// SPDX-License-Identifier: GPL-2.0-or-later
#ifndef _LINUX_REF_TRACKER_H
#define _LINUX_REF_TRACKER_H
#include <linux/refcount.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/stackdepot.h>

#define __ostream_printf __printf(2, 3)

struct ref_tracker;

struct ref_tracker_dir {
#ifdef CONFIG_REF_TRACKER
        spinlock_t              lock;
        unsigned int            quarantine_avail;
        refcount_t              untracked;
        refcount_t              no_tracker;
        bool                    dead;
        struct list_head        list; /* List of active trackers */
        struct list_head        quarantine; /* List of dead trackers */
        const char              *class; /* object classname */
#endif
};

#ifdef CONFIG_REF_TRACKER

#ifdef CONFIG_DEBUG_FS

void ref_tracker_dir_debugfs(struct ref_tracker_dir *dir);
void ref_tracker_dir_symlink(struct ref_tracker_dir *dir, const char *fmt, ...);

#else /* CONFIG_DEBUG_FS */

static inline void ref_tracker_dir_debugfs(struct ref_tracker_dir *dir)
{
}

static inline __ostream_printf
void ref_tracker_dir_symlink(struct ref_tracker_dir *dir, const char *fmt, ...)
{
}

#endif /* CONFIG_DEBUG_FS */

/**
 * ref_tracker_dir_init - initialize a ref_tracker dir
 * @dir: ref_tracker_dir to be initialized
 * @quarantine_count: max number of entries to be tracked
 * @class: pointer to static string that describes object type
 *
 * Initialize a ref_tracker_dir. If debugfs is configured, then a file
 * will also be created for it under the top-level ref_tracker debugfs
 * directory.
 *
 * Note that @class must point to a static string.
 */
static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir,
                                        unsigned int quarantine_count,
                                        const char *class)
{
        INIT_LIST_HEAD(&dir->list);
        INIT_LIST_HEAD(&dir->quarantine);
        spin_lock_init(&dir->lock);
        dir->quarantine_avail = quarantine_count;
        dir->dead = false;
        refcount_set(&dir->untracked, 1);
        refcount_set(&dir->no_tracker, 1);
        dir->class = class;
        ref_tracker_dir_debugfs(dir);
        stack_depot_init();
}

void ref_tracker_dir_exit(struct ref_tracker_dir *dir);

void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir,
                                  unsigned int display_limit);

void ref_tracker_dir_print(struct ref_tracker_dir *dir,
                           unsigned int display_limit);

int ref_tracker_dir_snprint(struct ref_tracker_dir *dir, char *buf, size_t size);

int ref_tracker_alloc(struct ref_tracker_dir *dir,
                      struct ref_tracker **trackerp, gfp_t gfp);

int ref_tracker_free(struct ref_tracker_dir *dir,
                     struct ref_tracker **trackerp);

#else /* CONFIG_REF_TRACKER */

static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir,
                                        unsigned int quarantine_count,
                                        const char *class)
{
}

static inline void ref_tracker_dir_debugfs(struct ref_tracker_dir *dir)
{
}

static inline __ostream_printf
void ref_tracker_dir_symlink(struct ref_tracker_dir *dir, const char *fmt, ...)
{
}

static inline void ref_tracker_dir_exit(struct ref_tracker_dir *dir)
{
}

static inline void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir,
                                                unsigned int display_limit)
{
}

static inline void ref_tracker_dir_print(struct ref_tracker_dir *dir,
                                         unsigned int display_limit)
{
}

static inline int ref_tracker_dir_snprint(struct ref_tracker_dir *dir,
                                          char *buf, size_t size)
{
        return 0;
}

static inline int ref_tracker_alloc(struct ref_tracker_dir *dir,
                                    struct ref_tracker **trackerp,
                                    gfp_t gfp)
{
        return 0;
}

static inline int ref_tracker_free(struct ref_tracker_dir *dir,
                                   struct ref_tracker **trackerp)
{
        return 0;
}

#endif

#endif /* _LINUX_REF_TRACKER_H */