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