linux/include/linux/debugfs.h
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   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
  24struct device;
  25struct file_operations;
  26struct srcu_struct;
  27
  28struct debugfs_blob_wrapper {
  29        void *data;
  30        unsigned long size;
  31};
  32
  33struct debugfs_reg32 {
  34        char *name;
  35        unsigned long offset;
  36};
  37
  38struct debugfs_regset32 {
  39        const struct debugfs_reg32 *regs;
  40        int nregs;
  41        void __iomem *base;
  42};
  43
  44extern struct dentry *arch_debugfs_dir;
  45
  46extern struct srcu_struct debugfs_srcu;
  47
  48#if defined(CONFIG_DEBUG_FS)
  49
  50struct dentry *debugfs_create_file(const char *name, umode_t mode,
  51                                   struct dentry *parent, void *data,
  52                                   const struct file_operations *fops);
  53struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode,
  54                                   struct dentry *parent, void *data,
  55                                   const struct file_operations *fops);
  56
  57struct 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
  62struct dentry *debugfs_create_dir(const char *name, struct dentry *parent);
  63
  64struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
  65                                      const char *dest);
  66
  67struct dentry *debugfs_create_automount(const char *name,
  68                                        struct dentry *parent,
  69                                        struct vfsmount *(*f)(void *),
  70                                        void *data);
  71
  72void debugfs_remove(struct dentry *dentry);
  73void debugfs_remove_recursive(struct dentry *dentry);
  74
  75int debugfs_use_file_start(const struct dentry *dentry, int *srcu_idx)
  76        __acquires(&debugfs_srcu);
  77
  78void debugfs_use_file_finish(int srcu_idx) __releases(&debugfs_srcu);
  79
  80ssize_t debugfs_attr_read(struct file *file, char __user *buf,
  81                        size_t len, loff_t *ppos);
  82ssize_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)           \
  86static 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}                                                                       \
  91static 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
 100struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
 101                struct dentry *new_dir, const char *new_name);
 102
 103struct dentry *debugfs_create_u8(const char *name, umode_t mode,
 104                                 struct dentry *parent, u8 *value);
 105struct dentry *debugfs_create_u16(const char *name, umode_t mode,
 106                                  struct dentry *parent, u16 *value);
 107struct dentry *debugfs_create_u32(const char *name, umode_t mode,
 108                                  struct dentry *parent, u32 *value);
 109struct dentry *debugfs_create_u64(const char *name, umode_t mode,
 110                                  struct dentry *parent, u64 *value);
 111struct dentry *debugfs_create_ulong(const char *name, umode_t mode,
 112                                    struct dentry *parent, unsigned long *value);
 113struct dentry *debugfs_create_x8(const char *name, umode_t mode,
 114                                 struct dentry *parent, u8 *value);
 115struct dentry *debugfs_create_x16(const char *name, umode_t mode,
 116                                  struct dentry *parent, u16 *value);
 117struct dentry *debugfs_create_x32(const char *name, umode_t mode,
 118                                  struct dentry *parent, u32 *value);
 119struct dentry *debugfs_create_x64(const char *name, umode_t mode,
 120                                  struct dentry *parent, u64 *value);
 121struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
 122                                     struct dentry *parent, size_t *value);
 123struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
 124                                     struct dentry *parent, atomic_t *value);
 125struct dentry *debugfs_create_bool(const char *name, umode_t mode,
 126                                  struct dentry *parent, bool *value);
 127
 128struct dentry *debugfs_create_blob(const char *name, umode_t mode,
 129                                  struct dentry *parent,
 130                                  struct debugfs_blob_wrapper *blob);
 131
 132struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
 133                                     struct dentry *parent,
 134                                     struct debugfs_regset32 *regset);
 135
 136void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
 137                          int nregs, void __iomem *base, char *prefix);
 138
 139struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
 140                                        struct dentry *parent,
 141                                        u32 *array, u32 elements);
 142
 143struct 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
 148bool debugfs_initialized(void);
 149
 150ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
 151                               size_t count, loff_t *ppos);
 152
 153ssize_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
 166static 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
 173static 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
 181static inline struct dentry *debugfs_create_dir(const char *name,
 182                                                struct dentry *parent)
 183{
 184        return ERR_PTR(-ENODEV);
 185}
 186
 187static 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
 194static 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
 202static inline void debugfs_remove(struct dentry *dentry)
 203{ }
 204
 205static inline void debugfs_remove_recursive(struct dentry *dentry)
 206{ }
 207
 208static inline int debugfs_use_file_start(const struct dentry *dentry,
 209                                        int *srcu_idx)
 210        __acquires(&debugfs_srcu)
 211{
 212        return 0;
 213}
 214
 215static 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
 222static 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
 228static 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
 235static 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
 242static 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
 249static 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
 256static 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
 263static 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
 270static 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
 277static 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
 284static 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
 291static 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
 297static 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
 304static 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
 311static 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
 318static 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
 323static inline bool debugfs_initialized(void)
 324{
 325        return false;
 326}
 327
 328static 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
 335static 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
 344static 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
 351static 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
 361