// 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;
        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);

/**
 * debugfs_create_file - create a file in the debugfs filesystem
 * @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.
 * @data: a pointer to something that the caller will want to get to later
 *        on.  The inode.i_private pointer will point to this value on
 *        the open() call.
 * @fops: a pointer to a struct file_operations or struct debugfs_short_fops that
 *        should be used for this file.
 *
 * This is the basic "create a file" function for debugfs.  It allows for a
 * wide range of flexibility in creating a file, or a directory (if you want
 * to create a directory, the debugfs_create_dir() function is
 * recommended to be used instead.)
 *
 * This function will return a pointer to a dentry if it succeeds.  This
 * pointer must be passed to the debugfs_remove() function when the file is
 * to be removed (no automatic cleanup happens if your module is unloaded,
 * you are responsible here.)  If an error occurs, ERR_PTR(-ERROR) will be
 * returned.
 *
 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
 * returned.
 *
 * If fops points to a struct debugfs_short_fops, then simple_open() will be
 * used for the open, and only read/write/llseek are supported and are proxied,
 * so no module reference or release are needed.
 *
 * NOTE: it's expected that most callers should _ignore_ the errors returned
 * by this function. Other debugfs functions handle the fact that the "dentry"
 * passed to them could be an error and they don't crash in that case.
 * Drivers should generally work fine even if debugfs fails to init anyway.
 */
#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);

/**
 * struct debugfs_cancellation - cancellation data
 * @list: internal, for keeping track
 * @cancel: callback to call
 * @cancel_data: extra data for the callback to call
 */
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)

/**
 * 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