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 #ifdef CONFIG_X86_MCE
 139                 seq_printf(p, "TRM: ");
 140                 for_each_online_cpu(j)
 141                         seq_printf(p, "%10u ", cpu_pda(j)->irq_thermal_count);
 142                 seq_printf(p, "  Thermal event interrupts\n");
 143                 seq_printf(p, "THR: ");
 144                 for_each_online_cpu(j)
 145                         seq_printf(p, "%10u ", cpu_pda(j)->irq_threshold_count);
 146                 seq_printf(p, "  Threshold APIC interrupts\n");
 147 #endif
 148                 seq_printf(p, "SPU: ");
 149                 for_each_online_cpu(j)
 150                         seq_printf(p, "%10u ", cpu_pda(j)->irq_spurious_count);
 151                 seq_printf(p, "  Spurious interrupts\n");
 152                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
 153         }
 154         return 0;
 155 }
 156
 157 /*
 158  * /proc/stat helpers
 159  */
 160 u64 arch_irq_stat_cpu(unsigned int cpu)
 161 {
 162         u64 sum = cpu_pda(cpu)->__nmi_count;
 163
 164         sum += cpu_pda(cpu)->apic_timer_irqs;
 165 #ifdef CONFIG_SMP
 166         sum += cpu_pda(cpu)->irq_resched_count;
 167         sum += cpu_pda(cpu)->irq_call_count;
 168         sum += cpu_pda(cpu)->irq_tlb_count;
 169 #endif
 170 #ifdef CONFIG_X86_MCE
 171         sum += cpu_pda(cpu)->irq_thermal_count;
 172         sum += cpu_pda(cpu)->irq_threshold_count;
 173 #endif
 174         sum += cpu_pda(cpu)->irq_spurious_count;
 175         return sum;
 176 }
 177
 178 u64 arch_irq_stat(void)
 179 {
 180         return atomic_read(&irq_err_count);
 181 }
 182
 183 /*
 184  * do_IRQ handles all normal device IRQ's (the special
 185  * SMP cross-CPU interrupts have their own specific
 186  * handlers).
 187  */
 188 asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
 189 {
 190         struct pt_regs *old_regs = set_irq_regs(regs);
 191
 192         /* high bit used in ret_from_ code  */
 193         unsigned vector = ~regs->orig_ax;
 194         unsigned irq;
 195
 196         exit_idle();
 197         irq_enter();
 198         irq = __get_cpu_var(vector_irq)[vector];
 199
 200 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 201         stack_overflow_check(regs);
 202 #endif
 203
 204         if (likely(irq < NR_IRQS))
 205                 generic_handle_irq(irq);
 206         else {
 207                 if (!disable_apic)
 208                         ack_APIC_irq();
 209
 210                 if (printk_ratelimit())
 211                         printk(KERN_EMERG "%s: %d.%d No irq handler for vector\n",
 212                                 __func__, smp_processor_id(), vector);
 213         }
 214
 215         irq_exit();
 216
 217         set_irq_regs(old_regs);
 218         return 1;
 219 }
 220
 221 #ifdef CONFIG_HOTPLUG_CPU
 222 void fixup_irqs(cpumask_t map)
 223 {
 224         unsigned int irq;
 225         static int warned;
 226
 227         for (irq = 0; irq < NR_IRQS; irq++) {
 228                 cpumask_t mask;
 229                 int break_affinity = 0;
 230                 int set_affinity = 1;
 231
 232                 if (irq == 2)
 233                         continue;
 234
 235                 /* interrupt's are disabled at this point */
 236                 spin_lock(&irq_desc[irq].lock);
 237
 238                 if (!irq_has_action(irq) ||
 239                     cpus_equal(irq_desc[irq].affinity, map)) {
 240                         spin_unlock(&irq_desc[irq].lock);
 241                         continue;
 242                 }
 243
 244                 cpus_and(mask, irq_desc[irq].affinity, map);
 245                 if (cpus_empty(mask)) {
 246                         break_affinity = 1;
 247                         mask = map;
 248                 }
 249
 250                 if (irq_desc[irq].chip->mask)
 251                         irq_desc[irq].chip->mask(irq);
 252
 253                 if (irq_desc[irq].chip->set_affinity)
 254                         irq_desc[irq].chip->set_affinity(irq, mask);
 255                 else if (!(warned++))
 256                         set_affinity = 0;
 257
 258                 if (irq_desc[irq].chip->unmask)
 259                         irq_desc[irq].chip->unmask(irq);
 260
 261                 spin_unlock(&irq_desc[irq].lock);
 262
 263                 if (break_affinity && set_affinity)
 264                         printk("Broke affinity for irq %i\n", irq);
 265                 else if (!set_affinity)
 266                         printk("Cannot set affinity for irq %i\n", irq);
 267         }
 268
 269         /* That doesn't seem sufficient.  Give it 1ms. */
 270         local_irq_enable();
 271         mdelay(1);
 272         local_irq_disable();
 273 }
 274 #endif
 275
 276 extern void call_softirq(void);
 277
 278 asmlinkage void do_softirq(void)
 279 {
 280         __u32 pending;
 281         unsigned long flags;
 282
 283         if (in_interrupt())
 284                 return;
 285
 286         local_irq_save(flags);
 287         pending = local_softirq_pending();
 288         /* Switch to interrupt stack */
 289         if (pending) {
 290                 call_softirq();
 291                 WARN_ON_ONCE(softirq_count());
 292         }
 293         local_irq_restore(flags);
 294 }