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 typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *);
  58
  59 #if defined(CONFIG_DEBUG_FS)
  60
  61 struct dentry *debugfs_lookup(const char *name, struct dentry *parent);
  62
  63 struct dentry *debugfs_create_file(const char *name, umode_t mode,
  64                                    struct dentry *parent, void *data,
  65                                    const struct file_operations *fops);
  66 struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode,
  67                                    struct dentry *parent, void *data,
  68                                    const struct file_operations *fops);
  69
  70 struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
  71                                         struct dentry *parent, void *data,
  72                                         const struct file_operations *fops,
  73                                         loff_t file_size);
  74
  75 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent);
  76
  77 struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
  78                                       const char *dest);
  79
  80 struct dentry *debugfs_create_automount(const char *name,
  81                                         struct dentry *parent,
  82                                         debugfs_automount_t f,
  83                                         void *data);
  84
  85 void debugfs_remove(struct dentry *dentry);
  86 #define debugfs_remove_recursive debugfs_remove
  87
  88 const struct file_operations *debugfs_real_fops(const struct file *filp);
  89
  90 int debugfs_file_get(struct dentry *dentry);
  91 void debugfs_file_put(struct dentry *dentry);
  92
  93 ssize_t debugfs_attr_read(struct file *file, char __user *buf,
  94                         size_t len, loff_t *ppos);
  95 ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
  96                         size_t len, loff_t *ppos);
  97
  98 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
  99                 struct dentry *new_dir, const char *new_name);
 100
 101 void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent,
 102                        u8 *value);
 103 void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent,
 104                         u16 *value);
 105 struct dentry *debugfs_create_u32(const char *name, umode_t mode,
 106                                   struct dentry *parent, u32 *value);
 107 void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent,
 108                         u64 *value);
 109 struct dentry *debugfs_create_ulong(const char *name, umode_t mode,
 110                                     struct dentry *parent, unsigned long *value);
 111 void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent,
 112                        u8 *value);
 113 void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent,
 114                         u16 *value);
 115 void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent,
 116                         u32 *value);
 117 void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent,
 118                         u64 *value);
 119 void debugfs_create_size_t(const char *name, umode_t mode,
 120                            struct dentry *parent, size_t *value);
 121 void debugfs_create_atomic_t(const char *name, umode_t mode,
 122                              struct dentry *parent, atomic_t *value);
 123 struct dentry *debugfs_create_bool(const char *name, umode_t mode,
 124                                   struct dentry *parent, bool *value);
 125
 126 struct dentry *debugfs_create_blob(const char *name, umode_t mode,
 127                                   struct dentry *parent,
 128                                   struct debugfs_blob_wrapper *blob);
 129
 130 struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
 131                                      struct dentry *parent,
 132                                      struct debugfs_regset32 *regset);
 133
 134 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
 135                           int nregs, void __iomem *base, char *prefix);
 136
 137 void debugfs_create_u32_array(const char *name, umode_t mode,
 138                               struct dentry *parent, 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                                         debugfs_automount_t f,
 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 void debugfs_create_u8(const char *name, umode_t mode,
 249                                      struct dentry *parent, u8 *value) { }
 250
 251 static inline void debugfs_create_u16(const char *name, umode_t mode,
 252                                       struct dentry *parent, u16 *value) { }
 253
 254 static inline struct dentry *debugfs_create_u32(const char *name, umode_t mode,
 255                                                 struct dentry *parent,
 256                                                 u32 *value)
 257 {
 258         return ERR_PTR(-ENODEV);
 259 }
 260
 261 static inline void debugfs_create_u64(const char *name, umode_t mode,
 262                                       struct dentry *parent, u64 *value) { }
 263
 264 static inline struct dentry *debugfs_create_ulong(const char *name,
 265                                                 umode_t mode,
 266                                                 struct dentry *parent,
 267                                                 unsigned long *value)
 268 {
 269         return ERR_PTR(-ENODEV);
 270 }
 271
 272 static inline void debugfs_create_x8(const char *name, umode_t mode,
 273                                      struct dentry *parent, u8 *value) { }
 274
 275 static inline void debugfs_create_x16(const char *name, umode_t mode,
 276                                       struct dentry *parent, u16 *value) { }
 277
 278 static inline void debugfs_create_x32(const char *name, umode_t mode,
 279                                       struct dentry *parent, u32 *value) { }
 280
 281 static inline void debugfs_create_x64(const char *name, umode_t mode,
 282                                       struct dentry *parent, u64 *value) { }
 283
 284 static inline void debugfs_create_size_t(const char *name, umode_t mode,
 285                                          struct dentry *parent, size_t *value)
 286 { }
 287
 288 static inline void debugfs_create_atomic_t(const char *name, umode_t mode,
 289                                            struct dentry *parent,
 290                                            atomic_t *value)
 291 { }
 292
 293 static inline struct dentry *debugfs_create_bool(const char *name, umode_t mode,
 294                                                  struct dentry *parent,
 295                                                  bool *value)
 296 {
 297         return ERR_PTR(-ENODEV);
 298 }
 299
 300 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode,
 301                                   struct dentry *parent,
 302                                   struct debugfs_blob_wrapper *blob)
 303 {
 304         return ERR_PTR(-ENODEV);
 305 }
 306
 307 static inline struct dentry *debugfs_create_regset32(const char *name,
 308                                    umode_t mode, struct dentry *parent,
 309                                    struct debugfs_regset32 *regset)
 310 {
 311         return ERR_PTR(-ENODEV);
 312 }
 313
 314 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
 315                          int nregs, void __iomem *base, char *prefix)
 316 {
 317 }
 318
 319 static inline bool debugfs_initialized(void)
 320 {
 321         return false;
 322 }
 323
 324 static inline void debugfs_create_u32_array(const char *name, umode_t mode,
 325                                             struct dentry *parent, u32 *array,
 326                                             u32 elements)
 327 {
 328 }
 329
 330 static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev,
 331                                                          const char *name,
 332                                                          struct dentry *parent,
 333                                            int (*read_fn)(struct seq_file *s,
 334                                                           void *data))
 335 {
 336         return ERR_PTR(-ENODEV);
 337 }
 338
 339 static 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
 346 static 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
 353 #endif
 354
 355 /**
 356  * debugfs_create_xul - create a debugfs file that is used to read and write an
 357  * unsigned long value, formatted in hexadecimal
 358  * @name: a pointer to a string containing the name of the file to create.
 359  * @mode: the permission that the file should have
 360  * @parent: a pointer to the parent dentry for this file.  This should be a
 361  *          directory dentry if set.  If this parameter is %NULL, then the
 362  *          file will be created in the root of the debugfs filesystem.
 363  * @value: a pointer to the variable that the file should read to and write
 364  *         from.
 365  */
 366 static inline void debugfs_create_xul(const char *name, umode_t mode,
 367                                       struct dentry *parent,
 368                                       unsigned long *value)
 369 {
 370         if (sizeof(*value) == sizeof(u32))
 371                 debugfs_create_x32(name, mode, parent, (u32 *)value);
 372         else
 373                 debugfs_create_x64(name, mode, parent, (u64 *)value);
 374 }
 375
 376 #endif