 0;
  86
  87                 spin_lock_irqsave(&irq_desc[i].lock, flags);
  88 #ifndef CONFIG_SMP
  89                 any_count = kstat_irqs(i);
  90 #else
  91                 for_each_online_cpu(j)
  92                         any_count |= kstat_cpu(j).irqs[i];
  93 #endif
  94                 action = irq_desc[i].action;
  95                 if (!action && !any_count)
  96                         goto skip;
  97                 seq_printf(p, "%3d: ",i);
  98 #ifndef CONFIG_SMP
  99                 seq_printf(p, "%10u ", kstat_irqs(i));
 100 #else
 101                 for_each_online_cpu(j)
 102                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 103 #endif
 104                 seq_printf(p, " %8s", irq_desc[i].chip->name);
 105                 seq_printf(p, "-%-8s", irq_desc[i].name);
 106
 107                 if (action) {
 108                         seq_printf(p, "  %s", action->name);
 109                         while ((action = action->next) != NULL)
 110                                 seq_printf(p, ", %s", action->name);
 111                 }
 112                 seq_putc(p, '\n');
 113 skip:
 114                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
 115         } else if (i == NR_IRQS) {
 116                 seq_printf(p, "NMI: ");
 117                 for_each_online_cpu(j)
 118                         seq_printf(p, "%10u ", cpu_pda(j)->__nmi_count);
 119                 seq_printf(p, "  Non-maskable interrupts\n");
 120                 seq_printf(p, "LOC: ");
 121                 for_each_online_cpu(j)
 122                         seq_printf(p, "%10u ", cpu_pda(j)->apic_timer_irqs);
 123                 seq_printf(p, "  Local timer interrupts\n");
 124 #ifdef CONFIG_SMP
 125                 seq_printf(p, "RES: ");
 126                 for_each_online_cpu(j)
 127                         seq_printf(p, "%10u ", cpu_pda(j)->irq_resched_count);
 128                 seq_printf(p, "  Rescheduling interrupts\n");
 129                 seq_printf(p, "CAL: ");
 130                 for_each_online_cpu(j)
 131                         seq_printf(p, "%10u ", cpu_pda(j)->irq_call_count);
 132                 seq_printf(p, "  function call interrupts\n");
 133                 seq_printf(p, "TLB: ");
 134                 for_each_online_cpu(j)
 135                         seq_printf(p, "%10u ", cpu_pda(j)->irq_tlb_count);
 136                 seq_printf(p, "  TLB shootdowns\n");
 137 #endif
 138                 seq_printf(p, "TRM: ");
 139                 for_each_online_cpu(j)
 140                         seq_printf(p, "%10u ", cpu_pda(j)->irq_thermal_count);
 141                 seq_printf(p, "  Thermal event interrupts\n");
 142                 seq_printf(p, "THR: ");
 143                 for_each_online_cpu(j)
 144                         seq_printf(p, "%10u ", cpu_pda(j)->irq_threshold_count);
 145                 seq_printf(p, "  Threshold APIC interrupts\n");
 146                 seq_printf(p, "SPU: ");
 147                 for_each_online_cpu(j)
 148                         seq_printf(p, "%10u ", cpu_pda(j)->irq_spurious_count);
 149                 seq_printf(p, "  Spurious interrupts\n");
 150                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
 151         }
 152         return 0;
 153 }
 154
 155 /*
 156  * do_IRQ handles all normal device IRQ's (the special
 157  * SMP cross-CPU interrupts have their own specific
 158  * handlers).
 159  */
 160 asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
 161 {
 162         struct pt_regs *old_regs = set_irq_regs(regs);
 163
 164         /* high bit used in ret_from_ code  */
 165         unsigned vector = ~regs->orig_ax;
 166         unsigned irq;
 167
 168         exit_idle();
 169         irq_enter();
 170         irq = __get_cpu_var(vector_irq)[vector];
 171
 172 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 173         stack_overflow_check(regs);
 174 #endif
 175
 176         if (likely(irq < NR_IRQS))
 177                 generic_handle_irq(irq);
 178         else {
 179                 if (!disable_apic)
 180                         ack_APIC_irq();
 181
 182                 if (printk_ratelimit())
 183                         printk(KERN_EMERG "%s: %d.%d No irq handler for vector\n",
 184                                 __func__, smp_processor_id(), vector);
 185         }
 186
 187         irq_exit();
 188
 189         set_irq_regs(old_regs);
 190         return 1;
 191 }
 192
 193 #ifdef CONFIG_HOTPLUG_CPU
 194 void fixup_irqs(cpumask_t map)
 195 {
 196         unsigned int irq;
 197         static int warned;
 198
 199         for (irq = 0; irq < NR_IRQS; irq++) {
 200                 cpumask_t mask;
 201                 int break_affinity = 0;
 202                 int set_affinity = 1;
 203
 204                 if (irq == 2)
 205                         continue;
 206
 207                 /* interrupt's are disabled at this point */
 208                 spin_lock(&irq_desc[irq].lock);
 209
 210                 if (!irq_has_action(irq) ||
 211                     cpus_equal(irq_desc[irq].affinity, map)) {
 212                         spin_unlock(&irq_desc[irq].lock);
 213                         continue;
 214                 }
 215
 216                 cpus_and(mask, irq_desc[irq].affinity, map);
 217                 if (cpus_empty(mask)) {
 218                         break_affinity = 1;
 219                         mask = map;
 220                 }
 221
 222                 if (irq_desc[irq].chip->mask)
 223                         irq_desc[irq].chip->mask(irq);
 224
 225                 if (irq_desc[irq].chip->set_affinity)
 226                         irq_desc[irq].chip->set_affinity(irq, mask);
 227                 else if (!(warned++))
 228                         set_affinity = 0;
 229
 230                 if (irq_desc[irq].chip->unmask)
 231                         irq_desc[irq].chip->unmask(irq);
 232
 233                 spin_unlock(&irq_desc[irq].lock);
 234
 235                 if (break_affinity && set_affinity)
 236                         printk("Broke affinity for irq %i\n", irq);
 237                 else if (!set_affinity)
 238                         printk("Cannot set affinity for irq %i\n", irq);
 239         }
 240
 241         /* That doesn't seem sufficient.  Give it 1ms. */
 242         local_irq_enable();
 243         mdelay(1);
 244         local_irq_disable();
 245 }
 246 #endif
 247
 248 extern void call_softirq(void);
 249
 250 asmlinkage void do_softirq(void)
 251 {
 252         __u32 pending;
 253         unsigned long flags;
 254
 255         if (in_interrupt())
 256                 return;
 257
 258         local_irq_save(flags);
 259         pending = local_softirq_pending();
 260         /* Switch to interrupt stack */
 261         if (pending) {
 262                 call_softirq();
 263                 WARN_ON_ONCE(softirq_count());
 264         }
 265         local_irq_restore(flags);
 266 }