+++ /dev/null
-/*
- * linux/arch/i386/kernel/irq.c
- *
- * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
- *
- * This file contains the lowest level x86-specific interrupt
- * entry, irq-stacks and irq statistics code. All the remaining
- * irq logic is done by the generic kernel/irq/ code and
- * by the x86-specific irq controller code. (e.g. i8259.c and
- * io_apic.c.)
- */
-
-#include <asm/uaccess.h>
-#include <linux/module.h>
-#include <linux/seq_file.h>
-#include <linux/interrupt.h>
-#include <linux/kernel_stat.h>
-
-#ifndef CONFIG_X86_LOCAL_APIC
-/*
- * 'what should we do if we get a hw irq event on an illegal vector'.
- * each architecture has to answer this themselves.
- */
-void ack_bad_irq(unsigned int irq)
-{
- printk("unexpected IRQ trap at vector %02x\n", irq);
-}
-#endif
-
-#ifdef CONFIG_4KSTACKS
-/*
- * per-CPU IRQ handling contexts (thread information and stack)
- */
-union irq_ctx {
- struct thread_info tinfo;
- u32 stack[THREAD_SIZE/sizeof(u32)];
-};
-
-static union irq_ctx *hardirq_ctx[NR_CPUS];
-static union irq_ctx *softirq_ctx[NR_CPUS];
-#endif
-
-/*
- * do_IRQ handles all normal device IRQ's (the special
- * SMP cross-CPU interrupts have their own specific
- * handlers).
- */
-fastcall unsigned int do_IRQ(struct pt_regs *regs)
-{
- /* high bits used in ret_from_ code */
- int irq = regs->orig_eax & 0xff;
-#ifdef CONFIG_4KSTACKS
- union irq_ctx *curctx, *irqctx;
- u32 *isp;
-#endif
-
- irq_enter();
-#ifdef CONFIG_DEBUG_STACKOVERFLOW
- /* Debugging check for stack overflow: is there less than 1KB free? */
- {
- long esp;
-
- __asm__ __volatile__("andl %%esp,%0" :
- "=r" (esp) : "0" (THREAD_SIZE - 1));
- if (unlikely(esp < (sizeof(struct thread_info) + STACK_WARN))) {
- printk("do_IRQ: stack overflow: %ld\n",
- esp - sizeof(struct thread_info));
- dump_stack();
- }
- }
-#endif
-
-#ifdef CONFIG_4KSTACKS
-
- curctx = (union irq_ctx *) current_thread_info();
- irqctx = hardirq_ctx[smp_processor_id()];
-
- /*
- * this is where we switch to the IRQ stack. However, if we are
- * already using the IRQ stack (because we interrupted a hardirq
- * handler) we can't do that and just have to keep using the
- * current stack (which is the irq stack already after all)
- */
- if (curctx != irqctx) {
- int arg1, arg2, ebx;
-
- /* build the stack frame on the IRQ stack */
- isp = (u32*) ((char*)irqctx + sizeof(*irqctx));
- irqctx->tinfo.task = curctx->tinfo.task;
- irqctx->tinfo.previous_esp = current_stack_pointer;
-
- asm volatile(
- " xchgl %%ebx,%%esp \n"
- " call __do_IRQ \n"
- " movl %%ebx,%%esp \n"
- : "=a" (arg1), "=d" (arg2), "=b" (ebx)
- : "0" (irq), "1" (regs), "2" (isp)
- : "memory", "cc", "ecx"
- );
- } else
-#endif
- __do_IRQ(irq, regs);
-
- irq_exit();
-
- return 1;
-}
-
-#ifdef CONFIG_4KSTACKS
-
-/*
- * These should really be __section__(".bss.page_aligned") as well, but
- * gcc's 3.0 and earlier don't handle that correctly.
- */
-static char softirq_stack[NR_CPUS * THREAD_SIZE]
- __attribute__((__aligned__(THREAD_SIZE)));
-
-static char hardirq_stack[NR_CPUS * THREAD_SIZE]
- __attribute__((__aligned__(THREAD_SIZE)));
-
-/*
- * allocate per-cpu stacks for hardirq and for softirq processing
- */
-void irq_ctx_init(int cpu)
-{
- union irq_ctx *irqctx;
-
- if (hardirq_ctx[cpu])
- return;
-
- irqctx = (union irq_ctx*) &hardirq_stack[cpu*THREAD_SIZE];
- irqctx->tinfo.task = NULL;
- irqctx->tinfo.exec_domain = NULL;
- irqctx->tinfo.cpu = cpu;
- irqctx->tinfo.preempt_count = HARDIRQ_OFFSET;
- irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
-
- hardirq_ctx[cpu] = irqctx;
-
- irqctx = (union irq_ctx*) &softirq_stack[cpu*THREAD_SIZE];
- irqctx->tinfo.task = NULL;
- irqctx->tinfo.exec_domain = NULL;
- irqctx->tinfo.cpu = cpu;
- irqctx->tinfo.preempt_count = SOFTIRQ_OFFSET;
- irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
-
- softirq_ctx[cpu] = irqctx;
-
- printk("CPU %u irqstacks, hard=%p soft=%p\n",
- cpu,hardirq_ctx[cpu],softirq_ctx[cpu]);
-}
-
-extern asmlinkage void __do_softirq(void);
-
-asmlinkage void do_softirq(void)
-{
- unsigned long flags;
- struct thread_info *curctx;
- union irq_ctx *irqctx;
- u32 *isp;
-
- if (in_interrupt())
- return;
-
- local_irq_save(flags);
-
- if (local_softirq_pending()) {
- curctx = current_thread_info();
- irqctx = softirq_ctx[smp_processor_id()];
- irqctx->tinfo.task = curctx->task;
- irqctx->tinfo.previous_esp = current_stack_pointer;
-
- /* build the stack frame on the softirq stack */
- isp = (u32*) ((char*)irqctx + sizeof(*irqctx));
-
- asm volatile(
- " xchgl %%ebx,%%esp \n"
- " call __do_softirq \n"
- " movl %%ebx,%%esp \n"
- : "=b"(isp)
- : "0"(isp)
- : "memory", "cc", "edx", "ecx", "eax"
- );
- }
-
- local_irq_restore(flags);
-}
-
-EXPORT_SYMBOL(do_softirq);
-#endif
-
-/*
- * Interrupt statistics:
- */
-
-atomic_t irq_err_count;
-
-/*
- * /proc/interrupts printing:
- */
-
-int show_interrupts(struct seq_file *p, void *v)
-{
- int i = *(loff_t *) v, j;
- struct irqaction * action;
- unsigned long flags;
-
- if (i == 0) {
- seq_printf(p, " ");
- for (j=0; j<NR_CPUS; j++)
- if (cpu_online(j))
- seq_printf(p, "CPU%d ",j);
- seq_putc(p, '\n');
- }
-
- if (i < NR_IRQS) {
- spin_lock_irqsave(&irq_desc[i].lock, flags);
- action = irq_desc[i].action;
- if (!action)
- goto skip;
- seq_printf(p, "%3d: ",i);
-#ifndef CONFIG_SMP
- seq_printf(p, "%10u ", kstat_irqs(i));
-#else
- for (j = 0; j < NR_CPUS; j++)
- if (cpu_online(j))
- seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
-#endif
- seq_printf(p, " %14s", irq_desc[i].handler->typename);
- seq_printf(p, " %s", action->name);
-
- for (action=action->next; action; action = action->next)
- seq_printf(p, ", %s", action->name);
-
- seq_putc(p, '\n');
-skip:
- spin_unlock_irqrestore(&irq_desc[i].lock, flags);
- } else if (i == NR_IRQS) {
- seq_printf(p, "NMI: ");
- for (j = 0; j < NR_CPUS; j++)
- if (cpu_online(j))
- seq_printf(p, "%10u ", nmi_count(j));
- seq_putc(p, '\n');
-#ifdef CONFIG_X86_LOCAL_APIC
- seq_printf(p, "LOC: ");
- for (j = 0; j < NR_CPUS; j++)
- if (cpu_online(j))
- seq_printf(p, "%10u ",
- irq_stat[j].apic_timer_irqs);
- seq_putc(p, '\n');
-#endif
- seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
-#if defined(CONFIG_X86_IO_APIC)
- seq_printf(p, "MIS: %10u\n", atomic_read(&irq_mis_count));
-#endif
- }
- return 0;
-}
projects / xen.git / commitdiff