Merge branches 'irq/genirq', 'irq/sparseirq' and 'irq/urgent' into irq/core
[linux-2.6.git] / kernel / irq / numa_migrate.c
1 /*
2  * NUMA irq-desc migration code
3  *
4  * Migrate IRQ data structures (irq_desc, chip_data, etc.) over to
5  * the new "home node" of the IRQ.
6  */
7
8 #include <linux/irq.h>
9 #include <linux/module.h>
10 #include <linux/random.h>
11 #include <linux/interrupt.h>
12 #include <linux/kernel_stat.h>
13
14 #include "internals.h"
15
16 static void init_copy_kstat_irqs(struct irq_desc *old_desc,
17                                  struct irq_desc *desc,
18                                  int cpu, int nr)
19 {
20         init_kstat_irqs(desc, cpu, nr);
21
22         if (desc->kstat_irqs != old_desc->kstat_irqs)
23                 memcpy(desc->kstat_irqs, old_desc->kstat_irqs,
24                          nr * sizeof(*desc->kstat_irqs));
25 }
26
27 static void free_kstat_irqs(struct irq_desc *old_desc, struct irq_desc *desc)
28 {
29         if (old_desc->kstat_irqs == desc->kstat_irqs)
30                 return;
31
32         kfree(old_desc->kstat_irqs);
33         old_desc->kstat_irqs = NULL;
34 }
35
36 static void init_copy_one_irq_desc(int irq, struct irq_desc *old_desc,
37                  struct irq_desc *desc, int cpu)
38 {
39         memcpy(desc, old_desc, sizeof(struct irq_desc));
40         spin_lock_init(&desc->lock);
41         desc->cpu = cpu;
42         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
43         init_copy_kstat_irqs(old_desc, desc, cpu, nr_cpu_ids);
44         arch_init_copy_chip_data(old_desc, desc, cpu);
45 }
46
47 static void free_one_irq_desc(struct irq_desc *old_desc, struct irq_desc *desc)
48 {
49         free_kstat_irqs(old_desc, desc);
50         arch_free_chip_data(old_desc, desc);
51 }
52
53 static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
54                                                 int cpu)
55 {
56         struct irq_desc *desc;
57         unsigned int irq;
58         unsigned long flags;
59         int node;
60
61         irq = old_desc->irq;
62
63         spin_lock_irqsave(&sparse_irq_lock, flags);
64
65         /* We have to check it to avoid races with another CPU */
66         desc = irq_desc_ptrs[irq];
67
68         if (desc && old_desc != desc)
69                 goto out_unlock;
70
71         node = cpu_to_node(cpu);
72         desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
73         if (!desc) {
74                 printk(KERN_ERR "irq %d: can not get new irq_desc for migration.\n", irq);
75                 /* still use old one */
76                 desc = old_desc;
77                 goto out_unlock;
78         }
79         init_copy_one_irq_desc(irq, old_desc, desc, cpu);
80
81         irq_desc_ptrs[irq] = desc;
82         spin_unlock_irqrestore(&sparse_irq_lock, flags);
83
84         /* free the old one */
85         free_one_irq_desc(old_desc, desc);
86         spin_unlock(&old_desc->lock);
87         kfree(old_desc);
88         spin_lock(&desc->lock);
89
90         return desc;
91
92 out_unlock:
93         spin_unlock_irqrestore(&sparse_irq_lock, flags);
94
95         return desc;
96 }
97
98 struct irq_desc *move_irq_desc(struct irq_desc *desc, int cpu)
99 {
100         int old_cpu;
101         int node, old_node;
102
103         /* those all static, do move them */
104         if (desc->irq < NR_IRQS_LEGACY)
105                 return desc;
106
107         old_cpu = desc->cpu;
108         if (old_cpu != cpu) {
109                 node = cpu_to_node(cpu);
110                 old_node = cpu_to_node(old_cpu);
111                 if (old_node != node)
112                         desc = __real_move_irq_desc(desc, cpu);
113                 else
114                         desc->cpu = cpu;
115         }
116
117         return desc;
118 }
119