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