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