x86_64: Report the pending irq if available in smp_affinity
[linux-2.6.git] / kernel / irq / proc.c
1 /*
2  * linux/kernel/irq/proc.c
3  *
4  * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
5  *
6  * This file contains the /proc/irq/ handling code.
7  */
8
9 #include <linux/irq.h>
10 #include <linux/proc_fs.h>
11 #include <linux/interrupt.h>
12
13 #include "internals.h"
14
15 static struct proc_dir_entry *root_irq_dir;
16
17 #ifdef CONFIG_SMP
18
19 static int irq_affinity_read_proc(char *page, char **start, off_t off,
20                                   int count, int *eof, void *data)
21 {
22         struct irq_desc *desc = irq_desc + (long)data;
23         cpumask_t *mask = &desc->affinity;
24         int len;
25
26 #ifdef CONFIG_GENERIC_PENDING_IRQ
27         if (desc->status & IRQ_MOVE_PENDING)
28                 mask = &desc->pending_mask;
29 #endif
30         len = cpumask_scnprintf(page, count, *mask);
31
32         if (count - len < 2)
33                 return -EINVAL;
34         len += sprintf(page + len, "\n");
35         return len;
36 }
37
38 #ifndef is_affinity_mask_valid
39 #define is_affinity_mask_valid(val) 1
40 #endif
41
42 int no_irq_affinity;
43 static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
44                                    unsigned long count, void *data)
45 {
46         unsigned int irq = (int)(long)data, full_count = count, err;
47         cpumask_t new_value, tmp;
48
49         if (!irq_desc[irq].chip->set_affinity || no_irq_affinity ||
50             irq_balancing_disabled(irq))
51                 return -EIO;
52
53         err = cpumask_parse_user(buffer, count, new_value);
54         if (err)
55                 return err;
56
57         if (!is_affinity_mask_valid(new_value))
58                 return -EINVAL;
59
60         /*
61          * Do not allow disabling IRQs completely - it's a too easy
62          * way to make the system unusable accidentally :-) At least
63          * one online CPU still has to be targeted.
64          */
65         cpus_and(tmp, new_value, cpu_online_map);
66         if (cpus_empty(tmp))
67                 /* Special case for empty set - allow the architecture
68                    code to set default SMP affinity. */
69                 return select_smp_affinity(irq) ? -EINVAL : full_count;
70
71         irq_set_affinity(irq, new_value);
72
73         return full_count;
74 }
75
76 #endif
77
78 #define MAX_NAMELEN 128
79
80 static int name_unique(unsigned int irq, struct irqaction *new_action)
81 {
82         struct irq_desc *desc = irq_desc + irq;
83         struct irqaction *action;
84         unsigned long flags;
85         int ret = 1;
86
87         spin_lock_irqsave(&desc->lock, flags);
88         for (action = desc->action ; action; action = action->next) {
89                 if ((action != new_action) && action->name &&
90                                 !strcmp(new_action->name, action->name)) {
91                         ret = 0;
92                         break;
93                 }
94         }
95         spin_unlock_irqrestore(&desc->lock, flags);
96         return ret;
97 }
98
99 void register_handler_proc(unsigned int irq, struct irqaction *action)
100 {
101         char name [MAX_NAMELEN];
102
103         if (!irq_desc[irq].dir || action->dir || !action->name ||
104                                         !name_unique(irq, action))
105                 return;
106
107         memset(name, 0, MAX_NAMELEN);
108         snprintf(name, MAX_NAMELEN, "%s", action->name);
109
110         /* create /proc/irq/1234/handler/ */
111         action->dir = proc_mkdir(name, irq_desc[irq].dir);
112 }
113
114 #undef MAX_NAMELEN
115
116 #define MAX_NAMELEN 10
117
118 void register_irq_proc(unsigned int irq)
119 {
120         char name [MAX_NAMELEN];
121
122         if (!root_irq_dir ||
123                 (irq_desc[irq].chip == &no_irq_chip) ||
124                         irq_desc[irq].dir)
125                 return;
126
127         memset(name, 0, MAX_NAMELEN);
128         sprintf(name, "%d", irq);
129
130         /* create /proc/irq/1234 */
131         irq_desc[irq].dir = proc_mkdir(name, root_irq_dir);
132
133 #ifdef CONFIG_SMP
134         {
135                 struct proc_dir_entry *entry;
136
137                 /* create /proc/irq/<irq>/smp_affinity */
138                 entry = create_proc_entry("smp_affinity", 0600, irq_desc[irq].dir);
139
140                 if (entry) {
141                         entry->data = (void *)(long)irq;
142                         entry->read_proc = irq_affinity_read_proc;
143                         entry->write_proc = irq_affinity_write_proc;
144                 }
145         }
146 #endif
147 }
148
149 #undef MAX_NAMELEN
150
151 void unregister_handler_proc(unsigned int irq, struct irqaction *action)
152 {
153         if (action->dir)
154                 remove_proc_entry(action->dir->name, irq_desc[irq].dir);
155 }
156
157 void init_irq_proc(void)
158 {
159         int i;
160
161         /* create /proc/irq */
162         root_irq_dir = proc_mkdir("irq", NULL);
163         if (!root_irq_dir)
164                 return;
165
166         /*
167          * Create entries for all existing IRQs.
168          */
169         for (i = 0; i < NR_IRQS; i++)
170                 register_irq_proc(i);
171 }
172