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 | |
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 | |
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 | |
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 | |
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 | |
163 | int icc_debugfs_client_init(struct dentry *icc_dir) |
164 | { |
165 | return 0; |
166 | } |
167 | |
168 | #endif |
169 | |