include/linux/debugfs.h

   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 };
  39
  40 extern struct dentry *arch_debugfs_dir;
  41
  42 #define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt)           \
  43 static int __fops ## _open(struct inode *inode, struct file *file)      \
  44 {                                                                       \
  45         __simple_attr_check_format(__fmt, 0ull);                        \
  46         return simple_attr_open(inode, file, __get, __set, __fmt);      \
  47 }                                                                       \
  48 static const struct file_operations __fops = {                          \
  49         .owner   = THIS_MODULE,                                         \
  50         .open    = __fops ## _open,                                     \
  51         .release = simple_attr_release,                                 \
  52         .read    = debugfs_attr_read,                                   \
  53         .write   = debugfs_attr_write,                                  \
  54         .llseek  = no_llseek,                                           \
  55 }
  56
  57 #if defined(CONFIG_DEBUG_FS)
  58
  59 struct dentry *debugfs_lookup(const char *name, struct dentry *parent);
  60
  61 struct dentry *debugfs_create_file(const char *name, umode_t mode,
  62                                    struct dentry *parent, void *data,
  63                                    const struct file_operations *fops);
  64 struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode,
  65                                    struct dentry *parent, void *data,
  66                                    const struct file_operations *fops);
  67
  68 struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
  69                                         struct dentry *parent, void *data,
  70                                         const struct file_operations *fops,
  71                                         loff_t file_size);
  72
  73 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent);
  74
  75 struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
  76                                       const char *dest);
  77
  78 typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *);
  79 struct dentry *debugfs_create_automount(const char *name,
  80                                         struct dentry *parent,
  81                                         debugfs_automount_t f,
  82                                         void *data);
  83
  84 void debugfs_remove(struct dentry *dentry);
  85 void debugfs_remove_recursive(struct dentry *dentry);
  86
  87 const struct file_operations *debugfs_real_fops(const struct file *filp);
  88
  89 int debugfs_file_get(struct dentry *dentry);
  90 void debugfs_file_put(struct dentry *dentry);
  91
  92 ssize_t debugfs_attr_read(struct file *file, char __user *buf,
  93                         size_t len, loff_t *ppos);
  94 ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
  95                         size_t len, loff_t *ppos);
  96
  97 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
  98                 struct dentry *new_dir, const char *new_name);
  99
 100 struct dentry *debugfs_create_u8(const char *name, umode_t mode,
 101                                  struct dentry *parent, u8 *value);
 102 struct dentry *debugfs_create_u16(const char *name, umode_t mode,
 103                                   struct dentry *parent, u16 *value);
 104 struct dentry *debugfs_create_u32(const char *name, umode_t mode,
 105                                   struct dentry *parent, u32 *value);
 106 struct dentry *debugfs_create_u64(const char *name, umode_t mode,
 107                                   struct dentry *parent, u64 *value);
 108 struct dentry *debugfs_create_ulong(const char *name, umode_t mode,
 109                                     struct dentry *parent, unsigned long *value);
 110 struct dentry *debugfs_create_x8(const char *name, umode_t mode,
 111                                  struct dentry *parent, u8 *value);
 112 struct dentry *debugfs_create_x16(const char *name, umode_t mode,
 113                                   struct dentry *parent, u16 *value);
 114 struct dentry *debugfs_create_x32(const char *name, umode_t mode,
 115                                   struct dentry *parent, u32 *value);
 116 struct dentry *debugfs_create_x64(const char *name, umode_t mode,
 117                                   struct dentry *parent, u64 *value);
 118 struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
 119                                      struct dentry *parent, size_t *value);
 120 struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
 121                                      struct dentry *parent, atomic_t *value);
 122 struct dentry *debugfs_create_bool(const char *name, umode_t mode,
 123                                   struct dentry *parent, bool *value);
 124
 125 struct dentry *debugfs_create_blob(const char *name, umode_t mode,
 126                                   struct dentry *parent,
 127                                   struct debugfs_blob_wrapper *blob);
 128
 129 struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
 130                                      struct dentry *parent,
 131                                      struct debugfs_regset32 *regset);
 132
 133 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
 134                           int nregs, void __iomem *base, char *prefix);
 135
 136 struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
 137                                         struct dentry *parent,
 138                                         u32 *array, u32 elements);
 139
 140 struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name,
 141                                            struct dentry *parent,
 142                                            int (*read_fn)(struct seq_file *s,
 143                                                           void *data));
 144
 145 bool debugfs_initialized(void);
 146
 147 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
 148                                size_t count, loff_t *ppos);
 149
 150 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
 151                                 size_t count, loff_t *ppos);
 152
 153 #else
 154
 155 #include <linux/err.h>
 156
 157 /*
 158  * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled
 159  * so users have a chance to detect if there was a real error or not.  We don't
 160  * want to duplicate the design decision mistakes of procfs and devfs again.
 161  */
 162
 163 static inline struct dentry *debugfs_lookup(const char *name,
 164                                             struct dentry *parent)
 165 {
 166         return ERR_PTR(-ENODEV);
 167 }
 168
 169 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode,
 170                                         struct dentry *parent, void *data,
 171                                         const struct file_operations *fops)
 172 {
 173         return ERR_PTR(-ENODEV);
 174 }
 175
 176 static inline struct dentry *debugfs_create_file_unsafe(const char *name,
 177                                         umode_t mode, struct dentry *parent,
 178                                         void *data,
 179                                         const struct file_operations *fops)
 180 {
 181         return ERR_PTR(-ENODEV);
 182 }
 183
 184 static inline struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
 185                                         struct dentry *parent, void *data,
 186                                         const struct file_operations *fops,
 187                                         loff_t file_size)
 188 {
 189         return ERR_PTR(-ENODEV);
 190 }
 191
 192 static inline struct dentry *debugfs_create_dir(const char *name,
 193                                                 struct dentry *parent)
 194 {
 195         return ERR_PTR(-ENODEV);
 196 }
 197
 198 static inline struct dentry *debugfs_create_symlink(const char *name,
 199                                                     struct dentry *parent,
 200                                                     const char *dest)
 201 {
 202         return ERR_PTR(-ENODEV);
 203 }
 204
 205 static inline struct dentry *debugfs_create_automount(const char *name,
 206                                         struct dentry *parent,
 207                                         struct vfsmount *(*f)(void *),
 208                                         void *data)
 209 {
 210         return ERR_PTR(-ENODEV);
 211 }
 212
 213 static inline void debugfs_remove(struct dentry *dentry)
 214 { }
 215
 216 static inline void debugfs_remove_recursive(struct dentry *dentry)
 217 { }
 218
 219 const struct file_operations *debugfs_real_fops(const struct file *filp);
 220
 221 static inline int debugfs_file_get(struct dentry *dentry)
 222 {
 223         return 0;
 224 }
 225
 226 static inline void debugfs_file_put(struct dentry *dentry)
 227 { }
 228
 229 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf,
 230                                         size_t len, loff_t *ppos)
 231 {
 232         return -ENODEV;
 233 }
 234
 235 static inline ssize_t debugfs_attr_write(struct file *file,
 236                                         const char __user *buf,
 237                                         size_t len, loff_t *ppos)
 238 {
 239         return -ENODEV;
 240 }
 241
 242 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
 243                 struct dentry *new_dir, char *new_name)
 244 {
 245         return ERR_PTR(-ENODEV);
 246 }
 247
 248 static inline struct dentry *debugfs_create_u8(const char *name, umode_t mode,
 249                                                struct dentry *parent,
 250                                                u8 *value)
 251 {
 252         return ERR_PTR(-ENODEV);
 253 }
 254
 255 static inline struct dentry *debugfs_create_u16(const char *name, umode_t mode,
 256                                                 struct dentry *parent,
 257                                                 u16 *value)
 258 {
 259         return ERR_PTR(-ENODEV);
 260 }
 261
 262 static inline struct dentry *debugfs_create_u32(const char *name, umode_t mode,
 263                                                 struct dentry *parent,
 264                                                 u32 *value)
 265 {
 266         return ERR_PTR(-ENODEV);
 267 }
 268
 269 static inline struct dentry *debugfs_create_u64(const char *name, umode_t mode,
 270                                                 struct dentry *parent,
 271                                                 u64 *value)
 272 {
 273         return ERR_PTR(-ENODEV);
 274 }
 275
 276 static inline struct dentry *debugfs_create_ulong(const char *name,
 277                                                 umode_t mode,
 278                                                 struct dentry *parent,
 279                                                 unsigned long *value)
 280 {
 281         return ERR_PTR(-ENODEV);
 282 }
 283
 284 static inline struct dentry *debugfs_create_x8(const char *name, umode_t mode,
 285                                                struct dentry *parent,
 286                                                u8 *value)
 287 {
 288         return ERR_PTR(-ENODEV);
 289 }
 290
 291 static inline struct dentry *debugfs_create_x16(const char *name, umode_t mode,
 292                                                 struct dentry *parent,
 293                                                 u16 *value)
 294 {
 295         return ERR_PTR(-ENODEV);
 296 }
 297
 298 static inline struct dentry *debugfs_create_x32(const char *name, umode_t mode,
 299                                                 struct dentry *parent,
 300                                                 u32 *value)
 301 {
 302         return ERR_PTR(-ENODEV);
 303 }
 304
 305 static inline struct dentry *debugfs_create_x64(const char *name, umode_t mode,
 306                                                 struct dentry *parent,
 307                                                 u64 *value)
 308 {
 309         return ERR_PTR(-ENODEV);
 310 }
 311
 312 static inline struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
 313                                      struct dentry *parent,
 314                                      size_t *value)
 315 {
 316         return ERR_PTR(-ENODEV);
 317 }
 318
 319 static inline struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
 320                                      struct dentry *parent, atomic_t *value)
 321 {
 322         return ERR_PTR(-ENODEV);
 323 }
 324
 325 static inline struct dentry *debugfs_create_bool(const char *name, umode_t mode,
 326                                                  struct dentry *parent,
 327                                                  bool *value)
 328 {
 329         return ERR_PTR(-ENODEV);
 330 }
 331
 332 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode,
 333                                   struct dentry *parent,
 334                                   struct debugfs_blob_wrapper *blob)
 335 {
 336         return ERR_PTR(-ENODEV);
 337 }
 338
 339 static inline struct dentry *debugfs_create_regset32(const char *name,
 340                                    umode_t mode, struct dentry *parent,
 341                                    struct debugfs_regset32 *regset)
 342 {
 343         return ERR_PTR(-ENODEV);
 344 }
 345
 346 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
 347                          int nregs, void __iomem *base, char *prefix)
 348 {
 349 }
 350
 351 static inline bool debugfs_initialized(void)
 352 {
 353         return false;
 354 }
 355
 356 static inline struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
 357                                         struct dentry *parent,
 358                                         u32 *array, u32 elements)
 359 {
 360         return ERR_PTR(-ENODEV);
 361 }
 362
 363 static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev,
 364                                                          const char *name,
 365                                                          struct dentry *parent,
 366                                            int (*read_fn)(struct seq_file *s,
 367                                                           void *data))
 368 {
 369         return ERR_PTR(-ENODEV);
 370 }
 371
 372 static inline ssize_t debugfs_read_file_bool(struct file *file,
 373                                              char __user *user_buf,
 374                                              size_t count, loff_t *ppos)
 375 {
 376         return -ENODEV;
 377 }
 378
 379 static inline ssize_t debugfs_write_file_bool(struct file *file,
 380                                               const char __user *user_buf,
 381                                               size_t count, loff_t *ppos)
 382 {
 383         return -ENODEV;
 384 }
 385
 386 #endif
 387
 388 #endif