debugfs.h (11485B)
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(__fops, __get, __set, __fmt) \ 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 = debugfs_attr_write, \ 60 .llseek = no_llseek, \ 61} 62 63typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *); 64 65#if defined(CONFIG_DEBUG_FS) 66 67struct dentry *debugfs_lookup(const char *name, struct dentry *parent); 68 69struct dentry *debugfs_create_file(const char *name, umode_t mode, 70 struct dentry *parent, void *data, 71 const struct file_operations *fops); 72struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode, 73 struct dentry *parent, void *data, 74 const struct file_operations *fops); 75 76void 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 81struct dentry *debugfs_create_dir(const char *name, struct dentry *parent); 82 83struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, 84 const char *dest); 85 86struct dentry *debugfs_create_automount(const char *name, 87 struct dentry *parent, 88 debugfs_automount_t f, 89 void *data); 90 91void debugfs_remove(struct dentry *dentry); 92#define debugfs_remove_recursive debugfs_remove 93 94const struct file_operations *debugfs_real_fops(const struct file *filp); 95 96int debugfs_file_get(struct dentry *dentry); 97void debugfs_file_put(struct dentry *dentry); 98 99ssize_t debugfs_attr_read(struct file *file, char __user *buf, 100 size_t len, loff_t *ppos); 101ssize_t debugfs_attr_write(struct file *file, const char __user *buf, 102 size_t len, loff_t *ppos); 103 104struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 105 struct dentry *new_dir, const char *new_name); 106 107void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent, 108 u8 *value); 109void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent, 110 u16 *value); 111void debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent, 112 u32 *value); 113void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent, 114 u64 *value); 115void debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent, 116 unsigned long *value); 117void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent, 118 u8 *value); 119void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent, 120 u16 *value); 121void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent, 122 u32 *value); 123void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent, 124 u64 *value); 125void debugfs_create_size_t(const char *name, umode_t mode, 126 struct dentry *parent, size_t *value); 127void debugfs_create_atomic_t(const char *name, umode_t mode, 128 struct dentry *parent, atomic_t *value); 129void debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent, 130 bool *value); 131void debugfs_create_str(const char *name, umode_t mode, 132 struct dentry *parent, char **value); 133 134struct dentry *debugfs_create_blob(const char *name, umode_t mode, 135 struct dentry *parent, 136 struct debugfs_blob_wrapper *blob); 137 138void debugfs_create_regset32(const char *name, umode_t mode, 139 struct dentry *parent, 140 struct debugfs_regset32 *regset); 141 142void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 143 int nregs, void __iomem *base, char *prefix); 144 145void debugfs_create_u32_array(const char *name, umode_t mode, 146 struct dentry *parent, 147 struct debugfs_u32_array *array); 148 149void debugfs_create_devm_seqfile(struct device *dev, const char *name, 150 struct dentry *parent, 151 int (*read_fn)(struct seq_file *s, void *data)); 152 153bool debugfs_initialized(void); 154 155ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf, 156 size_t count, loff_t *ppos); 157 158ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, 159 size_t count, loff_t *ppos); 160 161ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf, 162 size_t count, loff_t *ppos); 163 164#else 165 166#include <linux/err.h> 167 168/* 169 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled 170 * so users have a chance to detect if there was a real error or not. We don't 171 * want to duplicate the design decision mistakes of procfs and devfs again. 172 */ 173 174static inline struct dentry *debugfs_lookup(const char *name, 175 struct dentry *parent) 176{ 177 return ERR_PTR(-ENODEV); 178} 179 180static inline struct dentry *debugfs_create_file(const char *name, umode_t mode, 181 struct dentry *parent, void *data, 182 const struct file_operations *fops) 183{ 184 return ERR_PTR(-ENODEV); 185} 186 187static inline struct dentry *debugfs_create_file_unsafe(const char *name, 188 umode_t mode, struct dentry *parent, 189 void *data, 190 const struct file_operations *fops) 191{ 192 return ERR_PTR(-ENODEV); 193} 194 195static inline void debugfs_create_file_size(const char *name, umode_t mode, 196 struct dentry *parent, void *data, 197 const struct file_operations *fops, 198 loff_t file_size) 199{ } 200 201static inline struct dentry *debugfs_create_dir(const char *name, 202 struct dentry *parent) 203{ 204 return ERR_PTR(-ENODEV); 205} 206 207static inline struct dentry *debugfs_create_symlink(const char *name, 208 struct dentry *parent, 209 const char *dest) 210{ 211 return ERR_PTR(-ENODEV); 212} 213 214static inline struct dentry *debugfs_create_automount(const char *name, 215 struct dentry *parent, 216 debugfs_automount_t f, 217 void *data) 218{ 219 return ERR_PTR(-ENODEV); 220} 221 222static inline void debugfs_remove(struct dentry *dentry) 223{ } 224 225static inline void debugfs_remove_recursive(struct dentry *dentry) 226{ } 227 228const struct file_operations *debugfs_real_fops(const struct file *filp); 229 230static inline int debugfs_file_get(struct dentry *dentry) 231{ 232 return 0; 233} 234 235static inline void debugfs_file_put(struct dentry *dentry) 236{ } 237 238static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf, 239 size_t len, loff_t *ppos) 240{ 241 return -ENODEV; 242} 243 244static inline ssize_t debugfs_attr_write(struct file *file, 245 const char __user *buf, 246 size_t len, loff_t *ppos) 247{ 248 return -ENODEV; 249} 250 251static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, 252 struct dentry *new_dir, char *new_name) 253{ 254 return ERR_PTR(-ENODEV); 255} 256 257static inline void debugfs_create_u8(const char *name, umode_t mode, 258 struct dentry *parent, u8 *value) { } 259 260static inline void debugfs_create_u16(const char *name, umode_t mode, 261 struct dentry *parent, u16 *value) { } 262 263static inline void debugfs_create_u32(const char *name, umode_t mode, 264 struct dentry *parent, u32 *value) { } 265 266static inline void debugfs_create_u64(const char *name, umode_t mode, 267 struct dentry *parent, u64 *value) { } 268 269static inline void debugfs_create_ulong(const char *name, umode_t mode, 270 struct dentry *parent, 271 unsigned long *value) { } 272 273static inline void debugfs_create_x8(const char *name, umode_t mode, 274 struct dentry *parent, u8 *value) { } 275 276static inline void debugfs_create_x16(const char *name, umode_t mode, 277 struct dentry *parent, u16 *value) { } 278 279static inline void debugfs_create_x32(const char *name, umode_t mode, 280 struct dentry *parent, u32 *value) { } 281 282static inline void debugfs_create_x64(const char *name, umode_t mode, 283 struct dentry *parent, u64 *value) { } 284 285static inline void debugfs_create_size_t(const char *name, umode_t mode, 286 struct dentry *parent, size_t *value) 287{ } 288 289static inline void debugfs_create_atomic_t(const char *name, umode_t mode, 290 struct dentry *parent, 291 atomic_t *value) 292{ } 293 294static inline void debugfs_create_bool(const char *name, umode_t mode, 295 struct dentry *parent, bool *value) { } 296 297static inline void debugfs_create_str(const char *name, umode_t mode, 298 struct dentry *parent, 299 char **value) 300{ } 301 302static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode, 303 struct dentry *parent, 304 struct debugfs_blob_wrapper *blob) 305{ 306 return ERR_PTR(-ENODEV); 307} 308 309static inline void debugfs_create_regset32(const char *name, umode_t mode, 310 struct dentry *parent, 311 struct debugfs_regset32 *regset) 312{ 313} 314 315static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 316 int nregs, void __iomem *base, char *prefix) 317{ 318} 319 320static inline bool debugfs_initialized(void) 321{ 322 return false; 323} 324 325static inline void debugfs_create_u32_array(const char *name, umode_t mode, 326 struct dentry *parent, 327 struct debugfs_u32_array *array) 328{ 329} 330 331static inline void debugfs_create_devm_seqfile(struct device *dev, 332 const char *name, 333 struct dentry *parent, 334 int (*read_fn)(struct seq_file *s, 335 void *data)) 336{ 337} 338 339static 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 346static 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 353static inline ssize_t debugfs_read_file_str(struct file *file, 354 char __user *user_buf, 355 size_t count, loff_t *ppos) 356{ 357 return -ENODEV; 358} 359 360#endif 361 362/** 363 * debugfs_create_xul - create a debugfs file that is used to read and write an 364 * unsigned long value, formatted in hexadecimal 365 * @name: a pointer to a string containing the name of the file to create. 366 * @mode: the permission that the file should have 367 * @parent: a pointer to the parent dentry for this file. This should be a 368 * directory dentry if set. If this parameter is %NULL, then the 369 * file will be created in the root of the debugfs filesystem. 370 * @value: a pointer to the variable that the file should read to and write 371 * from. 372 */ 373static inline void debugfs_create_xul(const char *name, umode_t mode, 374 struct dentry *parent, 375 unsigned long *value) 376{ 377 if (sizeof(*value) == sizeof(u32)) 378 debugfs_create_x32(name, mode, parent, (u32 *)value); 379 else 380 debugfs_create_x64(name, mode, parent, (u64 *)value); 381} 382 383#endif