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183 lines · 3.8 KiB

1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
4 */
5#include <linux/debugfs.h>
6#include <linux/interconnect.h>
7#include <linux/platform_device.h>
8
9#include "internal.h"
10
11/*
12 * This can be dangerous, therefore don't provide any real compile time
13 * configuration option for this feature.
14 * People who want to use this will need to modify the source code directly.
15 */
16#undef INTERCONNECT_ALLOW_WRITE_DEBUGFS
17
18#if defined(INTERCONNECT_ALLOW_WRITE_DEBUGFS) && defined(CONFIG_DEBUG_FS)
19
20static LIST_HEAD(debugfs_paths);
21static DEFINE_MUTEX(debugfs_lock);
22
23static struct platform_device *pdev;
24static struct icc_path *cur_path;
25
26static char *src_node;
27static char *dst_node;
28static u32 avg_bw;
29static u32 peak_bw;
30static u32 tag;
31
32struct debugfs_path {
33 const char *src;
34 const char *dst;
35 struct icc_path *path;
36 struct list_head list;
37};
38
39static struct icc_path *get_path(const char *src, const char *dst)
40{
41 struct debugfs_path *path;
42
43 list_for_each_entry(path, &debugfs_paths, list) {
44 if (!strcmp(path->src, src) && !strcmp(path->dst, dst))
45 return path->path;
46 }
47
48 return NULL;
49}
50
51static int icc_get_set(void *data, u64 val)
52{
53 struct debugfs_path *debugfs_path;
54 char *src, *dst;
55 int ret = 0;
56
57 mutex_lock(&debugfs_lock);
58
59 rcu_read_lock();
60 src = rcu_dereference(src_node);
61 dst = rcu_dereference(dst_node);
62
63 /*
64 * If we've already looked up a path, then use the existing one instead
65 * of calling icc_get() again. This allows for updating previous BW
66 * votes when "get" is written to multiple times for multiple paths.
67 */
68 cur_path = get_path(src, dst);
69 if (cur_path) {
70 rcu_read_unlock();
71 goto out;
72 }
73
74 src = kstrdup(src, GFP_ATOMIC);
75 dst = kstrdup(dst, GFP_ATOMIC);
76 rcu_read_unlock();
77
78 if (!src || !dst) {
79 ret = -ENOMEM;
80 goto err_free;
81 }
82
83 cur_path = icc_get(&pdev->dev, src, dst);
84 if (IS_ERR(cur_path)) {
85 ret = PTR_ERR(cur_path);
86 goto err_free;
87 }
88
89 debugfs_path = kzalloc_obj(*debugfs_path);
90 if (!debugfs_path) {
91 ret = -ENOMEM;
92 goto err_put;
93 }
94
95 debugfs_path->path = cur_path;
96 debugfs_path->src = src;
97 debugfs_path->dst = dst;
98 list_add_tail(&debugfs_path->list, &debugfs_paths);
99
100 goto out;
101
102err_put:
103 icc_put(cur_path);
104err_free:
105 kfree(src);
106 kfree(dst);
107out:
108 mutex_unlock(&debugfs_lock);
109 return ret;
110}
111
112DEFINE_DEBUGFS_ATTRIBUTE(icc_get_fops, NULL, icc_get_set, "%llu\n");
113
114static int icc_commit_set(void *data, u64 val)
115{
116 int ret;
117
118 mutex_lock(&debugfs_lock);
119
120 if (!cur_path) {
121 ret = -EINVAL;
122 goto out;
123 }
124
125 if (IS_ERR(cur_path)) {
126 ret = PTR_ERR(cur_path);
127 goto out;
128 }
129
130 icc_set_tag(cur_path, tag);
131 ret = icc_set_bw(cur_path, avg_bw, peak_bw);
132out:
133 mutex_unlock(&debugfs_lock);
134 return ret;
135}
136
137DEFINE_DEBUGFS_ATTRIBUTE(icc_commit_fops, NULL, icc_commit_set, "%llu\n");
138
139int icc_debugfs_client_init(struct dentry *icc_dir)
140{
141 struct dentry *client_dir;
142 int ret;
143
144 pdev = platform_device_alloc("icc-debugfs-client", PLATFORM_DEVID_NONE);
145 if (!pdev)
146 return -ENOMEM;
147
148 ret = platform_device_add(pdev);
149 if (ret) {
150 pr_err("%s: failed to add platform device: %d\n", __func__, ret);
151 platform_device_put(pdev);
152 return ret;
153 }
154
155 src_node = kstrdup("", GFP_KERNEL);
156 dst_node = kstrdup("", GFP_KERNEL);
157 if (!src_node || !dst_node) {
158 kfree(dst_node);
159 kfree(src_node);
160 return -ENOMEM;
161 }
162
163 client_dir = debugfs_create_dir("test_client", icc_dir);
164
165 debugfs_create_str("src_node", 0600, client_dir, &src_node);
166 debugfs_create_str("dst_node", 0600, client_dir, &dst_node);
167 debugfs_create_file("get", 0200, client_dir, NULL, &icc_get_fops);
168 debugfs_create_u32("avg_bw", 0600, client_dir, &avg_bw);
169 debugfs_create_u32("peak_bw", 0600, client_dir, &peak_bw);
170 debugfs_create_u32("tag", 0600, client_dir, &tag);
171 debugfs_create_file("commit", 0200, client_dir, NULL, &icc_commit_fops);
172
173 return 0;
174}
175
176#else
177
178int icc_debugfs_client_init(struct dentry *icc_dir)
179{
180 return 0;
181}
182
183#endif