x86, sparseirq: move irq_desc according to smp_affinity, v7
[linux-2.6.git] / kernel / irq / numa_migrate.c
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