arch/x86_64/kernel/irq-xen.c

   1 /*
   2  *      linux/arch/x86_64/kernel/irq.c
   3  *
   4  *      Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
   5  *
   6  * This file contains the lowest level x86_64-specific interrupt
   7  * entry and irq statistics code. All the remaining irq logic is
   8  * done by the generic kernel/irq/ code and in the
   9  * x86_64-specific irq controller code. (e.g. i8259.c and
  10  * io_apic.c.)
  11  */
  12
  13 #include <linux/kernel_stat.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/seq_file.h>
  16 #include <linux/module.h>
  17 #include <linux/delay.h>
  18 #include <linux/vs_context.h>
  19 #include <asm/uaccess.h>
  20 #include <asm/io_apic.h>
  21 #include <asm/idle.h>
  22
  23 atomic_t irq_err_count;
  24 #ifdef CONFIG_X86_IO_APIC
  25 #ifdef APIC_MISMATCH_DEBUG
  26 atomic_t irq_mis_count;
  27 #endif
  28 #endif
  29
  30 #ifdef CONFIG_DEBUG_STACKOVERFLOW
  31 /*
  32  * Probabilistic stack overflow check:
  33  *
  34  * Only check the stack in process context, because everything else
  35  * runs on the big interrupt stacks. Checking reliably is too expensive,
  36  * so we just check from interrupts.
  37  */
  38 static inline void stack_overflow_check(struct pt_regs *regs)
  39 {
  40         u64 curbase = (u64) current->thread_info;
  41         static unsigned long warned = -60*HZ;
  42
  43         if (regs->rsp >= curbase && regs->rsp <= curbase + THREAD_SIZE &&
  44             regs->rsp <  curbase + sizeof(struct thread_info) + 128 &&
  45             time_after(jiffies, warned + 60*HZ)) {
  46                 printk("do_IRQ: %s near stack overflow (cur:%Lx,rsp:%lx)\n",
  47                        current->comm, curbase, regs->rsp);
  48                 show_stack(NULL,NULL);
  49                 warned = jiffies;
  50         }
  51 }
  52 #endif
  53
  54 /*
  55  * Generic, controller-independent functions:
  56  */
  57
  58 int show_interrupts(struct seq_file *p, void *v)
  59 {
  60         int i = *(loff_t *) v, j;
  61         struct irqaction * action;
  62         unsigned long flags;
  63
  64         if (i == 0) {
  65                 seq_printf(p, "           ");
  66                 for_each_online_cpu(j)
  67                         seq_printf(p, "CPU%-8d       ",j);
  68                 seq_putc(p, '\n');
  69         }
  70
  71         if (i < NR_IRQS) {
  72                 spin_lock_irqsave(&irq_desc[i].lock, flags);
  73                 action = irq_desc[i].action;
  74                 if (!action)
  75                         goto skip;
  76                 seq_printf(p, "%3d: ",i);
  77 #ifndef CONFIG_SMP
  78                 seq_printf(p, "%10u ", kstat_irqs(i));
  79 #else
  80                 for_each_online_cpu(j)
  81                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
  82 #endif
  83                 seq_printf(p, " %14s", irq_desc[i].chip->typename);
  84
  85                 seq_printf(p, "  %s", action->name);
  86                 for (action=action->next; action; action = action->next)
  87                         seq_printf(p, ", %s", action->name);
  88                 seq_putc(p, '\n');
  89 skip:
  90                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
  91         } else if (i == NR_IRQS) {
  92                 seq_printf(p, "NMI: ");
  93                 for_each_online_cpu(j)
  94                         seq_printf(p, "%10u ", cpu_pda(j)->__nmi_count);
  95                 seq_putc(p, '\n');
  96 #ifdef CONFIG_X86_LOCAL_APIC
  97                 seq_printf(p, "LOC: ");
  98                 for_each_online_cpu(j)
  99                         seq_printf(p, "%10u ", cpu_pda(j)->apic_timer_irqs);
 100                 seq_putc(p, '\n');
 101 #endif
 102                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
 103 #ifdef CONFIG_X86_IO_APIC
 104 #ifdef APIC_MISMATCH_DEBUG
 105                 seq_printf(p, "MIS: %10u\n", atomic_read(&irq_mis_count));
 106 #endif
 107 #endif
 108         }
 109         return 0;
 110 }
 111
 112 /*
 113  * do_IRQ handles all normal device IRQ's (the special
 114  * SMP cross-CPU interrupts have their own specific
 115  * handlers).
 116  */
 117 asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
 118 {
 119         /* high bit used in ret_from_ code  */
 120         unsigned irq = ~regs->orig_rax;
 121         struct vx_info_save vxis;
 122
 123         if (unlikely(irq >= NR_IRQS)) {
 124                 printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
 125                                         __FUNCTION__, irq);
 126                 BUG();
 127         }
 128
 129         exit_idle();
 130         irq_enter();
 131
 132 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 133         stack_overflow_check(regs);
 134 #endif
 135         __enter_vx_admin(&vxis);
 136         __do_IRQ(irq, regs);
 137         __leave_vx_admin(&vxis);
 138         irq_exit();
 139
 140         return 1;
 141 }
 142
 143 #ifdef CONFIG_HOTPLUG_CPU
 144 void fixup_irqs(cpumask_t map)
 145 {
 146         unsigned int irq;
 147         static int warned;
 148
 149         for (irq = 0; irq < NR_IRQS; irq++) {
 150                 cpumask_t mask;
 151                 if (irq == 2)
 152                         continue;
 153
 154                 cpus_and(mask, irq_desc[irq].affinity, map);
 155                 if (any_online_cpu(mask) == NR_CPUS) {
 156                         printk("Breaking affinity for irq %i\n", irq);
 157                         mask = map;
 158                 }
 159                 if (irq_desc[irq].chip->set_affinity)
 160                         irq_desc[irq].chip->set_affinity(irq, mask);
 161                 else if (irq_desc[irq].action && !(warned++))
 162                         printk("Cannot set affinity for irq %i\n", irq);
 163         }
 164
 165         /* That doesn't seem sufficient.  Give it 1ms. */
 166         local_irq_enable();
 167         mdelay(1);
 168         local_irq_disable();
 169 }
 170 #endif
 171
 172 extern void call_softirq(void);
 173
 174 asmlinkage void do_softirq(void)
 175 {
 176         __u32 pending;
 177         unsigned long flags;
 178
 179         if (in_interrupt())
 180                 return;
 181
 182         local_irq_save(flags);
 183         pending = local_softirq_pending();
 184         /* Switch to interrupt stack */
 185         if (pending) {
 186                 call_softirq();
 187                 WARN_ON_ONCE(softirq_count());
 188         }
 189         local_irq_restore(flags);
 190 }
 191 EXPORT_SYMBOL(do_softirq);
 192
 193 #ifndef CONFIG_X86_LOCAL_APIC
 194 /*
 195  * 'what should we do if we get a hw irq event on an illegal vector'.
 196  * each architecture has to answer this themselves.
 197  */
 198 void ack_bad_irq(unsigned int irq)
 199 {
 200         printk("unexpected IRQ trap at vector %02x\n", irq);
 201 }
 202 #endif