xref: /openbmc/linux/kernel/irq/proc.c (revision e4c0d0e2) 
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 
16 #include "internals.h"
17 
18 static struct proc_dir_entry *root_irq_dir;
19 
20 #ifdef CONFIG_SMP
21 
22 static int show_irq_affinity(int type, struct seq_file *m, void *v)
23 {
24 	struct irq_desc *desc = irq_to_desc((long)m->private);
25 	const struct cpumask *mask = desc->irq_data.affinity;
26 
27 #ifdef CONFIG_GENERIC_PENDING_IRQ
28 	if (irqd_is_setaffinity_pending(&desc->irq_data))
29 		mask = desc->pending_mask;
30 #endif
31 	if (type)
32 		seq_cpumask_list(m, mask);
33 	else
34 		seq_cpumask(m, mask);
35 	seq_putc(m, '\n');
36 	return 0;
37 }
38 
39 static int irq_affinity_hint_proc_show(struct seq_file *m, void *v)
40 {
41 	struct irq_desc *desc = irq_to_desc((long)m->private);
42 	unsigned long flags;
43 	cpumask_var_t mask;
44 
45 	if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
46 		return -ENOMEM;
47 
48 	raw_spin_lock_irqsave(&desc->lock, flags);
49 	if (desc->affinity_hint)
50 		cpumask_copy(mask, desc->affinity_hint);
51 	raw_spin_unlock_irqrestore(&desc->lock, flags);
52 
53 	seq_cpumask(m, mask);
54 	seq_putc(m, '\n');
55 	free_cpumask_var(mask);
56 
57 	return 0;
58 }
59 
60 #ifndef is_affinity_mask_valid
61 #define is_affinity_mask_valid(val) 1
62 #endif
63 
64 int no_irq_affinity;
65 static int irq_affinity_proc_show(struct seq_file *m, void *v)
66 {
67 	return show_irq_affinity(0, m, v);
68 }
69 
70 static int irq_affinity_list_proc_show(struct seq_file *m, void *v)
71 {
72 	return show_irq_affinity(1, m, v);
73 }
74 
75 
76 static ssize_t write_irq_affinity(int type, struct file *file,
77 		const char __user *buffer, size_t count, loff_t *pos)
78 {
79 	unsigned int irq = (int)(long)PDE(file->f_path.dentry->d_inode)->data;
80 	cpumask_var_t new_value;
81 	int err;
82 
83 	if (!irq_can_set_affinity(irq) || no_irq_affinity)
84 		return -EIO;
85 
86 	if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
87 		return -ENOMEM;
88 
89 	if (type)
90 		err = cpumask_parselist_user(buffer, count, new_value);
91 	else
92 		err = cpumask_parse_user(buffer, count, new_value);
93 	if (err)
94 		goto free_cpumask;
95 
96 	if (!is_affinity_mask_valid(new_value)) {
97 		err = -EINVAL;
98 		goto free_cpumask;
99 	}
100 
101 	/*
102 	 * Do not allow disabling IRQs completely - it's a too easy
103 	 * way to make the system unusable accidentally :-) At least
104 	 * one online CPU still has to be targeted.
105 	 */
106 	if (!cpumask_intersects(new_value, cpu_online_mask)) {
107 		/* Special case for empty set - allow the architecture
108 		   code to set default SMP affinity. */
109 		err = irq_select_affinity_usr(irq, new_value) ? -EINVAL : count;
110 	} else {
111 		irq_set_affinity(irq, new_value);
112 		err = count;
113 	}
114 
115 free_cpumask:
116 	free_cpumask_var(new_value);
117 	return err;
118 }
119 
120 static ssize_t irq_affinity_proc_write(struct file *file,
121 		const char __user *buffer, size_t count, loff_t *pos)
122 {
123 	return write_irq_affinity(0, file, buffer, count, pos);
124 }
125 
126 static ssize_t irq_affinity_list_proc_write(struct file *file,
127 		const char __user *buffer, size_t count, loff_t *pos)
128 {
129 	return write_irq_affinity(1, file, buffer, count, pos);
130 }
131 
132 static int irq_affinity_proc_open(struct inode *inode, struct file *file)
133 {
134 	return single_open(file, irq_affinity_proc_show, PDE(inode)->data);
135 }
136 
137 static int irq_affinity_list_proc_open(struct inode *inode, struct file *file)
138 {
139 	return single_open(file, irq_affinity_list_proc_show, PDE(inode)->data);
140 }
141 
142 static int irq_affinity_hint_proc_open(struct inode *inode, struct file *file)
143 {
144 	return single_open(file, irq_affinity_hint_proc_show, PDE(inode)->data);
145 }
146 
147 static const struct file_operations irq_affinity_proc_fops = {
148 	.open		= irq_affinity_proc_open,
149 	.read		= seq_read,
150 	.llseek		= seq_lseek,
151 	.release	= single_release,
152 	.write		= irq_affinity_proc_write,
153 };
154 
155 static const struct file_operations irq_affinity_hint_proc_fops = {
156 	.open		= irq_affinity_hint_proc_open,
157 	.read		= seq_read,
158 	.llseek		= seq_lseek,
159 	.release	= single_release,
160 };
161 
162 static const struct file_operations irq_affinity_list_proc_fops = {
163 	.open		= irq_affinity_list_proc_open,
164 	.read		= seq_read,
165 	.llseek		= seq_lseek,
166 	.release	= single_release,
167 	.write		= irq_affinity_list_proc_write,
168 };
169 
170 static int default_affinity_show(struct seq_file *m, void *v)
171 {
172 	seq_cpumask(m, irq_default_affinity);
173 	seq_putc(m, '\n');
174 	return 0;
175 }
176 
177 static ssize_t default_affinity_write(struct file *file,
178 		const char __user *buffer, size_t count, loff_t *ppos)
179 {
180 	cpumask_var_t new_value;
181 	int err;
182 
183 	if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
184 		return -ENOMEM;
185 
186 	err = cpumask_parse_user(buffer, count, new_value);
187 	if (err)
188 		goto out;
189 
190 	if (!is_affinity_mask_valid(new_value)) {
191 		err = -EINVAL;
192 		goto out;
193 	}
194 
195 	/*
196 	 * Do not allow disabling IRQs completely - it's a too easy
197 	 * way to make the system unusable accidentally :-) At least
198 	 * one online CPU still has to be targeted.
199 	 */
200 	if (!cpumask_intersects(new_value, cpu_online_mask)) {
201 		err = -EINVAL;
202 		goto out;
203 	}
204 
205 	cpumask_copy(irq_default_affinity, new_value);
206 	err = count;
207 
208 out:
209 	free_cpumask_var(new_value);
210 	return err;
211 }
212 
213 static int default_affinity_open(struct inode *inode, struct file *file)
214 {
215 	return single_open(file, default_affinity_show, PDE(inode)->data);
216 }
217 
218 static const struct file_operations default_affinity_proc_fops = {
219 	.open		= default_affinity_open,
220 	.read		= seq_read,
221 	.llseek		= seq_lseek,
222 	.release	= single_release,
223 	.write		= default_affinity_write,
224 };
225 
226 static int irq_node_proc_show(struct seq_file *m, void *v)
227 {
228 	struct irq_desc *desc = irq_to_desc((long) m->private);
229 
230 	seq_printf(m, "%d\n", desc->irq_data.node);
231 	return 0;
232 }
233 
234 static int irq_node_proc_open(struct inode *inode, struct file *file)
235 {
236 	return single_open(file, irq_node_proc_show, PDE(inode)->data);
237 }
238 
239 static const struct file_operations irq_node_proc_fops = {
240 	.open		= irq_node_proc_open,
241 	.read		= seq_read,
242 	.llseek		= seq_lseek,
243 	.release	= single_release,
244 };
245 #endif
246 
247 static int irq_spurious_proc_show(struct seq_file *m, void *v)
248 {
249 	struct irq_desc *desc = irq_to_desc((long) m->private);
250 
251 	seq_printf(m, "count %u\n" "unhandled %u\n" "last_unhandled %u ms\n",
252 		   desc->irq_count, desc->irqs_unhandled,
253 		   jiffies_to_msecs(desc->last_unhandled));
254 	return 0;
255 }
256 
257 static int irq_spurious_proc_open(struct inode *inode, struct file *file)
258 {
259 	return single_open(file, irq_spurious_proc_show, PDE(inode)->data);
260 }
261 
262 static const struct file_operations irq_spurious_proc_fops = {
263 	.open		= irq_spurious_proc_open,
264 	.read		= seq_read,
265 	.llseek		= seq_lseek,
266 	.release	= single_release,
267 };
268 
269 #define MAX_NAMELEN 128
270 
271 static int name_unique(unsigned int irq, struct irqaction *new_action)
272 {
273 	struct irq_desc *desc = irq_to_desc(irq);
274 	struct irqaction *action;
275 	unsigned long flags;
276 	int ret = 1;
277 
278 	raw_spin_lock_irqsave(&desc->lock, flags);
279 	for (action = desc->action ; action; action = action->next) {
280 		if ((action != new_action) && action->name &&
281 				!strcmp(new_action->name, action->name)) {
282 			ret = 0;
283 			break;
284 		}
285 	}
286 	raw_spin_unlock_irqrestore(&desc->lock, flags);
287 	return ret;
288 }
289 
290 void register_handler_proc(unsigned int irq, struct irqaction *action)
291 {
292 	char name [MAX_NAMELEN];
293 	struct irq_desc *desc = irq_to_desc(irq);
294 
295 	if (!desc->dir || action->dir || !action->name ||
296 					!name_unique(irq, action))
297 		return;
298 
299 	memset(name, 0, MAX_NAMELEN);
300 	snprintf(name, MAX_NAMELEN, "%s", action->name);
301 
302 	/* create /proc/irq/1234/handler/ */
303 	action->dir = proc_mkdir(name, desc->dir);
304 }
305 
306 #undef MAX_NAMELEN
307 
308 #define MAX_NAMELEN 10
309 
310 void register_irq_proc(unsigned int irq, struct irq_desc *desc)
311 {
312 	char name [MAX_NAMELEN];
313 
314 	if (!root_irq_dir || (desc->irq_data.chip == &no_irq_chip) || desc->dir)
315 		return;
316 
317 	memset(name, 0, MAX_NAMELEN);
318 	sprintf(name, "%d", irq);
319 
320 	/* create /proc/irq/1234 */
321 	desc->dir = proc_mkdir(name, root_irq_dir);
322 	if (!desc->dir)
323 		return;
324 
325 #ifdef CONFIG_SMP
326 	/* create /proc/irq/<irq>/smp_affinity */
327 	proc_create_data("smp_affinity", 0600, desc->dir,
328 			 &irq_affinity_proc_fops, (void *)(long)irq);
329 
330 	/* create /proc/irq/<irq>/affinity_hint */
331 	proc_create_data("affinity_hint", 0400, desc->dir,
332 			 &irq_affinity_hint_proc_fops, (void *)(long)irq);
333 
334 	/* create /proc/irq/<irq>/smp_affinity_list */
335 	proc_create_data("smp_affinity_list", 0600, desc->dir,
336 			 &irq_affinity_list_proc_fops, (void *)(long)irq);
337 
338 	proc_create_data("node", 0444, desc->dir,
339 			 &irq_node_proc_fops, (void *)(long)irq);
340 #endif
341 
342 	proc_create_data("spurious", 0444, desc->dir,
343 			 &irq_spurious_proc_fops, (void *)(long)irq);
344 }
345 
346 void unregister_irq_proc(unsigned int irq, struct irq_desc *desc)
347 {
348 	char name [MAX_NAMELEN];
349 
350 	if (!root_irq_dir || !desc->dir)
351 		return;
352 #ifdef CONFIG_SMP
353 	remove_proc_entry("smp_affinity", desc->dir);
354 	remove_proc_entry("affinity_hint", desc->dir);
355 	remove_proc_entry("smp_affinity_list", desc->dir);
356 	remove_proc_entry("node", desc->dir);
357 #endif
358 	remove_proc_entry("spurious", desc->dir);
359 
360 	memset(name, 0, MAX_NAMELEN);
361 	sprintf(name, "%u", irq);
362 	remove_proc_entry(name, root_irq_dir);
363 }
364 
365 #undef MAX_NAMELEN
366 
367 void unregister_handler_proc(unsigned int irq, struct irqaction *action)
368 {
369 	if (action->dir) {
370 		struct irq_desc *desc = irq_to_desc(irq);
371 
372 		remove_proc_entry(action->dir->name, desc->dir);
373 	}
374 }
375 
376 static void register_default_affinity_proc(void)
377 {
378 #ifdef CONFIG_SMP
379 	proc_create("irq/default_smp_affinity", 0600, NULL,
380 		    &default_affinity_proc_fops);
381 #endif
382 }
383 
384 void init_irq_proc(void)
385 {
386 	unsigned int irq;
387 	struct irq_desc *desc;
388 
389 	/* create /proc/irq */
390 	root_irq_dir = proc_mkdir("irq", NULL);
391 	if (!root_irq_dir)
392 		return;
393 
394 	register_default_affinity_proc();
395 
396 	/*
397 	 * Create entries for all existing IRQs.
398 	 */
399 	for_each_irq_desc(irq, desc) {
400 		if (!desc)
401 			continue;
402 
403 		register_irq_proc(irq, desc);
404 	}
405 }
406 
407 #ifdef CONFIG_GENERIC_IRQ_SHOW
408 
409 int __weak arch_show_interrupts(struct seq_file *p, int prec)
410 {
411 	return 0;
412 }
413 
414 #ifndef ACTUAL_NR_IRQS
415 # define ACTUAL_NR_IRQS nr_irqs
416 #endif
417 
418 int show_interrupts(struct seq_file *p, void *v)
419 {
420 	static int prec;
421 
422 	unsigned long flags, any_count = 0;
423 	int i = *(loff_t *) v, j;
424 	struct irqaction *action;
425 	struct irq_desc *desc;
426 
427 	if (i > ACTUAL_NR_IRQS)
428 		return 0;
429 
430 	if (i == ACTUAL_NR_IRQS)
431 		return arch_show_interrupts(p, prec);
432 
433 	/* print header and calculate the width of the first column */
434 	if (i == 0) {
435 		for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
436 			j *= 10;
437 
438 		seq_printf(p, "%*s", prec + 8, "");
439 		for_each_online_cpu(j)
440 			seq_printf(p, "CPU%-8d", j);
441 		seq_putc(p, '\n');
442 	}
443 
444 	desc = irq_to_desc(i);
445 	if (!desc)
446 		return 0;
447 
448 	raw_spin_lock_irqsave(&desc->lock, flags);
449 	for_each_online_cpu(j)
450 		any_count |= kstat_irqs_cpu(i, j);
451 	action = desc->action;
452 	if (!action && !any_count)
453 		goto out;
454 
455 	seq_printf(p, "%*d: ", prec, i);
456 	for_each_online_cpu(j)
457 		seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
458 
459 	if (desc->irq_data.chip) {
460 		if (desc->irq_data.chip->irq_print_chip)
461 			desc->irq_data.chip->irq_print_chip(&desc->irq_data, p);
462 		else if (desc->irq_data.chip->name)
463 			seq_printf(p, " %8s", desc->irq_data.chip->name);
464 		else
465 			seq_printf(p, " %8s", "-");
466 	} else {
467 		seq_printf(p, " %8s", "None");
468 	}
469 #ifdef CONFIG_GENERIC_IRQ_SHOW_LEVEL
470 	seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge");
471 #endif
472 	if (desc->name)
473 		seq_printf(p, "-%-8s", desc->name);
474 
475 	if (action) {
476 		seq_printf(p, "  %s", action->name);
477 		while ((action = action->next) != NULL)
478 			seq_printf(p, ", %s", action->name);
479 	}
480 
481 	seq_putc(p, '\n');
482 out:
483 	raw_spin_unlock_irqrestore(&desc->lock, flags);
484 	return 0;
485 }
486 #endif
487