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_size(const char *name, umode_t mode, 200 struct dentry *parent, void *data, 201 const struct file_operations *fops, 202 loff_t file_size) 203 { 204 return ERR_PTR(-ENODEV); 205 } 206 207 static inline struct dentry *debugfs_create_dir(const char *name, 208 struct dentry *parent) 209 { 210 return ERR_PTR(-ENODEV); 211 } 212 213 static inline struct dentry *debugfs_create_symlink(const char *name, 214 struct dentry *parent, 215 const char *dest) 216 { 217 return ERR_PTR(-ENODEV); 218 } 219 220 static inline struct dentry *debugfs_create_automount(const char *name, 221 struct dentry *parent, 222 struct vfsmount *(*f)(void *), 223 void *data) 224 { 225 return ERR_PTR(-ENODEV); 226 } 227 228 static inline void debugfs_remove(struct dentry *dentry) 229 { } 230 231 static inline void debugfs_remove_recursive(struct dentry *dentry) 232 { } 233 234 static inline int debugfs_use_file_start(const struct dentry *dentry, 235 int *srcu_idx) 236 __acquires(&debugfs_srcu) 237 { 238 return 0; 239 } 240 241 static inline void debugfs_use_file_finish(int srcu_idx) 242 __releases(&debugfs_srcu) 243 { } 244 245 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf, 246 size_t len, loff_t *ppos) 247 { 248 return -ENODEV; 249 } 250 251 static inline ssize_t debugfs_attr_write(struct file *file, 252 const char __user *buf, 253 size_t len, loff_t *ppos) 254 { 255 return -ENODEV; 256 } 257 258 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 259 struct dentry *new_dir, char *new_name) 260 { 261 return ERR_PTR(-ENODEV); 262 } 263 264 static inline struct dentry *debugfs_create_u8(const char *name, umode_t mode, 265 struct dentry *parent, 266 u8 *value) 267 { 268 return ERR_PTR(-ENODEV); 269 } 270 271 static inline struct dentry *debugfs_create_u16(const char *name, umode_t mode, 272 struct dentry *parent, 273 u16 *value) 274 { 275 return ERR_PTR(-ENODEV); 276 } 277 278 static inline struct dentry *debugfs_create_u32(const char *name, umode_t mode, 279 struct dentry *parent, 280 u32 *value) 281 { 282 return ERR_PTR(-ENODEV); 283 } 284 285 static inline struct dentry *debugfs_create_u64(const char *name, umode_t mode, 286 struct dentry *parent, 287 u64 *value) 288 { 289 return ERR_PTR(-ENODEV); 290 } 291 292 static inline struct dentry *debugfs_create_x8(const char *name, umode_t mode, 293 struct dentry *parent, 294 u8 *value) 295 { 296 return ERR_PTR(-ENODEV); 297 } 298 299 static inline struct dentry *debugfs_create_x16(const char *name, umode_t mode, 300 struct dentry *parent, 301 u16 *value) 302 { 303 return ERR_PTR(-ENODEV); 304 } 305 306 static inline struct dentry *debugfs_create_x32(const char *name, umode_t mode, 307 struct dentry *parent, 308 u32 *value) 309 { 310 return ERR_PTR(-ENODEV); 311 } 312 313 static inline struct dentry *debugfs_create_x64(const char *name, umode_t mode, 314 struct dentry *parent, 315 u64 *value) 316 { 317 return ERR_PTR(-ENODEV); 318 } 319 320 static inline struct dentry *debugfs_create_size_t(const char *name, umode_t mode, 321 struct dentry *parent, 322 size_t *value) 323 { 324 return ERR_PTR(-ENODEV); 325 } 326 327 static inline struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, 328 struct dentry *parent, atomic_t *value) 329 { 330 return ERR_PTR(-ENODEV); 331 } 332 333 static inline struct dentry *debugfs_create_bool(const char *name, umode_t mode, 334 struct dentry *parent, 335 bool *value) 336 { 337 return ERR_PTR(-ENODEV); 338 } 339 340 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode, 341 struct dentry *parent, 342 struct debugfs_blob_wrapper *blob) 343 { 344 return ERR_PTR(-ENODEV); 345 } 346 347 static inline struct dentry *debugfs_create_regset32(const char *name, 348 umode_t mode, struct dentry *parent, 349 struct debugfs_regset32 *regset) 350 { 351 return ERR_PTR(-ENODEV); 352 } 353 354 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 355 int nregs, void __iomem *base, char *prefix) 356 { 357 } 358 359 static inline bool debugfs_initialized(void) 360 { 361 return false; 362 } 363 364 static inline struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, 365 struct dentry *parent, 366 u32 *array, u32 elements) 367 { 368 return ERR_PTR(-ENODEV); 369 } 370 371 static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev, 372 const char *name, 373 struct dentry *parent, 374 int (*read_fn)(struct seq_file *s, 375 void *data)) 376 { 377 return ERR_PTR(-ENODEV); 378 } 379 380 static inline ssize_t debugfs_read_file_bool(struct file *file, 381 char __user *user_buf, 382 size_t count, loff_t *ppos) 383 { 384 return -ENODEV; 385 } 386 387 static inline ssize_t debugfs_write_file_bool(struct file *file, 388 const char __user *user_buf, 389 size_t count, loff_t *ppos) 390 { 391 return -ENODEV; 392 } 393 394 #endif 395 396 #endif 397