include/linux/debugfs.h

   1 /*
   2  *  debugfs.h - a tiny little debug file system
   3  *
   4  *  Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
   5  *  Copyright (C) 2004 IBM Inc.
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License version
   9  *      2 as published by the Free Software Foundation.
  10  *
  11  *  debugfs is for people to use instead of /proc or /sys.
  12  *  See Documentation/DocBook/filesystems for more details.
  13  */
  14
  15 #ifndef _DEBUGFS_H_
  16 #define _DEBUGFS_H_
  17
  18 #include <linux/fs.h>
  19 #include <linux/seq_file.h>
  20
  21 #include <linux/types.h>
  22 #include <linux/compiler.h>
  23
  24 struct device;
  25 struct file_operations;
  26 struct srcu_struct;
  27
  28 struct debugfs_blob_wrapper {
  29         void *data;
  30         unsigned long size;
  31 };
  32
  33 struct debugfs_reg32 {
  34         char *name;
  35         unsigned long offset;
  36 };
  37
  38 struct debugfs_regset32 {
  39         const struct debugfs_reg32 *regs;
  40         int nregs;
  41         void __iomem *base;
  42 };
  43
  44 extern struct dentry *arch_debugfs_dir;
  45
  46 extern struct srcu_struct debugfs_srcu;
  47
  48 /**
  49  * debugfs_real_fops - getter for the real file operation
  50  * @filp: a pointer to a struct file
  51  *
  52  * Must only be called under the protection established by
  53  * debugfs_use_file_start().
  54  */
  55 static inline const struct file_operations *
  56 debugfs_real_fops(const struct file *filp)
  57         __must_hold(&debugfs_srcu)
  58 {
  59         /*
  60          * Neither the pointer to the struct file_operations, nor its
  61          * contents ever change -- srcu_dereference() is not needed here.
  62          */
  63         return filp->f_path.dentry->d_fsdata;
  64 }
  65
  66 #define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt)           \
  67 static int __fops ## _open(struct inode *inode, struct file *file)      \
  68 {                                                                       \
  69         __simple_attr_check_format(__fmt, 0ull);                        \
  70         return simple_attr_open(inode, file, __get, __set, __fmt);      \
  71 }                                                                       \
  72 static const struct file_operations __fops = {                          \
  73         .owner   = THIS_MODULE,                                         \
  74         .open    = __fops ## _open,                                     \
  75         .release = simple_attr_release,                                 \
  76         .read    = debugfs_attr_read,                                   \
  77         .write   = debugfs_attr_write,                                  \
  78         .llseek  = generic_file_llseek,                                 \
  79 }
  80
  81 #if defined(CONFIG_DEBUG_FS)
  82
  83 struct dentry *debugfs_create_file(const char *name, umode_t mode,
  84                                    struct dentry *parent, void *data,
  85                                    const struct file_operations *fops);
  86 struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode,
  87                                    struct dentry *parent, void *data,
  88                                    const struct file_operations *fops);
  89
  90 struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
  91                                         struct dentry *parent, void *data,
  92                                         const struct file_operations *fops,
  93                                         loff_t file_size);
  94
  95 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent);
  96
  97 struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
  98                                       const char *dest);
  99
 100 struct dentry *debugfs_create_automount(const char *name,
 101                                         struct dentry *parent,
 102                                         struct vfsmount *(*f)(void *),
 103                                         void *data);
 104
 105 void debugfs_remove(struct dentry *dentry);
 106 void debugfs_remove_recursive(struct dentry *dentry);
 107
 108 int debugfs_use_file_start(const struct dentry *dentry, int *srcu_idx)
 109         __acquires(&debugfs_srcu);
 110
 111 void debugfs_use_file_finish(int srcu_idx) __releases(&debugfs_srcu);
 112
 113 ssize_t debugfs_attr_read(struct file *file, char __user *buf,
 114                         size_t len, loff_t *ppos);
 115 ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
 116                         size_t len, loff_t *ppos);
 117
 118 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
 119                 struct dentry *new_dir, const char *new_name);
 120
 121 struct dentry *debugfs_create_u8(const char *name, umode_t mode,
 122                                  struct dentry *parent, u8 *value);
 123 struct dentry *debugfs_create_u16(const char *name, umode_t mode,
 124                                   struct dentry *parent, u16 *value);
 125 struct dentry *debugfs_create_u32(const char *name, umode_t mode,
 126                                   struct dentry *parent, u32 *value);
 127 struct dentry *debugfs_create_u64(const char *name, umode_t mode,
 128                                   struct dentry *parent, u64 *value);
 129 struct dentry *debugfs_create_ulong(const char *name, umode_t mode,
 130                                     struct dentry *parent, unsigned long *value);
 131 struct dentry *debugfs_create_x8(const char *name, umode_t mode,
 132                                  struct dentry *parent, u8 *value);
 133 struct dentry *debugfs_create_x16(const char *name, umode_t mode,
 134                                   struct dentry *parent, u16 *value);
 135 struct dentry *debugfs_create_x32(const char *name, umode_t mode,
 136                                   struct dentry *parent, u32 *value);
 137 struct dentry *debugfs_create_x64(const char *name, umode_t mode,
 138                                   struct dentry *parent, u64 *value);
 139 struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
 140                                      struct dentry *parent, size_t *value);
 141 struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
 142                                      struct dentry *parent, atomic_t *value);
 143 struct dentry *debugfs_create_bool(const char *name, umode_t mode,
 144                                   struct dentry *parent, bool *value);
 145
 146 struct dentry *debugfs_create_blob(const char *name, umode_t mode,
 147                                   struct dentry *parent,
 148                                   struct debugfs_blob_wrapper *blob);
 149
 150 struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
 151                                      struct dentry *parent,
 152                                      struct debugfs_regset32 *regset);
 153
 154 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
 155                           int nregs, void __iomem *base, char *prefix);
 156
 157 struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
 158                                         struct dentry *parent,
 159                                         u32 *array, u32 elements);
 160
 161 struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name,
 162                                            struct dentry *parent,
 163                                            int (*read_fn)(struct seq_file *s,
 164                                                           void *data));
 165
 166 bool debugfs_initialized(void);
 167
 168 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
 169                                size_t count, loff_t *ppos);
 170
 171 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
 172                                 size_t count, loff_t *ppos);
 173
 174 #else
 175
 176 #include <linux/err.h>
 177
 178 /*
 179  * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled
 180  * so users have a chance to detect if there was a real error or not.  We don't
 181  * want to duplicate the design decision mistakes of procfs and devfs again.
 182  */
 183
 184 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode,
 185                                         struct dentry *parent, void *data,
 186                                         const struct file_operations *fops)
 187 {
 188         return ERR_PTR(-ENODEV);
 189 }
 190
 191 static inline struct dentry *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         return ERR_PTR(-ENODEV);
 197 }
 198
 199 static inline struct dentry *debugfs_create_dir(const char *name,
 200                                                 struct dentry *parent)
 201 {
 202         return ERR_PTR(-ENODEV);
 203 }
 204
 205 static inline struct dentry *debugfs_create_symlink(const char *name,
 206                                                     struct dentry *parent,
 207                                                     const char *dest)
 208 {
 209         return ERR_PTR(-ENODEV);
 210 }
 211
 212 static inline struct dentry *debugfs_create_automount(const char *name,
 213                                         struct dentry *parent,
 214                                         struct vfsmount *(*f)(void *),
 215                                         void *data)
 216 {
 217         return ERR_PTR(-ENODEV);
 218 }
 219
 220 static inline void debugfs_remove(struct dentry *dentry)
 221 { }
 222
 223 static inline void debugfs_remove_recursive(struct dentry *dentry)
 224 { }
 225
 226 static inline int debugfs_use_file_start(const struct dentry *dentry,
 227                                         int *srcu_idx)
 228         __acquires(&debugfs_srcu)
 229 {
 230         return 0;
 231 }
 232
 233 static inline void debugfs_use_file_finish(int srcu_idx)
 234         __releases(&debugfs_srcu)
 235 { }
 236
 237 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf,
 238                                         size_t len, loff_t *ppos)
 239 {
 240         return -ENODEV;
 241 }
 242
 243 static inline ssize_t debugfs_attr_write(struct file *file,
 244                                         const char __user *buf,
 245                                         size_t len, loff_t *ppos)
 246 {
 247         return -ENODEV;
 248 }
 249
 250 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
 251                 struct dentry *new_dir, char *new_name)
 252 {
 253         return ERR_PTR(-ENODEV);
 254 }
 255
 256 static inline struct dentry *debugfs_create_u8(const char *name, umode_t mode,
 257                                                struct dentry *parent,
 258                                                u8 *value)
 259 {
 260         return ERR_PTR(-ENODEV);
 261 }
 262
 263 static inline struct dentry *debugfs_create_u16(const char *name, umode_t mode,
 264                                                 struct dentry *parent,
 265                                                 u16 *value)
 266 {
 267         return ERR_PTR(-ENODEV);
 268 }
 269
 270 static inline struct dentry *debugfs_create_u32(const char *name, umode_t mode,
 271                                                 struct dentry *parent,
 272                                                 u32 *value)
 273 {
 274         return ERR_PTR(-ENODEV);
 275 }
 276
 277 static inline struct dentry *debugfs_create_u64(const char *name, umode_t mode,
 278                                                 struct dentry *parent,
 279                                                 u64 *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