| Yinghai Lu | 48a1b10 | 2008-12-11 00:15:01 -0800 | [diff] [blame^] | 1 | /* |
| 2 | * linux/kernel/irq/handle.c |
| 3 | * |
| 4 | * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar |
| 5 | * Copyright (C) 2005-2006, Thomas Gleixner, Russell King |
| 6 | * |
| 7 | * This file contains the core interrupt handling code. |
| 8 | * |
| 9 | * Detailed information is available in Documentation/DocBook/genericirq |
| 10 | * |
| 11 | */ |
| 12 | |
| 13 | #include <linux/irq.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/random.h> |
| 16 | #include <linux/interrupt.h> |
| 17 | #include <linux/kernel_stat.h> |
| 18 | |
| 19 | #include "internals.h" |
| 20 | |
| 21 | static void init_copy_kstat_irqs(struct irq_desc *old_desc, |
| 22 | struct irq_desc *desc, |
| 23 | int cpu, int nr) |
| 24 | { |
| 25 | unsigned long bytes; |
| 26 | |
| 27 | init_kstat_irqs(desc, cpu, nr); |
| 28 | |
| 29 | if (desc->kstat_irqs != old_desc->kstat_irqs) { |
| 30 | /* Compute how many bytes we need per irq and allocate them */ |
| 31 | bytes = nr * sizeof(unsigned int); |
| 32 | |
| 33 | memcpy(desc->kstat_irqs, old_desc->kstat_irqs, bytes); |
| 34 | } |
| 35 | } |
| 36 | |
| 37 | static void free_kstat_irqs(struct irq_desc *old_desc, struct irq_desc *desc) |
| 38 | { |
| 39 | if (old_desc->kstat_irqs == desc->kstat_irqs) |
| 40 | return; |
| 41 | |
| 42 | kfree(old_desc->kstat_irqs); |
| 43 | old_desc->kstat_irqs = NULL; |
| 44 | } |
| 45 | |
| 46 | static void init_copy_one_irq_desc(int irq, struct irq_desc *old_desc, |
| 47 | struct irq_desc *desc, int cpu) |
| 48 | { |
| 49 | memcpy(desc, old_desc, sizeof(struct irq_desc)); |
| 50 | desc->cpu = cpu; |
| 51 | lockdep_set_class(&desc->lock, &irq_desc_lock_class); |
| 52 | init_copy_kstat_irqs(old_desc, desc, cpu, nr_cpu_ids); |
| 53 | arch_init_copy_chip_data(old_desc, desc, cpu); |
| 54 | } |
| 55 | |
| 56 | static void free_one_irq_desc(struct irq_desc *old_desc, struct irq_desc *desc) |
| 57 | { |
| 58 | free_kstat_irqs(old_desc, desc); |
| 59 | arch_free_chip_data(old_desc, desc); |
| 60 | } |
| 61 | |
| 62 | static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc, |
| 63 | int cpu) |
| 64 | { |
| 65 | struct irq_desc *desc; |
| 66 | unsigned int irq; |
| 67 | unsigned long flags; |
| 68 | int node; |
| 69 | |
| 70 | irq = old_desc->irq; |
| 71 | |
| 72 | spin_lock_irqsave(&sparse_irq_lock, flags); |
| 73 | |
| 74 | /* We have to check it to avoid races with another CPU */ |
| 75 | desc = irq_desc_ptrs[irq]; |
| 76 | |
| 77 | if (desc && old_desc != desc) |
| 78 | goto out_unlock; |
| 79 | |
| 80 | node = cpu_to_node(cpu); |
| 81 | desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node); |
| 82 | printk(KERN_DEBUG " move irq_desc for %d to cpu %d node %d\n", |
| 83 | irq, cpu, node); |
| 84 | if (!desc) { |
| 85 | printk(KERN_ERR "can not get new irq_desc for moving\n"); |
| 86 | /* still use old one */ |
| 87 | desc = old_desc; |
| 88 | goto out_unlock; |
| 89 | } |
| 90 | init_copy_one_irq_desc(irq, old_desc, desc, cpu); |
| 91 | |
| 92 | irq_desc_ptrs[irq] = desc; |
| 93 | |
| 94 | /* free the old one */ |
| 95 | free_one_irq_desc(old_desc, desc); |
| 96 | kfree(old_desc); |
| 97 | |
| 98 | out_unlock: |
| 99 | spin_unlock_irqrestore(&sparse_irq_lock, flags); |
| 100 | |
| 101 | return desc; |
| 102 | } |
| 103 | |
| 104 | struct irq_desc *move_irq_desc(struct irq_desc *desc, int cpu) |
| 105 | { |
| 106 | int old_cpu; |
| 107 | int node, old_node; |
| 108 | |
| 109 | /* those all static, do move them */ |
| 110 | if (desc->irq < NR_IRQS_LEGACY) |
| 111 | return desc; |
| 112 | |
| 113 | old_cpu = desc->cpu; |
| 114 | printk(KERN_DEBUG |
| 115 | "try to move irq_desc from cpu %d to %d\n", old_cpu, cpu); |
| 116 | if (old_cpu != cpu) { |
| 117 | node = cpu_to_node(cpu); |
| 118 | old_node = cpu_to_node(old_cpu); |
| 119 | if (old_node != node) |
| 120 | desc = __real_move_irq_desc(desc, cpu); |
| 121 | else |
| 122 | desc->cpu = cpu; |
| 123 | } |
| 124 | |
| 125 | return desc; |
| 126 | } |
| 127 | |