vchiq_debugfs.c

  1// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
  2/*
  3 * Copyright (c) 2014 Raspberry Pi (Trading) Ltd. All rights reserved.
  4 * Copyright (c) 2010-2012 Broadcom. All rights reserved.
  5 */
  6
  7#include <linux/debugfs.h>
  8#include <linux/raspberrypi/vchiq_core.h>
  9#include <linux/raspberrypi/vchiq_arm.h>
 10#include <linux/raspberrypi/vchiq_debugfs.h>
 11
 12#ifdef CONFIG_DEBUG_FS
 13
 14#define DEBUGFS_WRITE_BUF_SIZE 256
 15
 16/* Global 'vchiq' debugfs and clients entry used by all instances */
 17static struct dentry *vchiq_dbg_dir;
 18static struct dentry *vchiq_dbg_clients;
 19
 20static int debugfs_usecount_show(struct seq_file *f, void *offset)
 21{
 22	struct vchiq_instance *instance = f->private;
 23	int use_count;
 24
 25	use_count = vchiq_instance_get_use_count(instance);
 26	seq_printf(f, "%d\n", use_count);
 27
 28	return 0;
 29}
 30DEFINE_SHOW_ATTRIBUTE(debugfs_usecount);
 31
 32static int debugfs_trace_show(struct seq_file *f, void *offset)
 33{
 34	struct vchiq_instance *instance = f->private;
 35	int trace;
 36
 37	trace = vchiq_instance_get_trace(instance);
 38	seq_printf(f, "%s\n", trace ? "Y" : "N");
 39
 40	return 0;
 41}
 42
 43static int vchiq_dump_show(struct seq_file *f, void *offset)
 44{
 45	struct vchiq_state *state = f->private;
 46
 47	vchiq_dump_state(f, state);
 48
 49	return 0;
 50}
 51DEFINE_SHOW_ATTRIBUTE(vchiq_dump);
 52
 53static int debugfs_trace_open(struct inode *inode, struct file *file)
 54{
 55	return single_open(file, debugfs_trace_show, inode->i_private);
 56}
 57
 58static ssize_t debugfs_trace_write(struct file *file,
 59	const char __user *buffer,
 60	size_t count, loff_t *ppos)
 61{
 62	struct seq_file *f = (struct seq_file *)file->private_data;
 63	struct vchiq_instance *instance = f->private;
 64	char firstchar;
 65
 66	if (copy_from_user(&firstchar, buffer, 1))
 67		return -EFAULT;
 68
 69	switch (firstchar) {
 70	case 'Y':
 71	case 'y':
 72	case '1':
 73		vchiq_instance_set_trace(instance, 1);
 74		break;
 75	case 'N':
 76	case 'n':
 77	case '0':
 78		vchiq_instance_set_trace(instance, 0);
 79		break;
 80	default:
 81		break;
 82	}
 83
 84	*ppos += count;
 85
 86	return count;
 87}
 88
 89static const struct file_operations debugfs_trace_fops = {
 90	.owner		= THIS_MODULE,
 91	.open		= debugfs_trace_open,
 92	.write		= debugfs_trace_write,
 93	.read		= seq_read,
 94	.llseek		= seq_lseek,
 95	.release	= single_release,
 96};
 97
 98/* add an instance (process) to the debugfs entries */
 99void vchiq_debugfs_add_instance(struct vchiq_instance *instance)
100{
101	char pidstr[16];
102	struct dentry *top;
103
104	snprintf(pidstr, sizeof(pidstr), "%d",
105		 vchiq_instance_get_pid(instance));
106
107	top = debugfs_create_dir(pidstr, vchiq_dbg_clients);
108
109	debugfs_create_file("use_count", 0444, top, instance,
110			    &debugfs_usecount_fops);
111	debugfs_create_file("trace", 0644, top, instance, &debugfs_trace_fops);
112
113	vchiq_instance_get_debugfs_node(instance)->dentry = top;
114}
115
116void vchiq_debugfs_remove_instance(struct vchiq_instance *instance)
117{
118	struct vchiq_debugfs_node *node =
119				vchiq_instance_get_debugfs_node(instance);
120
121	debugfs_remove_recursive(node->dentry);
122}
123
124void vchiq_debugfs_init(struct vchiq_state *state)
125{
126	vchiq_dbg_dir = debugfs_create_dir("vchiq", NULL);
127	vchiq_dbg_clients = debugfs_create_dir("clients", vchiq_dbg_dir);
128
129	debugfs_create_file("state", S_IFREG | 0444, vchiq_dbg_dir, state,
130			    &vchiq_dump_fops);
131}
132
133/* remove all the debugfs entries */
134void vchiq_debugfs_deinit(void)
135{
136	debugfs_remove_recursive(vchiq_dbg_dir);
137}
138
139#else /* CONFIG_DEBUG_FS */
140
141void vchiq_debugfs_init(struct vchiq_state *state)
142{
143}
144
145void vchiq_debugfs_deinit(void)
146{
147}
148
149void vchiq_debugfs_add_instance(struct vchiq_instance *instance)
150{
151}
152
153void vchiq_debugfs_remove_instance(struct vchiq_instance *instance)
154{
155}
156
157#endif /* CONFIG_DEBUG_FS */