1 /* 2 * debugfs.h - a tiny little debug file system 3 * 4 * Copyright (C) 2004 Greg Kroah-Hartman <[email protected]> 5 * Copyright (C) 2004 IBM Inc. 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License version 9 * 2 as published by the Free Software Foundation. 10 * 11 * debugfs is for people to use instead of /proc or /sys. 12 * See Documentation/filesystems/ for more details. 13 */ 14 15 #ifndef _DEBUGFS_H_ 16 #define _DEBUGFS_H_ 17 18 #include <linux/fs.h> 19 #include <linux/seq_file.h> 20 21 #include <linux/types.h> 22 #include <linux/compiler.h> 23 24 struct device; 25 struct file_operations; 26 struct srcu_struct; 27 28 struct debugfs_blob_wrapper { 29 void *data; 30 unsigned long size; 31 }; 32 33 struct debugfs_reg32 { 34 char *name; 35 unsigned long offset; 36 }; 37 38 struct debugfs_regset32 { 39 const struct debugfs_reg32 *regs; 40 int nregs; 41 void __iomem *base; 42 }; 43 44 extern struct dentry *arch_debugfs_dir; 45 46 extern struct srcu_struct debugfs_srcu; 47 48 /** 49 * debugfs_real_fops - getter for the real file operation 50 * @filp: a pointer to a struct file 51 * 52 * Must only be called under the protection established by 53 * debugfs_use_file_start(). 54 */ 55 static inline const struct file_operations *debugfs_real_fops(const struct file *filp) 56 __must_hold(&debugfs_srcu) 57 { 58 /* 59 * Neither the pointer to the struct file_operations, nor its 60 * contents ever change -- srcu_dereference() is not needed here. 61 */ 62 return filp->f_path.dentry->d_fsdata; 63 } 64 65 #define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \ 66 static int __fops ## _open(struct inode *inode, struct file *file) \ 67 { \ 68 __simple_attr_check_format(__fmt, 0ull); \ 69 return simple_attr_open(inode, file, __get, __set, __fmt); \ 70 } \ 71 static const struct file_operations __fops = { \ 72 .owner = THIS_MODULE, \ 73 .open = __fops ## _open, \ 74 .release = simple_attr_release, \ 75 .read = debugfs_attr_read, \ 76 .write = debugfs_attr_write, \ 77 .llseek = no_llseek, \ 78 } 79 80 #if defined(CONFIG_DEBUG_FS) 81 82 struct dentry *debugfs_lookup(const char *name, struct dentry *parent); 83 84 struct dentry *debugfs_create_file(const char *name, umode_t mode, 85 struct dentry *parent, void *data, 86 const struct file_operations *fops); 87 struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode, 88 struct dentry *parent, void *data, 89 const struct file_operations *fops); 90 91 struct dentry *debugfs_create_file_size(const char *name, umode_t mode, 92 struct dentry *parent, void *data, 93 const struct file_operations *fops, 94 loff_t file_size); 95 96 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent); 97 98 struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, 99 const char *dest); 100 101 typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *); 102 struct dentry *debugfs_create_automount(const char *name, 103 struct dentry *parent, 104 debugfs_automount_t f, 105 void *data); 106 107 void debugfs_remove(struct dentry *dentry); 108 void debugfs_remove_recursive(struct dentry *dentry); 109 110 int debugfs_use_file_start(const struct dentry *dentry, int *srcu_idx) 111 __acquires(&debugfs_srcu); 112 113 void debugfs_use_file_finish(int srcu_idx) __releases(&debugfs_srcu); 114 115 ssize_t debugfs_attr_read(struct file *file, char __user *buf, 116 size_t len, loff_t *ppos); 117 ssize_t debugfs_attr_write(struct file *file, const char __user *buf, 118 size_t len, loff_t *ppos); 119 120 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 121 struct dentry *new_dir, const char *new_name); 122 123 struct dentry *debugfs_create_u8(const char *name, umode_t mode, 124 struct dentry *parent, u8 *value); 125 struct dentry *debugfs_create_u16(const char *name, umode_t mode, 126 struct dentry *parent, u16 *value); 127 struct dentry *debugfs_create_u32(const char *name, umode_t mode, 128 struct dentry *parent, u32 *value); 129 struct dentry *debugfs_create_u64(const char *name, umode_t mode, 130 struct dentry *parent, u64 *value); 131 struct dentry *debugfs_create_ulong(const char *name, umode_t mode, 132 struct dentry *parent, unsigned long *value); 133 struct dentry *debugfs_create_x8(const char *name, umode_t mode, 134 struct dentry *parent, u8 *value); 135 struct dentry *debugfs_create_x16(const char *name, umode_t mode, 136 struct dentry *parent, u16 *value); 137 struct dentry *debugfs_create_x32(const char *name, umode_t mode, 138 struct dentry *parent, u32 *value); 139 struct dentry *debugfs_create_x64(const char *name, umode_t mode, 140 struct dentry *parent, u64 *value); 141 struct dentry *debugfs_create_size_t(const char *name, umode_t mode, 142 struct dentry *parent, size_t *value); 143 struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, 144 struct dentry *parent, atomic_t *value); 145 struct dentry *debugfs_create_bool(const char *name, umode_t mode, 146 struct dentry *parent, bool *value); 147 148 struct dentry *debugfs_create_blob(const char *name, umode_t mode, 149 struct dentry *parent, 150 struct debugfs_blob_wrapper *blob); 151 152 struct dentry *debugfs_create_regset32(const char *name, umode_t mode, 153 struct dentry *parent, 154 struct debugfs_regset32 *regset); 155 156 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 157 int nregs, void __iomem *base, char *prefix); 158 159 struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, 160 struct dentry *parent, 161 u32 *array, u32 elements); 162 163 struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name, 164 struct dentry *parent, 165 int (*read_fn)(struct seq_file *s, 166 void *data)); 167 168 bool debugfs_initialized(void); 169 170 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf, 171 size_t count, loff_t *ppos); 172 173 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, 174 size_t count, loff_t *ppos); 175 176 #else 177 178 #include <linux/err.h> 179 180 /* 181 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled 182 * so users have a chance to detect if there was a real error or not. We don't 183 * want to duplicate the design decision mistakes of procfs and devfs again. 184 */ 185 186 static inline struct dentry *debugfs_lookup(const char *name, 187 struct dentry *parent) 188 { 189 return ERR_PTR(-ENODEV); 190 } 191 192 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode, 193 struct dentry *parent, void *data, 194 const struct file_operations *fops) 195 { 196 return ERR_PTR(-ENODEV); 197 } 198 199 static inline struct dentry *debugfs_create_file_unsafe(const char *name, 200 umode_t mode, struct dentry *parent, 201 void *data, 202 const struct file_operations *fops) 203 { 204 return ERR_PTR(-ENODEV); 205 } 206 207 static inline struct dentry *debugfs_create_file_size(const char *name, umode_t mode, 208 struct dentry *parent, void *data, 209 const struct file_operations *fops, 210 loff_t file_size) 211 { 212 return ERR_PTR(-ENODEV); 213 } 214 215 static inline struct dentry *debugfs_create_dir(const char *name, 216 struct dentry *parent) 217 { 218 return ERR_PTR(-ENODEV); 219 } 220 221 static inline struct dentry *debugfs_create_symlink(const char *name, 222 struct dentry *parent, 223 const char *dest) 224 { 225 return ERR_PTR(-ENODEV); 226 } 227 228 static inline struct dentry *debugfs_create_automount(const char *name, 229 struct dentry *parent, 230 struct vfsmount *(*f)(void *), 231 void *data) 232 { 233 return ERR_PTR(-ENODEV); 234 } 235 236 static inline void debugfs_remove(struct dentry *dentry) 237 { } 238 239 static inline void debugfs_remove_recursive(struct dentry *dentry) 240 { } 241 242 static inline int debugfs_use_file_start(const struct dentry *dentry, 243 int *srcu_idx) 244 __acquires(&debugfs_srcu) 245 { 246 return 0; 247 } 248 249 static inline void debugfs_use_file_finish(int srcu_idx) 250 __releases(&debugfs_srcu) 251 { } 252 253 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf, 254 size_t len, loff_t *ppos) 255 { 256 return -ENODEV; 257 } 258 259 static inline ssize_t debugfs_attr_write(struct file *file, 260 const char __user *buf, 261 size_t len, loff_t *ppos) 262 { 263 return -ENODEV; 264 } 265 266 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 267 struct dentry *new_dir, char *new_name) 268 { 269 return ERR_PTR(-ENODEV); 270 } 271 272 static inline struct dentry *debugfs_create_u8(const char *name, umode_t mode, 273 struct dentry *parent, 274 u8 *value) 275 { 276 return ERR_PTR(-ENODEV); 277 } 278 279 static inline struct dentry *debugfs_create_u16(const char *name, umode_t mode, 280 struct dentry *parent, 281 u16 *value) 282 { 283 return ERR_PTR(-ENODEV); 284 } 285 286 static inline struct dentry *debugfs_create_u32(const char *name, umode_t mode, 287 struct dentry *parent, 288 u32 *value) 289 { 290 return ERR_PTR(-ENODEV); 291 } 292 293 static inline struct dentry *debugfs_create_u64(const char *name, umode_t mode, 294 struct dentry *parent, 295 u64 *value) 296 { 297 return ERR_PTR(-ENODEV); 298 } 299 300 static inline struct dentry *debugfs_create_ulong(const char *name, 301 umode_t mode, 302 struct dentry *parent, 303 unsigned long *value) 304 { 305 return ERR_PTR(-ENODEV); 306 } 307 308 static inline struct dentry *debugfs_create_x8(const char *name, umode_t mode, 309 struct dentry *parent, 310 u8 *value) 311 { 312 return ERR_PTR(-ENODEV); 313 } 314 315 static inline struct dentry *debugfs_create_x16(const char *name, umode_t mode, 316 struct dentry *parent, 317 u16 *value) 318 { 319 return ERR_PTR(-ENODEV); 320 } 321 322 static inline struct dentry *debugfs_create_x32(const char *name, umode_t mode, 323 struct dentry *parent, 324 u32 *value) 325 { 326 return ERR_PTR(-ENODEV); 327 } 328 329 static inline struct dentry *debugfs_create_x64(const char *name, umode_t mode, 330 struct dentry *parent, 331 u64 *value) 332 { 333 return ERR_PTR(-ENODEV); 334 } 335 336 static inline struct dentry *debugfs_create_size_t(const char *name, umode_t mode, 337 struct dentry *parent, 338 size_t *value) 339 { 340 return ERR_PTR(-ENODEV); 341 } 342 343 static inline struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, 344 struct dentry *parent, atomic_t *value) 345 { 346 return ERR_PTR(-ENODEV); 347 } 348 349 static inline struct dentry *debugfs_create_bool(const char *name, umode_t mode, 350 struct dentry *parent, 351 bool *value) 352 { 353 return ERR_PTR(-ENODEV); 354 } 355 356 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode, 357 struct dentry *parent, 358 struct debugfs_blob_wrapper *blob) 359 { 360 return ERR_PTR(-ENODEV); 361 } 362 363 static inline struct dentry *debugfs_create_regset32(const char *name, 364 umode_t mode, struct dentry *parent, 365 struct debugfs_regset32 *regset) 366 { 367 return ERR_PTR(-ENODEV); 368 } 369 370 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 371 int nregs, void __iomem *base, char *prefix) 372 { 373 } 374 375 static inline bool debugfs_initialized(void) 376 { 377 return false; 378 } 379 380 static inline struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, 381 struct dentry *parent, 382 u32 *array, u32 elements) 383 { 384 return ERR_PTR(-ENODEV); 385 } 386 387 static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev, 388 const char *name, 389 struct dentry *parent, 390 int (*read_fn)(struct seq_file *s, 391 void *data)) 392 { 393 return ERR_PTR(-ENODEV); 394 } 395 396 static inline ssize_t debugfs_read_file_bool(struct file *file, 397 char __user *user_buf, 398 size_t count, loff_t *ppos) 399 { 400 return -ENODEV; 401 } 402 403 static inline ssize_t debugfs_write_file_bool(struct file *file, 404 const char __user *user_buf, 405 size_t count, loff_t *ppos) 406 { 407 return -ENODEV; 408 } 409 410 #endif 411 412 #endif 413