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 #if defined(CONFIG_DEBUG_FS)
  49
  50 struct dentry *debugfs_create_file(const char *name, umode_t mode,
  51                                    struct dentry *parent, void *data,
  52                                    const struct file_operations *fops);
  53 struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode,
  54                                    struct dentry *parent, void *data,
  55                                    const struct file_operations *fops);
  56
  57 struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
  58                                         struct dentry *parent, void *data,
  59                                         const struct file_operations *fops,
  60                                         loff_t file_size);
  61
  62 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent);
  63
  64 struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
  65                                       const char *dest);
  66
  67 struct dentry *debugfs_create_automount(const char *name,
  68                                         struct dentry *parent,
  69                                         struct vfsmount *(*f)(void *),
  70                                         void *data);
  71
  72 void debugfs_remove(struct dentry *dentry);
  73 void debugfs_remove_recursive(struct dentry *dentry);
  74
  75 int debugfs_use_file_start(const struct dentry *dentry, int *srcu_idx)
  76         __acquires(&debugfs_srcu);
  77
  78 void debugfs_use_file_finish(int srcu_idx) __releases(&debugfs_srcu);
  79
  80 ssize_t debugfs_attr_read(struct file *file, char __user *buf,
  81                         size_t len, loff_t *ppos);
  82 ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
  83                         size_t len, loff_t *ppos);
  84
  85 #define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt)           \
  86 static int __fops ## _open(struct inode *inode, struct file *file)      \
  87 {                                                                       \
  88         __simple_attr_check_format(__fmt, 0ull);                        \
  89         return simple_attr_open(inode, file, __get, __set, __fmt);      \
  90 }                                                                       \
  91 static const struct file_operations __fops = {                          \
  92         .owner   = THIS_MODULE,                                 \
  93         .open    = __fops ## _open,                                     \
  94         .release = simple_attr_release,                         \
  95         .read    = debugfs_attr_read,                                   \
  96         .write   = debugfs_attr_write,                                  \
  97         .llseek  = generic_file_llseek,                         \
  98 }
  99
 100 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
 101                 struct dentry *new_dir, const char *new_name);
 102
 103 struct dentry *debugfs_create_u8(const char *name, umode_t mode,
 104                                  struct dentry *parent, u8 *value);
 105 struct dentry *debugfs_create_u16(const char *name, umode_t mode,
 106                                   struct dentry *parent, u16 *value);
 107 struct dentry *debugfs_create_u32(const char *name, umode_t mode,
 108                                   struct dentry *parent, u32 *value);
 109 struct dentry *debugfs_create_u64(const char *name, umode_t mode,
 110                                   struct dentry *parent, u64 *value);
 111 struct dentry *debugfs_create_ulong(const char *name, umode_t mode,
 112                                     struct dentry *parent, unsigned long *value);
 113 struct dentry *debugfs_create_x8(const char *name, umode_t mode,
 114                                  struct dentry *parent, u8 *value);
 115 struct dentry *debugfs_create_x16(const char *name, umode_t mode,
 116                                   struct dentry *parent, u16 *value);
 117 struct dentry *debugfs_create_x32(const char *name, umode_t mode,
 118                                   struct dentry *parent, u32 *value);
 119 struct dentry *debugfs_create_x64(const char *name, umode_t mode,
 120                                   struct dentry *parent, u64 *value);
 121 struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
 122                                      struct dentry *parent, size_t *value);
 123 struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
 124                                      struct dentry *parent, atomic_t *value);
 125 struct dentry *debugfs_create_bool(const char *name, umode_t mode,
 126                                   struct dentry *parent, bool *value);
 127
 128 struct dentry *debugfs_create_blob(const char *name, umode_t mode,
 129                                   struct dentry *parent,
 130                                   struct debugfs_blob_wrapper *blob);
 131
 132 struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
 133                                      struct dentry *parent,
 134                                      struct debugfs_regset32 *regset);
 135
 136 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
 137                           int nregs, void __iomem *base, char *prefix);
 138
 139 struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
 140                                         struct dentry *parent,
 141                                         u32 *array, u32 elements);
 142
 143 struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name,
 144                                            struct dentry *parent,
 145                                            int (*read_fn)(struct seq_file *s,
 146                                                           void *data));
 147
 148 bool debugfs_initialized(void);
 149
 150 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
 151                                size_t count, loff_t *ppos);
 152
 153 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
 154                                 size_t count, loff_t *ppos);
 155
 156 #else
 157
 158 #include <linux/err.h>
 159
 160 /*
 161  * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled
 162  * so users have a chance to detect if there was a real error or not.  We don't
 163  * want to duplicate the design decision mistakes of procfs and devfs again.
 164  */
 165
 166 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode,
 167                                         struct dentry *parent, void *data,
 168                                         const struct file_operations *fops)
 169 {
 170         return ERR_PTR(-ENODEV);
 171 }
 172
 173 static inline struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
 174                                         struct dentry *parent, void *data,
 175                                         const struct file_operations *fops,
 176                                         loff_t file_size)
 177 {
 178         return ERR_PTR(-ENODEV);
 179 }
 180
 181 static inline struct dentry *debugfs_create_dir(const char *name,
 182                                                 struct dentry *parent)
 183 {
 184         return ERR_PTR(-ENODEV);
 185 }
 186
 187 static inline struct dentry *debugfs_create_symlink(const char *name,
 188                                                     struct dentry *parent,
 189                                                     const char *dest)
 190 {
 191         return ERR_PTR(-ENODEV);
 192 }
 193
 194 static inline struct dentry *debugfs_create_automount(const char *name,
 195                                         struct dentry *parent,
 196                                         struct vfsmount *(*f)(void *),
 197                                         void *data)
 198 {
 199         return ERR_PTR(-ENODEV);
 200 }
 201
 202 static inline void debugfs_remove(struct dentry *dentry)
 203 { }
 204
 205 static inline void debugfs_remove_recursive(struct dentry *dentry)
 206 { }
 207
 208 static inline int debugfs_use_file_start(const struct dentry *dentry,
 209                                         int *srcu_idx)
 210         __acquires(&debugfs_srcu)
 211 {
 212         return 0;
 213 }
 214
 215 static inline void debugfs_use_file_finish(int srcu_idx)
 216         __releases(&debugfs_srcu)
 217 { }
 218
 219 #define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt)   \
 220         static const struct file_operations __fops = { 0 }
 221
 222 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
 223                 struct dentry *new_dir, char *new_name)
 224 {
 225         return ERR_PTR(-ENODEV);
 226 }
 227
 228 static inline struct dentry *debugfs_create_u8(const char *name, umode_t mode,
 229                                                struct dentry *parent,
 230                                                u8 *value)
 231 {
 232         return ERR_PTR(-ENODEV);
 233 }
 234
 235 static inline struct dentry *debugfs_create_u16(const char *name, umode_t mode,
 236                                                 struct dentry *parent,
 237                                                 u16 *value)
 238 {
 239         return ERR_PTR(-ENODEV);
 240 }
 241
 242 static inline struct dentry *debugfs_create_u32(const char *name, umode_t mode,
 243                                                 struct dentry *parent,
 244                                                 u32 *value)
 245 {
 246         return ERR_PTR(-ENODEV);
 247 }
 248
 249 static inline struct dentry *debugfs_create_u64(const char *name, umode_t mode,
 250                                                 struct dentry *parent,
 251                                                 u64 *value)
 252 {
 253         return ERR_PTR(-ENODEV);
 254 }
 255
 256 static inline struct dentry *debugfs_create_x8(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_x16(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_x32(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_x64(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_size_t(const char *name, umode_t mode,
 285                                      struct dentry *parent,
 286                                      size_t *value)
 287 {
 288         return ERR_PTR(-ENODEV);
 289 }
 290
 291 static inline struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
 292                                      struct dentry *parent, atomic_t *value)
 293 {
 294         return ERR_PTR(-ENODEV);
 295 }
 296
 297 static inline struct dentry *debugfs_create_bool(const char *name, umode_t mode,
 298                                                  struct dentry *parent,
 299                                                  bool *value)
 300 {
 301         return ERR_PTR(-ENODEV);
 302 }
 303
 304 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode,
 305                                   struct dentry *parent,
 306                                   struct debugfs_blob_wrapper *blob)
 307 {
 308         return ERR_PTR(-ENODEV);
 309 }
 310
 311 static inline struct dentry *debugfs_create_regset32(const char *name,
 312                                    umode_t mode, struct dentry *parent,
 313                                    struct debugfs_regset32 *regset)
 314 {
 315         return ERR_PTR(-ENODEV);
 316 }
 317
 318 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
 319                          int nregs, void __iomem *base, char *prefix)
 320 {
 321 }
 322
 323 static inline bool debugfs_initialized(void)
 324 {
 325         return false;
 326 }
 327
 328 static inline struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
 329                                         struct dentry *parent,
 330                                         u32 *array, u32 elements)
 331 {
 332         return ERR_PTR(-ENODEV);
 333 }
 334
 335 static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev,
 336                                                          const char *name,
 337                                                          struct dentry *parent,
 338                                            int (*read_fn)(struct seq_file *s,
 339                                                           void *data))
 340 {
 341         return ERR_PTR(-ENODEV);
 342 }
 343
 344 static inline ssize_t debugfs_read_file_bool(struct file *file,
 345                                              char __user *user_buf,
 346                                              size_t count, loff_t *ppos)
 347 {
 348         return -ENODEV;
 349 }
 350
 351 static inline ssize_t debugfs_write_file_bool(struct file *file,
 352                                               const char __user *user_buf,
 353                                               size_t count, loff_t *ppos)
 354 {
 355         return -ENODEV;
 356 }
 357
 358 #endif
 359
 360 #endif