Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[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 node, int nr)
19 {
20         init_kstat_irqs(desc, node, 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 bool init_copy_one_irq_desc(int irq, struct irq_desc *old_desc,
37                  struct irq_desc *desc, int node)
38 {
39         memcpy(desc, old_desc, sizeof(struct irq_desc));
40         if (!alloc_desc_masks(desc, node, false)) {
41                 printk(KERN_ERR "irq %d: can not get new irq_desc cpumask "
42                                 "for migration.\n", irq);
43                 return false;
44         }
45         raw_spin_lock_init(&desc->lock);
46         desc->node = node;
47         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
48         init_copy_kstat_irqs(old_desc, desc, node, nr_cpu_ids);
49         init_copy_desc_masks(old_desc, desc);
50         arch_init_copy_chip_data(old_desc, desc, node);
51         return true;
52 }
53
54 static void free_one_irq_desc(struct irq_desc *old_desc, struct irq_desc *desc)
55 {
56         free_kstat_irqs(old_desc, desc);
57         free_desc_masks(old_desc, desc);
58         arch_free_chip_data(old_desc, desc);
59 }
60
61 static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
62                                                 int node)
63 {
64         struct irq_desc *desc;
65         unsigned int irq;
66         unsigned long flags;
67
68         irq = old_desc->irq;
69
70         raw_spin_lock_irqsave(&sparse_irq_lock, flags);
71
72         /* We have to check it to avoid races with another CPU */
73         desc = irq_to_desc(irq);
74
75         if (desc && old_desc != desc)
76                 goto out_unlock;
77
78         desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
79         if (!desc) {
80                 printk(KERN_ERR "irq %d: can not get new irq_desc "
81                                 "for migration.\n", irq);
82                 /* still use old one */
83                 desc = old_desc;
84                 goto out_unlock;
85         }
86         if (!init_copy_one_irq_desc(irq, old_desc, desc, node)) {
87                 /* still use old one */
88                 kfree(desc);
89                 desc = old_desc;
90                 goto out_unlock;
91         }
92
93         replace_irq_desc(irq, desc);
94         raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
95
96         /* free the old one */
97         free_one_irq_desc(old_desc, desc);
98         kfree(old_desc);
99
100         return desc;
101
102 out_unlock:
103         raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
104
105         return desc;
106 }
107
108 struct irq_desc *move_irq_desc(struct irq_desc *desc, int node)
109 {
110         /* those static or target node is -1, do not move them */
111         if (desc->irq < NR_IRQS_LEGACY || node == -1)
112                 return desc;
113
114         if (desc->node != node)
115                 desc = __real_move_irq_desc(desc, node);
116
117         return desc;
118 }
119