xref: /openbmc/linux/kernel/irq/debugfs.c (revision d0e22329)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright 2017 Thomas Gleixner <tglx@linutronix.de>
3 
4 #include <linux/irqdomain.h>
5 #include <linux/irq.h>
6 #include <linux/uaccess.h>
7 
8 #include "internals.h"
9 
10 static struct dentry *irq_dir;
11 
12 struct irq_bit_descr {
13 	unsigned int	mask;
14 	char		*name;
15 };
16 #define BIT_MASK_DESCR(m)	{ .mask = m, .name = #m }
17 
18 static void irq_debug_show_bits(struct seq_file *m, int ind, unsigned int state,
19 				const struct irq_bit_descr *sd, int size)
20 {
21 	int i;
22 
23 	for (i = 0; i < size; i++, sd++) {
24 		if (state & sd->mask)
25 			seq_printf(m, "%*s%s\n", ind + 12, "", sd->name);
26 	}
27 }
28 
29 #ifdef CONFIG_SMP
30 static void irq_debug_show_masks(struct seq_file *m, struct irq_desc *desc)
31 {
32 	struct irq_data *data = irq_desc_get_irq_data(desc);
33 	struct cpumask *msk;
34 
35 	msk = irq_data_get_affinity_mask(data);
36 	seq_printf(m, "affinity: %*pbl\n", cpumask_pr_args(msk));
37 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
38 	msk = irq_data_get_effective_affinity_mask(data);
39 	seq_printf(m, "effectiv: %*pbl\n", cpumask_pr_args(msk));
40 #endif
41 #ifdef CONFIG_GENERIC_PENDING_IRQ
42 	msk = desc->pending_mask;
43 	seq_printf(m, "pending:  %*pbl\n", cpumask_pr_args(msk));
44 #endif
45 }
46 #else
47 static void irq_debug_show_masks(struct seq_file *m, struct irq_desc *desc) { }
48 #endif
49 
50 static const struct irq_bit_descr irqchip_flags[] = {
51 	BIT_MASK_DESCR(IRQCHIP_SET_TYPE_MASKED),
52 	BIT_MASK_DESCR(IRQCHIP_EOI_IF_HANDLED),
53 	BIT_MASK_DESCR(IRQCHIP_MASK_ON_SUSPEND),
54 	BIT_MASK_DESCR(IRQCHIP_ONOFFLINE_ENABLED),
55 	BIT_MASK_DESCR(IRQCHIP_SKIP_SET_WAKE),
56 	BIT_MASK_DESCR(IRQCHIP_ONESHOT_SAFE),
57 	BIT_MASK_DESCR(IRQCHIP_EOI_THREADED),
58 	BIT_MASK_DESCR(IRQCHIP_SUPPORTS_LEVEL_MSI),
59 };
60 
61 static void
62 irq_debug_show_chip(struct seq_file *m, struct irq_data *data, int ind)
63 {
64 	struct irq_chip *chip = data->chip;
65 
66 	if (!chip) {
67 		seq_printf(m, "chip: None\n");
68 		return;
69 	}
70 	seq_printf(m, "%*schip:    %s\n", ind, "", chip->name);
71 	seq_printf(m, "%*sflags:   0x%lx\n", ind + 1, "", chip->flags);
72 	irq_debug_show_bits(m, ind, chip->flags, irqchip_flags,
73 			    ARRAY_SIZE(irqchip_flags));
74 }
75 
76 static void
77 irq_debug_show_data(struct seq_file *m, struct irq_data *data, int ind)
78 {
79 	seq_printf(m, "%*sdomain:  %s\n", ind, "",
80 		   data->domain ? data->domain->name : "");
81 	seq_printf(m, "%*shwirq:   0x%lx\n", ind + 1, "", data->hwirq);
82 	irq_debug_show_chip(m, data, ind + 1);
83 	if (data->domain && data->domain->ops && data->domain->ops->debug_show)
84 		data->domain->ops->debug_show(m, NULL, data, ind + 1);
85 #ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
86 	if (!data->parent_data)
87 		return;
88 	seq_printf(m, "%*sparent:\n", ind + 1, "");
89 	irq_debug_show_data(m, data->parent_data, ind + 4);
90 #endif
91 }
92 
93 static const struct irq_bit_descr irqdata_states[] = {
94 	BIT_MASK_DESCR(IRQ_TYPE_EDGE_RISING),
95 	BIT_MASK_DESCR(IRQ_TYPE_EDGE_FALLING),
96 	BIT_MASK_DESCR(IRQ_TYPE_LEVEL_HIGH),
97 	BIT_MASK_DESCR(IRQ_TYPE_LEVEL_LOW),
98 	BIT_MASK_DESCR(IRQD_LEVEL),
99 
100 	BIT_MASK_DESCR(IRQD_ACTIVATED),
101 	BIT_MASK_DESCR(IRQD_IRQ_STARTED),
102 	BIT_MASK_DESCR(IRQD_IRQ_DISABLED),
103 	BIT_MASK_DESCR(IRQD_IRQ_MASKED),
104 	BIT_MASK_DESCR(IRQD_IRQ_INPROGRESS),
105 
106 	BIT_MASK_DESCR(IRQD_PER_CPU),
107 	BIT_MASK_DESCR(IRQD_NO_BALANCING),
108 
109 	BIT_MASK_DESCR(IRQD_SINGLE_TARGET),
110 	BIT_MASK_DESCR(IRQD_MOVE_PCNTXT),
111 	BIT_MASK_DESCR(IRQD_AFFINITY_SET),
112 	BIT_MASK_DESCR(IRQD_SETAFFINITY_PENDING),
113 	BIT_MASK_DESCR(IRQD_AFFINITY_MANAGED),
114 	BIT_MASK_DESCR(IRQD_MANAGED_SHUTDOWN),
115 	BIT_MASK_DESCR(IRQD_CAN_RESERVE),
116 
117 	BIT_MASK_DESCR(IRQD_FORWARDED_TO_VCPU),
118 
119 	BIT_MASK_DESCR(IRQD_WAKEUP_STATE),
120 	BIT_MASK_DESCR(IRQD_WAKEUP_ARMED),
121 };
122 
123 static const struct irq_bit_descr irqdesc_states[] = {
124 	BIT_MASK_DESCR(_IRQ_NOPROBE),
125 	BIT_MASK_DESCR(_IRQ_NOREQUEST),
126 	BIT_MASK_DESCR(_IRQ_NOTHREAD),
127 	BIT_MASK_DESCR(_IRQ_NOAUTOEN),
128 	BIT_MASK_DESCR(_IRQ_NESTED_THREAD),
129 	BIT_MASK_DESCR(_IRQ_PER_CPU_DEVID),
130 	BIT_MASK_DESCR(_IRQ_IS_POLLED),
131 	BIT_MASK_DESCR(_IRQ_DISABLE_UNLAZY),
132 };
133 
134 static const struct irq_bit_descr irqdesc_istates[] = {
135 	BIT_MASK_DESCR(IRQS_AUTODETECT),
136 	BIT_MASK_DESCR(IRQS_SPURIOUS_DISABLED),
137 	BIT_MASK_DESCR(IRQS_POLL_INPROGRESS),
138 	BIT_MASK_DESCR(IRQS_ONESHOT),
139 	BIT_MASK_DESCR(IRQS_REPLAY),
140 	BIT_MASK_DESCR(IRQS_WAITING),
141 	BIT_MASK_DESCR(IRQS_PENDING),
142 	BIT_MASK_DESCR(IRQS_SUSPENDED),
143 };
144 
145 
146 static int irq_debug_show(struct seq_file *m, void *p)
147 {
148 	struct irq_desc *desc = m->private;
149 	struct irq_data *data;
150 
151 	raw_spin_lock_irq(&desc->lock);
152 	data = irq_desc_get_irq_data(desc);
153 	seq_printf(m, "handler:  %pf\n", desc->handle_irq);
154 	seq_printf(m, "device:   %s\n", desc->dev_name);
155 	seq_printf(m, "status:   0x%08x\n", desc->status_use_accessors);
156 	irq_debug_show_bits(m, 0, desc->status_use_accessors, irqdesc_states,
157 			    ARRAY_SIZE(irqdesc_states));
158 	seq_printf(m, "istate:   0x%08x\n", desc->istate);
159 	irq_debug_show_bits(m, 0, desc->istate, irqdesc_istates,
160 			    ARRAY_SIZE(irqdesc_istates));
161 	seq_printf(m, "ddepth:   %u\n", desc->depth);
162 	seq_printf(m, "wdepth:   %u\n", desc->wake_depth);
163 	seq_printf(m, "dstate:   0x%08x\n", irqd_get(data));
164 	irq_debug_show_bits(m, 0, irqd_get(data), irqdata_states,
165 			    ARRAY_SIZE(irqdata_states));
166 	seq_printf(m, "node:     %d\n", irq_data_get_node(data));
167 	irq_debug_show_masks(m, desc);
168 	irq_debug_show_data(m, data, 0);
169 	raw_spin_unlock_irq(&desc->lock);
170 	return 0;
171 }
172 
173 static int irq_debug_open(struct inode *inode, struct file *file)
174 {
175 	return single_open(file, irq_debug_show, inode->i_private);
176 }
177 
178 static ssize_t irq_debug_write(struct file *file, const char __user *user_buf,
179 			       size_t count, loff_t *ppos)
180 {
181 	struct irq_desc *desc = file_inode(file)->i_private;
182 	char buf[8] = { 0, };
183 	size_t size;
184 
185 	size = min(sizeof(buf) - 1, count);
186 	if (copy_from_user(buf, user_buf, size))
187 		return -EFAULT;
188 
189 	if (!strncmp(buf, "trigger", size)) {
190 		unsigned long flags;
191 		int err;
192 
193 		/* Try the HW interface first */
194 		err = irq_set_irqchip_state(irq_desc_get_irq(desc),
195 					    IRQCHIP_STATE_PENDING, true);
196 		if (!err)
197 			return count;
198 
199 		/*
200 		 * Otherwise, try to inject via the resend interface,
201 		 * which may or may not succeed.
202 		 */
203 		chip_bus_lock(desc);
204 		raw_spin_lock_irqsave(&desc->lock, flags);
205 
206 		if (irq_settings_is_level(desc)) {
207 			/* Can't do level, sorry */
208 			err = -EINVAL;
209 		} else {
210 			desc->istate |= IRQS_PENDING;
211 			check_irq_resend(desc);
212 			err = 0;
213 		}
214 
215 		raw_spin_unlock_irqrestore(&desc->lock, flags);
216 		chip_bus_sync_unlock(desc);
217 
218 		return err ? err : count;
219 	}
220 
221 	return count;
222 }
223 
224 static const struct file_operations dfs_irq_ops = {
225 	.open		= irq_debug_open,
226 	.write		= irq_debug_write,
227 	.read		= seq_read,
228 	.llseek		= seq_lseek,
229 	.release	= single_release,
230 };
231 
232 void irq_debugfs_copy_devname(int irq, struct device *dev)
233 {
234 	struct irq_desc *desc = irq_to_desc(irq);
235 	const char *name = dev_name(dev);
236 
237 	if (name)
238 		desc->dev_name = kstrdup(name, GFP_KERNEL);
239 }
240 
241 void irq_add_debugfs_entry(unsigned int irq, struct irq_desc *desc)
242 {
243 	char name [10];
244 
245 	if (!irq_dir || !desc || desc->debugfs_file)
246 		return;
247 
248 	sprintf(name, "%d", irq);
249 	desc->debugfs_file = debugfs_create_file(name, 0644, irq_dir, desc,
250 						 &dfs_irq_ops);
251 }
252 
253 static int __init irq_debugfs_init(void)
254 {
255 	struct dentry *root_dir;
256 	int irq;
257 
258 	root_dir = debugfs_create_dir("irq", NULL);
259 	if (!root_dir)
260 		return -ENOMEM;
261 
262 	irq_domain_debugfs_init(root_dir);
263 
264 	irq_dir = debugfs_create_dir("irqs", root_dir);
265 
266 	irq_lock_sparse();
267 	for_each_active_irq(irq)
268 		irq_add_debugfs_entry(irq, irq_to_desc(irq));
269 	irq_unlock_sparse();
270 
271 	return 0;
272 }
273 __initcall(irq_debugfs_init);
274