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