1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * debugfs.h - a tiny little debug file system 4 * 5 * Copyright (C) 2004 Greg Kroah-Hartman <[email protected]> 6 * Copyright (C) 2004 IBM Inc. 7 * 8 * debugfs is for people to use instead of /proc or /sys. 9 * See Documentation/filesystems/ for more details. 10 */ 11 12 #ifndef _DEBUGFS_H_ 13 #define _DEBUGFS_H_ 14 15 #include <linux/fs.h> 16 #include <linux/seq_file.h> 17 18 #include <linux/types.h> 19 #include <linux/compiler.h> 20 21 struct device; 22 struct file_operations; 23 24 struct debugfs_blob_wrapper { 25 void *data; 26 unsigned long size; 27 }; 28 29 struct debugfs_reg32 { 30 char *name; 31 unsigned long offset; 32 }; 33 34 struct debugfs_regset32 { 35 const struct debugfs_reg32 *regs; 36 int nregs; 37 void __iomem *base; 38 }; 39 40 extern struct dentry *arch_debugfs_dir; 41 42 #define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \ 43 static int __fops ## _open(struct inode *inode, struct file *file) \ 44 { \ 45 __simple_attr_check_format(__fmt, 0ull); \ 46 return simple_attr_open(inode, file, __get, __set, __fmt); \ 47 } \ 48 static const struct file_operations __fops = { \ 49 .owner = THIS_MODULE, \ 50 .open = __fops ## _open, \ 51 .release = simple_attr_release, \ 52 .read = debugfs_attr_read, \ 53 .write = debugfs_attr_write, \ 54 .llseek = no_llseek, \ 55 } 56 57 typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *); 58 59 #if defined(CONFIG_DEBUG_FS) 60 61 struct dentry *debugfs_lookup(const char *name, struct dentry *parent); 62 63 struct dentry *debugfs_create_file(const char *name, umode_t mode, 64 struct dentry *parent, void *data, 65 const struct file_operations *fops); 66 struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode, 67 struct dentry *parent, void *data, 68 const struct file_operations *fops); 69 70 void debugfs_create_file_size(const char *name, umode_t mode, 71 struct dentry *parent, void *data, 72 const struct file_operations *fops, 73 loff_t file_size); 74 75 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent); 76 77 struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, 78 const char *dest); 79 80 struct dentry *debugfs_create_automount(const char *name, 81 struct dentry *parent, 82 debugfs_automount_t f, 83 void *data); 84 85 void debugfs_remove(struct dentry *dentry); 86 #define debugfs_remove_recursive debugfs_remove 87 88 const struct file_operations *debugfs_real_fops(const struct file *filp); 89 90 int debugfs_file_get(struct dentry *dentry); 91 void debugfs_file_put(struct dentry *dentry); 92 93 ssize_t debugfs_attr_read(struct file *file, char __user *buf, 94 size_t len, loff_t *ppos); 95 ssize_t debugfs_attr_write(struct file *file, const char __user *buf, 96 size_t len, loff_t *ppos); 97 98 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 99 struct dentry *new_dir, const char *new_name); 100 101 void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent, 102 u8 *value); 103 void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent, 104 u16 *value); 105 struct dentry *debugfs_create_u32(const char *name, umode_t mode, 106 struct dentry *parent, u32 *value); 107 void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent, 108 u64 *value); 109 struct dentry *debugfs_create_ulong(const char *name, umode_t mode, 110 struct dentry *parent, unsigned long *value); 111 void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent, 112 u8 *value); 113 void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent, 114 u16 *value); 115 void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent, 116 u32 *value); 117 void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent, 118 u64 *value); 119 void debugfs_create_size_t(const char *name, umode_t mode, 120 struct dentry *parent, size_t *value); 121 void debugfs_create_atomic_t(const char *name, umode_t mode, 122 struct dentry *parent, atomic_t *value); 123 struct dentry *debugfs_create_bool(const char *name, umode_t mode, 124 struct dentry *parent, bool *value); 125 126 struct dentry *debugfs_create_blob(const char *name, umode_t mode, 127 struct dentry *parent, 128 struct debugfs_blob_wrapper *blob); 129 130 void debugfs_create_regset32(const char *name, umode_t mode, 131 struct dentry *parent, 132 struct debugfs_regset32 *regset); 133 134 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 135 int nregs, void __iomem *base, char *prefix); 136 137 void debugfs_create_u32_array(const char *name, umode_t mode, 138 struct dentry *parent, u32 *array, u32 elements); 139 140 struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name, 141 struct dentry *parent, 142 int (*read_fn)(struct seq_file *s, 143 void *data)); 144 145 bool debugfs_initialized(void); 146 147 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf, 148 size_t count, loff_t *ppos); 149 150 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, 151 size_t count, loff_t *ppos); 152 153 #else 154 155 #include <linux/err.h> 156 157 /* 158 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled 159 * so users have a chance to detect if there was a real error or not. We don't 160 * want to duplicate the design decision mistakes of procfs and devfs again. 161 */ 162 163 static inline struct dentry *debugfs_lookup(const char *name, 164 struct dentry *parent) 165 { 166 return ERR_PTR(-ENODEV); 167 } 168 169 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode, 170 struct dentry *parent, void *data, 171 const struct file_operations *fops) 172 { 173 return ERR_PTR(-ENODEV); 174 } 175 176 static inline struct dentry *debugfs_create_file_unsafe(const char *name, 177 umode_t mode, struct dentry *parent, 178 void *data, 179 const struct file_operations *fops) 180 { 181 return ERR_PTR(-ENODEV); 182 } 183 184 static inline void debugfs_create_file_size(const char *name, umode_t mode, 185 struct dentry *parent, void *data, 186 const struct file_operations *fops, 187 loff_t file_size) 188 { } 189 190 static inline struct dentry *debugfs_create_dir(const char *name, 191 struct dentry *parent) 192 { 193 return ERR_PTR(-ENODEV); 194 } 195 196 static inline struct dentry *debugfs_create_symlink(const char *name, 197 struct dentry *parent, 198 const char *dest) 199 { 200 return ERR_PTR(-ENODEV); 201 } 202 203 static inline struct dentry *debugfs_create_automount(const char *name, 204 struct dentry *parent, 205 debugfs_automount_t f, 206 void *data) 207 { 208 return ERR_PTR(-ENODEV); 209 } 210 211 static inline void debugfs_remove(struct dentry *dentry) 212 { } 213 214 static inline void debugfs_remove_recursive(struct dentry *dentry) 215 { } 216 217 const struct file_operations *debugfs_real_fops(const struct file *filp); 218 219 static inline int debugfs_file_get(struct dentry *dentry) 220 { 221 return 0; 222 } 223 224 static inline void debugfs_file_put(struct dentry *dentry) 225 { } 226 227 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf, 228 size_t len, loff_t *ppos) 229 { 230 return -ENODEV; 231 } 232 233 static inline ssize_t debugfs_attr_write(struct file *file, 234 const char __user *buf, 235 size_t len, loff_t *ppos) 236 { 237 return -ENODEV; 238 } 239 240 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 241 struct dentry *new_dir, char *new_name) 242 { 243 return ERR_PTR(-ENODEV); 244 } 245 246 static inline void debugfs_create_u8(const char *name, umode_t mode, 247 struct dentry *parent, u8 *value) { } 248 249 static inline void debugfs_create_u16(const char *name, umode_t mode, 250 struct dentry *parent, u16 *value) { } 251 252 static inline struct dentry *debugfs_create_u32(const char *name, umode_t mode, 253 struct dentry *parent, 254 u32 *value) 255 { 256 return ERR_PTR(-ENODEV); 257 } 258 259 static inline void debugfs_create_u64(const char *name, umode_t mode, 260 struct dentry *parent, u64 *value) { } 261 262 static inline struct dentry *debugfs_create_ulong(const char *name, 263 umode_t mode, 264 struct dentry *parent, 265 unsigned long *value) 266 { 267 return ERR_PTR(-ENODEV); 268 } 269 270 static inline void debugfs_create_x8(const char *name, umode_t mode, 271 struct dentry *parent, u8 *value) { } 272 273 static inline void debugfs_create_x16(const char *name, umode_t mode, 274 struct dentry *parent, u16 *value) { } 275 276 static inline void debugfs_create_x32(const char *name, umode_t mode, 277 struct dentry *parent, u32 *value) { } 278 279 static inline void debugfs_create_x64(const char *name, umode_t mode, 280 struct dentry *parent, u64 *value) { } 281 282 static inline void debugfs_create_size_t(const char *name, umode_t mode, 283 struct dentry *parent, size_t *value) 284 { } 285 286 static inline void debugfs_create_atomic_t(const char *name, umode_t mode, 287 struct dentry *parent, 288 atomic_t *value) 289 { } 290 291 static inline struct dentry *debugfs_create_bool(const char *name, umode_t mode, 292 struct dentry *parent, 293 bool *value) 294 { 295 return ERR_PTR(-ENODEV); 296 } 297 298 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode, 299 struct dentry *parent, 300 struct debugfs_blob_wrapper *blob) 301 { 302 return ERR_PTR(-ENODEV); 303 } 304 305 static inline void debugfs_create_regset32(const char *name, umode_t mode, 306 struct dentry *parent, 307 struct debugfs_regset32 *regset) 308 { 309 } 310 311 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 312 int nregs, void __iomem *base, char *prefix) 313 { 314 } 315 316 static inline bool debugfs_initialized(void) 317 { 318 return false; 319 } 320 321 static inline void debugfs_create_u32_array(const char *name, umode_t mode, 322 struct dentry *parent, u32 *array, 323 u32 elements) 324 { 325 } 326 327 static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev, 328 const char *name, 329 struct dentry *parent, 330 int (*read_fn)(struct seq_file *s, 331 void *data)) 332 { 333 return ERR_PTR(-ENODEV); 334 } 335 336 static inline ssize_t debugfs_read_file_bool(struct file *file, 337 char __user *user_buf, 338 size_t count, loff_t *ppos) 339 { 340 return -ENODEV; 341 } 342 343 static inline ssize_t debugfs_write_file_bool(struct file *file, 344 const char __user *user_buf, 345 size_t count, loff_t *ppos) 346 { 347 return -ENODEV; 348 } 349 350 #endif 351 352 /** 353 * debugfs_create_xul - create a debugfs file that is used to read and write an 354 * unsigned long value, formatted in hexadecimal 355 * @name: a pointer to a string containing the name of the file to create. 356 * @mode: the permission that the file should have 357 * @parent: a pointer to the parent dentry for this file. This should be a 358 * directory dentry if set. If this parameter is %NULL, then the 359 * file will be created in the root of the debugfs filesystem. 360 * @value: a pointer to the variable that the file should read to and write 361 * from. 362 */ 363 static inline void debugfs_create_xul(const char *name, umode_t mode, 364 struct dentry *parent, 365 unsigned long *value) 366 { 367 if (sizeof(*value) == sizeof(u32)) 368 debugfs_create_x32(name, mode, parent, (u32 *)value); 369 else 370 debugfs_create_x64(name, mode, parent, (u64 *)value); 371 } 372 373 #endif 374