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