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 <greg@kroah.com> 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_XSIGNED(__fops, __get, __set, __fmt, __is_signed) \ 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 = (__is_signed) ? debugfs_attr_write_signed : debugfs_attr_write, \ 60 .llseek = no_llseek, \ 61 } 62 63 #define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \ 64 DEFINE_DEBUGFS_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, false) 65 66 #define DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(__fops, __get, __set, __fmt) \ 67 DEFINE_DEBUGFS_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, true) 68 69 typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *); 70 71 #if defined(CONFIG_DEBUG_FS) 72 73 struct dentry *debugfs_lookup(const char *name, struct dentry *parent); 74 75 struct dentry *debugfs_create_file(const char *name, umode_t mode, 76 struct dentry *parent, void *data, 77 const struct file_operations *fops); 78 struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode, 79 struct dentry *parent, void *data, 80 const struct file_operations *fops); 81 82 void debugfs_create_file_size(const char *name, umode_t mode, 83 struct dentry *parent, void *data, 84 const struct file_operations *fops, 85 loff_t file_size); 86 87 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent); 88 89 struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, 90 const char *dest); 91 92 struct dentry *debugfs_create_automount(const char *name, 93 struct dentry *parent, 94 debugfs_automount_t f, 95 void *data); 96 97 void debugfs_remove(struct dentry *dentry); 98 #define debugfs_remove_recursive debugfs_remove 99 100 void debugfs_lookup_and_remove(const char *name, struct dentry *parent); 101 102 const struct file_operations *debugfs_real_fops(const struct file *filp); 103 104 int debugfs_file_get(struct dentry *dentry); 105 void debugfs_file_put(struct dentry *dentry); 106 107 ssize_t debugfs_attr_read(struct file *file, char __user *buf, 108 size_t len, loff_t *ppos); 109 ssize_t debugfs_attr_write(struct file *file, const char __user *buf, 110 size_t len, loff_t *ppos); 111 ssize_t debugfs_attr_write_signed(struct file *file, const char __user *buf, 112 size_t len, loff_t *ppos); 113 114 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 115 struct dentry *new_dir, const char *new_name); 116 117 void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent, 118 u8 *value); 119 void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent, 120 u16 *value); 121 void debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent, 122 u32 *value); 123 void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent, 124 u64 *value); 125 void debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent, 126 unsigned long *value); 127 void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent, 128 u8 *value); 129 void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent, 130 u16 *value); 131 void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent, 132 u32 *value); 133 void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent, 134 u64 *value); 135 void debugfs_create_size_t(const char *name, umode_t mode, 136 struct dentry *parent, size_t *value); 137 void debugfs_create_atomic_t(const char *name, umode_t mode, 138 struct dentry *parent, atomic_t *value); 139 void debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent, 140 bool *value); 141 void debugfs_create_str(const char *name, umode_t mode, 142 struct dentry *parent, char **value); 143 144 struct dentry *debugfs_create_blob(const char *name, umode_t mode, 145 struct dentry *parent, 146 struct debugfs_blob_wrapper *blob); 147 148 void debugfs_create_regset32(const char *name, umode_t mode, 149 struct dentry *parent, 150 struct debugfs_regset32 *regset); 151 152 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 153 int nregs, void __iomem *base, char *prefix); 154 155 void debugfs_create_u32_array(const char *name, umode_t mode, 156 struct dentry *parent, 157 struct debugfs_u32_array *array); 158 159 void debugfs_create_devm_seqfile(struct device *dev, const char *name, 160 struct dentry *parent, 161 int (*read_fn)(struct seq_file *s, void *data)); 162 163 bool debugfs_initialized(void); 164 165 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf, 166 size_t count, loff_t *ppos); 167 168 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, 169 size_t count, loff_t *ppos); 170 171 ssize_t debugfs_read_file_str(struct file *file, 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_lookup(const char *name, 185 struct dentry *parent) 186 { 187 return ERR_PTR(-ENODEV); 188 } 189 190 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode, 191 struct dentry *parent, void *data, 192 const struct file_operations *fops) 193 { 194 return ERR_PTR(-ENODEV); 195 } 196 197 static inline struct dentry *debugfs_create_file_unsafe(const char *name, 198 umode_t mode, struct dentry *parent, 199 void *data, 200 const struct file_operations *fops) 201 { 202 return ERR_PTR(-ENODEV); 203 } 204 205 static inline void debugfs_create_file_size(const char *name, umode_t mode, 206 struct dentry *parent, void *data, 207 const struct file_operations *fops, 208 loff_t file_size) 209 { } 210 211 static inline struct dentry *debugfs_create_dir(const char *name, 212 struct dentry *parent) 213 { 214 return ERR_PTR(-ENODEV); 215 } 216 217 static inline struct dentry *debugfs_create_symlink(const char *name, 218 struct dentry *parent, 219 const char *dest) 220 { 221 return ERR_PTR(-ENODEV); 222 } 223 224 static inline struct dentry *debugfs_create_automount(const char *name, 225 struct dentry *parent, 226 debugfs_automount_t f, 227 void *data) 228 { 229 return ERR_PTR(-ENODEV); 230 } 231 232 static inline void debugfs_remove(struct dentry *dentry) 233 { } 234 235 static inline void debugfs_remove_recursive(struct dentry *dentry) 236 { } 237 238 static inline void debugfs_lookup_and_remove(const char *name, 239 struct dentry *parent) 240 { } 241 242 const struct file_operations *debugfs_real_fops(const struct file *filp); 243 244 static inline int debugfs_file_get(struct dentry *dentry) 245 { 246 return 0; 247 } 248 249 static inline void debugfs_file_put(struct dentry *dentry) 250 { } 251 252 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf, 253 size_t len, loff_t *ppos) 254 { 255 return -ENODEV; 256 } 257 258 static inline ssize_t debugfs_attr_write(struct file *file, 259 const char __user *buf, 260 size_t len, loff_t *ppos) 261 { 262 return -ENODEV; 263 } 264 265 static inline ssize_t debugfs_attr_write_signed(struct file *file, 266 const char __user *buf, 267 size_t len, loff_t *ppos) 268 { 269 return -ENODEV; 270 } 271 272 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 273 struct dentry *new_dir, char *new_name) 274 { 275 return ERR_PTR(-ENODEV); 276 } 277 278 static inline void debugfs_create_u8(const char *name, umode_t mode, 279 struct dentry *parent, u8 *value) { } 280 281 static inline void debugfs_create_u16(const char *name, umode_t mode, 282 struct dentry *parent, u16 *value) { } 283 284 static inline void debugfs_create_u32(const char *name, umode_t mode, 285 struct dentry *parent, u32 *value) { } 286 287 static inline void debugfs_create_u64(const char *name, umode_t mode, 288 struct dentry *parent, u64 *value) { } 289 290 static inline void debugfs_create_ulong(const char *name, umode_t mode, 291 struct dentry *parent, 292 unsigned long *value) { } 293 294 static inline void debugfs_create_x8(const char *name, umode_t mode, 295 struct dentry *parent, u8 *value) { } 296 297 static inline void debugfs_create_x16(const char *name, umode_t mode, 298 struct dentry *parent, u16 *value) { } 299 300 static inline void debugfs_create_x32(const char *name, umode_t mode, 301 struct dentry *parent, u32 *value) { } 302 303 static inline void debugfs_create_x64(const char *name, umode_t mode, 304 struct dentry *parent, u64 *value) { } 305 306 static inline void debugfs_create_size_t(const char *name, umode_t mode, 307 struct dentry *parent, size_t *value) 308 { } 309 310 static inline void debugfs_create_atomic_t(const char *name, umode_t mode, 311 struct dentry *parent, 312 atomic_t *value) 313 { } 314 315 static inline void debugfs_create_bool(const char *name, umode_t mode, 316 struct dentry *parent, bool *value) { } 317 318 static inline void debugfs_create_str(const char *name, umode_t mode, 319 struct dentry *parent, 320 char **value) 321 { } 322 323 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode, 324 struct dentry *parent, 325 struct debugfs_blob_wrapper *blob) 326 { 327 return ERR_PTR(-ENODEV); 328 } 329 330 static inline void debugfs_create_regset32(const char *name, umode_t mode, 331 struct dentry *parent, 332 struct debugfs_regset32 *regset) 333 { 334 } 335 336 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 337 int nregs, void __iomem *base, char *prefix) 338 { 339 } 340 341 static inline bool debugfs_initialized(void) 342 { 343 return false; 344 } 345 346 static inline void debugfs_create_u32_array(const char *name, umode_t mode, 347 struct dentry *parent, 348 struct debugfs_u32_array *array) 349 { 350 } 351 352 static inline void debugfs_create_devm_seqfile(struct device *dev, 353 const char *name, 354 struct dentry *parent, 355 int (*read_fn)(struct seq_file *s, 356 void *data)) 357 { 358 } 359 360 static inline ssize_t debugfs_read_file_bool(struct file *file, 361 char __user *user_buf, 362 size_t count, loff_t *ppos) 363 { 364 return -ENODEV; 365 } 366 367 static inline ssize_t debugfs_write_file_bool(struct file *file, 368 const char __user *user_buf, 369 size_t count, loff_t *ppos) 370 { 371 return -ENODEV; 372 } 373 374 static inline ssize_t debugfs_read_file_str(struct file *file, 375 char __user *user_buf, 376 size_t count, loff_t *ppos) 377 { 378 return -ENODEV; 379 } 380 381 #endif 382 383 /** 384 * debugfs_create_xul - create a debugfs file that is used to read and write an 385 * unsigned long value, formatted in hexadecimal 386 * @name: a pointer to a string containing the name of the file to create. 387 * @mode: the permission that the file should have 388 * @parent: a pointer to the parent dentry for this file. This should be a 389 * directory dentry if set. If this parameter is %NULL, then the 390 * file will be created in the root of the debugfs filesystem. 391 * @value: a pointer to the variable that the file should read to and write 392 * from. 393 */ 394 static inline void debugfs_create_xul(const char *name, umode_t mode, 395 struct dentry *parent, 396 unsigned long *value) 397 { 398 if (sizeof(*value) == sizeof(u32)) 399 debugfs_create_x32(name, mode, parent, (u32 *)value); 400 else 401 debugfs_create_x64(name, mode, parent, (u64 *)value); 402 } 403 404 #endif 405