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
20 static LIST_HEAD(debugfs_paths);
21 static DEFINE_MUTEX(debugfs_lock);
22
23 static struct platform_device *pdev;
24 static struct icc_path *cur_path;
25
26 static char *src_node;
27 static char *dst_node;
28 static u32 avg_bw;
29 static u32 peak_bw;
30 static u32 tag;
31
32 struct debugfs_path {
33 const char *src;
34 const char *dst;
35 struct icc_path *path;
36 struct list_head list;
37 };
38
get_path(const char * src,const char * dst)39 static 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
icc_get_set(void * data,u64 val)51 static 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(sizeof(*debugfs_path), GFP_KERNEL);
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
102 err_put:
103 icc_put(cur_path);
104 err_free:
105 kfree(src);
106 kfree(dst);
107 out:
108 mutex_unlock(&debugfs_lock);
109 return ret;
110 }
111
112 DEFINE_DEBUGFS_ATTRIBUTE(icc_get_fops, NULL, icc_get_set, "%llu\n");
113
icc_commit_set(void * data,u64 val)114 static int icc_commit_set(void *data, u64 val)
115 {
116 int ret;
117
118 mutex_lock(&debugfs_lock);
119
120 if (IS_ERR_OR_NULL(cur_path)) {
121 ret = PTR_ERR(cur_path);
122 goto out;
123 }
124
125 icc_set_tag(cur_path, tag);
126 ret = icc_set_bw(cur_path, avg_bw, peak_bw);
127 out:
128 mutex_unlock(&debugfs_lock);
129 return ret;
130 }
131
132 DEFINE_DEBUGFS_ATTRIBUTE(icc_commit_fops, NULL, icc_commit_set, "%llu\n");
133
icc_debugfs_client_init(struct dentry * icc_dir)134 int icc_debugfs_client_init(struct dentry *icc_dir)
135 {
136 struct dentry *client_dir;
137 int ret;
138
139 pdev = platform_device_alloc("icc-debugfs-client", PLATFORM_DEVID_NONE);
140
141 ret = platform_device_add(pdev);
142 if (ret) {
143 pr_err("%s: failed to add platform device: %d\n", __func__, ret);
144 platform_device_put(pdev);
145 return ret;
146 }
147
148 client_dir = debugfs_create_dir("test_client", icc_dir);
149
150 debugfs_create_str("src_node", 0600, client_dir, &src_node);
151 debugfs_create_str("dst_node", 0600, client_dir, &dst_node);
152 debugfs_create_file("get", 0200, client_dir, NULL, &icc_get_fops);
153 debugfs_create_u32("avg_bw", 0600, client_dir, &avg_bw);
154 debugfs_create_u32("peak_bw", 0600, client_dir, &peak_bw);
155 debugfs_create_u32("tag", 0600, client_dir, &tag);
156 debugfs_create_file("commit", 0200, client_dir, NULL, &icc_commit_fops);
157
158 return 0;
159 }
160
161 #else
162
icc_debugfs_client_init(struct dentry * icc_dir)163 int icc_debugfs_client_init(struct dentry *icc_dir)
164 {
165 return 0;
166 }
167
168 #endif
169