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 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 void debugfs_create_devm_seqfile(struct device *dev, const char *name, 148 struct dentry *parent, 149 int (*read_fn)(struct seq_file *s, void *data)); 150 151 bool debugfs_initialized(void); 152 153 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf, 154 size_t count, loff_t *ppos); 155 156 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, 157 size_t count, loff_t *ppos); 158 159 #else 160 161 #include <linux/err.h> 162 163 /* 164 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled 165 * so users have a chance to detect if there was a real error or not. We don't 166 * want to duplicate the design decision mistakes of procfs and devfs again. 167 */ 168 169 static inline struct dentry *debugfs_lookup(const char *name, 170 struct dentry *parent) 171 { 172 return ERR_PTR(-ENODEV); 173 } 174 175 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode, 176 struct dentry *parent, void *data, 177 const struct file_operations *fops) 178 { 179 return ERR_PTR(-ENODEV); 180 } 181 182 static inline struct dentry *debugfs_create_file_unsafe(const char *name, 183 umode_t mode, struct dentry *parent, 184 void *data, 185 const struct file_operations *fops) 186 { 187 return ERR_PTR(-ENODEV); 188 } 189 190 static inline void debugfs_create_file_size(const char *name, umode_t mode, 191 struct dentry *parent, void *data, 192 const struct file_operations *fops, 193 loff_t file_size) 194 { } 195 196 static inline struct dentry *debugfs_create_dir(const char *name, 197 struct dentry *parent) 198 { 199 return ERR_PTR(-ENODEV); 200 } 201 202 static inline struct dentry *debugfs_create_symlink(const char *name, 203 struct dentry *parent, 204 const char *dest) 205 { 206 return ERR_PTR(-ENODEV); 207 } 208 209 static inline struct dentry *debugfs_create_automount(const char *name, 210 struct dentry *parent, 211 debugfs_automount_t f, 212 void *data) 213 { 214 return ERR_PTR(-ENODEV); 215 } 216 217 static inline void debugfs_remove(struct dentry *dentry) 218 { } 219 220 static inline void debugfs_remove_recursive(struct dentry *dentry) 221 { } 222 223 const struct file_operations *debugfs_real_fops(const struct file *filp); 224 225 static inline int debugfs_file_get(struct dentry *dentry) 226 { 227 return 0; 228 } 229 230 static inline void debugfs_file_put(struct dentry *dentry) 231 { } 232 233 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf, 234 size_t len, loff_t *ppos) 235 { 236 return -ENODEV; 237 } 238 239 static inline ssize_t debugfs_attr_write(struct file *file, 240 const char __user *buf, 241 size_t len, loff_t *ppos) 242 { 243 return -ENODEV; 244 } 245 246 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 247 struct dentry *new_dir, char *new_name) 248 { 249 return ERR_PTR(-ENODEV); 250 } 251 252 static inline void debugfs_create_u8(const char *name, umode_t mode, 253 struct dentry *parent, u8 *value) { } 254 255 static inline void debugfs_create_u16(const char *name, umode_t mode, 256 struct dentry *parent, u16 *value) { } 257 258 static inline void debugfs_create_u32(const char *name, umode_t mode, 259 struct dentry *parent, u32 *value) { } 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 void debugfs_create_regset32(const char *name, umode_t mode, 308 struct dentry *parent, 309 struct debugfs_regset32 *regset) 310 { 311 } 312 313 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 314 int nregs, void __iomem *base, char *prefix) 315 { 316 } 317 318 static inline bool debugfs_initialized(void) 319 { 320 return false; 321 } 322 323 static inline void debugfs_create_u32_array(const char *name, umode_t mode, 324 struct dentry *parent, 325 struct debugfs_u32_array *array) 326 { 327 } 328 329 static inline void debugfs_create_devm_seqfile(struct device *dev, 330 const char *name, 331 struct dentry *parent, 332 int (*read_fn)(struct seq_file *s, 333 void *data)) 334 { 335 } 336 337 static inline ssize_t debugfs_read_file_bool(struct file *file, 338 char __user *user_buf, 339 size_t count, loff_t *ppos) 340 { 341 return -ENODEV; 342 } 343 344 static inline ssize_t debugfs_write_file_bool(struct file *file, 345 const char __user *user_buf, 346 size_t count, loff_t *ppos) 347 { 348 return -ENODEV; 349 } 350 351 #endif 352 353 /** 354 * debugfs_create_xul - create a debugfs file that is used to read and write an 355 * unsigned long value, formatted in hexadecimal 356 * @name: a pointer to a string containing the name of the file to create. 357 * @mode: the permission that the file should have 358 * @parent: a pointer to the parent dentry for this file. This should be a 359 * directory dentry if set. If this parameter is %NULL, then the 360 * file will be created in the root of the debugfs filesystem. 361 * @value: a pointer to the variable that the file should read to and write 362 * from. 363 */ 364 static inline void debugfs_create_xul(const char *name, umode_t mode, 365 struct dentry *parent, 366 unsigned long *value) 367 { 368 if (sizeof(*value) == sizeof(u32)) 369 debugfs_create_x32(name, mode, parent, (u32 *)value); 370 else 371 debugfs_create_x64(name, mode, parent, (u64 *)value); 372 } 373 374 #endif 375