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 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); 131 132 struct dentry *debugfs_create_blob(const char *name, umode_t mode, 133 struct dentry *parent, 134 struct debugfs_blob_wrapper *blob); 135 136 void debugfs_create_regset32(const char *name, umode_t mode, 137 struct dentry *parent, 138 struct debugfs_regset32 *regset); 139 140 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 141 int nregs, void __iomem *base, char *prefix); 142 143 void debugfs_create_u32_array(const char *name, umode_t mode, 144 struct dentry *parent, 145 struct debugfs_u32_array *array); 146 147 struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name, 148 struct dentry *parent, 149 int (*read_fn)(struct seq_file *s, 150 void *data)); 151 152 bool debugfs_initialized(void); 153 154 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf, 155 size_t count, loff_t *ppos); 156 157 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, 158 size_t count, loff_t *ppos); 159 160 #else 161 162 #include <linux/err.h> 163 164 /* 165 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled 166 * so users have a chance to detect if there was a real error or not. We don't 167 * want to duplicate the design decision mistakes of procfs and devfs again. 168 */ 169 170 static inline struct dentry *debugfs_lookup(const char *name, 171 struct dentry *parent) 172 { 173 return ERR_PTR(-ENODEV); 174 } 175 176 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode, 177 struct dentry *parent, void *data, 178 const struct file_operations *fops) 179 { 180 return ERR_PTR(-ENODEV); 181 } 182 183 static inline struct dentry *debugfs_create_file_unsafe(const char *name, 184 umode_t mode, struct dentry *parent, 185 void *data, 186 const struct file_operations *fops) 187 { 188 return ERR_PTR(-ENODEV); 189 } 190 191 static inline void debugfs_create_file_size(const char *name, umode_t mode, 192 struct dentry *parent, void *data, 193 const struct file_operations *fops, 194 loff_t file_size) 195 { } 196 197 static inline struct dentry *debugfs_create_dir(const char *name, 198 struct dentry *parent) 199 { 200 return ERR_PTR(-ENODEV); 201 } 202 203 static inline struct dentry *debugfs_create_symlink(const char *name, 204 struct dentry *parent, 205 const char *dest) 206 { 207 return ERR_PTR(-ENODEV); 208 } 209 210 static inline struct dentry *debugfs_create_automount(const char *name, 211 struct dentry *parent, 212 debugfs_automount_t f, 213 void *data) 214 { 215 return ERR_PTR(-ENODEV); 216 } 217 218 static inline void debugfs_remove(struct dentry *dentry) 219 { } 220 221 static inline void debugfs_remove_recursive(struct dentry *dentry) 222 { } 223 224 const struct file_operations *debugfs_real_fops(const struct file *filp); 225 226 static inline int debugfs_file_get(struct dentry *dentry) 227 { 228 return 0; 229 } 230 231 static inline void debugfs_file_put(struct dentry *dentry) 232 { } 233 234 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf, 235 size_t len, loff_t *ppos) 236 { 237 return -ENODEV; 238 } 239 240 static inline ssize_t debugfs_attr_write(struct file *file, 241 const char __user *buf, 242 size_t len, loff_t *ppos) 243 { 244 return -ENODEV; 245 } 246 247 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 248 struct dentry *new_dir, char *new_name) 249 { 250 return ERR_PTR(-ENODEV); 251 } 252 253 static inline void debugfs_create_u8(const char *name, umode_t mode, 254 struct dentry *parent, u8 *value) { } 255 256 static inline void debugfs_create_u16(const char *name, umode_t mode, 257 struct dentry *parent, u16 *value) { } 258 259 static inline void debugfs_create_u32(const char *name, umode_t mode, 260 struct dentry *parent, u32 *value) { } 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 void debugfs_create_regset32(const char *name, umode_t mode, 309 struct dentry *parent, 310 struct debugfs_regset32 *regset) 311 { 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, 326 struct debugfs_u32_array *array) 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