// 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>

#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;
};

extern struct dentry *arch_debugfs_dir;

#define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt)           \
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   = debugfs_attr_write,                                  \
        .llseek  = no_llseek,                                           \
}

typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *);

#if defined(CONFIG_DEBUG_FS)

struct dentry *debugfs_lookup(const char *name, struct dentry *parent);

struct dentry *debugfs_create_file(const char *name, umode_t mode,
                                   struct dentry *parent, void *data,
                                   const struct file_operations *fops);
struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode,
                                   struct dentry *parent, void *data,
                                   const struct file_operations *fops);

struct dentry *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);
void debugfs_remove_recursive(struct dentry *dentry);

const struct file_operations *debugfs_real_fops(const struct file *filp);

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);

struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
                struct dentry *new_dir, const char *new_name);

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);
struct dentry *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);
struct dentry *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);
struct dentry *debugfs_create_bool(const char *name, umode_t mode,
                                  struct dentry *parent, bool *value);

struct dentry *debugfs_create_blob(const char *name, umode_t mode,
                                  struct dentry *parent,
                                  struct debugfs_blob_wrapper *blob);

struct dentry *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, u32 *array, u32 elements);

struct dentry *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);

#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(const char *name, umode_t mode,
                                        struct dentry *parent, void *data,
                                        const struct file_operations *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 struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
                                        struct dentry *parent, void *data,
                                        const struct file_operations *fops,
                                        loff_t file_size)
{
        return ERR_PTR(-ENODEV);
}

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)
{ }

const struct file_operations *debugfs_real_fops(const struct file *filp);

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 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
                struct dentry *new_dir, char *new_name)
{
        return ERR_PTR(-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 struct dentry *debugfs_create_u32(const char *name, umode_t mode,
                                                struct dentry *parent,
                                                u32 *value)
{
        return ERR_PTR(-ENODEV);
}

static inline void debugfs_create_u64(const char *name, umode_t mode,
                                      struct dentry *parent, u64 *value) { }

static inline struct dentry *debugfs_create_ulong(const char *name,
                                                umode_t mode,
                                                struct dentry *parent,
                                                unsigned long *value)
{
        return ERR_PTR(-ENODEV);
}

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 struct dentry *debugfs_create_bool(const char *name, umode_t mode,
                                                 struct dentry *parent,
                                                 bool *value)
{
        return ERR_PTR(-ENODEV);
}

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 struct dentry *debugfs_create_regset32(const char *name,
                                   umode_t mode, struct dentry *parent,
                                   struct debugfs_regset32 *regset)
{
        return ERR_PTR(-ENODEV);
}

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, u32 *array,
                                            u32 elements)
{
}

static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev,
                                                         const char *name,
                                                         struct dentry *parent,
                                           int (*read_fn)(struct seq_file *s,
                                                          void *data))
{
        return ERR_PTR(-ENODEV);
}

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;
}

#endif

/**
 * debugfs_create_xul - create a debugfs file that is used to read and write an
 * unsigned long value, formatted in hexadecimal
 * @name: a pointer to a string containing the name of the file to create.
 * @mode: the permission that the file should have
 * @parent: a pointer to the parent dentry for this file.  This should be a
 *          directory dentry if set.  If this parameter is %NULL, then the
 *          file will be created in the root of the debugfs filesystem.
 * @value: a pointer to the variable that the file should read to and write
 *         from.
 */
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