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/DocBook/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 = generic_file_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 struct dentry *debugfs_create_automount(const char *name, 102 struct dentry *parent, 103 struct vfsmount *(*f)(void *), 104 void *data); 105 106 void debugfs_remove(struct dentry *dentry); 107 void debugfs_remove_recursive(struct dentry *dentry); 108 109 int debugfs_use_file_start(const struct dentry *dentry, int *srcu_idx) 110 __acquires(&debugfs_srcu); 111 112 void debugfs_use_file_finish(int srcu_idx) __releases(&debugfs_srcu); 113 114 ssize_t debugfs_attr_read(struct file *file, char __user *buf, 115 size_t len, loff_t *ppos); 116 ssize_t debugfs_attr_write(struct file *file, const char __user *buf, 117 size_t len, loff_t *ppos); 118 119 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 120 struct dentry *new_dir, const char *new_name); 121 122 struct dentry *debugfs_create_u8(const char *name, umode_t mode, 123 struct dentry *parent, u8 *value); 124 struct dentry *debugfs_create_u16(const char *name, umode_t mode, 125 struct dentry *parent, u16 *value); 126 struct dentry *debugfs_create_u32(const char *name, umode_t mode, 127 struct dentry *parent, u32 *value); 128 struct dentry *debugfs_create_u64(const char *name, umode_t mode, 129 struct dentry *parent, u64 *value); 130 struct dentry *debugfs_create_ulong(const char *name, umode_t mode, 131 struct dentry *parent, unsigned long *value); 132 struct dentry *debugfs_create_x8(const char *name, umode_t mode, 133 struct dentry *parent, u8 *value); 134 struct dentry *debugfs_create_x16(const char *name, umode_t mode, 135 struct dentry *parent, u16 *value); 136 struct dentry *debugfs_create_x32(const char *name, umode_t mode, 137 struct dentry *parent, u32 *value); 138 struct dentry *debugfs_create_x64(const char *name, umode_t mode, 139 struct dentry *parent, u64 *value); 140 struct dentry *debugfs_create_size_t(const char *name, umode_t mode, 141 struct dentry *parent, size_t *value); 142 struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, 143 struct dentry *parent, atomic_t *value); 144 struct dentry *debugfs_create_bool(const char *name, umode_t mode, 145 struct dentry *parent, bool *value); 146 147 struct dentry *debugfs_create_blob(const char *name, umode_t mode, 148 struct dentry *parent, 149 struct debugfs_blob_wrapper *blob); 150 151 struct dentry *debugfs_create_regset32(const char *name, umode_t mode, 152 struct dentry *parent, 153 struct debugfs_regset32 *regset); 154 155 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 156 int nregs, void __iomem *base, char *prefix); 157 158 struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, 159 struct dentry *parent, 160 u32 *array, u32 elements); 161 162 struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name, 163 struct dentry *parent, 164 int (*read_fn)(struct seq_file *s, 165 void *data)); 166 167 bool debugfs_initialized(void); 168 169 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf, 170 size_t count, loff_t *ppos); 171 172 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, 173 size_t count, loff_t *ppos); 174 175 #else 176 177 #include <linux/err.h> 178 179 /* 180 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled 181 * so users have a chance to detect if there was a real error or not. We don't 182 * want to duplicate the design decision mistakes of procfs and devfs again. 183 */ 184 185 static inline struct dentry *debugfs_lookup(const char *name, 186 struct dentry *parent) 187 { 188 return ERR_PTR(-ENODEV); 189 } 190 191 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode, 192 struct dentry *parent, void *data, 193 const struct file_operations *fops) 194 { 195 return ERR_PTR(-ENODEV); 196 } 197 198 static inline struct dentry *debugfs_create_file_size(const char *name, umode_t mode, 199 struct dentry *parent, void *data, 200 const struct file_operations *fops, 201 loff_t file_size) 202 { 203 return ERR_PTR(-ENODEV); 204 } 205 206 static inline struct dentry *debugfs_create_dir(const char *name, 207 struct dentry *parent) 208 { 209 return ERR_PTR(-ENODEV); 210 } 211 212 static inline struct dentry *debugfs_create_symlink(const char *name, 213 struct dentry *parent, 214 const char *dest) 215 { 216 return ERR_PTR(-ENODEV); 217 } 218 219 static inline struct dentry *debugfs_create_automount(const char *name, 220 struct dentry *parent, 221 struct vfsmount *(*f)(void *), 222 void *data) 223 { 224 return ERR_PTR(-ENODEV); 225 } 226 227 static inline void debugfs_remove(struct dentry *dentry) 228 { } 229 230 static inline void debugfs_remove_recursive(struct dentry *dentry) 231 { } 232 233 static inline int debugfs_use_file_start(const struct dentry *dentry, 234 int *srcu_idx) 235 __acquires(&debugfs_srcu) 236 { 237 return 0; 238 } 239 240 static inline void debugfs_use_file_finish(int srcu_idx) 241 __releases(&debugfs_srcu) 242 { } 243 244 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf, 245 size_t len, loff_t *ppos) 246 { 247 return -ENODEV; 248 } 249 250 static inline ssize_t debugfs_attr_write(struct file *file, 251 const char __user *buf, 252 size_t len, loff_t *ppos) 253 { 254 return -ENODEV; 255 } 256 257 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 258 struct dentry *new_dir, char *new_name) 259 { 260 return ERR_PTR(-ENODEV); 261 } 262 263 static inline struct dentry *debugfs_create_u8(const char *name, umode_t mode, 264 struct dentry *parent, 265 u8 *value) 266 { 267 return ERR_PTR(-ENODEV); 268 } 269 270 static inline struct dentry *debugfs_create_u16(const char *name, umode_t mode, 271 struct dentry *parent, 272 u16 *value) 273 { 274 return ERR_PTR(-ENODEV); 275 } 276 277 static inline struct dentry *debugfs_create_u32(const char *name, umode_t mode, 278 struct dentry *parent, 279 u32 *value) 280 { 281 return ERR_PTR(-ENODEV); 282 } 283 284 static inline struct dentry *debugfs_create_u64(const char *name, umode_t mode, 285 struct dentry *parent, 286 u64 *value) 287 { 288 return ERR_PTR(-ENODEV); 289 } 290 291 static inline struct dentry *debugfs_create_x8(const char *name, umode_t mode, 292 struct dentry *parent, 293 u8 *value) 294 { 295 return ERR_PTR(-ENODEV); 296 } 297 298 static inline struct dentry *debugfs_create_x16(const char *name, umode_t mode, 299 struct dentry *parent, 300 u16 *value) 301 { 302 return ERR_PTR(-ENODEV); 303 } 304 305 static inline struct dentry *debugfs_create_x32(const char *name, umode_t mode, 306 struct dentry *parent, 307 u32 *value) 308 { 309 return ERR_PTR(-ENODEV); 310 } 311 312 static inline struct dentry *debugfs_create_x64(const char *name, umode_t mode, 313 struct dentry *parent, 314 u64 *value) 315 { 316 return ERR_PTR(-ENODEV); 317 } 318 319 static inline struct dentry *debugfs_create_size_t(const char *name, umode_t mode, 320 struct dentry *parent, 321 size_t *value) 322 { 323 return ERR_PTR(-ENODEV); 324 } 325 326 static inline struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, 327 struct dentry *parent, atomic_t *value) 328 { 329 return ERR_PTR(-ENODEV); 330 } 331 332 static inline struct dentry *debugfs_create_bool(const char *name, umode_t mode, 333 struct dentry *parent, 334 bool *value) 335 { 336 return ERR_PTR(-ENODEV); 337 } 338 339 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode, 340 struct dentry *parent, 341 struct debugfs_blob_wrapper *blob) 342 { 343 return ERR_PTR(-ENODEV); 344 } 345 346 static inline struct dentry *debugfs_create_regset32(const char *name, 347 umode_t mode, struct dentry *parent, 348 struct debugfs_regset32 *regset) 349 { 350 return ERR_PTR(-ENODEV); 351 } 352 353 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 354 int nregs, void __iomem *base, char *prefix) 355 { 356 } 357 358 static inline bool debugfs_initialized(void) 359 { 360 return false; 361 } 362 363 static inline struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, 364 struct dentry *parent, 365 u32 *array, u32 elements) 366 { 367 return ERR_PTR(-ENODEV); 368 } 369 370 static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev, 371 const char *name, 372 struct dentry *parent, 373 int (*read_fn)(struct seq_file *s, 374 void *data)) 375 { 376 return ERR_PTR(-ENODEV); 377 } 378 379 static inline ssize_t debugfs_read_file_bool(struct file *file, 380 char __user *user_buf, 381 size_t count, loff_t *ppos) 382 { 383 return -ENODEV; 384 } 385 386 static inline ssize_t debugfs_write_file_bool(struct file *file, 387 const char __user *user_buf, 388 size_t count, loff_t *ppos) 389 { 390 return -ENODEV; 391 } 392 393 #endif 394 395 #endif 396