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_create_file(const char *name, umode_t mode, 83 struct dentry *parent, void *data, 84 const struct file_operations *fops); 85 struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode, 86 struct dentry *parent, void *data, 87 const struct file_operations *fops); 88 89 struct dentry *debugfs_create_file_size(const char *name, umode_t mode, 90 struct dentry *parent, void *data, 91 const struct file_operations *fops, 92 loff_t file_size); 93 94 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent); 95 96 struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, 97 const char *dest); 98 99 struct dentry *debugfs_create_automount(const char *name, 100 struct dentry *parent, 101 struct vfsmount *(*f)(void *), 102 void *data); 103 104 void debugfs_remove(struct dentry *dentry); 105 void debugfs_remove_recursive(struct dentry *dentry); 106 107 int debugfs_use_file_start(const struct dentry *dentry, int *srcu_idx) 108 __acquires(&debugfs_srcu); 109 110 void debugfs_use_file_finish(int srcu_idx) __releases(&debugfs_srcu); 111 112 ssize_t debugfs_attr_read(struct file *file, char __user *buf, 113 size_t len, loff_t *ppos); 114 ssize_t debugfs_attr_write(struct file *file, const char __user *buf, 115 size_t len, loff_t *ppos); 116 117 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 118 struct dentry *new_dir, const char *new_name); 119 120 struct dentry *debugfs_create_u8(const char *name, umode_t mode, 121 struct dentry *parent, u8 *value); 122 struct dentry *debugfs_create_u16(const char *name, umode_t mode, 123 struct dentry *parent, u16 *value); 124 struct dentry *debugfs_create_u32(const char *name, umode_t mode, 125 struct dentry *parent, u32 *value); 126 struct dentry *debugfs_create_u64(const char *name, umode_t mode, 127 struct dentry *parent, u64 *value); 128 struct dentry *debugfs_create_ulong(const char *name, umode_t mode, 129 struct dentry *parent, unsigned long *value); 130 struct dentry *debugfs_create_x8(const char *name, umode_t mode, 131 struct dentry *parent, u8 *value); 132 struct dentry *debugfs_create_x16(const char *name, umode_t mode, 133 struct dentry *parent, u16 *value); 134 struct dentry *debugfs_create_x32(const char *name, umode_t mode, 135 struct dentry *parent, u32 *value); 136 struct dentry *debugfs_create_x64(const char *name, umode_t mode, 137 struct dentry *parent, u64 *value); 138 struct dentry *debugfs_create_size_t(const char *name, umode_t mode, 139 struct dentry *parent, size_t *value); 140 struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, 141 struct dentry *parent, atomic_t *value); 142 struct dentry *debugfs_create_bool(const char *name, umode_t mode, 143 struct dentry *parent, bool *value); 144 145 struct dentry *debugfs_create_blob(const char *name, umode_t mode, 146 struct dentry *parent, 147 struct debugfs_blob_wrapper *blob); 148 149 struct dentry *debugfs_create_regset32(const char *name, umode_t mode, 150 struct dentry *parent, 151 struct debugfs_regset32 *regset); 152 153 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 154 int nregs, void __iomem *base, char *prefix); 155 156 struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, 157 struct dentry *parent, 158 u32 *array, u32 elements); 159 160 struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name, 161 struct dentry *parent, 162 int (*read_fn)(struct seq_file *s, 163 void *data)); 164 165 bool debugfs_initialized(void); 166 167 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf, 168 size_t count, loff_t *ppos); 169 170 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, 171 size_t count, loff_t *ppos); 172 173 #else 174 175 #include <linux/err.h> 176 177 /* 178 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled 179 * so users have a chance to detect if there was a real error or not. We don't 180 * want to duplicate the design decision mistakes of procfs and devfs again. 181 */ 182 183 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode, 184 struct dentry *parent, void *data, 185 const struct file_operations *fops) 186 { 187 return ERR_PTR(-ENODEV); 188 } 189 190 static inline struct dentry *debugfs_create_file_size(const char *name, umode_t mode, 191 struct dentry *parent, void *data, 192 const struct file_operations *fops, 193 loff_t file_size) 194 { 195 return ERR_PTR(-ENODEV); 196 } 197 198 static inline struct dentry *debugfs_create_dir(const char *name, 199 struct dentry *parent) 200 { 201 return ERR_PTR(-ENODEV); 202 } 203 204 static inline struct dentry *debugfs_create_symlink(const char *name, 205 struct dentry *parent, 206 const char *dest) 207 { 208 return ERR_PTR(-ENODEV); 209 } 210 211 static inline struct dentry *debugfs_create_automount(const char *name, 212 struct dentry *parent, 213 struct vfsmount *(*f)(void *), 214 void *data) 215 { 216 return ERR_PTR(-ENODEV); 217 } 218 219 static inline void debugfs_remove(struct dentry *dentry) 220 { } 221 222 static inline void debugfs_remove_recursive(struct dentry *dentry) 223 { } 224 225 static inline int debugfs_use_file_start(const struct dentry *dentry, 226 int *srcu_idx) 227 __acquires(&debugfs_srcu) 228 { 229 return 0; 230 } 231 232 static inline void debugfs_use_file_finish(int srcu_idx) 233 __releases(&debugfs_srcu) 234 { } 235 236 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf, 237 size_t len, loff_t *ppos) 238 { 239 return -ENODEV; 240 } 241 242 static inline ssize_t debugfs_attr_write(struct file *file, 243 const char __user *buf, 244 size_t len, loff_t *ppos) 245 { 246 return -ENODEV; 247 } 248 249 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 250 struct dentry *new_dir, char *new_name) 251 { 252 return ERR_PTR(-ENODEV); 253 } 254 255 static inline struct dentry *debugfs_create_u8(const char *name, umode_t mode, 256 struct dentry *parent, 257 u8 *value) 258 { 259 return ERR_PTR(-ENODEV); 260 } 261 262 static inline struct dentry *debugfs_create_u16(const char *name, umode_t mode, 263 struct dentry *parent, 264 u16 *value) 265 { 266 return ERR_PTR(-ENODEV); 267 } 268 269 static inline struct dentry *debugfs_create_u32(const char *name, umode_t mode, 270 struct dentry *parent, 271 u32 *value) 272 { 273 return ERR_PTR(-ENODEV); 274 } 275 276 static inline struct dentry *debugfs_create_u64(const char *name, umode_t mode, 277 struct dentry *parent, 278 u64 *value) 279 { 280 return ERR_PTR(-ENODEV); 281 } 282 283 static inline struct dentry *debugfs_create_x8(const char *name, umode_t mode, 284 struct dentry *parent, 285 u8 *value) 286 { 287 return ERR_PTR(-ENODEV); 288 } 289 290 static inline struct dentry *debugfs_create_x16(const char *name, umode_t mode, 291 struct dentry *parent, 292 u16 *value) 293 { 294 return ERR_PTR(-ENODEV); 295 } 296 297 static inline struct dentry *debugfs_create_x32(const char *name, umode_t mode, 298 struct dentry *parent, 299 u32 *value) 300 { 301 return ERR_PTR(-ENODEV); 302 } 303 304 static inline struct dentry *debugfs_create_x64(const char *name, umode_t mode, 305 struct dentry *parent, 306 u64 *value) 307 { 308 return ERR_PTR(-ENODEV); 309 } 310 311 static inline struct dentry *debugfs_create_size_t(const char *name, umode_t mode, 312 struct dentry *parent, 313 size_t *value) 314 { 315 return ERR_PTR(-ENODEV); 316 } 317 318 static inline struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, 319 struct dentry *parent, atomic_t *value) 320 { 321 return ERR_PTR(-ENODEV); 322 } 323 324 static inline struct dentry *debugfs_create_bool(const char *name, umode_t mode, 325 struct dentry *parent, 326 bool *value) 327 { 328 return ERR_PTR(-ENODEV); 329 } 330 331 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode, 332 struct dentry *parent, 333 struct debugfs_blob_wrapper *blob) 334 { 335 return ERR_PTR(-ENODEV); 336 } 337 338 static inline struct dentry *debugfs_create_regset32(const char *name, 339 umode_t mode, struct dentry *parent, 340 struct debugfs_regset32 *regset) 341 { 342 return ERR_PTR(-ENODEV); 343 } 344 345 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 346 int nregs, void __iomem *base, char *prefix) 347 { 348 } 349 350 static inline bool debugfs_initialized(void) 351 { 352 return false; 353 } 354 355 static inline struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, 356 struct dentry *parent, 357 u32 *array, u32 elements) 358 { 359 return ERR_PTR(-ENODEV); 360 } 361 362 static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev, 363 const char *name, 364 struct dentry *parent, 365 int (*read_fn)(struct seq_file *s, 366 void *data)) 367 { 368 return ERR_PTR(-ENODEV); 369 } 370 371 static inline ssize_t debugfs_read_file_bool(struct file *file, 372 char __user *user_buf, 373 size_t count, loff_t *ppos) 374 { 375 return -ENODEV; 376 } 377 378 static inline ssize_t debugfs_write_file_bool(struct file *file, 379 const char __user *user_buf, 380 size_t count, loff_t *ppos) 381 { 382 return -ENODEV; 383 } 384 385 #endif 386 387 #endif 388