/* SPDX-License-Identifier: GPL-2.0 */
#ifndef IOU_ALLOC_CACHE_H
#define IOU_ALLOC_CACHE_H

#include <linux/io_uring_types.h>
#include <linux/kasan.h>

/*
 * Don't allow the cache to grow beyond this size.
 */
#define IO_ALLOC_CACHE_MAX      128

void io_alloc_cache_free(struct io_alloc_cache *cache,
                         void (*free)(const void *));
bool io_alloc_cache_init(struct io_alloc_cache *cache,
                         unsigned max_nr, unsigned int size,
                         unsigned int init_bytes);

void *io_cache_alloc_new(struct io_alloc_cache *cache, gfp_t gfp);

static inline bool io_alloc_cache_put(struct io_alloc_cache *cache,
                                      void *entry)
{
        if (cache->nr_cached < cache->max_cached) {
                if (!kasan_mempool_poison_object(entry))
                        return false;
                cache->entries[cache->nr_cached++] = entry;
                return true;
        }
        return false;
}

static inline void *io_alloc_cache_get(struct io_alloc_cache *cache)
{
        if (cache->nr_cached) {
                void *entry = cache->entries[--cache->nr_cached];

                /*
                 * If KASAN is enabled, always clear the initial bytes that
                 * must be zeroed post alloc, in case any of them overlap
                 * with KASAN storage.
                 */
#if defined(CONFIG_KASAN)
                kasan_mempool_unpoison_object(entry, cache->elem_size);
                if (cache->init_clear)
                        memset(entry, 0, cache->init_clear);
#endif
                return entry;
        }

        return NULL;
}

static inline void *io_cache_alloc(struct io_alloc_cache *cache, gfp_t gfp)
{
        void *obj;

        obj = io_alloc_cache_get(cache);
        if (obj)
                return obj;
        return io_cache_alloc_new(cache, gfp);
}

static inline void io_cache_free(struct io_alloc_cache *cache, void *obj)
{
        if (!io_alloc_cache_put(cache, obj))
                kfree(obj);
}

#endif