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 * 56 debugfs_real_fops(const struct file *filp) 57 __must_hold(&debugfs_srcu) 58 { 59 /* 60 * Neither the pointer to the struct file_operations, nor its 61 * contents ever change -- srcu_dereference() is not needed here. 62 */ 63 return filp->f_path.dentry->d_fsdata; 64 } 65 66 #define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \ 67 static int __fops ## _open(struct inode *inode, struct file *file) \ 68 { \ 69 __simple_attr_check_format(__fmt, 0ull); \ 70 return simple_attr_open(inode, file, __get, __set, __fmt); \ 71 } \ 72 static const struct file_operations __fops = { \ 73 .owner = THIS_MODULE, \ 74 .open = __fops ## _open, \ 75 .release = simple_attr_release, \ 76 .read = debugfs_attr_read, \ 77 .write = debugfs_attr_write, \ 78 .llseek = generic_file_llseek, \ 79 } 80 81 #if defined(CONFIG_DEBUG_FS) 82 83 struct dentry *debugfs_create_file(const char *name, umode_t mode, 84 struct dentry *parent, void *data, 85 const struct file_operations *fops); 86 struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode, 87 struct dentry *parent, void *data, 88 const struct file_operations *fops); 89 90 struct dentry *debugfs_create_file_size(const char *name, umode_t mode, 91 struct dentry *parent, void *data, 92 const struct file_operations *fops, 93 loff_t file_size); 94 95 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent); 96 97 struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, 98 const char *dest); 99 100 struct dentry *debugfs_create_automount(const char *name, 101 struct dentry *parent, 102 struct vfsmount *(*f)(void *), 103 void *data); 104 105 void debugfs_remove(struct dentry *dentry); 106 void debugfs_remove_recursive(struct dentry *dentry); 107 108 int debugfs_use_file_start(const struct dentry *dentry, int *srcu_idx) 109 __acquires(&debugfs_srcu); 110 111 void debugfs_use_file_finish(int srcu_idx) __releases(&debugfs_srcu); 112 113 ssize_t debugfs_attr_read(struct file *file, char __user *buf, 114 size_t len, loff_t *ppos); 115 ssize_t debugfs_attr_write(struct file *file, const char __user *buf, 116 size_t len, loff_t *ppos); 117 118 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 119 struct dentry *new_dir, const char *new_name); 120 121 struct dentry *debugfs_create_u8(const char *name, umode_t mode, 122 struct dentry *parent, u8 *value); 123 struct dentry *debugfs_create_u16(const char *name, umode_t mode, 124 struct dentry *parent, u16 *value); 125 struct dentry *debugfs_create_u32(const char *name, umode_t mode, 126 struct dentry *parent, u32 *value); 127 struct dentry *debugfs_create_u64(const char *name, umode_t mode, 128 struct dentry *parent, u64 *value); 129 struct dentry *debugfs_create_ulong(const char *name, umode_t mode, 130 struct dentry *parent, unsigned long *value); 131 struct dentry *debugfs_create_x8(const char *name, umode_t mode, 132 struct dentry *parent, u8 *value); 133 struct dentry *debugfs_create_x16(const char *name, umode_t mode, 134 struct dentry *parent, u16 *value); 135 struct dentry *debugfs_create_x32(const char *name, umode_t mode, 136 struct dentry *parent, u32 *value); 137 struct dentry *debugfs_create_x64(const char *name, umode_t mode, 138 struct dentry *parent, u64 *value); 139 struct dentry *debugfs_create_size_t(const char *name, umode_t mode, 140 struct dentry *parent, size_t *value); 141 struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, 142 struct dentry *parent, atomic_t *value); 143 struct dentry *debugfs_create_bool(const char *name, umode_t mode, 144 struct dentry *parent, bool *value); 145 146 struct dentry *debugfs_create_blob(const char *name, umode_t mode, 147 struct dentry *parent, 148 struct debugfs_blob_wrapper *blob); 149 150 struct dentry *debugfs_create_regset32(const char *name, umode_t mode, 151 struct dentry *parent, 152 struct debugfs_regset32 *regset); 153 154 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 155 int nregs, void __iomem *base, char *prefix); 156 157 struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, 158 struct dentry *parent, 159 u32 *array, u32 elements); 160 161 struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name, 162 struct dentry *parent, 163 int (*read_fn)(struct seq_file *s, 164 void *data)); 165 166 bool debugfs_initialized(void); 167 168 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf, 169 size_t count, loff_t *ppos); 170 171 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, 172 size_t count, loff_t *ppos); 173 174 #else 175 176 #include <linux/err.h> 177 178 /* 179 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled 180 * so users have a chance to detect if there was a real error or not. We don't 181 * want to duplicate the design decision mistakes of procfs and devfs again. 182 */ 183 184 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode, 185 struct dentry *parent, void *data, 186 const struct file_operations *fops) 187 { 188 return ERR_PTR(-ENODEV); 189 } 190 191 static inline struct dentry *debugfs_create_file_size(const char *name, umode_t mode, 192 struct dentry *parent, void *data, 193 const struct file_operations *fops, 194 loff_t file_size) 195 { 196 return ERR_PTR(-ENODEV); 197 } 198 199 static inline struct dentry *debugfs_create_dir(const char *name, 200 struct dentry *parent) 201 { 202 return ERR_PTR(-ENODEV); 203 } 204 205 static inline struct dentry *debugfs_create_symlink(const char *name, 206 struct dentry *parent, 207 const char *dest) 208 { 209 return ERR_PTR(-ENODEV); 210 } 211 212 static inline struct dentry *debugfs_create_automount(const char *name, 213 struct dentry *parent, 214 struct vfsmount *(*f)(void *), 215 void *data) 216 { 217 return ERR_PTR(-ENODEV); 218 } 219 220 static inline void debugfs_remove(struct dentry *dentry) 221 { } 222 223 static inline void debugfs_remove_recursive(struct dentry *dentry) 224 { } 225 226 static inline int debugfs_use_file_start(const struct dentry *dentry, 227 int *srcu_idx) 228 __acquires(&debugfs_srcu) 229 { 230 return 0; 231 } 232 233 static inline void debugfs_use_file_finish(int srcu_idx) 234 __releases(&debugfs_srcu) 235 { } 236 237 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf, 238 size_t len, loff_t *ppos) 239 { 240 return -ENODEV; 241 } 242 243 static inline ssize_t debugfs_attr_write(struct file *file, 244 const char __user *buf, 245 size_t len, loff_t *ppos) 246 { 247 return -ENODEV; 248 } 249 250 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 251 struct dentry *new_dir, char *new_name) 252 { 253 return ERR_PTR(-ENODEV); 254 } 255 256 static inline struct dentry *debugfs_create_u8(const char *name, umode_t mode, 257 struct dentry *parent, 258 u8 *value) 259 { 260 return ERR_PTR(-ENODEV); 261 } 262 263 static inline struct dentry *debugfs_create_u16(const char *name, umode_t mode, 264 struct dentry *parent, 265 u16 *value) 266 { 267 return ERR_PTR(-ENODEV); 268 } 269 270 static inline struct dentry *debugfs_create_u32(const char *name, umode_t mode, 271 struct dentry *parent, 272 u32 *value) 273 { 274 return ERR_PTR(-ENODEV); 275 } 276 277 static inline struct dentry *debugfs_create_u64(const char *name, umode_t mode, 278 struct dentry *parent, 279 u64 *value) 280 { 281 return ERR_PTR(-ENODEV); 282 } 283 284 static inline struct dentry *debugfs_create_x8(const char *name, umode_t mode, 285 struct dentry *parent, 286 u8 *value) 287 { 288 return ERR_PTR(-ENODEV); 289 } 290 291 static inline struct dentry *debugfs_create_x16(const char *name, umode_t mode, 292 struct dentry *parent, 293 u16 *value) 294 { 295 return ERR_PTR(-ENODEV); 296 } 297 298 static inline struct dentry *debugfs_create_x32(const char *name, umode_t mode, 299 struct dentry *parent, 300 u32 *value) 301 { 302 return ERR_PTR(-ENODEV); 303 } 304 305 static inline struct dentry *debugfs_create_x64(const char *name, umode_t mode, 306 struct dentry *parent, 307 u64 *value) 308 { 309 return ERR_PTR(-ENODEV); 310 } 311 312 static inline struct dentry *debugfs_create_size_t(const char *name, umode_t mode, 313 struct dentry *parent, 314 size_t *value) 315 { 316 return ERR_PTR(-ENODEV); 317 } 318 319 static inline struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, 320 struct dentry *parent, atomic_t *value) 321 { 322 return ERR_PTR(-ENODEV); 323 } 324 325 static inline struct dentry *debugfs_create_bool(const char *name, umode_t mode, 326 struct dentry *parent, 327 bool *value) 328 { 329 return ERR_PTR(-ENODEV); 330 } 331 332 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode, 333 struct dentry *parent, 334 struct debugfs_blob_wrapper *blob) 335 { 336 return ERR_PTR(-ENODEV); 337 } 338 339 static inline struct dentry *debugfs_create_regset32(const char *name, 340 umode_t mode, struct dentry *parent, 341 struct debugfs_regset32 *regset) 342 { 343 return ERR_PTR(-ENODEV); 344 } 345 346 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 347 int nregs, void __iomem *base, char *prefix) 348 { 349 } 350 351 static inline bool debugfs_initialized(void) 352 { 353 return false; 354 } 355 356 static inline struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, 357 struct dentry *parent, 358 u32 *array, u32 elements) 359 { 360 return ERR_PTR(-ENODEV); 361 } 362 363 static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev, 364 const char *name, 365 struct dentry *parent, 366 int (*read_fn)(struct seq_file *s, 367 void *data)) 368 { 369 return ERR_PTR(-ENODEV); 370 } 371 372 static inline ssize_t debugfs_read_file_bool(struct file *file, 373 char __user *user_buf, 374 size_t count, loff_t *ppos) 375 { 376 return -ENODEV; 377 } 378 379 static inline ssize_t debugfs_write_file_bool(struct file *file, 380 const char __user *user_buf, 381 size_t count, loff_t *ppos) 382 { 383 return -ENODEV; 384 } 385 386 #endif 387 388 #endif 389