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   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 #ifdef CONFIG_HAVE_SPARSE_IRQ
  81         desc = (struct irq_desc *)v;
  82         entries = -1U;
  83         i = desc->irq;
  84         if (!desc->next)
  85                 tail = 1;
  86 #else
  87         entries = nr_irqs - 1;
  88         i = *(loff_t *) v;
  89         if (i == nr_irqs)
  90                 tail = 1;
  91         else
  92                 desc = irq_to_desc(i);
  93 #endif
  94
  95         if (i == 0) {
  96                 seq_printf(p, "           ");
  97                 for_each_online_cpu(j)
  98                         seq_printf(p, "CPU%-8d",j);
  99                 seq_putc(p, '\n');
 100         }
 101
 102         if (i <= entries) {
 103                 unsigned any_count = 0;
 104
 105                 spin_lock_irqsave(&desc->lock, flags);
 106 #ifndef CONFIG_SMP
 107                 any_count = kstat_irqs(i);
 108 #else
 109                 for_each_online_cpu(j)
 110                         any_count |= kstat_irqs_cpu(i, j);
 111 #endif
 112                 action = desc->action;
 113                 if (!action && !any_count)
 114                         goto skip;
 115                 seq_printf(p, "%3d: ", i);
 116 #ifndef CONFIG_SMP
 117                 seq_printf(p, "%10u ", kstat_irqs(i));
 118 #else
 119                 for_each_online_cpu(j)
 120                         seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 121 #endif
 122                 seq_printf(p, " %8s", desc->chip->name);
 123                 seq_printf(p, "-%-8s", desc->name);
 124
 125                 if (action) {
 126                         seq_printf(p, "  %s", action->name);
 127                         while ((action = action->next) != NULL)
 128                                 seq_printf(p, ", %s", action->name);
 129                 }
 130                 seq_putc(p, '\n');
 131 skip:
 132                 spin_unlock_irqrestore(&desc->lock, flags);
 133         }
 134
 135         if (tail) {
 136                 seq_printf(p, "NMI: ");
 137                 for_each_online_cpu(j)
 138                         seq_printf(p, "%10u ", cpu_pda(j)->__nmi_count);
 139                 seq_printf(p, "  Non-maskable interrupts\n");
 140                 seq_printf(p, "LOC: ");
 141                 for_each_online_cpu(j)
 142                         seq_printf(p, "%10u ", cpu_pda(j)->apic_timer_irqs);
 143                 seq_printf(p, "  Local timer interrupts\n");
 144 #ifdef CONFIG_SMP
 145                 seq_printf(p, "RES: ");
 146                 for_each_online_cpu(j)
 147                         seq_printf(p, "%10u ", cpu_pda(j)->irq_resched_count);
 148                 seq_printf(p, "  Rescheduling interrupts\n");
 149                 seq_printf(p, "CAL: ");
 150                 for_each_online_cpu(j)
 151                         seq_printf(p, "%10u ", cpu_pda(j)->irq_call_count);
 152                 seq_printf(p, "  Function call interrupts\n");
 153                 seq_printf(p, "TLB: ");
 154                 for_each_online_cpu(j)
 155                         seq_printf(p, "%10u ", cpu_pda(j)->irq_tlb_count);
 156                 seq_printf(p, "  TLB shootdowns\n");
 157 #endif
 158 #ifdef CONFIG_X86_MCE
 159                 seq_printf(p, "TRM: ");
 160                 for_each_online_cpu(j)
 161                         seq_printf(p, "%10u ", cpu_pda(j)->irq_thermal_count);
 162                 seq_printf(p, "  Thermal event interrupts\n");
 163                 seq_printf(p, "THR: ");
 164                 for_each_online_cpu(j)
 165                         seq_printf(p, "%10u ", cpu_pda(j)->irq_threshold_count);
 166                 seq_printf(p, "  Threshold APIC interrupts\n");
 167 #endif
 168                 seq_printf(p, "SPU: ");
 169                 for_each_online_cpu(j)
 170                         seq_printf(p, "%10u ", cpu_pda(j)->irq_spurious_count);
 171                 seq_printf(p, "  Spurious interrupts\n");
 172                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
 173         }
 174
 175         return 0;
 176 }
 177
 178 /*
 179  * /proc/stat helpers
 180  */
 181 u64 arch_irq_stat_cpu(unsigned int cpu)
 182 {
 183         u64 sum = cpu_pda(cpu)->__nmi_count;
 184
 185         sum += cpu_pda(cpu)->apic_timer_irqs;
 186 #ifdef CONFIG_SMP
 187         sum += cpu_pda(cpu)->irq_resched_count;
 188         sum += cpu_pda(cpu)->irq_call_count;
 189         sum += cpu_pda(cpu)->irq_tlb_count;
 190 #endif
 191 #ifdef CONFIG_X86_MCE
 192         sum += cpu_pda(cpu)->irq_thermal_count;
 193         sum += cpu_pda(cpu)->irq_threshold_count;
 194 #endif
 195         sum += cpu_pda(cpu)->irq_spurious_count;
 196         return sum;
 197 }
 198
 199 u64 arch_irq_stat(void)
 200 {
 201         return atomic_read(&irq_err_count);
 202 }
 203
 204 /*
 205  * do_IRQ handles all normal device IRQ's (the special
 206  * SMP cross-CPU interrupts have their own specific
 207  * handlers).
 208  */
 209 asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
 210 {
 211         struct pt_regs *old_regs = set_irq_regs(regs);
 212         struct irq_desc *desc;
 213
 214         /* high bit used in ret_from_ code  */
 215         unsigned vector = ~regs->orig_ax;
 216         unsigned irq;
 217
 218         exit_idle();
 219         irq_enter();
 220         irq = __get_cpu_var(vector_irq)[vector];
 221
 222 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 223         stack_overflow_check(regs);
 224 #endif
 225
 226         desc = irq_to_desc(irq);
 227         if (likely(desc))
 228                 generic_handle_irq_desc(irq, desc);
 229         else {
 230                 if (!disable_apic)
 231                         ack_APIC_irq();
 232
 233                 if (printk_ratelimit())
 234                         printk(KERN_EMERG "%s: %d.%d No irq handler for vector\n",
 235                                 __func__, smp_processor_id(), vector);
 236         }
 237
 238         irq_exit();
 239
 240         set_irq_regs(old_regs);
 241         return 1;
 242 }
 243
 244 #ifdef CONFIG_HOTPLUG_CPU
 245 void fixup_irqs(cpumask_t map)
 246 {
 247         unsigned int irq;
 248         static int warned;
 249         struct irq_desc *desc;
 250
 251         for_each_irq_desc(irq, desc) {
 252                 cpumask_t mask;
 253                 int break_affinity = 0;
 254                 int set_affinity = 1;
 255
 256                 if (irq == 2)
 257                         continue;
 258
 259                 /* interrupt's are disabled at this point */
 260                 spin_lock(&desc->lock);
 261
 262                 if (!irq_has_action(irq) ||
 263                     cpus_equal(desc->affinity, map)) {
 264                         spin_unlock(&desc->lock);
 265                         continue;
 266                 }
 267
 268                 cpus_and(mask, desc->affinity, map);
 269                 if (cpus_empty(mask)) {
 270                         break_affinity = 1;
 271                         mask = map;
 272                 }
 273
 274                 if (desc->chip->mask)
 275                         desc->chip->mask(irq);
 276
 277                 if (desc->chip->set_affinity)
 278                         desc->chip->set_affinity(irq, mask);
 279                 else if (!(warned++))
 280                         set_affinity = 0;
 281
 282                 if (desc->chip->unmask)
 283                         desc->chip->unmask(irq);
 284
 285                 spin_unlock(&desc->lock);
 286
 287                 if (break_affinity && set_affinity)
 288                         printk("Broke affinity for irq %i\n", irq);
 289                 else if (!set_affinity)
 290                         printk("Cannot set affinity for irq %i\n", irq);
 291         }
 292
 293         /* That doesn't seem sufficient.  Give it 1ms. */
 294         local_irq_enable();
 295         mdelay(1);
 296         local_irq_disable();
 297 }
 298 #endif
 299
 300 extern void call_softirq(void);
 301
 302 asmlinkage void do_softirq(void)
 303 {
 304         __u32 pending;
 305         unsigned long flags;
 306
 307         if (in_interrupt())
 308                 return;
 309
 310         local_irq_save(flags);
 311         pending = local_softirq_pending();
 312         /* Switch to interrupt stack */
 313         if (pending) {
 314                 call_softirq();
 315                 WARN_ON_ONCE(softirq_count());
 316         }
 317         local_irq_restore(flags);
 318 }