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 static int show_other_interrupts(struct seq_file *p)
  72 {
  73         int j;
  74
  75         seq_printf(p, "NMI: ");
  76         for_each_online_cpu(j)
  77                 seq_printf(p, "%10u ", cpu_pda(j)->__nmi_count);
  78         seq_printf(p, "  Non-maskable interrupts\n");
  79         seq_printf(p, "LOC: ");
  80         for_each_online_cpu(j)
  81                 seq_printf(p, "%10u ", cpu_pda(j)->apic_timer_irqs);
  82         seq_printf(p, "  Local timer interrupts\n");
  83 #ifdef CONFIG_SMP
  84         seq_printf(p, "RES: ");
  85         for_each_online_cpu(j)
  86                 seq_printf(p, "%10u ", cpu_pda(j)->irq_resched_count);
  87         seq_printf(p, "  Rescheduling interrupts\n");
  88         seq_printf(p, "CAL: ");
  89         for_each_online_cpu(j)
  90                 seq_printf(p, "%10u ", cpu_pda(j)->irq_call_count);
  91         seq_printf(p, "  Function call interrupts\n");
  92         seq_printf(p, "TLB: ");
  93         for_each_online_cpu(j)
  94                 seq_printf(p, "%10u ", cpu_pda(j)->irq_tlb_count);
  95         seq_printf(p, "  TLB shootdowns\n");
  96 #endif
  97 #ifdef CONFIG_X86_MCE
  98         seq_printf(p, "TRM: ");
  99         for_each_online_cpu(j)
 100                 seq_printf(p, "%10u ", cpu_pda(j)->irq_thermal_count);
 101         seq_printf(p, "  Thermal event interrupts\n");
 102         seq_printf(p, "THR: ");
 103         for_each_online_cpu(j)
 104                 seq_printf(p, "%10u ", cpu_pda(j)->irq_threshold_count);
 105         seq_printf(p, "  Threshold APIC interrupts\n");
 106 #endif
 107         seq_printf(p, "SPU: ");
 108         for_each_online_cpu(j)
 109                 seq_printf(p, "%10u ", cpu_pda(j)->irq_spurious_count);
 110         seq_printf(p, "  Spurious interrupts\n");
 111         seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
 112
 113         return 0;
 114 }
 115
 116 int show_interrupts(struct seq_file *p, void *v)
 117 {
 118         unsigned long flags, any_count = 0;
 119         int i = *(loff_t *) v, j;
 120         struct irqaction *action;
 121         struct irq_desc *desc;
 122
 123         if (i > nr_irqs)
 124                 return 0;
 125
 126         if (i == nr_irqs)
 127                 return show_other_interrupts(p);
 128
 129         /* print header */
 130         if (i == 0) {
 131                 seq_printf(p, "           ");
 132                 for_each_online_cpu(j)
 133                         seq_printf(p, "CPU%-8d",j);
 134                 seq_putc(p, '\n');
 135         }
 136
 137         desc = irq_to_desc(i);
 138         spin_lock_irqsave(&desc->lock, flags);
 139 #ifndef CONFIG_SMP
 140         any_count = kstat_irqs(i);
 141 #else
 142         for_each_online_cpu(j)
 143                 any_count |= kstat_irqs_cpu(i, j);
 144 #endif
 145         action = desc->action;
 146         if (!action && !any_count)
 147                 goto out;
 148
 149         seq_printf(p, "%3d: ", i);
 150 #ifndef CONFIG_SMP
 151         seq_printf(p, "%10u ", kstat_irqs(i));
 152 #else
 153         for_each_online_cpu(j)
 154                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 155 #endif
 156         seq_printf(p, " %8s", desc->chip->name);
 157         seq_printf(p, "-%-8s", desc->name);
 158
 159         if (action) {
 160                 seq_printf(p, "  %s", action->name);
 161                 while ((action = action->next) != NULL)
 162                         seq_printf(p, ", %s", action->name);
 163         }
 164
 165         seq_putc(p, '\n');
 166 out:
 167         spin_unlock_irqrestore(&desc->lock, flags);
 168         return 0;
 169 }
 170
 171 /*
 172  * /proc/stat helpers
 173  */
 174 u64 arch_irq_stat_cpu(unsigned int cpu)
 175 {
 176         u64 sum = cpu_pda(cpu)->__nmi_count;
 177
 178         sum += cpu_pda(cpu)->apic_timer_irqs;
 179 #ifdef CONFIG_SMP
 180         sum += cpu_pda(cpu)->irq_resched_count;
 181         sum += cpu_pda(cpu)->irq_call_count;
 182         sum += cpu_pda(cpu)->irq_tlb_count;
 183 #endif
 184 #ifdef CONFIG_X86_MCE
 185         sum += cpu_pda(cpu)->irq_thermal_count;
 186         sum += cpu_pda(cpu)->irq_threshold_count;
 187 #endif
 188         sum += cpu_pda(cpu)->irq_spurious_count;
 189         return sum;
 190 }
 191
 192 u64 arch_irq_stat(void)
 193 {
 194         return atomic_read(&irq_err_count);
 195 }
 196
 197 /*
 198  * do_IRQ handles all normal device IRQ's (the special
 199  * SMP cross-CPU interrupts have their own specific
 200  * handlers).
 201  */
 202 asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
 203 {
 204         struct pt_regs *old_regs = set_irq_regs(regs);
 205         struct irq_desc *desc;
 206
 207         /* high bit used in ret_from_ code  */
 208         unsigned vector = ~regs->orig_ax;
 209         unsigned irq;
 210
 211         exit_idle();
 212         irq_enter();
 213         irq = __get_cpu_var(vector_irq)[vector];
 214
 215 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 216         stack_overflow_check(regs);
 217 #endif
 218
 219         desc = irq_to_desc(irq);
 220         if (likely(desc))
 221                 generic_handle_irq_desc(irq, desc);
 222         else {
 223                 if (!disable_apic)
 224                         ack_APIC_irq();
 225
 226                 if (printk_ratelimit())
 227                         printk(KERN_EMERG "%s: %d.%d No irq handler for vector\n",
 228                                 __func__, smp_processor_id(), vector);
 229         }
 230
 231         irq_exit();
 232
 233         set_irq_regs(old_regs);
 234         return 1;
 235 }
 236
 237 #ifdef CONFIG_HOTPLUG_CPU
 238 void fixup_irqs(cpumask_t map)
 239 {
 240         unsigned int irq;
 241         static int warned;
 242         struct irq_desc *desc;
 243
 244         for_each_irq_desc(irq, desc) {
 245                 cpumask_t mask;
 246                 int break_affinity = 0;
 247                 int set_affinity = 1;
 248
 249                 if (irq == 2)
 250                         continue;
 251
 252                 /* interrupt's are disabled at this point */
 253                 spin_lock(&desc->lock);
 254
 255                 if (!irq_has_action(irq) ||
 256                     cpus_equal(desc->affinity, map)) {
 257                         spin_unlock(&desc->lock);
 258                         continue;
 259                 }
 260
 261                 cpus_and(mask, desc->affinity, map);
 262                 if (cpus_empty(mask)) {
 263                         break_affinity = 1;
 264                         mask = map;
 265                 }
 266
 267                 if (desc->chip->mask)
 268                         desc->chip->mask(irq);
 269
 270                 if (desc->chip->set_affinity)
 271                         desc->chip->set_affinity(irq, mask);
 272                 else if (!(warned++))
 273                         set_affinity = 0;
 274
 275                 if (desc->chip->unmask)
 276                         desc->chip->unmask(irq);
 277
 278                 spin_unlock(&desc->lock);
 279
 280                 if (break_affinity && set_affinity)
 281                         printk("Broke affinity for irq %i\n", irq);
 282                 else if (!set_affinity)
 283                         printk("Cannot set affinity for irq %i\n", irq);
 284         }
 285
 286         /* That doesn't seem sufficient.  Give it 1ms. */
 287         local_irq_enable();
 288         mdelay(1);
 289         local_irq_disable();
 290 }
 291 #endif
 292
 293 extern void call_softirq(void);
 294
 295 asmlinkage void do_softirq(void)
 296 {
 297         __u32 pending;
 298         unsigned long flags;
 299
 300         if (in_interrupt())
 301                 return;
 302
 303         local_irq_save(flags);
 304         pending = local_softirq_pending();
 305         /* Switch to interrupt stack */
 306         if (pending) {
 307                 call_softirq();
 308                 WARN_ON_ONCE(softirq_count());
 309         }
 310         local_irq_restore(flags);
 311 }