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 21struct device; 22struct file_operations; 23 24struct debugfs_blob_wrapper { 25 void *data; 26 unsigned long size; 27}; 28 29struct debugfs_reg32 { 30 char *name; 31 unsigned long offset; 32}; 33 34struct 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 41struct debugfs_u32_array { 42 u32 *array; 43 u32 n_elements; 44}; 45 46extern struct dentry *arch_debugfs_dir; 47 48#define DEFINE_DEBUGFS_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, __is_signed) \ 49static 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} \ 54static 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 = (__is_signed) ? debugfs_attr_write_signed : debugfs_attr_write, \ 60 .llseek = no_llseek, \ 61} 62 63#define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \ 64 DEFINE_DEBUGFS_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, false) 65 66#define DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(__fops, __get, __set, __fmt) \ 67 DEFINE_DEBUGFS_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, true) 68 69typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *); 70 71#if defined(CONFIG_DEBUG_FS) 72 73struct dentry *debugfs_lookup(const char *name, struct dentry *parent); 74 75struct dentry *debugfs_create_file(const char *name, umode_t mode, 76 struct dentry *parent, void *data, 77 const struct file_operations *fops); 78struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode, 79 struct dentry *parent, void *data, 80 const struct file_operations *fops); 81 82void debugfs_create_file_size(const char *name, umode_t mode, 83 struct dentry *parent, void *data, 84 const struct file_operations *fops, 85 loff_t file_size); 86 87struct dentry *debugfs_create_dir(const char *name, struct dentry *parent); 88 89struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, 90 const char *dest); 91 92struct dentry *debugfs_create_automount(const char *name, 93 struct dentry *parent, 94 debugfs_automount_t f, 95 void *data); 96 97void debugfs_remove(struct dentry *dentry); 98#define debugfs_remove_recursive debugfs_remove 99 100void debugfs_lookup_and_remove(const char *name, struct dentry *parent); 101 102const struct file_operations *debugfs_real_fops(const struct file *filp); 103 104int debugfs_file_get(struct dentry *dentry); 105void debugfs_file_put(struct dentry *dentry); 106 107ssize_t debugfs_attr_read(struct file *file, char __user *buf, 108 size_t len, loff_t *ppos); 109ssize_t debugfs_attr_write(struct file *file, const char __user *buf, 110 size_t len, loff_t *ppos); 111ssize_t debugfs_attr_write_signed(struct file *file, const char __user *buf, 112 size_t len, loff_t *ppos); 113 114struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 115 struct dentry *new_dir, const char *new_name); 116 117void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent, 118 u8 *value); 119void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent, 120 u16 *value); 121void debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent, 122 u32 *value); 123void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent, 124 u64 *value); 125void debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent, 126 unsigned long *value); 127void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent, 128 u8 *value); 129void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent, 130 u16 *value); 131void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent, 132 u32 *value); 133void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent, 134 u64 *value); 135void debugfs_create_size_t(const char *name, umode_t mode, 136 struct dentry *parent, size_t *value); 137void debugfs_create_atomic_t(const char *name, umode_t mode, 138 struct dentry *parent, atomic_t *value); 139void debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent, 140 bool *value); 141void debugfs_create_str(const char *name, umode_t mode, 142 struct dentry *parent, char **value); 143 144struct dentry *debugfs_create_blob(const char *name, umode_t mode, 145 struct dentry *parent, 146 struct debugfs_blob_wrapper *blob); 147 148void debugfs_create_regset32(const char *name, umode_t mode, 149 struct dentry *parent, 150 struct debugfs_regset32 *regset); 151 152void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 153 int nregs, void __iomem *base, char *prefix); 154 155void debugfs_create_u32_array(const char *name, umode_t mode, 156 struct dentry *parent, 157 struct debugfs_u32_array *array); 158 159void debugfs_create_devm_seqfile(struct device *dev, const char *name, 160 struct dentry *parent, 161 int (*read_fn)(struct seq_file *s, void *data)); 162 163bool debugfs_initialized(void); 164 165ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf, 166 size_t count, loff_t *ppos); 167 168ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, 169 size_t count, loff_t *ppos); 170 171ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf, 172 size_t count, loff_t *ppos); 173 174/** 175 * struct debugfs_cancellation - cancellation data 176 * @list: internal, for keeping track 177 * @cancel: callback to call 178 * @cancel_data: extra data for the callback to call 179 */ 180struct debugfs_cancellation { 181 struct list_head list; 182 void (*cancel)(struct dentry *, void *); 183 void *cancel_data; 184}; 185 186void __acquires(cancellation) 187debugfs_enter_cancellation(struct file *file, 188 struct debugfs_cancellation *cancellation); 189void __releases(cancellation) 190debugfs_leave_cancellation(struct file *file, 191 struct debugfs_cancellation *cancellation); 192 193#else 194 195#include <linux/err.h> 196 197/* 198 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled 199 * so users have a chance to detect if there was a real error or not. We don't 200 * want to duplicate the design decision mistakes of procfs and devfs again. 201 */ 202 203static inline struct dentry *debugfs_lookup(const char *name, 204 struct dentry *parent) 205{ 206 return ERR_PTR(-ENODEV); 207} 208 209static inline struct dentry *debugfs_create_file(const char *name, umode_t mode, 210 struct dentry *parent, void *data, 211 const struct file_operations *fops) 212{ 213 return ERR_PTR(-ENODEV); 214} 215 216static inline struct dentry *debugfs_create_file_unsafe(const char *name, 217 umode_t mode, struct dentry *parent, 218 void *data, 219 const struct file_operations *fops) 220{ 221 return ERR_PTR(-ENODEV); 222} 223 224static inline void debugfs_create_file_size(const char *name, umode_t mode, 225 struct dentry *parent, void *data, 226 const struct file_operations *fops, 227 loff_t file_size) 228{ } 229 230static inline struct dentry *debugfs_create_dir(const char *name, 231 struct dentry *parent) 232{ 233 return ERR_PTR(-ENODEV); 234} 235 236static inline struct dentry *debugfs_create_symlink(const char *name, 237 struct dentry *parent, 238 const char *dest) 239{ 240 return ERR_PTR(-ENODEV); 241} 242 243static inline struct dentry *debugfs_create_automount(const char *name, 244 struct dentry *parent, 245 debugfs_automount_t f, 246 void *data) 247{ 248 return ERR_PTR(-ENODEV); 249} 250 251static inline void debugfs_remove(struct dentry *dentry) 252{ } 253 254static inline void debugfs_remove_recursive(struct dentry *dentry) 255{ } 256 257static inline void debugfs_lookup_and_remove(const char *name, 258 struct dentry *parent) 259{ } 260 261const struct file_operations *debugfs_real_fops(const struct file *filp); 262 263static inline int debugfs_file_get(struct dentry *dentry) 264{ 265 return 0; 266} 267 268static inline void debugfs_file_put(struct dentry *dentry) 269{ } 270 271static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf, 272 size_t len, loff_t *ppos) 273{ 274 return -ENODEV; 275} 276 277static inline ssize_t debugfs_attr_write(struct file *file, 278 const char __user *buf, 279 size_t len, loff_t *ppos) 280{ 281 return -ENODEV; 282} 283 284static inline ssize_t debugfs_attr_write_signed(struct file *file, 285 const char __user *buf, 286 size_t len, loff_t *ppos) 287{ 288 return -ENODEV; 289} 290 291static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 292 struct dentry *new_dir, char *new_name) 293{ 294 return ERR_PTR(-ENODEV); 295} 296 297static inline void debugfs_create_u8(const char *name, umode_t mode, 298 struct dentry *parent, u8 *value) { } 299 300static inline void debugfs_create_u16(const char *name, umode_t mode, 301 struct dentry *parent, u16 *value) { } 302 303static inline void debugfs_create_u32(const char *name, umode_t mode, 304 struct dentry *parent, u32 *value) { } 305 306static inline void debugfs_create_u64(const char *name, umode_t mode, 307 struct dentry *parent, u64 *value) { } 308 309static inline void debugfs_create_ulong(const char *name, umode_t mode, 310 struct dentry *parent, 311 unsigned long *value) { } 312 313static inline void debugfs_create_x8(const char *name, umode_t mode, 314 struct dentry *parent, u8 *value) { } 315 316static inline void debugfs_create_x16(const char *name, umode_t mode, 317 struct dentry *parent, u16 *value) { } 318 319static inline void debugfs_create_x32(const char *name, umode_t mode, 320 struct dentry *parent, u32 *value) { } 321 322static inline void debugfs_create_x64(const char *name, umode_t mode, 323 struct dentry *parent, u64 *value) { } 324 325static inline void debugfs_create_size_t(const char *name, umode_t mode, 326 struct dentry *parent, size_t *value) 327{ } 328 329static inline void debugfs_create_atomic_t(const char *name, umode_t mode, 330 struct dentry *parent, 331 atomic_t *value) 332{ } 333 334static inline void debugfs_create_bool(const char *name, umode_t mode, 335 struct dentry *parent, bool *value) { } 336 337static inline void debugfs_create_str(const char *name, umode_t mode, 338 struct dentry *parent, 339 char **value) 340{ } 341 342static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode, 343 struct dentry *parent, 344 struct debugfs_blob_wrapper *blob) 345{ 346 return ERR_PTR(-ENODEV); 347} 348 349static inline void debugfs_create_regset32(const char *name, umode_t mode, 350 struct dentry *parent, 351 struct debugfs_regset32 *regset) 352{ 353} 354 355static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 356 int nregs, void __iomem *base, char *prefix) 357{ 358} 359 360static inline bool debugfs_initialized(void) 361{ 362 return false; 363} 364 365static inline void debugfs_create_u32_array(const char *name, umode_t mode, 366 struct dentry *parent, 367 struct debugfs_u32_array *array) 368{ 369} 370 371static inline void debugfs_create_devm_seqfile(struct device *dev, 372 const char *name, 373 struct dentry *parent, 374 int (*read_fn)(struct seq_file *s, 375 void *data)) 376{ 377} 378 379static inline ssize_t debugfs_read_file_bool(struct file *file, 380 char __user *user_buf, 381 size_t count, loff_t *ppos) 382{ 383 return -ENODEV; 384} 385 386static inline ssize_t debugfs_write_file_bool(struct file *file, 387 const char __user *user_buf, 388 size_t count, loff_t *ppos) 389{ 390 return -ENODEV; 391} 392 393static inline ssize_t debugfs_read_file_str(struct file *file, 394 char __user *user_buf, 395 size_t count, loff_t *ppos) 396{ 397 return -ENODEV; 398} 399 400#endif 401 402/** 403 * debugfs_create_xul - create a debugfs file that is used to read and write an 404 * unsigned long value, formatted in hexadecimal 405 * @name: a pointer to a string containing the name of the file to create. 406 * @mode: the permission that the file should have 407 * @parent: a pointer to the parent dentry for this file. This should be a 408 * directory dentry if set. If this parameter is %NULL, then the 409 * file will be created in the root of the debugfs filesystem. 410 * @value: a pointer to the variable that the file should read to and write 411 * from. 412 */ 413static inline void debugfs_create_xul(const char *name, umode_t mode, 414 struct dentry *parent, 415 unsigned long *value) 416{ 417 if (sizeof(*value) == sizeof(u32)) 418 debugfs_create_x32(name, mode, parent, (u32 *)value); 419 else 420 debugfs_create_x64(name, mode, parent, (u64 *)value); 421} 422 423#endif 424