/*
- * linux/arch/i386/kernel/irq.c
- *
* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
*
* This file contains the lowest level x86-specific interrupt
DEFINE_PER_CPU(struct pt_regs *, irq_regs);
EXPORT_PER_CPU_SYMBOL(irq_regs);
-/*
- * '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)
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+/* Debugging check for stack overflow: is there less than 1KB free? */
+static int check_stack_overflow(void)
{
- printk(KERN_ERR "unexpected IRQ trap at vector %02x\n", irq);
+ long sp;
-#ifdef CONFIG_X86_LOCAL_APIC
- /*
- * Currently unexpected vectors happen only on SMP and APIC.
- * We _must_ ack these because every local APIC has only N
- * irq slots per priority level, and a 'hanging, unacked' IRQ
- * holds up an irq slot - in excessive cases (when multiple
- * unexpected vectors occur) that might lock up the APIC
- * completely.
- * But only ack when the APIC is enabled -AK
- */
- if (cpu_has_apic)
- ack_APIC_irq();
-#endif
+ __asm__ __volatile__("andl %%esp,%0" :
+ "=r" (sp) : "0" (THREAD_SIZE - 1));
+
+ return sp < (sizeof(struct thread_info) + STACK_WARN);
+}
+
+static void print_stack_overflow(void)
+{
+ printk(KERN_WARNING "low stack detected by irq handler\n");
+ dump_stack();
}
+#else
+static inline int check_stack_overflow(void) { return 0; }
+static inline void print_stack_overflow(void) { }
+#endif
+
#ifdef CONFIG_4KSTACKS
/*
* per-CPU IRQ handling contexts (thread information and stack)
static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly;
static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly;
-#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)
-{
- struct pt_regs *old_regs;
- /* high bit used in ret_from_ code */
- int irq = ~regs->orig_eax;
- struct irq_desc *desc = irq_desc + irq;
-#ifdef CONFIG_4KSTACKS
- union irq_ctx *curctx, *irqctx;
- u32 *isp;
-#endif
+static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss;
+static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss;
- if (unlikely((unsigned)irq >= NR_IRQS)) {
- printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
- __FUNCTION__, irq);
- BUG();
- }
-
- old_regs = set_irq_regs(regs);
- 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
+static void call_on_stack(void *func, void *stack)
+{
+ asm volatile("xchgl %%ebx,%%esp \n"
+ "call *%%edi \n"
+ "movl %%ebx,%%esp \n"
+ : "=b" (stack)
+ : "0" (stack),
+ "D"(func)
+ : "memory", "cc", "edx", "ecx", "eax");
+}
-#ifdef CONFIG_4KSTACKS
+static inline int
+execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq)
+{
+ union irq_ctx *curctx, *irqctx;
+ u32 *isp, arg1, arg2;
curctx = (union irq_ctx *) current_thread_info();
irqctx = hardirq_ctx[smp_processor_id()];
* 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;
+ if (unlikely(curctx == irqctx))
+ return 0;
- /* 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;
-
- /*
- * Copy the softirq bits in preempt_count so that the
- * softirq checks work in the hardirq context.
- */
- irqctx->tinfo.preempt_count =
- (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |
- (curctx->tinfo.preempt_count & SOFTIRQ_MASK);
-
- asm volatile(
- " xchgl %%ebx,%%esp \n"
- " call *%%edi \n"
- " movl %%ebx,%%esp \n"
- : "=a" (arg1), "=d" (arg2), "=b" (ebx)
- : "0" (irq), "1" (desc), "2" (isp),
- "D" (desc->handle_irq)
- : "memory", "cc"
- );
- } else
-#endif
- desc->handle_irq(irq, desc);
+ /* 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;
- irq_exit();
- set_irq_regs(old_regs);
+ /*
+ * Copy the softirq bits in preempt_count so that the
+ * softirq checks work in the hardirq context.
+ */
+ irqctx->tinfo.preempt_count =
+ (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |
+ (curctx->tinfo.preempt_count & SOFTIRQ_MASK);
+
+ if (unlikely(overflow))
+ call_on_stack(print_stack_overflow, isp);
+
+ asm volatile("xchgl %%ebx,%%esp \n"
+ "call *%%edi \n"
+ "movl %%ebx,%%esp \n"
+ : "=a" (arg1), "=d" (arg2), "=b" (isp)
+ : "0" (irq), "1" (desc), "2" (isp),
+ "D" (desc->handle_irq)
+ : "memory", "cc", "ecx");
return 1;
}
-#ifdef CONFIG_4KSTACKS
-
-static char softirq_stack[NR_CPUS * THREAD_SIZE]
- __attribute__((__section__(".bss.page_aligned")));
-
-static char hardirq_stack[NR_CPUS * THREAD_SIZE]
- __attribute__((__section__(".bss.page_aligned")));
-
/*
* allocate per-cpu stacks for hardirq and for softirq processing
*/
-void irq_ctx_init(int cpu)
+void __cpuinit irq_ctx_init(int cpu)
{
union irq_ctx *irqctx;
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);
+ 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 = 0;
- irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
+ irqctx->tinfo.task = NULL;
+ irqctx->tinfo.exec_domain = NULL;
+ irqctx->tinfo.cpu = cpu;
+ irqctx->tinfo.preempt_count = 0;
+ 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]);
+ printk(KERN_DEBUG "CPU %u irqstacks, hard=%p soft=%p\n",
+ cpu,hardirq_ctx[cpu],softirq_ctx[cpu]);
}
void irq_ctx_exit(int cpu)
hardirq_ctx[cpu] = NULL;
}
-extern asmlinkage void __do_softirq(void);
-
asmlinkage void do_softirq(void)
{
unsigned long flags;
/* 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"
- );
+ call_on_stack(__do_softirq, isp);
/*
* Shouldnt happen, we returned above if in_interrupt():
- */
+ */
WARN_ON_ONCE(softirq_count());
}
local_irq_restore(flags);
}
-EXPORT_SYMBOL(do_softirq);
+#else
+static inline int
+execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq) { return 0; }
#endif
/*
- * Interrupt statistics:
+ * do_IRQ handles all normal device IRQ's (the special
+ * SMP cross-CPU interrupts have their own specific
+ * handlers).
*/
+unsigned int do_IRQ(struct pt_regs *regs)
+{
+ struct pt_regs *old_regs;
+ /* high bit used in ret_from_ code */
+ int overflow;
+ unsigned vector = ~regs->orig_ax;
+ struct irq_desc *desc;
+ unsigned irq;
-atomic_t irq_err_count;
-/*
- * /proc/interrupts printing:
- */
+ old_regs = set_irq_regs(regs);
+ irq_enter();
+ irq = __get_cpu_var(vector_irq)[vector];
-int show_interrupts(struct seq_file *p, void *v)
-{
- int i = *(loff_t *) v, j;
- struct irqaction * action;
- unsigned long flags;
+ overflow = check_stack_overflow();
- if (i == 0) {
- seq_printf(p, " ");
- for_each_online_cpu(j)
- seq_printf(p, "CPU%-8d",j);
- seq_putc(p, '\n');
+ desc = irq_to_desc(irq);
+ if (unlikely(!desc)) {
+ printk(KERN_EMERG "%s: cannot handle IRQ %d vector %#x cpu %d\n",
+ __func__, irq, vector, smp_processor_id());
+ BUG();
}
- 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_each_online_cpu(j)
- seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
-#endif
- seq_printf(p, " %8s", irq_desc[i].chip->name);
- seq_printf(p, "-%-8s", irq_desc[i].name);
- 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_each_online_cpu(j)
- seq_printf(p, "%10u ", nmi_count(j));
- seq_putc(p, '\n');
-#ifdef CONFIG_X86_LOCAL_APIC
- seq_printf(p, "LOC: ");
- for_each_online_cpu(j)
- seq_printf(p, "%10u ",
- per_cpu(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
+ if (!execute_on_irq_stack(overflow, desc, irq)) {
+ if (unlikely(overflow))
+ print_stack_overflow();
+ desc->handle_irq(irq, desc);
}
- return 0;
+
+ irq_exit();
+ set_irq_regs(old_regs);
+ return 1;
}
#ifdef CONFIG_HOTPLUG_CPU
{
unsigned int irq;
static int warned;
+ struct irq_desc *desc;
- for (irq = 0; irq < NR_IRQS; irq++) {
+ for_each_irq_desc(irq, desc) {
cpumask_t mask;
+
if (irq == 2)
continue;
- cpus_and(mask, irq_desc[irq].affinity, map);
+ cpus_and(mask, desc->affinity, map);
if (any_online_cpu(mask) == NR_CPUS) {
printk("Breaking affinity for irq %i\n", irq);
mask = map;
}
- if (irq_desc[irq].chip->set_affinity)
- irq_desc[irq].chip->set_affinity(irq, mask);
- else if (irq_desc[irq].action && !(warned++))
+ if (desc->chip->set_affinity)
+ desc->chip->set_affinity(irq, mask);
+ else if (desc->action && !(warned++))
printk("Cannot set affinity for irq %i\n", irq);
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff