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