alloc_cache.h

 1#ifndef IOU_ALLOC_CACHE_H
 2#define IOU_ALLOC_CACHE_H
 3
 4#include <linux/io_uring_types.h>
 5
 6/*
 7 * Don't allow the cache to grow beyond this size.
 8 */
 9#define IO_ALLOC_CACHE_MAX	128
10
11void io_alloc_cache_free(struct io_alloc_cache *cache,
12			 void (*free)(const void *));
13bool io_alloc_cache_init(struct io_alloc_cache *cache,
14			 unsigned max_nr, unsigned int size,
15			 unsigned int init_bytes);
16
17void *io_cache_alloc_new(struct io_alloc_cache *cache, gfp_t gfp);
18
19static inline bool io_alloc_cache_put(struct io_alloc_cache *cache,
20				      void *entry)
21{
22	if (cache->nr_cached < cache->max_cached) {
23		if (!kasan_mempool_poison_object(entry))
24			return false;
25		cache->entries[cache->nr_cached++] = entry;
26		return true;
27	}
28	return false;
29}
30
31static inline void *io_alloc_cache_get(struct io_alloc_cache *cache)
32{
33	if (cache->nr_cached) {
34		void *entry = cache->entries[--cache->nr_cached];
35
36		/*
37		 * If KASAN is enabled, always clear the initial bytes that
38		 * must be zeroed post alloc, in case any of them overlap
39		 * with KASAN storage.
40		 */
41#if defined(CONFIG_KASAN)
42		kasan_mempool_unpoison_object(entry, cache->elem_size);
43		if (cache->init_clear)
44			memset(entry, 0, cache->init_clear);
45#endif
46		return entry;
47	}
48
49	return NULL;
50}
51
52static inline void *io_cache_alloc(struct io_alloc_cache *cache, gfp_t gfp)
53{
54	void *obj;
55
56	obj = io_alloc_cache_get(cache);
57	if (obj)
58		return obj;
59	return io_cache_alloc_new(cache, gfp);
60}
61
62static inline void io_cache_free(struct io_alloc_cache *cache, void *obj)
63{
64	if (!io_alloc_cache_put(cache, obj))
65		kfree(obj);
66}
67
68#endif