1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * debugfs.h - a tiny little debug file system 4 * 5 * Copyright (C) 2004 Greg Kroah-Hartman <[email protected]> 6 * Copyright (C) 2004 IBM Inc. 7 * 8 * debugfs is for people to use instead of /proc or /sys. 9 * See Documentation/filesystems/ for more details. 10 */ 11 12 #ifndef _DEBUGFS_H_ 13 #define _DEBUGFS_H_ 14 15 #include <linux/fs.h> 16 #include <linux/seq_file.h> 17 18 #include <linux/types.h> 19 #include <linux/compiler.h> 20 21 struct device; 22 struct file_operations; 23 24 struct debugfs_blob_wrapper { 25 void *data; 26 unsigned long size; 27 }; 28 29 struct debugfs_reg32 { 30 char *name; 31 unsigned long offset; 32 }; 33 34 struct debugfs_regset32 { 35 const struct debugfs_reg32 *regs; 36 int nregs; 37 void __iomem *base; 38 struct device *dev; /* Optional device for Runtime PM */ 39 }; 40 41 struct debugfs_u32_array { 42 u32 *array; 43 u32 n_elements; 44 }; 45 46 extern struct dentry *arch_debugfs_dir; 47 48 #define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \ 49 static int __fops ## _open(struct inode *inode, struct file *file) \ 50 { \ 51 __simple_attr_check_format(__fmt, 0ull); \ 52 return simple_attr_open(inode, file, __get, __set, __fmt); \ 53 } \ 54 static const struct file_operations __fops = { \ 55 .owner = THIS_MODULE, \ 56 .open = __fops ## _open, \ 57 .release = simple_attr_release, \ 58 .read = debugfs_attr_read, \ 59 .write = debugfs_attr_write, \ 60 .llseek = no_llseek, \ 61 } 62 63 typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *); 64 65 #if defined(CONFIG_DEBUG_FS) 66 67 struct dentry *debugfs_lookup(const char *name, struct dentry *parent); 68 69 struct dentry *debugfs_create_file(const char *name, umode_t mode, 70 struct dentry *parent, void *data, 71 const struct file_operations *fops); 72 struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode, 73 struct dentry *parent, void *data, 74 const struct file_operations *fops); 75 76 void debugfs_create_file_size(const char *name, umode_t mode, 77 struct dentry *parent, void *data, 78 const struct file_operations *fops, 79 loff_t file_size); 80 81 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent); 82 83 struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, 84 const char *dest); 85 86 struct dentry *debugfs_create_automount(const char *name, 87 struct dentry *parent, 88 debugfs_automount_t f, 89 void *data); 90 91 void debugfs_remove(struct dentry *dentry); 92 #define debugfs_remove_recursive debugfs_remove 93 94 const struct file_operations *debugfs_real_fops(const struct file *filp); 95 96 int debugfs_file_get(struct dentry *dentry); 97 void debugfs_file_put(struct dentry *dentry); 98 99 ssize_t debugfs_attr_read(struct file *file, char __user *buf, 100 size_t len, loff_t *ppos); 101 ssize_t debugfs_attr_write(struct file *file, const char __user *buf, 102 size_t len, loff_t *ppos); 103 104 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 105 struct dentry *new_dir, const char *new_name); 106 107 void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent, 108 u8 *value); 109 void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent, 110 u16 *value); 111 void debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent, 112 u32 *value); 113 void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent, 114 u64 *value); 115 struct dentry *debugfs_create_ulong(const char *name, umode_t mode, 116 struct dentry *parent, unsigned long *value); 117 void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent, 118 u8 *value); 119 void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent, 120 u16 *value); 121 void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent, 122 u32 *value); 123 void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent, 124 u64 *value); 125 void debugfs_create_size_t(const char *name, umode_t mode, 126 struct dentry *parent, size_t *value); 127 void debugfs_create_atomic_t(const char *name, umode_t mode, 128 struct dentry *parent, atomic_t *value); 129 struct dentry *debugfs_create_bool(const char *name, umode_t mode, 130 struct dentry *parent, bool *value); 131 void debugfs_create_str(const char *name, umode_t mode, 132 struct dentry *parent, char **value); 133 134 struct dentry *debugfs_create_blob(const char *name, umode_t mode, 135 struct dentry *parent, 136 struct debugfs_blob_wrapper *blob); 137 138 void debugfs_create_regset32(const char *name, umode_t mode, 139 struct dentry *parent, 140 struct debugfs_regset32 *regset); 141 142 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 143 int nregs, void __iomem *base, char *prefix); 144 145 void debugfs_create_u32_array(const char *name, umode_t mode, 146 struct dentry *parent, 147 struct debugfs_u32_array *array); 148 149 void debugfs_create_devm_seqfile(struct device *dev, const char *name, 150 struct dentry *parent, 151 int (*read_fn)(struct seq_file *s, void *data)); 152 153 bool debugfs_initialized(void); 154 155 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf, 156 size_t count, loff_t *ppos); 157 158 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, 159 size_t count, loff_t *ppos); 160 161 ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf, 162 size_t count, loff_t *ppos); 163 164 #else 165 166 #include <linux/err.h> 167 168 /* 169 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled 170 * so users have a chance to detect if there was a real error or not. We don't 171 * want to duplicate the design decision mistakes of procfs and devfs again. 172 */ 173 174 static inline struct dentry *debugfs_lookup(const char *name, 175 struct dentry *parent) 176 { 177 return ERR_PTR(-ENODEV); 178 } 179 180 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode, 181 struct dentry *parent, void *data, 182 const struct file_operations *fops) 183 { 184 return ERR_PTR(-ENODEV); 185 } 186 187 static inline struct dentry *debugfs_create_file_unsafe(const char *name, 188 umode_t mode, struct dentry *parent, 189 void *data, 190 const struct file_operations *fops) 191 { 192 return ERR_PTR(-ENODEV); 193 } 194 195 static inline void debugfs_create_file_size(const char *name, umode_t mode, 196 struct dentry *parent, void *data, 197 const struct file_operations *fops, 198 loff_t file_size) 199 { } 200 201 static inline struct dentry *debugfs_create_dir(const char *name, 202 struct dentry *parent) 203 { 204 return ERR_PTR(-ENODEV); 205 } 206 207 static inline struct dentry *debugfs_create_symlink(const char *name, 208 struct dentry *parent, 209 const char *dest) 210 { 211 return ERR_PTR(-ENODEV); 212 } 213 214 static inline struct dentry *debugfs_create_automount(const char *name, 215 struct dentry *parent, 216 debugfs_automount_t f, 217 void *data) 218 { 219 return ERR_PTR(-ENODEV); 220 } 221 222 static inline void debugfs_remove(struct dentry *dentry) 223 { } 224 225 static inline void debugfs_remove_recursive(struct dentry *dentry) 226 { } 227 228 const struct file_operations *debugfs_real_fops(const struct file *filp); 229 230 static inline int debugfs_file_get(struct dentry *dentry) 231 { 232 return 0; 233 } 234 235 static inline void debugfs_file_put(struct dentry *dentry) 236 { } 237 238 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf, 239 size_t len, loff_t *ppos) 240 { 241 return -ENODEV; 242 } 243 244 static inline ssize_t debugfs_attr_write(struct file *file, 245 const char __user *buf, 246 size_t len, loff_t *ppos) 247 { 248 return -ENODEV; 249 } 250 251 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 252 struct dentry *new_dir, char *new_name) 253 { 254 return ERR_PTR(-ENODEV); 255 } 256 257 static inline void debugfs_create_u8(const char *name, umode_t mode, 258 struct dentry *parent, u8 *value) { } 259 260 static inline void debugfs_create_u16(const char *name, umode_t mode, 261 struct dentry *parent, u16 *value) { } 262 263 static inline void debugfs_create_u32(const char *name, umode_t mode, 264 struct dentry *parent, u32 *value) { } 265 266 static inline void debugfs_create_u64(const char *name, umode_t mode, 267 struct dentry *parent, u64 *value) { } 268 269 static inline struct dentry *debugfs_create_ulong(const char *name, 270 umode_t mode, 271 struct dentry *parent, 272 unsigned long *value) 273 { 274 return ERR_PTR(-ENODEV); 275 } 276 277 static inline void debugfs_create_x8(const char *name, umode_t mode, 278 struct dentry *parent, u8 *value) { } 279 280 static inline void debugfs_create_x16(const char *name, umode_t mode, 281 struct dentry *parent, u16 *value) { } 282 283 static inline void debugfs_create_x32(const char *name, umode_t mode, 284 struct dentry *parent, u32 *value) { } 285 286 static inline void debugfs_create_x64(const char *name, umode_t mode, 287 struct dentry *parent, u64 *value) { } 288 289 static inline void debugfs_create_size_t(const char *name, umode_t mode, 290 struct dentry *parent, size_t *value) 291 { } 292 293 static inline void debugfs_create_atomic_t(const char *name, umode_t mode, 294 struct dentry *parent, 295 atomic_t *value) 296 { } 297 298 static inline struct dentry *debugfs_create_bool(const char *name, umode_t mode, 299 struct dentry *parent, 300 bool *value) 301 { 302 return ERR_PTR(-ENODEV); 303 } 304 305 static inline void debugfs_create_str(const char *name, umode_t mode, 306 struct dentry *parent, 307 char **value) 308 { } 309 310 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode, 311 struct dentry *parent, 312 struct debugfs_blob_wrapper *blob) 313 { 314 return ERR_PTR(-ENODEV); 315 } 316 317 static inline void debugfs_create_regset32(const char *name, umode_t mode, 318 struct dentry *parent, 319 struct debugfs_regset32 *regset) 320 { 321 } 322 323 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 324 int nregs, void __iomem *base, char *prefix) 325 { 326 } 327 328 static inline bool debugfs_initialized(void) 329 { 330 return false; 331 } 332 333 static inline void debugfs_create_u32_array(const char *name, umode_t mode, 334 struct dentry *parent, 335 struct debugfs_u32_array *array) 336 { 337 } 338 339 static inline void debugfs_create_devm_seqfile(struct device *dev, 340 const char *name, 341 struct dentry *parent, 342 int (*read_fn)(struct seq_file *s, 343 void *data)) 344 { 345 } 346 347 static inline ssize_t debugfs_read_file_bool(struct file *file, 348 char __user *user_buf, 349 size_t count, loff_t *ppos) 350 { 351 return -ENODEV; 352 } 353 354 static inline ssize_t debugfs_write_file_bool(struct file *file, 355 const char __user *user_buf, 356 size_t count, loff_t *ppos) 357 { 358 return -ENODEV; 359 } 360 361 static inline ssize_t debugfs_read_file_str(struct file *file, 362 char __user *user_buf, 363 size_t count, loff_t *ppos) 364 { 365 return -ENODEV; 366 } 367 368 #endif 369 370 /** 371 * debugfs_create_xul - create a debugfs file that is used to read and write an 372 * unsigned long value, formatted in hexadecimal 373 * @name: a pointer to a string containing the name of the file to create. 374 * @mode: the permission that the file should have 375 * @parent: a pointer to the parent dentry for this file. This should be a 376 * directory dentry if set. If this parameter is %NULL, then the 377 * file will be created in the root of the debugfs filesystem. 378 * @value: a pointer to the variable that the file should read to and write 379 * from. 380 */ 381 static inline void debugfs_create_xul(const char *name, umode_t mode, 382 struct dentry *parent, 383 unsigned long *value) 384 { 385 if (sizeof(*value) == sizeof(u32)) 386 debugfs_create_x32(name, mode, parent, (u32 *)value); 387 else 388 debugfs_create_x64(name, mode, parent, (u64 *)value); 389 } 390 391 #endif 392