summaryrefslogtreecommitdiffstats
path: root/drivers/interconnect/debugfs-client.c
blob: bc3fd8a7b9eb41d1f4b4db4842df840590952ffb (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
 */
#include <linux/debugfs.h>
#include <linux/interconnect.h>
#include <linux/platform_device.h>

#include "internal.h"

/*
 * This can be dangerous, therefore don't provide any real compile time
 * configuration option for this feature.
 * People who want to use this will need to modify the source code directly.
 */
#undef INTERCONNECT_ALLOW_WRITE_DEBUGFS

#if defined(INTERCONNECT_ALLOW_WRITE_DEBUGFS) && defined(CONFIG_DEBUG_FS)

static LIST_HEAD(debugfs_paths);
static DEFINE_MUTEX(debugfs_lock);

static struct platform_device *pdev;
static struct icc_path *cur_path;

static char *src_node;
static char *dst_node;
static u32 avg_bw;
static u32 peak_bw;
static u32 tag;

struct debugfs_path {
	const char *src;
	const char *dst;
	struct icc_path *path;
	struct list_head list;
};

static struct icc_path *get_path(const char *src, const char *dst)
{
	struct debugfs_path *path;

	list_for_each_entry(path, &debugfs_paths, list) {
		if (!strcmp(path->src, src) && !strcmp(path->dst, dst))
			return path->path;
	}

	return NULL;
}

static int icc_get_set(void *data, u64 val)
{
	struct debugfs_path *debugfs_path;
	char *src, *dst;
	int ret = 0;

	mutex_lock(&debugfs_lock);

	rcu_read_lock();
	src = rcu_dereference(src_node);
	dst = rcu_dereference(dst_node);

	/*
	 * If we've already looked up a path, then use the existing one instead
	 * of calling icc_get() again. This allows for updating previous BW
	 * votes when "get" is written to multiple times for multiple paths.
	 */
	cur_path = get_path(src, dst);
	if (cur_path) {
		rcu_read_unlock();
		goto out;
	}

	src = kstrdup(src, GFP_ATOMIC);
	dst = kstrdup(dst, GFP_ATOMIC);
	rcu_read_unlock();

	if (!src || !dst) {
		ret = -ENOMEM;
		goto err_free;
	}

	cur_path = icc_get(&pdev->dev, src, dst);
	if (IS_ERR(cur_path)) {
		ret = PTR_ERR(cur_path);
		goto err_free;
	}

	debugfs_path = kzalloc(sizeof(*debugfs_path), GFP_KERNEL);
	if (!debugfs_path) {
		ret = -ENOMEM;
		goto err_put;
	}

	debugfs_path->path = cur_path;
	debugfs_path->src = src;
	debugfs_path->dst = dst;
	list_add_tail(&debugfs_path->list, &debugfs_paths);

	goto out;

err_put:
	icc_put(cur_path);
err_free:
	kfree(src);
	kfree(dst);
out:
	mutex_unlock(&debugfs_lock);
	return ret;
}

DEFINE_DEBUGFS_ATTRIBUTE(icc_get_fops, NULL, icc_get_set, "%llu\n");

static int icc_commit_set(void *data, u64 val)
{
	int ret;

	mutex_lock(&debugfs_lock);

	if (IS_ERR_OR_NULL(cur_path)) {
		ret = PTR_ERR(cur_path);
		goto out;
	}

	icc_set_tag(cur_path, tag);
	ret = icc_set_bw(cur_path, avg_bw, peak_bw);
out:
	mutex_unlock(&debugfs_lock);
	return ret;
}

DEFINE_DEBUGFS_ATTRIBUTE(icc_commit_fops, NULL, icc_commit_set, "%llu\n");

int icc_debugfs_client_init(struct dentry *icc_dir)
{
	struct dentry *client_dir;
	int ret;

	pdev = platform_device_alloc("icc-debugfs-client", PLATFORM_DEVID_NONE);

	ret = platform_device_add(pdev);
	if (ret) {
		pr_err("%s: failed to add platform device: %d\n", __func__, ret);
		platform_device_put(pdev);
		return ret;
	}

	client_dir = debugfs_create_dir("test_client", icc_dir);

	debugfs_create_str("src_node", 0600, client_dir, &src_node);
	debugfs_create_str("dst_node", 0600, client_dir, &dst_node);
	debugfs_create_file("get", 0200, client_dir, NULL, &icc_get_fops);
	debugfs_create_u32("avg_bw", 0600, client_dir, &avg_bw);
	debugfs_create_u32("peak_bw", 0600, client_dir, &peak_bw);
	debugfs_create_u32("tag", 0600, client_dir, &tag);
	debugfs_create_file("commit", 0200, client_dir, NULL, &icc_commit_fops);

	return 0;
}

#else

int icc_debugfs_client_init(struct dentry *icc_dir)
{
	return 0;
}

#endif