debugfs.h

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// SPDX-License-Identifier: GPL-2.0
/*
 *  debugfs.h - a tiny little debug file system
 *
 *  Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
 *  Copyright (C) 2004 IBM Inc.
 *
 *  debugfs is for people to use instead of /proc or /sys.
 *  See Documentation/filesystems/ for more details.
 */
 
#ifndef _DEBUGFS_H_
#define _DEBUGFS_H_
 
#include <linux/fs.h>
#include <linux/seq_file.h>
 
/*
 * mainline includes <linux/atomic.h> here and the port dropped it. The include
 * is load-bearing for debugfs_create_atomic_t() below, whose only parameter is
 * an atomic_t * -- with the include missing the parameter is an unknown type
 * name, and because that function is itself only ever an empty stub in this
 * tree the error surfaces as a parse failure at its declaration rather than
 * anywhere a caller could have pointed at it.
 */
#include <linux/atomic.h>
 
#include <linux/types.h>
#include <linux/compiler.h>
 
struct device;
struct file_operations;
 
struct debugfs_blob_wrapper {
    void *data;
    unsigned long size;
};
 
struct debugfs_reg32 {
    char *name;
    unsigned long offset;
};
 
struct debugfs_regset32 {
    const struct debugfs_reg32 *regs;
    int nregs;
    void __iomem *base;
    struct device *dev; /* Optional device for Runtime PM */
};
 
struct debugfs_u32_array {
    u32 *array;
    u32 n_elements;
};
 
extern struct dentry *arch_debugfs_dir;
 
#define DEFINE_DEBUGFS_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, __is_signed)  \
static int __fops ## _open(struct inode *inode, struct file *file)  \
{                                   \
    __simple_attr_check_format(__fmt, 0ull);            \
    return simple_attr_open(inode, file, __get, __set, __fmt);  \
}                                   \
static const struct file_operations __fops = {              \
    .owner   = THIS_MODULE,                     \
    .open    = __fops ## _open,                 \
    .release = simple_attr_release,                 \
    .read    = debugfs_attr_read,                   \
    .write   = (__is_signed) ? debugfs_attr_write_signed : debugfs_attr_write,  \
}
 
#define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt)       \
    DEFINE_DEBUGFS_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, false)
 
#define DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(__fops, __get, __set, __fmt)    \
    DEFINE_DEBUGFS_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, true)
 
typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *);
 
struct debugfs_short_fops {
    ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
    ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *);
    loff_t (*llseek) (struct file *, loff_t, int);
};
 
#if defined(CONFIG_DEBUG_FS)
 
struct dentry *debugfs_lookup(const char *name, struct dentry *parent);
 
struct dentry *debugfs_create_file_full(const char *name, umode_t mode,
                    struct dentry *parent, void *data,
                    const void *aux,
                    const struct file_operations *fops);
struct dentry *debugfs_create_file_short(const char *name, umode_t mode,
                     struct dentry *parent, void *data,
                     const void *aux,
                     const struct debugfs_short_fops *fops);
 
#define debugfs_create_file(name, mode, parent, data, fops)         \
    _Generic(fops,                              \
         const struct file_operations *: debugfs_create_file_full,  \
         const struct debugfs_short_fops *: debugfs_create_file_short,  \
         struct file_operations *: debugfs_create_file_full,        \
         struct debugfs_short_fops *: debugfs_create_file_short)    \
        (name, mode, parent, data, NULL, fops)
 
#define debugfs_create_file_aux(name, mode, parent, data, aux, fops)        \
    _Generic(fops,                              \
         const struct file_operations *: debugfs_create_file_full,  \
         const struct debugfs_short_fops *: debugfs_create_file_short,  \
         struct file_operations *: debugfs_create_file_full,        \
         struct debugfs_short_fops *: debugfs_create_file_short)    \
        (name, mode, parent, data, aux, fops)
 
struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode,
                   struct dentry *parent, void *data,
                   const struct file_operations *fops);
 
void debugfs_create_file_size(const char *name, umode_t mode,
                  struct dentry *parent, void *data,
                  const struct file_operations *fops,
                  loff_t file_size);
 
struct dentry *debugfs_create_dir(const char *name, struct dentry *parent);
 
struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
                      const char *dest);
 
struct dentry *debugfs_create_automount(const char *name,
                    struct dentry *parent,
                    debugfs_automount_t f,
                    void *data);
 
void debugfs_remove(struct dentry *dentry);
#define debugfs_remove_recursive debugfs_remove
 
void debugfs_lookup_and_remove(const char *name, struct dentry *parent);
 
void *debugfs_get_aux(const struct file *file);
 
int debugfs_file_get(struct dentry *dentry);
void debugfs_file_put(struct dentry *dentry);
 
ssize_t debugfs_attr_read(struct file *file, char __user *buf,
            size_t len, loff_t *ppos);
ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
            size_t len, loff_t *ppos);
ssize_t debugfs_attr_write_signed(struct file *file, const char __user *buf,
            size_t len, loff_t *ppos);
 
int debugfs_change_name(struct dentry *dentry, const char *fmt, ...) __printf(2, 3);
 
void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent,
               u8 *value);
void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent,
            u16 *value);
void debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent,
            u32 *value);
void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent,
            u64 *value);
void debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent,
              unsigned long *value);
void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent,
               u8 *value);
void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent,
            u16 *value);
void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent,
            u32 *value);
void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent,
            u64 *value);
void debugfs_create_size_t(const char *name, umode_t mode,
               struct dentry *parent, size_t *value);
void debugfs_create_atomic_t(const char *name, umode_t mode,
                 struct dentry *parent, atomic_t *value);
void debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent,
             bool *value);
void debugfs_create_str(const char *name, umode_t mode,
            struct dentry *parent, char **value);
 
struct dentry *debugfs_create_blob(const char *name, umode_t mode,
                  struct dentry *parent,
                  struct debugfs_blob_wrapper *blob);
 
void debugfs_create_regset32(const char *name, umode_t mode,
                 struct dentry *parent,
                 struct debugfs_regset32 *regset);
 
void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
              int nregs, void __iomem *base, char *prefix);
 
void debugfs_create_u32_array(const char *name, umode_t mode,
                  struct dentry *parent,
                  struct debugfs_u32_array *array);
 
void debugfs_create_devm_seqfile(struct device *dev, const char *name,
                 struct dentry *parent,
                 int (*read_fn)(struct seq_file *s, void *data));
 
bool debugfs_initialized(void);
 
ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
                   size_t count, loff_t *ppos);
 
ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
                size_t count, loff_t *ppos);
 
ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf,
                  size_t count, loff_t *ppos);
 
context_lock_struct(debugfs_cancellation) {
    struct list_head list;
    void (*cancel)(struct dentry *, void *);
    void *cancel_data;
};
 
void debugfs_enter_cancellation(struct file *file,
                struct debugfs_cancellation *cancellation) __acquires(cancellation);
void debugfs_leave_cancellation(struct file *file,
                struct debugfs_cancellation *cancellation) __releases(cancellation);
 
#else
 
#include <linux/err.h>
 
/*
 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled
 * so users have a chance to detect if there was a real error or not.  We don't
 * want to duplicate the design decision mistakes of procfs and devfs again.
 */
 
static inline struct dentry *debugfs_lookup(const char *name,
                        struct dentry *parent)
{
    return ERR_PTR(-ENODEV);
}
 
static inline struct dentry *debugfs_create_file_aux(const char *name,
                    umode_t mode, struct dentry *parent,
                    void *data, void *aux,
                    const void *fops)
{
    return ERR_PTR(-ENODEV);
}
 
static inline struct dentry *debugfs_create_file(const char *name, umode_t mode,
                    struct dentry *parent, void *data,
                    const void *fops)
{
    return ERR_PTR(-ENODEV);
}
 
static inline struct dentry *debugfs_create_file_unsafe(const char *name,
                    umode_t mode, struct dentry *parent,
                    void *data,
                    const struct file_operations *fops)
{
    return ERR_PTR(-ENODEV);
}
 
static inline void debugfs_create_file_size(const char *name, umode_t mode,
                        struct dentry *parent, void *data,
                        const struct file_operations *fops,
                        loff_t file_size)
{ }
 
static inline struct dentry *debugfs_create_dir(const char *name,
                        struct dentry *parent)
{
    return ERR_PTR(-ENODEV);
}
 
static inline struct dentry *debugfs_create_symlink(const char *name,
                            struct dentry *parent,
                            const char *dest)
{
    return ERR_PTR(-ENODEV);
}
 
static inline struct dentry *debugfs_create_automount(const char *name,
                    struct dentry *parent,
                    debugfs_automount_t f,
                    void *data)
{
    return ERR_PTR(-ENODEV);
}
 
static inline void debugfs_remove(struct dentry *dentry)
{ }
 
static inline void debugfs_remove_recursive(struct dentry *dentry)
{ }
 
static inline void debugfs_lookup_and_remove(const char *name,
                         struct dentry *parent)
{ }
 
void *debugfs_get_aux(const struct file *file);
 
static inline int debugfs_file_get(struct dentry *dentry)
{
    return 0;
}
 
static inline void debugfs_file_put(struct dentry *dentry)
{ }
 
static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf,
                    size_t len, loff_t *ppos)
{
    return -ENODEV;
}
 
static inline ssize_t debugfs_attr_write(struct file *file,
                    const char __user *buf,
                    size_t len, loff_t *ppos)
{
    return -ENODEV;
}
 
static inline ssize_t debugfs_attr_write_signed(struct file *file,
                    const char __user *buf,
                    size_t len, loff_t *ppos)
{
    return -ENODEV;
}
 
static inline int __printf(2, 3) debugfs_change_name(struct dentry *dentry,
                    const char *fmt, ...)
{
    return -ENODEV;
}
 
static inline void debugfs_create_u8(const char *name, umode_t mode,
                     struct dentry *parent, u8 *value) { }
 
static inline void debugfs_create_u16(const char *name, umode_t mode,
                      struct dentry *parent, u16 *value) { }
 
static inline void debugfs_create_u32(const char *name, umode_t mode,
                      struct dentry *parent, u32 *value) { }
 
static inline void debugfs_create_u64(const char *name, umode_t mode,
                      struct dentry *parent, u64 *value) { }
 
static inline void debugfs_create_ulong(const char *name, umode_t mode,
                    struct dentry *parent,
                    unsigned long *value) { }
 
static inline void debugfs_create_x8(const char *name, umode_t mode,
                     struct dentry *parent, u8 *value) { }
 
static inline void debugfs_create_x16(const char *name, umode_t mode,
                      struct dentry *parent, u16 *value) { }
 
static inline void debugfs_create_x32(const char *name, umode_t mode,
                      struct dentry *parent, u32 *value) { }
 
static inline void debugfs_create_x64(const char *name, umode_t mode,
                      struct dentry *parent, u64 *value) { }
 
static inline void debugfs_create_size_t(const char *name, umode_t mode,
                     struct dentry *parent, size_t *value)
{ }
 
static inline void debugfs_create_atomic_t(const char *name, umode_t mode,
                       struct dentry *parent,
                       atomic_t *value)
{ }
 
static inline void debugfs_create_bool(const char *name, umode_t mode,
                       struct dentry *parent, bool *value) { }
 
static inline void debugfs_create_str(const char *name, umode_t mode,
                      struct dentry *parent,
                      char **value)
{ }
 
static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode,
                  struct dentry *parent,
                  struct debugfs_blob_wrapper *blob)
{
    return ERR_PTR(-ENODEV);
}
 
static inline void debugfs_create_regset32(const char *name, umode_t mode,
                       struct dentry *parent,
                       struct debugfs_regset32 *regset)
{
}
 
static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
             int nregs, void __iomem *base, char *prefix)
{
}
 
static inline bool debugfs_initialized(void)
{
    return false;
}
 
static inline void debugfs_create_u32_array(const char *name, umode_t mode,
                        struct dentry *parent,
                        struct debugfs_u32_array *array)
{
}
 
static inline void debugfs_create_devm_seqfile(struct device *dev,
                           const char *name,
                           struct dentry *parent,
                           int (*read_fn)(struct seq_file *s,
                                  void *data))
{
}
 
static inline ssize_t debugfs_read_file_bool(struct file *file,
                         char __user *user_buf,
                         size_t count, loff_t *ppos)
{
    return -ENODEV;
}
 
static inline ssize_t debugfs_write_file_bool(struct file *file,
                          const char __user *user_buf,
                          size_t count, loff_t *ppos)
{
    return -ENODEV;
}
 
static inline ssize_t debugfs_read_file_str(struct file *file,
                        char __user *user_buf,
                        size_t count, loff_t *ppos)
{
    return -ENODEV;
}
 
#endif
 
#define debugfs_create_file_aux_num(name, mode, parent, data, n, fops) \
    debugfs_create_file_aux(name, mode, parent, data, \
                (void *)(unsigned long)n, fops)
#define debugfs_get_aux_num(f) (unsigned long)debugfs_get_aux(f)
 
static inline void debugfs_create_xul(const char *name, umode_t mode,
                      struct dentry *parent,
                      unsigned long *value)
{
    if (sizeof(*value) == sizeof(u32))
        debugfs_create_x32(name, mode, parent, (u32 *)value);
    else
        debugfs_create_x64(name, mode, parent, (u64 *)value);
}
 
#endif