Change the kernel config for scenario test
[kvmfornfv.git] / kernel / 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/gfp.h>
11 #include <linux/proc_fs.h>
12 #include <linux/seq_file.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel_stat.h>
15 #include <linux/mutex.h>
16
17 #include "internals.h"
18
19 /*
20  * Access rules:
21  *
22  * procfs protects read/write of /proc/irq/N/ files against a
23  * concurrent free of the interrupt descriptor. remove_proc_entry()
24  * immediately prevents new read/writes to happen and waits for
25  * already running read/write functions to complete.
26  *
27  * We remove the proc entries first and then delete the interrupt
28  * descriptor from the radix tree and free it. So it is guaranteed
29  * that irq_to_desc(N) is valid as long as the read/writes are
30  * permitted by procfs.
31  *
32  * The read from /proc/interrupts is a different problem because there
33  * is no protection. So the lookup and the access to irqdesc
34  * information must be protected by sparse_irq_lock.
35  */
36 static struct proc_dir_entry *root_irq_dir;
37
38 #ifdef CONFIG_SMP
39
40 static int show_irq_affinity(int type, struct seq_file *m, void *v)
41 {
42         struct irq_desc *desc = irq_to_desc((long)m->private);
43         const struct cpumask *mask = desc->irq_common_data.affinity;
44
45 #ifdef CONFIG_GENERIC_PENDING_IRQ
46         if (irqd_is_setaffinity_pending(&desc->irq_data))
47                 mask = desc->pending_mask;
48 #endif
49         if (type)
50                 seq_printf(m, "%*pbl\n", cpumask_pr_args(mask));
51         else
52                 seq_printf(m, "%*pb\n", cpumask_pr_args(mask));
53         return 0;
54 }
55
56 static int irq_affinity_hint_proc_show(struct seq_file *m, void *v)
57 {
58         struct irq_desc *desc = irq_to_desc((long)m->private);
59         unsigned long flags;
60         cpumask_var_t mask;
61
62         if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
63                 return -ENOMEM;
64
65         raw_spin_lock_irqsave(&desc->lock, flags);
66         if (desc->affinity_hint)
67                 cpumask_copy(mask, desc->affinity_hint);
68         raw_spin_unlock_irqrestore(&desc->lock, flags);
69
70         seq_printf(m, "%*pb\n", cpumask_pr_args(mask));
71         free_cpumask_var(mask);
72
73         return 0;
74 }
75
76 #ifndef is_affinity_mask_valid
77 #define is_affinity_mask_valid(val) 1
78 #endif
79
80 int no_irq_affinity;
81 static int irq_affinity_proc_show(struct seq_file *m, void *v)
82 {
83         return show_irq_affinity(0, m, v);
84 }
85
86 static int irq_affinity_list_proc_show(struct seq_file *m, void *v)
87 {
88         return show_irq_affinity(1, m, v);
89 }
90
91
92 static ssize_t write_irq_affinity(int type, struct file *file,
93                 const char __user *buffer, size_t count, loff_t *pos)
94 {
95         unsigned int irq = (int)(long)PDE_DATA(file_inode(file));
96         cpumask_var_t new_value;
97         int err;
98
99         if (!irq_can_set_affinity(irq) || no_irq_affinity)
100                 return -EIO;
101
102         if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
103                 return -ENOMEM;
104
105         if (type)
106                 err = cpumask_parselist_user(buffer, count, new_value);
107         else
108                 err = cpumask_parse_user(buffer, count, new_value);
109         if (err)
110                 goto free_cpumask;
111
112         if (!is_affinity_mask_valid(new_value)) {
113                 err = -EINVAL;
114                 goto free_cpumask;
115         }
116
117         /*
118          * Do not allow disabling IRQs completely - it's a too easy
119          * way to make the system unusable accidentally :-) At least
120          * one online CPU still has to be targeted.
121          */
122         if (!cpumask_intersects(new_value, cpu_online_mask)) {
123                 /* Special case for empty set - allow the architecture
124                    code to set default SMP affinity. */
125                 err = irq_select_affinity_usr(irq, new_value) ? -EINVAL : count;
126         } else {
127                 irq_set_affinity(irq, new_value);
128                 err = count;
129         }
130
131 free_cpumask:
132         free_cpumask_var(new_value);
133         return err;
134 }
135
136 static ssize_t irq_affinity_proc_write(struct file *file,
137                 const char __user *buffer, size_t count, loff_t *pos)
138 {
139         return write_irq_affinity(0, file, buffer, count, pos);
140 }
141
142 static ssize_t irq_affinity_list_proc_write(struct file *file,
143                 const char __user *buffer, size_t count, loff_t *pos)
144 {
145         return write_irq_affinity(1, file, buffer, count, pos);
146 }
147
148 static int irq_affinity_proc_open(struct inode *inode, struct file *file)
149 {
150         return single_open(file, irq_affinity_proc_show, PDE_DATA(inode));
151 }
152
153 static int irq_affinity_list_proc_open(struct inode *inode, struct file *file)
154 {
155         return single_open(file, irq_affinity_list_proc_show, PDE_DATA(inode));
156 }
157
158 static int irq_affinity_hint_proc_open(struct inode *inode, struct file *file)
159 {
160         return single_open(file, irq_affinity_hint_proc_show, PDE_DATA(inode));
161 }
162
163 static const struct file_operations irq_affinity_proc_fops = {
164         .open           = irq_affinity_proc_open,
165         .read           = seq_read,
166         .llseek         = seq_lseek,
167         .release        = single_release,
168         .write          = irq_affinity_proc_write,
169 };
170
171 static const struct file_operations irq_affinity_hint_proc_fops = {
172         .open           = irq_affinity_hint_proc_open,
173         .read           = seq_read,
174         .llseek         = seq_lseek,
175         .release        = single_release,
176 };
177
178 static const struct file_operations irq_affinity_list_proc_fops = {
179         .open           = irq_affinity_list_proc_open,
180         .read           = seq_read,
181         .llseek         = seq_lseek,
182         .release        = single_release,
183         .write          = irq_affinity_list_proc_write,
184 };
185
186 static int default_affinity_show(struct seq_file *m, void *v)
187 {
188         seq_printf(m, "%*pb\n", cpumask_pr_args(irq_default_affinity));
189         return 0;
190 }
191
192 static ssize_t default_affinity_write(struct file *file,
193                 const char __user *buffer, size_t count, loff_t *ppos)
194 {
195         cpumask_var_t new_value;
196         int err;
197
198         if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
199                 return -ENOMEM;
200
201         err = cpumask_parse_user(buffer, count, new_value);
202         if (err)
203                 goto out;
204
205         if (!is_affinity_mask_valid(new_value)) {
206                 err = -EINVAL;
207                 goto out;
208         }
209
210         /*
211          * Do not allow disabling IRQs completely - it's a too easy
212          * way to make the system unusable accidentally :-) At least
213          * one online CPU still has to be targeted.
214          */
215         if (!cpumask_intersects(new_value, cpu_online_mask)) {
216                 err = -EINVAL;
217                 goto out;
218         }
219
220         cpumask_copy(irq_default_affinity, new_value);
221         err = count;
222
223 out:
224         free_cpumask_var(new_value);
225         return err;
226 }
227
228 static int default_affinity_open(struct inode *inode, struct file *file)
229 {
230         return single_open(file, default_affinity_show, PDE_DATA(inode));
231 }
232
233 static const struct file_operations default_affinity_proc_fops = {
234         .open           = default_affinity_open,
235         .read           = seq_read,
236         .llseek         = seq_lseek,
237         .release        = single_release,
238         .write          = default_affinity_write,
239 };
240
241 static int irq_node_proc_show(struct seq_file *m, void *v)
242 {
243         struct irq_desc *desc = irq_to_desc((long) m->private);
244
245         seq_printf(m, "%d\n", irq_desc_get_node(desc));
246         return 0;
247 }
248
249 static int irq_node_proc_open(struct inode *inode, struct file *file)
250 {
251         return single_open(file, irq_node_proc_show, PDE_DATA(inode));
252 }
253
254 static const struct file_operations irq_node_proc_fops = {
255         .open           = irq_node_proc_open,
256         .read           = seq_read,
257         .llseek         = seq_lseek,
258         .release        = single_release,
259 };
260 #endif
261
262 static int irq_spurious_proc_show(struct seq_file *m, void *v)
263 {
264         struct irq_desc *desc = irq_to_desc((long) m->private);
265
266         seq_printf(m, "count %u\n" "unhandled %u\n" "last_unhandled %u ms\n",
267                    desc->irq_count, desc->irqs_unhandled,
268                    jiffies_to_msecs(desc->last_unhandled));
269         return 0;
270 }
271
272 static int irq_spurious_proc_open(struct inode *inode, struct file *file)
273 {
274         return single_open(file, irq_spurious_proc_show, PDE_DATA(inode));
275 }
276
277 static const struct file_operations irq_spurious_proc_fops = {
278         .open           = irq_spurious_proc_open,
279         .read           = seq_read,
280         .llseek         = seq_lseek,
281         .release        = single_release,
282 };
283
284 #define MAX_NAMELEN 128
285
286 static int name_unique(unsigned int irq, struct irqaction *new_action)
287 {
288         struct irq_desc *desc = irq_to_desc(irq);
289         struct irqaction *action;
290         unsigned long flags;
291         int ret = 1;
292
293         raw_spin_lock_irqsave(&desc->lock, flags);
294         for (action = desc->action ; action; action = action->next) {
295                 if ((action != new_action) && action->name &&
296                                 !strcmp(new_action->name, action->name)) {
297                         ret = 0;
298                         break;
299                 }
300         }
301         raw_spin_unlock_irqrestore(&desc->lock, flags);
302         return ret;
303 }
304
305 void register_handler_proc(unsigned int irq, struct irqaction *action)
306 {
307         char name [MAX_NAMELEN];
308         struct irq_desc *desc = irq_to_desc(irq);
309
310         if (!desc->dir || action->dir || !action->name ||
311                                         !name_unique(irq, action))
312                 return;
313
314         memset(name, 0, MAX_NAMELEN);
315         snprintf(name, MAX_NAMELEN, "%s", action->name);
316
317         /* create /proc/irq/1234/handler/ */
318         action->dir = proc_mkdir(name, desc->dir);
319 }
320
321 #undef MAX_NAMELEN
322
323 #define MAX_NAMELEN 10
324
325 void register_irq_proc(unsigned int irq, struct irq_desc *desc)
326 {
327         static DEFINE_MUTEX(register_lock);
328         char name [MAX_NAMELEN];
329
330         if (!root_irq_dir || (desc->irq_data.chip == &no_irq_chip))
331                 return;
332
333         /*
334          * irq directories are registered only when a handler is
335          * added, not when the descriptor is created, so multiple
336          * tasks might try to register at the same time.
337          */
338         mutex_lock(&register_lock);
339
340         if (desc->dir)
341                 goto out_unlock;
342
343         memset(name, 0, MAX_NAMELEN);
344         sprintf(name, "%d", irq);
345
346         /* create /proc/irq/1234 */
347         desc->dir = proc_mkdir(name, root_irq_dir);
348         if (!desc->dir)
349                 goto out_unlock;
350
351 #ifdef CONFIG_SMP
352         /* create /proc/irq/<irq>/smp_affinity */
353         proc_create_data("smp_affinity", 0644, desc->dir,
354                          &irq_affinity_proc_fops, (void *)(long)irq);
355
356         /* create /proc/irq/<irq>/affinity_hint */
357         proc_create_data("affinity_hint", 0444, desc->dir,
358                          &irq_affinity_hint_proc_fops, (void *)(long)irq);
359
360         /* create /proc/irq/<irq>/smp_affinity_list */
361         proc_create_data("smp_affinity_list", 0644, desc->dir,
362                          &irq_affinity_list_proc_fops, (void *)(long)irq);
363
364         proc_create_data("node", 0444, desc->dir,
365                          &irq_node_proc_fops, (void *)(long)irq);
366 #endif
367
368         proc_create_data("spurious", 0444, desc->dir,
369                          &irq_spurious_proc_fops, (void *)(long)irq);
370
371 out_unlock:
372         mutex_unlock(&register_lock);
373 }
374
375 void unregister_irq_proc(unsigned int irq, struct irq_desc *desc)
376 {
377         char name [MAX_NAMELEN];
378
379         if (!root_irq_dir || !desc->dir)
380                 return;
381 #ifdef CONFIG_SMP
382         remove_proc_entry("smp_affinity", desc->dir);
383         remove_proc_entry("affinity_hint", desc->dir);
384         remove_proc_entry("smp_affinity_list", desc->dir);
385         remove_proc_entry("node", desc->dir);
386 #endif
387         remove_proc_entry("spurious", desc->dir);
388
389         memset(name, 0, MAX_NAMELEN);
390         sprintf(name, "%u", irq);
391         remove_proc_entry(name, root_irq_dir);
392 }
393
394 #undef MAX_NAMELEN
395
396 void unregister_handler_proc(unsigned int irq, struct irqaction *action)
397 {
398         proc_remove(action->dir);
399 }
400
401 static void register_default_affinity_proc(void)
402 {
403 #ifdef CONFIG_SMP
404         proc_create("irq/default_smp_affinity", 0644, NULL,
405                     &default_affinity_proc_fops);
406 #endif
407 }
408
409 void init_irq_proc(void)
410 {
411         unsigned int irq;
412         struct irq_desc *desc;
413
414         /* create /proc/irq */
415         root_irq_dir = proc_mkdir("irq", NULL);
416         if (!root_irq_dir)
417                 return;
418
419         register_default_affinity_proc();
420
421         /*
422          * Create entries for all existing IRQs.
423          */
424         for_each_irq_desc(irq, desc) {
425                 if (!desc)
426                         continue;
427
428                 register_irq_proc(irq, desc);
429         }
430 }
431
432 #ifdef CONFIG_GENERIC_IRQ_SHOW
433
434 int __weak arch_show_interrupts(struct seq_file *p, int prec)
435 {
436         return 0;
437 }
438
439 #ifndef ACTUAL_NR_IRQS
440 # define ACTUAL_NR_IRQS nr_irqs
441 #endif
442
443 int show_interrupts(struct seq_file *p, void *v)
444 {
445         static int prec;
446
447         unsigned long flags, any_count = 0;
448         int i = *(loff_t *) v, j;
449         struct irqaction *action;
450         struct irq_desc *desc;
451
452         if (i > ACTUAL_NR_IRQS)
453                 return 0;
454
455         if (i == ACTUAL_NR_IRQS)
456                 return arch_show_interrupts(p, prec);
457
458         /* print header and calculate the width of the first column */
459         if (i == 0) {
460                 for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
461                         j *= 10;
462
463                 seq_printf(p, "%*s", prec + 8, "");
464                 for_each_online_cpu(j)
465                         seq_printf(p, "CPU%-8d", j);
466                 seq_putc(p, '\n');
467         }
468
469         irq_lock_sparse();
470         desc = irq_to_desc(i);
471         if (!desc)
472                 goto outsparse;
473
474         raw_spin_lock_irqsave(&desc->lock, flags);
475         for_each_online_cpu(j)
476                 any_count |= kstat_irqs_cpu(i, j);
477         action = desc->action;
478         if ((!action || irq_desc_is_chained(desc)) && !any_count)
479                 goto out;
480
481         seq_printf(p, "%*d: ", prec, i);
482         for_each_online_cpu(j)
483                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
484
485         if (desc->irq_data.chip) {
486                 if (desc->irq_data.chip->irq_print_chip)
487                         desc->irq_data.chip->irq_print_chip(&desc->irq_data, p);
488                 else if (desc->irq_data.chip->name)
489                         seq_printf(p, " %8s", desc->irq_data.chip->name);
490                 else
491                         seq_printf(p, " %8s", "-");
492         } else {
493                 seq_printf(p, " %8s", "None");
494         }
495         if (desc->irq_data.domain)
496                 seq_printf(p, " %*d", prec, (int) desc->irq_data.hwirq);
497 #ifdef CONFIG_GENERIC_IRQ_SHOW_LEVEL
498         seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge");
499 #endif
500         if (desc->name)
501                 seq_printf(p, "-%-8s", desc->name);
502
503         if (action) {
504                 seq_printf(p, "  %s", action->name);
505                 while ((action = action->next) != NULL)
506                         seq_printf(p, ", %s", action->name);
507         }
508
509         seq_putc(p, '\n');
510 out:
511         raw_spin_unlock_irqrestore(&desc->lock, flags);
512 outsparse:
513         irq_unlock_sparse();
514         return 0;
515 }
516 #endif