summaryrefslogtreecommitdiffstats
path: root/kernel/irq/proc.c
blob: 0e97c142ce402b0492c876b909c40ac10d40c779 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
/*
 * linux/kernel/irq/proc.c
 *
 * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
 *
 * This file contains the /proc/irq/ handling code.
 */

#include <linux/irq.h>
#include <linux/gfp.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>

#include "internals.h"

/*
 * Access rules:
 *
 * procfs protects read/write of /proc/irq/N/ files against a
 * concurrent free of the interrupt descriptor. remove_proc_entry()
 * immediately prevents new read/writes to happen and waits for
 * already running read/write functions to complete.
 *
 * We remove the proc entries first and then delete the interrupt
 * descriptor from the radix tree and free it. So it is guaranteed
 * that irq_to_desc(N) is valid as long as the read/writes are
 * permitted by procfs.
 *
 * The read from /proc/interrupts is a different problem because there
 * is no protection. So the lookup and the access to irqdesc
 * information must be protected by sparse_irq_lock.
 */
static struct proc_dir_entry *root_irq_dir;

#ifdef CONFIG_SMP

static int show_irq_affinity(int type, struct seq_file *m, void *v)
{
	struct irq_desc *desc = irq_to_desc((long)m->private);
	const struct cpumask *mask = desc->irq_data.affinity;

#ifdef CONFIG_GENERIC_PENDING_IRQ
	if (irqd_is_setaffinity_pending(&desc->irq_data))
		mask = desc->pending_mask;
#endif
	if (type)
		seq_printf(m, "%*pbl\n", cpumask_pr_args(mask));
	else
		seq_printf(m, "%*pb\n", cpumask_pr_args(mask));
	return 0;
}

static int irq_affinity_hint_proc_show(struct seq_file *m, void *v)
{
	struct irq_desc *desc = irq_to_desc((long)m->private);
	unsigned long flags;
	cpumask_var_t mask;

	if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
		return -ENOMEM;

	raw_spin_lock_irqsave(&desc->lock, flags);
	if (desc->affinity_hint)
		cpumask_copy(mask, desc->affinity_hint);
	raw_spin_unlock_irqrestore(&desc->lock, flags);

	seq_printf(m, "%*pb\n", cpumask_pr_args(mask));
	free_cpumask_var(mask);

	return 0;
}

#ifndef is_affinity_mask_valid
#define is_affinity_mask_valid(val) 1
#endif

int no_irq_affinity;
static int irq_affinity_proc_show(struct seq_file *m, void *v)
{
	return show_irq_affinity(0, m, v);
}

static int irq_affinity_list_proc_show(struct seq_file *m, void *v)
{
	return show_irq_affinity(1, m, v);
}


static ssize_t write_irq_affinity(int type, struct file *file,
		const char __user *buffer, size_t count, loff_t *pos)
{
	unsigned int irq = (int)(long)PDE_DATA(file_inode(file));
	cpumask_var_t new_value;
	int err;

	if (!irq_can_set_affinity(irq) || no_irq_affinity)
		return -EIO;

	if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
		return -ENOMEM;

	if (type)
		err = cpumask_parselist_user(buffer, count, new_value);
	else
		err = cpumask_parse_user(buffer, count, new_value);
	if (err)
		goto free_cpumask;

	if (!is_affinity_mask_valid(new_value)) {
		err = -EINVAL;
		goto free_cpumask;
	}

	/*
	 * Do not allow disabling IRQs completely - it's a too easy
	 * way to make the system unusable accidentally :-) At least
	 * one online CPU still has to be targeted.
	 */
	if (!cpumask_intersects(new_value, cpu_online_mask)) {
		/* Special case for empty set - allow the architecture
		   code to set default SMP affinity. */
		err = irq_select_affinity_usr(irq, new_value) ? -EINVAL : count;
	} else {
		irq_set_affinity(irq, new_value);
		err = count;
	}

free_cpumask:
	free_cpumask_var(new_value);
	return err;
}

static ssize_t irq_affinity_proc_write(struct file *file,
		const char __user *buffer, size_t count, loff_t *pos)
{
	return write_irq_affinity(0, file, buffer, count, pos);
}

static ssize_t irq_affinity_list_proc_write(struct file *file,
		const char __user *buffer, size_t count, loff_t *pos)
{
	return write_irq_affinity(1, file, buffer, count, pos);
}

static int irq_affinity_proc_open(struct inode *inode, struct file *file)
{
	return single_open(file, irq_affinity_proc_show, PDE_DATA(inode));
}

static int irq_affinity_list_proc_open(struct inode *inode, struct file *file)
{
	return single_open(file, irq_affinity_list_proc_show, PDE_DATA(inode));
}

static int irq_affinity_hint_proc_open(struct inode *inode, struct file *file)
{
	return single_open(file, irq_affinity_hint_proc_show, PDE_DATA(inode));
}

static const struct file_operations irq_affinity_proc_fops = {
	.open		= irq_affinity_proc_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
	.write		= irq_affinity_proc_write,
};

static const struct file_operations irq_affinity_hint_proc_fops = {
	.open		= irq_affinity_hint_proc_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static const struct file_operations irq_affinity_list_proc_fops = {
	.open		= irq_affinity_list_proc_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
	.write		= irq_affinity_list_proc_write,
};

static int default_affinity_show(struct seq_file *m, void *v)
{
	seq_printf(m, "%*pb\n", cpumask_pr_args(irq_default_affinity));
	return 0;
}

static ssize_t default_affinity_write(struct file *file,
		const char __user *buffer, size_t count, loff_t *ppos)
{
	cpumask_var_t new_value;
	int err;

	if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
		return -ENOMEM;

	err = cpumask_parse_user(buffer, count, new_value);
	if (err)
		goto out;

	if (!is_affinity_mask_valid(new_value)) {
		err = -EINVAL;
		goto out;
	}

	/*
	 * Do not allow disabling IRQs completely - it's a too easy
	 * way to make the system unusable accidentally :-) At least
	 * one online CPU still has to be targeted.
	 */
	if (!cpumask_intersects(new_value, cpu_online_mask)) {
		err = -EINVAL;
		goto out;
	}

	cpumask_copy(irq_default_affinity, new_value);
	err = count;

out:
	free_cpumask_var(new_value);
	return err;
}

static int default_affinity_open(struct inode *inode, struct file *file)
{
	return single_open(file, default_affinity_show, PDE_DATA(inode));
}

static const struct file_operations default_affinity_proc_fops = {
	.open		= default_affinity_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
	.write		= default_affinity_write,
};

static int irq_node_proc_show(struct seq_file *m, void *v)
{
	struct irq_desc *desc = irq_to_desc((long) m->private);

	seq_printf(m, "%d\n", irq_desc_get_node(desc));
	return 0;
}

static int irq_node_proc_open(struct inode *inode, struct file *file)
{
	return single_open(file, irq_node_proc_show, PDE_DATA(inode));
}

static const struct file_operations irq_node_proc_fops = {
	.open		= irq_node_proc_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};
#endif

static int irq_spurious_proc_show(struct seq_file *m, void *v)
{
	struct irq_desc *desc = irq_to_desc((long) m->private);

	seq_printf(m, "count %u\n" "unhandled %u\n" "last_unhandled %u ms\n",
		   desc->irq_count, desc->irqs_unhandled,
		   jiffies_to_msecs(desc->last_unhandled));
	return 0;
}

static int irq_spurious_proc_open(struct inode *inode, struct file *file)
{
	return single_open(file, irq_spurious_proc_show, PDE_DATA(inode));
}

static const struct file_operations irq_spurious_proc_fops = {
	.open		= irq_spurious_proc_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

#define MAX_NAMELEN 128

static int name_unique(unsigned int irq, struct irqaction *new_action)
{
	struct irq_desc *desc = irq_to_desc(irq);
	struct irqaction *action;
	unsigned long flags;
	int ret = 1;

	raw_spin_lock_irqsave(&desc->lock, flags);
	for (action = desc->action ; action; action = action->next) {
		if ((action != new_action) && action->name &&
				!strcmp(new_action->name, action->name)) {
			ret = 0;
			break;
		}
	}
	raw_spin_unlock_irqrestore(&desc->lock, flags);
	return ret;
}

void register_handler_proc(unsigned int irq, struct irqaction *action)
{
	char name [MAX_NAMELEN];
	struct irq_desc *desc = irq_to_desc(irq);

	if (!desc->dir || action->dir || !action->name ||
					!name_unique(irq, action))
		return;

	memset(name, 0, MAX_NAMELEN);
	snprintf(name, MAX_NAMELEN, "%s", action->name);

	/* create /proc/irq/1234/handler/ */
	action->dir = proc_mkdir(name, desc->dir);
}

#undef MAX_NAMELEN

#define MAX_NAMELEN 10

void register_irq_proc(unsigned int irq, struct irq_desc *desc)
{
	char name [MAX_NAMELEN];

	if (!root_irq_dir || (desc->irq_data.chip == &no_irq_chip) || desc->dir)
		return;

	memset(name, 0, MAX_NAMELEN);
	sprintf(name, "%d", irq);

	/* create /proc/irq/1234 */
	desc->dir = proc_mkdir(name, root_irq_dir);
	if (!desc->dir)
		return;

#ifdef CONFIG_SMP
	/* create /proc/irq/<irq>/smp_affinity */
	proc_create_data("smp_affinity", 0644, desc->dir,
			 &irq_affinity_proc_fops, (void *)(long)irq);

	/* create /proc/irq/<irq>/affinity_hint */
	proc_create_data("affinity_hint", 0444, desc->dir,
			 &irq_affinity_hint_proc_fops, (void *)(long)irq);

	/* create /proc/irq/<irq>/smp_affinity_list */
	proc_create_data("smp_affinity_list", 0644, desc->dir,
			 &irq_affinity_list_proc_fops, (void *)(long)irq);

	proc_create_data("node", 0444, desc->dir,
			 &irq_node_proc_fops, (void *)(long)irq);
#endif

	proc_create_data("spurious", 0444, desc->dir,
			 &irq_spurious_proc_fops, (void *)(long)irq);
}

void unregister_irq_proc(unsigned int irq, struct irq_desc *desc)
{
	char name [MAX_NAMELEN];

	if (!root_irq_dir || !desc->dir)
		return;
#ifdef CONFIG_SMP
	remove_proc_entry("smp_affinity", desc->dir);
	remove_proc_entry("affinity_hint", desc->dir);
	remove_proc_entry("smp_affinity_list", desc->dir);
	remove_proc_entry("node", desc->dir);
#endif
	remove_proc_entry("spurious", desc->dir);

	memset(name, 0, MAX_NAMELEN);
	sprintf(name, "%u", irq);
	remove_proc_entry(name, root_irq_dir);
}

#undef MAX_NAMELEN

void unregister_handler_proc(unsigned int irq, struct irqaction *action)
{
	proc_remove(action->dir);
}

static void register_default_affinity_proc(void)
{
#ifdef CONFIG_SMP
	proc_create("irq/default_smp_affinity", 0644, NULL,
		    &default_affinity_proc_fops);
#endif
}

void init_irq_proc(void)
{
	unsigned int irq;
	struct irq_desc *desc;

	/* create /proc/irq */
	root_irq_dir = proc_mkdir("irq", NULL);
	if (!root_irq_dir)
		return;

	register_default_affinity_proc();

	/*
	 * Create entries for all existing IRQs.
	 */
	for_each_irq_desc(irq, desc) {
		if (!desc)
			continue;

		register_irq_proc(irq, desc);
	}
}

#ifdef CONFIG_GENERIC_IRQ_SHOW

int __weak arch_show_interrupts(struct seq_file *p, int prec)
{
	return 0;
}

#ifndef ACTUAL_NR_IRQS
# define ACTUAL_NR_IRQS nr_irqs
#endif

int show_interrupts(struct seq_file *p, void *v)
{
	static int prec;

	unsigned long flags, any_count = 0;
	int i = *(loff_t *) v, j;
	struct irqaction *action;
	struct irq_desc *desc;

	if (i > ACTUAL_NR_IRQS)
		return 0;

	if (i == ACTUAL_NR_IRQS)
		return arch_show_interrupts(p, prec);

	/* print header and calculate the width of the first column */
	if (i == 0) {
		for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
			j *= 10;

		seq_printf(p, "%*s", prec + 8, "");
		for_each_online_cpu(j)
			seq_printf(p, "CPU%-8d", j);
		seq_putc(p, '\n');
	}

	irq_lock_sparse();
	desc = irq_to_desc(i);
	if (!desc)
		goto outsparse;

	raw_spin_lock_irqsave(&desc->lock, flags);
	for_each_online_cpu(j)
		any_count |= kstat_irqs_cpu(i, j);
	action = desc->action;
	if (!action && !any_count)
		goto out;

	seq_printf(p, "%*d: ", prec, i);
	for_each_online_cpu(j)
		seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));

	if (desc->irq_data.chip) {
		if (desc->irq_data.chip->irq_print_chip)
			desc->irq_data.chip->irq_print_chip(&desc->irq_data, p);
		else if (desc->irq_data.chip->name)
			seq_printf(p, " %8s", desc->irq_data.chip->name);
		else
			seq_printf(p, " %8s", "-");
	} else {
		seq_printf(p, " %8s", "None");
	}
	if (desc->irq_data.domain)
		seq_printf(p, " %*d", prec, (int) desc->irq_data.hwirq);
#ifdef CONFIG_GENERIC_IRQ_SHOW_LEVEL
	seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge");
#endif
	if (desc->name)
		seq_printf(p, "-%-8s", desc->name);

	if (action) {
		seq_printf(p, "  %s", action->name);
		while ((action = action->next) != NULL)
			seq_printf(p, ", %s", action->name);
	}

	seq_putc(p, '\n');
out:
	raw_spin_unlock_irqrestore(&desc->lock, flags);
outsparse:
	irq_unlock_sparse();
	return 0;
}
#endif
OpenPOWER on IntegriCloud