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(__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 void debugfs_lookup_and_remove(const char *name, struct dentry *parent); 95 96 const struct file_operations *debugfs_real_fops(const struct file *filp); 97 98 int debugfs_file_get(struct dentry *dentry); 99 void debugfs_file_put(struct dentry *dentry); 100 101 ssize_t debugfs_attr_read(struct file *file, char __user *buf, 102 size_t len, loff_t *ppos); 103 ssize_t debugfs_attr_write(struct file *file, const char __user *buf, 104 size_t len, loff_t *ppos); 105 106 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 107 struct dentry *new_dir, const char *new_name); 108 109 void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent, 110 u8 *value); 111 void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent, 112 u16 *value); 113 void debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent, 114 u32 *value); 115 void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent, 116 u64 *value); 117 void debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent, 118 unsigned long *value); 119 void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent, 120 u8 *value); 121 void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent, 122 u16 *value); 123 void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent, 124 u32 *value); 125 void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent, 126 u64 *value); 127 void debugfs_create_size_t(const char *name, umode_t mode, 128 struct dentry *parent, size_t *value); 129 void debugfs_create_atomic_t(const char *name, umode_t mode, 130 struct dentry *parent, atomic_t *value); 131 void debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent, 132 bool *value); 133 void debugfs_create_str(const char *name, umode_t mode, 134 struct dentry *parent, char **value); 135 136 struct dentry *debugfs_create_blob(const char *name, umode_t mode, 137 struct dentry *parent, 138 struct debugfs_blob_wrapper *blob); 139 140 void debugfs_create_regset32(const char *name, umode_t mode, 141 struct dentry *parent, 142 struct debugfs_regset32 *regset); 143 144 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 145 int nregs, void __iomem *base, char *prefix); 146 147 void debugfs_create_u32_array(const char *name, umode_t mode, 148 struct dentry *parent, 149 struct debugfs_u32_array *array); 150 151 void debugfs_create_devm_seqfile(struct device *dev, const char *name, 152 struct dentry *parent, 153 int (*read_fn)(struct seq_file *s, void *data)); 154 155 bool debugfs_initialized(void); 156 157 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf, 158 size_t count, loff_t *ppos); 159 160 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, 161 size_t count, loff_t *ppos); 162 163 ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf, 164 size_t count, loff_t *ppos); 165 166 #else 167 168 #include <linux/err.h> 169 170 /* 171 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled 172 * so users have a chance to detect if there was a real error or not. We don't 173 * want to duplicate the design decision mistakes of procfs and devfs again. 174 */ 175 176 static inline struct dentry *debugfs_lookup(const char *name, 177 struct dentry *parent) 178 { 179 return ERR_PTR(-ENODEV); 180 } 181 182 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode, 183 struct dentry *parent, void *data, 184 const struct file_operations *fops) 185 { 186 return ERR_PTR(-ENODEV); 187 } 188 189 static inline struct dentry *debugfs_create_file_unsafe(const char *name, 190 umode_t mode, struct dentry *parent, 191 void *data, 192 const struct file_operations *fops) 193 { 194 return ERR_PTR(-ENODEV); 195 } 196 197 static inline void debugfs_create_file_size(const char *name, umode_t mode, 198 struct dentry *parent, void *data, 199 const struct file_operations *fops, 200 loff_t file_size) 201 { } 202 203 static inline struct dentry *debugfs_create_dir(const char *name, 204 struct dentry *parent) 205 { 206 return ERR_PTR(-ENODEV); 207 } 208 209 static inline struct dentry *debugfs_create_symlink(const char *name, 210 struct dentry *parent, 211 const char *dest) 212 { 213 return ERR_PTR(-ENODEV); 214 } 215 216 static inline struct dentry *debugfs_create_automount(const char *name, 217 struct dentry *parent, 218 debugfs_automount_t f, 219 void *data) 220 { 221 return ERR_PTR(-ENODEV); 222 } 223 224 static inline void debugfs_remove(struct dentry *dentry) 225 { } 226 227 static inline void debugfs_remove_recursive(struct dentry *dentry) 228 { } 229 230 static inline void debugfs_lookup_and_remove(const char *name, 231 struct dentry *parent) 232 { } 233 234 const struct file_operations *debugfs_real_fops(const struct file *filp); 235 236 static inline int debugfs_file_get(struct dentry *dentry) 237 { 238 return 0; 239 } 240 241 static inline void debugfs_file_put(struct dentry *dentry) 242 { } 243 244 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf, 245 size_t len, loff_t *ppos) 246 { 247 return -ENODEV; 248 } 249 250 static inline ssize_t debugfs_attr_write(struct file *file, 251 const char __user *buf, 252 size_t len, loff_t *ppos) 253 { 254 return -ENODEV; 255 } 256 257 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 258 struct dentry *new_dir, char *new_name) 259 { 260 return ERR_PTR(-ENODEV); 261 } 262 263 static inline void debugfs_create_u8(const char *name, umode_t mode, 264 struct dentry *parent, u8 *value) { } 265 266 static inline void debugfs_create_u16(const char *name, umode_t mode, 267 struct dentry *parent, u16 *value) { } 268 269 static inline void debugfs_create_u32(const char *name, umode_t mode, 270 struct dentry *parent, u32 *value) { } 271 272 static inline void debugfs_create_u64(const char *name, umode_t mode, 273 struct dentry *parent, u64 *value) { } 274 275 static inline void debugfs_create_ulong(const char *name, umode_t mode, 276 struct dentry *parent, 277 unsigned long *value) { } 278 279 static inline void debugfs_create_x8(const char *name, umode_t mode, 280 struct dentry *parent, u8 *value) { } 281 282 static inline void debugfs_create_x16(const char *name, umode_t mode, 283 struct dentry *parent, u16 *value) { } 284 285 static inline void debugfs_create_x32(const char *name, umode_t mode, 286 struct dentry *parent, u32 *value) { } 287 288 static inline void debugfs_create_x64(const char *name, umode_t mode, 289 struct dentry *parent, u64 *value) { } 290 291 static inline void debugfs_create_size_t(const char *name, umode_t mode, 292 struct dentry *parent, size_t *value) 293 { } 294 295 static inline void debugfs_create_atomic_t(const char *name, umode_t mode, 296 struct dentry *parent, 297 atomic_t *value) 298 { } 299 300 static inline void debugfs_create_bool(const char *name, umode_t mode, 301 struct dentry *parent, bool *value) { } 302 303 static inline void debugfs_create_str(const char *name, umode_t mode, 304 struct dentry *parent, 305 char **value) 306 { } 307 308 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode, 309 struct dentry *parent, 310 struct debugfs_blob_wrapper *blob) 311 { 312 return ERR_PTR(-ENODEV); 313 } 314 315 static inline void debugfs_create_regset32(const char *name, umode_t mode, 316 struct dentry *parent, 317 struct debugfs_regset32 *regset) 318 { 319 } 320 321 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 322 int nregs, void __iomem *base, char *prefix) 323 { 324 } 325 326 static inline bool debugfs_initialized(void) 327 { 328 return false; 329 } 330 331 static inline void debugfs_create_u32_array(const char *name, umode_t mode, 332 struct dentry *parent, 333 struct debugfs_u32_array *array) 334 { 335 } 336 337 static inline void debugfs_create_devm_seqfile(struct device *dev, 338 const char *name, 339 struct dentry *parent, 340 int (*read_fn)(struct seq_file *s, 341 void *data)) 342 { 343 } 344 345 static inline ssize_t debugfs_read_file_bool(struct file *file, 346 char __user *user_buf, 347 size_t count, loff_t *ppos) 348 { 349 return -ENODEV; 350 } 351 352 static inline ssize_t debugfs_write_file_bool(struct file *file, 353 const char __user *user_buf, 354 size_t count, loff_t *ppos) 355 { 356 return -ENODEV; 357 } 358 359 static inline ssize_t debugfs_read_file_str(struct file *file, 360 char __user *user_buf, 361 size_t count, loff_t *ppos) 362 { 363 return -ENODEV; 364 } 365 366 #endif 367 368 /** 369 * debugfs_create_xul - create a debugfs file that is used to read and write an 370 * unsigned long value, formatted in hexadecimal 371 * @name: a pointer to a string containing the name of the file to create. 372 * @mode: the permission that the file should have 373 * @parent: a pointer to the parent dentry for this file. This should be a 374 * directory dentry if set. If this parameter is %NULL, then the 375 * file will be created in the root of the debugfs filesystem. 376 * @value: a pointer to the variable that the file should read to and write 377 * from. 378 */ 379 static inline void debugfs_create_xul(const char *name, umode_t mode, 380 struct dentry *parent, 381 unsigned long *value) 382 { 383 if (sizeof(*value) == sizeof(u32)) 384 debugfs_create_x32(name, mode, parent, (u32 *)value); 385 else 386 debugfs_create_x64(name, mode, parent, (u64 *)value); 387 } 388 389 #endif 390