cgroups: add cpu_relax() calls in css_tryget() and cgroup_clear_css_refs()
[safe/jmp/linux-2.6] / kernel / irq / handle.c
index 7fc7bc3..3aba8d1 100644 (file)
@@ -1,9 +1,13 @@
 /*
  * linux/kernel/irq/handle.c
  *
- * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
+ * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
+ * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
  *
  * This file contains the core interrupt handling code.
+ *
+ * Detailed information is available in Documentation/DocBook/genericirq
+ *
  */
 
 #include <linux/irq.h>
 #include <linux/random.h>
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
+#include <linux/rculist.h>
+#include <linux/hash.h>
 
 #include "internals.h"
 
 /*
+ * lockdep: we want to handle all irq_desc locks as a single lock-class:
+ */
+struct lock_class_key irq_desc_lock_class;
+
+/**
+ * handle_bad_irq - handle spurious and unhandled irqs
+ * @irq:       the interrupt number
+ * @desc:      description of the interrupt
+ *
+ * Handles spurious and unhandled IRQ's. It also prints a debugmessage.
+ */
+void handle_bad_irq(unsigned int irq, struct irq_desc *desc)
+{
+       print_irq_desc(irq, desc);
+       kstat_incr_irqs_this_cpu(irq, desc);
+       ack_bad_irq(irq);
+}
+
+#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
+static void __init init_irq_default_affinity(void)
+{
+       alloc_bootmem_cpumask_var(&irq_default_affinity);
+       cpumask_setall(irq_default_affinity);
+}
+#else
+static void __init init_irq_default_affinity(void)
+{
+}
+#endif
+
+/*
  * Linux has a controller-independent interrupt architecture.
  * Every controller has a 'controller-template', that is used
  * by the main code to do the right thing. Each driver-visible
  *
  * Controller mappings for all interrupt sources:
  */
-struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned = {
+int nr_irqs = NR_IRQS;
+EXPORT_SYMBOL_GPL(nr_irqs);
+
+#ifdef CONFIG_SPARSE_IRQ
+static struct irq_desc irq_desc_init = {
+       .irq        = -1,
+       .status     = IRQ_DISABLED,
+       .chip       = &no_irq_chip,
+       .handle_irq = handle_bad_irq,
+       .depth      = 1,
+       .lock       = __SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
+#ifdef CONFIG_SMP
+       .affinity   = CPU_MASK_ALL
+#endif
+};
+
+void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr)
+{
+       unsigned long bytes;
+       char *ptr;
+       int node;
+
+       /* Compute how many bytes we need per irq and allocate them */
+       bytes = nr * sizeof(unsigned int);
+
+       node = cpu_to_node(cpu);
+       ptr = kzalloc_node(bytes, GFP_ATOMIC, node);
+       printk(KERN_DEBUG "  alloc kstat_irqs on cpu %d node %d\n", cpu, node);
+
+       if (ptr)
+               desc->kstat_irqs = (unsigned int *)ptr;
+}
+
+static void init_one_irq_desc(int irq, struct irq_desc *desc, int cpu)
+{
+       memcpy(desc, &irq_desc_init, sizeof(struct irq_desc));
+
+       spin_lock_init(&desc->lock);
+       desc->irq = irq;
+#ifdef CONFIG_SMP
+       desc->cpu = cpu;
+#endif
+       lockdep_set_class(&desc->lock, &irq_desc_lock_class);
+       init_kstat_irqs(desc, cpu, nr_cpu_ids);
+       if (!desc->kstat_irqs) {
+               printk(KERN_ERR "can not alloc kstat_irqs\n");
+               BUG_ON(1);
+       }
+       arch_init_chip_data(desc, cpu);
+}
+
+/*
+ * Protect the sparse_irqs:
+ */
+DEFINE_SPINLOCK(sparse_irq_lock);
+
+struct irq_desc *irq_desc_ptrs[NR_IRQS] __read_mostly;
+
+static struct irq_desc irq_desc_legacy[NR_IRQS_LEGACY] __cacheline_aligned_in_smp = {
+       [0 ... NR_IRQS_LEGACY-1] = {
+               .irq        = -1,
+               .status     = IRQ_DISABLED,
+               .chip       = &no_irq_chip,
+               .handle_irq = handle_bad_irq,
+               .depth      = 1,
+               .lock       = __SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
+#ifdef CONFIG_SMP
+               .affinity   = CPU_MASK_ALL
+#endif
+       }
+};
+
+/* FIXME: use bootmem alloc ...*/
+static unsigned int kstat_irqs_legacy[NR_IRQS_LEGACY][NR_CPUS];
+
+int __init early_irq_init(void)
+{
+       struct irq_desc *desc;
+       int legacy_count;
+       int i;
+
+       init_irq_default_affinity();
+
+       desc = irq_desc_legacy;
+       legacy_count = ARRAY_SIZE(irq_desc_legacy);
+
+       for (i = 0; i < legacy_count; i++) {
+               desc[i].irq = i;
+               desc[i].kstat_irqs = kstat_irqs_legacy[i];
+               lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
+
+               irq_desc_ptrs[i] = desc + i;
+       }
+
+       for (i = legacy_count; i < NR_IRQS; i++)
+               irq_desc_ptrs[i] = NULL;
+
+       return arch_early_irq_init();
+}
+
+struct irq_desc *irq_to_desc(unsigned int irq)
+{
+       return (irq < NR_IRQS) ? irq_desc_ptrs[irq] : NULL;
+}
+
+struct irq_desc *irq_to_desc_alloc_cpu(unsigned int irq, int cpu)
+{
+       struct irq_desc *desc;
+       unsigned long flags;
+       int node;
+
+       if (irq >= NR_IRQS) {
+               printk(KERN_WARNING "irq >= NR_IRQS in irq_to_desc_alloc: %d %d\n",
+                               irq, NR_IRQS);
+               WARN_ON(1);
+               return NULL;
+       }
+
+       desc = irq_desc_ptrs[irq];
+       if (desc)
+               return desc;
+
+       spin_lock_irqsave(&sparse_irq_lock, flags);
+
+       /* We have to check it to avoid races with another CPU */
+       desc = irq_desc_ptrs[irq];
+       if (desc)
+               goto out_unlock;
+
+       node = cpu_to_node(cpu);
+       desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
+       printk(KERN_DEBUG "  alloc irq_desc for %d on cpu %d node %d\n",
+                irq, cpu, node);
+       if (!desc) {
+               printk(KERN_ERR "can not alloc irq_desc\n");
+               BUG_ON(1);
+       }
+       init_one_irq_desc(irq, desc, cpu);
+
+       irq_desc_ptrs[irq] = desc;
+
+out_unlock:
+       spin_unlock_irqrestore(&sparse_irq_lock, flags);
+
+       return desc;
+}
+
+#else /* !CONFIG_SPARSE_IRQ */
+
+struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
        [0 ... NR_IRQS-1] = {
                .status = IRQ_DISABLED,
-               .chip = &no_irq_type,
-               .lock = SPIN_LOCK_UNLOCKED,
+               .chip = &no_irq_chip,
+               .handle_irq = handle_bad_irq,
+               .depth = 1,
+               .lock = __SPIN_LOCK_UNLOCKED(irq_desc->lock),
 #ifdef CONFIG_SMP
                .affinity = CPU_MASK_ALL
 #endif
        }
 };
 
+int __init early_irq_init(void)
+{
+       struct irq_desc *desc;
+       int count;
+       int i;
+
+       init_irq_default_affinity();
+
+       desc = irq_desc;
+       count = ARRAY_SIZE(irq_desc);
+
+       for (i = 0; i < count; i++)
+               desc[i].irq = i;
+
+       return arch_early_irq_init();
+}
+
+struct irq_desc *irq_to_desc(unsigned int irq)
+{
+       return (irq < NR_IRQS) ? irq_desc + irq : NULL;
+}
+
+struct irq_desc *irq_to_desc_alloc_cpu(unsigned int irq, int cpu)
+{
+       return irq_to_desc(irq);
+}
+#endif /* !CONFIG_SPARSE_IRQ */
+
 /*
- * Generic 'no controller' code
+ * What should we do if we get a hw irq event on an illegal vector?
+ * Each architecture has to answer this themself.
  */
-static void end_none(unsigned int irq) { }
-static void enable_none(unsigned int irq) { }
-static void disable_none(unsigned int irq) { }
-static void shutdown_none(unsigned int irq) { }
-static unsigned int startup_none(unsigned int irq) { return 0; }
-
-static void ack_none(unsigned int irq)
+static void ack_bad(unsigned int irq)
 {
-       /*
-        * 'what should we do if we get a hw irq event on an illegal vector'.
-        * each architecture has to answer this themself.
-        */
+       struct irq_desc *desc = irq_to_desc(irq);
+
+       print_irq_desc(irq, desc);
        ack_bad_irq(irq);
 }
 
-struct hw_interrupt_type no_irq_type = {
-       .typename =     "none",
-       .startup =      startup_none,
-       .shutdown =     shutdown_none,
-       .enable =       enable_none,
-       .disable =      disable_none,
-       .ack =          ack_none,
-       .end =          end_none,
-       .set_affinity = NULL
+/*
+ * NOP functions
+ */
+static void noop(unsigned int irq)
+{
+}
+
+static unsigned int noop_ret(unsigned int irq)
+{
+       return 0;
+}
+
+/*
+ * Generic no controller implementation
+ */
+struct irq_chip no_irq_chip = {
+       .name           = "none",
+       .startup        = noop_ret,
+       .shutdown       = noop,
+       .enable         = noop,
+       .disable        = noop,
+       .ack            = ack_bad,
+       .end            = noop,
+};
+
+/*
+ * Generic dummy implementation which can be used for
+ * real dumb interrupt sources
+ */
+struct irq_chip dummy_irq_chip = {
+       .name           = "dummy",
+       .startup        = noop_ret,
+       .shutdown       = noop,
+       .enable         = noop,
+       .disable        = noop,
+       .ack            = noop,
+       .mask           = noop,
+       .unmask         = noop,
+       .end            = noop,
 };
 
 /*
  * Special, empty irq handler:
  */
-irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs)
+irqreturn_t no_action(int cpl, void *dev_id)
 {
        return IRQ_NONE;
 }
@@ -79,39 +319,37 @@ irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs)
 /**
  * handle_IRQ_event - irq action chain handler
  * @irq:       the interrupt number
- * @regs:      pointer to a register structure
  * @action:    the interrupt action chain for this irq
  *
  * Handles the action chain of an irq event
  */
-irqreturn_t handle_IRQ_event(unsigned int irq, struct pt_regs *regs,
-                            struct irqaction *action)
+irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
 {
        irqreturn_t ret, retval = IRQ_NONE;
        unsigned int status = 0;
 
-       if (!(action->flags & SA_INTERRUPT))
-               local_irq_enable();
+       if (!(action->flags & IRQF_DISABLED))
+               local_irq_enable_in_hardirq();
 
        do {
-               ret = action->handler(irq, action->dev_id, regs);
+               ret = action->handler(irq, action->dev_id);
                if (ret == IRQ_HANDLED)
                        status |= action->flags;
                retval |= ret;
                action = action->next;
        } while (action);
 
-       if (status & SA_SAMPLE_RANDOM)
+       if (status & IRQF_SAMPLE_RANDOM)
                add_interrupt_randomness(irq);
        local_irq_disable();
 
        return retval;
 }
 
+#ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
 /**
  * __do_IRQ - original all in one highlevel IRQ handler
  * @irq:       the interrupt number
- * @regs:      pointer to a register structure
  *
  * __do_IRQ handles all normal device IRQ's (the special
  * SMP cross-CPU interrupts have their own specific
@@ -120,29 +358,39 @@ irqreturn_t handle_IRQ_event(unsigned int irq, struct pt_regs *regs,
  * This is the original x86 implementation which is used for every
  * interrupt type.
  */
-fastcall unsigned int __do_IRQ(unsigned int irq, struct pt_regs *regs)
+unsigned int __do_IRQ(unsigned int irq)
 {
-       struct irq_desc *desc = irq_desc + irq;
+       struct irq_desc *desc = irq_to_desc(irq);
        struct irqaction *action;
        unsigned int status;
 
-       kstat_this_cpu.irqs[irq]++;
+       kstat_incr_irqs_this_cpu(irq, desc);
+
        if (CHECK_IRQ_PER_CPU(desc->status)) {
                irqreturn_t action_ret;
 
                /*
                 * No locking required for CPU-local interrupts:
                 */
-               if (desc->chip->ack)
+               if (desc->chip->ack) {
                        desc->chip->ack(irq);
-               action_ret = handle_IRQ_event(irq, regs, desc->action);
+                       /* get new one */
+                       desc = irq_remap_to_desc(irq, desc);
+               }
+               if (likely(!(desc->status & IRQ_DISABLED))) {
+                       action_ret = handle_IRQ_event(irq, desc->action);
+                       if (!noirqdebug)
+                               note_interrupt(irq, desc, action_ret);
+               }
                desc->chip->end(irq);
                return 1;
        }
 
        spin_lock(&desc->lock);
-       if (desc->chip->ack)
+       if (desc->chip->ack) {
                desc->chip->ack(irq);
+               desc = irq_remap_to_desc(irq, desc);
+       }
        /*
         * REPLAY is when Linux resends an IRQ that was dropped earlier
         * WAITING is used by probe to mark irqs that are being tested
@@ -186,11 +434,11 @@ fastcall unsigned int __do_IRQ(unsigned int irq, struct pt_regs *regs)
 
                spin_unlock(&desc->lock);
 
-               action_ret = handle_IRQ_event(irq, regs, action);
+               action_ret = handle_IRQ_event(irq, action);
+               if (!noirqdebug)
+                       note_interrupt(irq, desc, action_ret);
 
                spin_lock(&desc->lock);
-               if (!noirqdebug)
-                       note_interrupt(irq, desc, action_ret, regs);
                if (likely(!(desc->status & IRQ_PENDING)))
                        break;
                desc->status &= ~IRQ_PENDING;
@@ -207,4 +455,24 @@ out:
 
        return 1;
 }
+#endif
+
+void early_init_irq_lock_class(void)
+{
+       struct irq_desc *desc;
+       int i;
+
+       for_each_irq_desc(i, desc) {
+               lockdep_set_class(&desc->lock, &irq_desc_lock_class);
+       }
+}
+
+#ifdef CONFIG_SPARSE_IRQ
+unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
+{
+       struct irq_desc *desc = irq_to_desc(irq);
+       return desc ? desc->kstat_irqs[cpu] : 0;
+}
+#endif
+EXPORT_SYMBOL(kstat_irqs_cpu);