Merge branch 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied...
[linux-2.6] / 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 bool 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         if (!init_alloc_desc_masks(desc, cpu, false)) {
41                 printk(KERN_ERR "irq %d: can not get new irq_desc cpumask "
42                                 "for migration.\n", irq);
43                 return false;
44         }
45         spin_lock_init(&desc->lock);
46         desc->cpu = cpu;
47         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
48         init_copy_kstat_irqs(old_desc, desc, cpu, nr_cpu_ids);
49         init_copy_desc_masks(old_desc, desc);
50         arch_init_copy_chip_data(old_desc, desc, cpu);
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 cpu)
63 {
64         struct irq_desc *desc;
65         unsigned int irq;
66         unsigned long flags;
67         int node;
68
69         irq = old_desc->irq;
70
71         spin_lock_irqsave(&sparse_irq_lock, flags);
72
73         /* We have to check it to avoid races with another CPU */
74         desc = irq_desc_ptrs[irq];
75
76         if (desc && old_desc != desc)
77                 goto out_unlock;
78
79         node = cpu_to_node(cpu);
80         desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
81         if (!desc) {
82                 printk(KERN_ERR "irq %d: can not get new irq_desc "
83                                 "for migration.\n", irq);
84                 /* still use old one */
85                 desc = old_desc;
86                 goto out_unlock;
87         }
88         if (!init_copy_one_irq_desc(irq, old_desc, desc, cpu)) {
89                 /* still use old one */
90                 kfree(desc);
91                 desc = old_desc;
92                 goto out_unlock;
93         }
94
95         irq_desc_ptrs[irq] = desc;
96         spin_unlock_irqrestore(&sparse_irq_lock, flags);
97
98         /* free the old one */
99         free_one_irq_desc(old_desc, desc);
100         spin_unlock(&old_desc->lock);
101         kfree(old_desc);
102         spin_lock(&desc->lock);
103
104         return desc;
105
106 out_unlock:
107         spin_unlock_irqrestore(&sparse_irq_lock, flags);
108
109         return desc;
110 }
111
112 struct irq_desc *move_irq_desc(struct irq_desc *desc, int cpu)
113 {
114         int old_cpu;
115         int node, old_node;
116
117         /* those all static, do move them */
118         if (desc->irq < NR_IRQS_LEGACY)
119                 return desc;
120
121         old_cpu = desc->cpu;
122         if (old_cpu != cpu) {
123                 node = cpu_to_node(cpu);
124                 old_node = cpu_to_node(old_cpu);
125                 if (old_node != node)
126                         desc = __real_move_irq_desc(desc, cpu);
127                 else
128                         desc->cpu = cpu;
129         }
130
131         return desc;
132 }
133